Dindigul Bypass to Samyanallore on Nh 7 in the State of Tamil Nadu Vol - II

8/12/2019 Dindigul Bypass to Samyanallore on Nh 7 in the State of Tamil Nadu Vol - II

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National Highways Authority of IndiaConsultancy Services for Feasibility study and Detailed Project Repor- for 6 Laning of Karur- Madurai section of NH-7 from Km 30518 to 426in the State of Tamil Nadu Consuttancy Package C-llMI

CONTRACT PACKAGE NS 81 TN)

VOLUME I1 DESIGN REPORTHIGHWAY AND STRUCTURES

January 2 5BCEQM vloint venture With

~ O O N S U 7 A N r s aatvee associates, , . . - .


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CH PTER - I2.0 P VEMENT DESIGN

2.1 Review of Pavement Design Methodology2.1 I Introduction2.1.2 TOR Requirements2.1.3 Pavement Design Methodology2.1.4 Pavement Condition Evaluation2.1.5 Crumbed Rubber Modified Bitumen2.1.6 Methodologies

2.2 Design Traffic2.2.1 Volume of Equivalent Standard Axles2.2.2 Expected Number of Axles by Category of Axle Load2.3 Flexible Pavement Design2.3.1 Design CBR2.3.2 Pavement Structure Design by IRC:37-20012.3.3 Comparison with Pavement Structure Designed by AASHTO

2.4 Overlay Design2.4.1 Overlay Design by IRC:81-19972.4.2 Comparison with AASHTO method

2.5 Rigid Pavement Design2.5.1 PCA Method for Rigid Pavement Design2.5.2 AASHTO Method for Rigid Pavement Design

2.6 Recommended Pavement Composition2.6.1 Flexible Option2.6.2 Rigid Option 14

2.7 Truck lay-by and Bus bay pavement 15

CH PTER -3.0 DR IN GE SCHEME

3.1 General3.2 Present Scenario3.3 Design Parameter

3.3.1 Longitudinal Gradient3.3.2 Cross SlopeI amber3.3.3 Pavement Internal Drainage3.3.4 Drainage of Subsurface Water

Contract Package: NS 81 TN)Volume 11Design Report Highways Structures)


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3.4 Strom Water Drainage Design3.4.1 Hydrological Design3.4.2 Design of Drain Section

3.5 Drainage System and Appurtenances3.5.1 Unlined Open Drain in Rural Section3.5.2 Unlined Drain in Urban Areas3.5.3 Median Drainage3.5.4 Drainage of High Embankments3.5.5 Drainage at Intersections3.5.6 Drainage at Flyovers and Bridges

3.6 Rain Water Harvesting Structures

CHAPTER- V4 0 MISCELLANEOUS DE SIGNS

4.1 General4.2 Toll Plaza4.3 Wayside Amenities4.4 Traffic Control and Safety Measures

4.4.1 Crash Barriers4.4.2 Road Signs4.4.3 Pavement Markings4.4.4 Lighting4.4.5 Kilometre Stones4.4.6 Delineators

4.5 Traffic Management and Safety during Construction4.5.1 lntroduction4.5.2 Traffic Management Plan4.5.3 Guiding Principles4.5.4 Components of the Construction Zone4.5.5 Other Aspects4.5.6 Traffic Control Devices4.5.7 Traffic Management Practices4.5.8 Temporary Diversions4.5.9 Precautions at Night4.5.10 Speed Control

254.6.1 Introduction 25 3

\n

Contract Package: NS81 TN)


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4.6.2 Soil Properties4.6.3 Stability Analysis4.6.4 Fill, Compaction and Erosion ControlAnnexure IAnnexure IIAnnexure Ill

CHAPTER- V5 0 DESIGNS OF STRUCTURES

5.1 General5.2 Design of Proposed Additional Bridges5.3 Hydraulic Data

5.3.1 Objective5.3.2 General Description of the Project Site5.3.3 Data Collection5.3.4 Hydrological and Hydraulic Study for Bridges

(Methodology and Approach)5.3.5 Summary and Recommendations

5.4 Geotechnical Investigations5.5 Design Standards for the Proposed Additional Bridges

5.5.1 Loading5.5.2 Foundations5.5.3 Substructure5.5.4 Superstructure5.5.5 Bearings5.5.6 Crash Barriers5.5.7 Expansion Joints5.5.8 Wearing Course5.5.9 Approach Slab5.5.1 Drainage Spouts5.5.1 1 Protection Works5.5.1 2 Untensioned Reinforcement5.5.13 Prestressing Cables5.5.14 Design Mixes

5.6 Repair and Rehabilitation of Bridges

LIST OF FIGURES/-

I

F ~ na l etailed Project Report Table of Contents :; \ iContract Package. NS 81(TN) ,\, >- .Volume II: Design Report (Highways Structures) '> ._


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hapter esign Standards


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1.3 Levels of Service (LOS)The Level of Service (LOS) characterizes the operating conditions on the roadway in terms oftraffic performance measures related to speed and travel time, freedom to manoeuvre, trafficinterruptions, and comfort and convenience. The levels of service range from level-of-serviceA(least congested) to level-of-service F (most congested). The Highways Capacity Manual (HCM)provides the following levels of service definitions:

1.4 Design Vehicle

Level of Service (LOS)ABCDEF

The selection of the appropriate design vehicle is a key element in good intersection designpractice. For most major intersections along the project road it is common practice toaccommodate the minimum turning path of a large Semi Truck Trailer (WB 18m). As perAASHTO (U.S.Practice) design guide the minimum turning radius of a tractor semi trailer truck(WB-18) is 18.2 m.

General Operating ConditionsFree flowReasonably free flowStable flowApproaching unstable flowUnstable lowForced or breakdown flow

1.5 Capacity Analysis

The capacity figures used for determining the desired carriageway width in differing terrain w.r.ttraffic volume and composition will be as per IRC : 64-1990. The capacity for differentcarriageway widths derived from the above mentioned source is given in the following Table:

Hourly Capacities for Different Lane ConfigurationsLane Configuration

4 lane

Capacity (PCUs per hour)I

2 lane 2500


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These capacity values are based on a design hour traffic flow of 8-10 and directionaldistribution of 67133 . The capacity for the urban road for different lane configurations may becalculated by using the above base hourly flows and applying actual design hour factor anddirectional split of the road.

The observed traffic volume when related with capacity, reveals the Volume Capacity (VIC) ratioof road sections. Since the sections of NH-7 vary with different carriageway widths, the VIC ratiohas been worked out by considering the average pavement width for each of the homogeneoussections.Capacity analysis is carried out to identify the present and future level of services at varioussections of project road. IRC 64: 1990 recommends Level of Service (LOS>B for rural roads.Thus it will be identified whether LOS-B is being maintained during the designed period of theproject. IRC has recommended the following design service volumes:

These values of Design Service Volume have been kept in view while considering improvementproposals for the project road.

1 6 Design Speed

Carriage Width

Two Lane

Four lane

Rural highways, except freeways, are normally designed for speeds of 80 to 120 kmlh dependingon terrain, driver expectancy and whether the design is for construction on new location orrehabilitation of an existing facility. For national highways the desirable (ruling) design speeds asper IRC: 73-1980 and IRC: 52-1981 design standards are 100 kmlh for plainlrolling terrain and50 kmlh for mountainous errains.

Curvature Degree m)

a) Low (0-50)b) High (above 50)

Terrain

Plain

Plain

Design speed of 100 Kmph. has been adopted based on NHAl Technical Circular Ref: NHAll PDGM Ty Tech. Circular12004 dated 1 8 ~ay, 2004.

Design Service VolumePCUIDay)

15,00012,500

35,000 (earth shoulder)40,000 (paved shoulder)

1.7 Cross Sectional ElementsFour types of cross sections are proposed for the project road undet consideration.section drawings are presented in Volume IX (A) Drawings High


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1.7.1 Lane RequirementAs per capacity analysis, it is concluded that provision of 2 X 2 lane road configuration would besufficient to cater to projected traffic volume at the desired level of service (LOS B) during theproject analysis period (2004-2033).

1.7.2 Lane WidthLane width has a significant influence on the safety and comfort of the travelling public. Thecapacity of a roadway is markedly affected by the lane width. In general, safety increases withwider lanes up to a width of about 3.7 m. The lane width as per IRC: 73-1980 is 3.5 m for designspeed of 100 kmlh.

1.7.3 ShouldersShoulders are a critical element of the roadway cross section. Shoulders provide recovery areafor errant vehicles; a refuge for stopped or disabled vehicles; and access for emergency andmaintenance vehicles. Shoulders can also provide an opportunity to improve sight distancethrough large cut sections. As per NHAl Guide lines 1.5m paved shoulder and 1.0 gravelshoulder is proposed.

1.7.4 MediansMedians on divided highways serve a variety of important purposes related to safety, trafficoperations, access control and aesthetics, including physical separation of opposing traffic flows;storage area for right-turning vehicles; provision of pedestrian refuge space; control of access byrestricting right-turns and U-turns to specific median openings; provision of physical space fortraffic control devices and bridge piers; and provision of physical space for landscaping toenhance highway aesthetics. As per NHAl Guidelines 4.5m raised median width in Rural as wellas Urban section is proposed.

1.7.5 Side SlopesAs per NHAl s instruction, slope of V: 2H has been adopted for earthen embankment upto 3mheight. Higher embankments have been designed for site specific condition with slopestabilisation measures such as gabionsl retaining structures. For cut section, slope of V: 1H hasbeen adopted for cutting upto 2m.

1.7.6 Right of Way (ROW)As per NHAl guidelines In general, Right of Way (ROlocations like junctions, rest areas, toll plazas, way SIproposed to accommodate these facilities.


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1.7.7 Pavement Camber (Cross-Fall)As per IRC: 73-1980 esign standards recommend Consultants propose a camber of 2.5 forthe main carriageway as well as the paved shoulders, and 3.5 for unpaved (gravel) shoulders.

1.7.8 KerbNHAl have instructed to provide I-shaped barrier type kerbs (225 mm above the pavementsurface) for main carriageway. However, it is desirable to provide kerbs at the intersections alsofor more positive traffic delineation, and collection of storm drainage. The kerb of semi- barriertype (150mm above pavement surface) has been provided at the intersections.

1.8 SuperelevationSuper elevation is provided for all the horizontal curves with radius less than 2000 m in order tocounteract the effect of centrifugal force. As per IRC : 38 -1988, uperelevation to fullycounteract the centrifugal force for 75 of the design speed of 100 kmlh neglecting the lateralfriction developed will be adopted in design. The super elevation 'e' has been calculated fromthe formula.or e = (v)' 1225Rwhere V is the design speed i.e., 100 Kph and R is the radius of the curve in metres.The maximum super elevation is limited to 7 as per codal requirement.

1.9 Sight DistanceAs per IRC recommendations, the minimum sight distance (Stopping sight distance) is 180 m.Desirable sight distance (Intermediate Sight Distance) is 360m .

1.10 Horizontal CurvesFor the design speed of 100 kmlh, the radius of more than 360 m has been provided for thehorizontal curves in our design. Wherever possible higher radii are adopted. The horizontalcurves with radius of curvature less than 2000 m, transition curves are provided on both ends ofcircular curve. The minimum transition lengths suggested in the IRC guideline are indicated inthe Table 1.1.

1 I Vertical AlignmentThe entire project stretch exists in plain terrain. The ruling and absolute maximum longitudinalgradients are recommended as 2.0 and 3.3 respectively. A minimum longitudinal gradient of0.3 has been adopted from drainage point of view. The longitudinal gradient of existingcarriageway will generally be maintained for new carriageway. Profile design of existingcarriageway will be done keeping in view having least profile corrective course (PCC) quantity.Due to changes in grade in the vertical alignment of the highway vertical curves at theintersection of the different grades will be provided in the design so as to smoothen the verticalprofile resulting in easing off of the changes in the gradisummit curves and valley curves will be introduced as perThe length of summit curve and valley curves (L) is g


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(a) For Summit Curvesi When the length of the curve is greater than the sight distanceL = ~ ~ ' 1 4 . 4ii) When the length of the curve is less than the sight distanceL=2S-4 .41N(b) For Valley Curvesi) when the len th of curve is greater than the stopping sight distance9L = NS / (1.5 + 0.035 S)ii) when the length of curve is less than the stopping sight distance

1.12 Standards for interchange elementsLengths of speed change lanes for interchanges recommended are given Table 1.2. Maximumvertical gradient of 3 generally would be adopted in design.

1.13 Median OpeningsMedian openings and control of accesses will be provided as per IRC: 62-1976. However,median openings will be limited to authorised intersections with public roads and will not providefor individual business needs. Where the median openings are provided at junctions, storagelanes have been considered.

Table 1.2 Details of

1.14 Subsurface Drainage

Speed change lanesDescription

RampLoop

Adequate drainage is a primary requirement for maintaining the structural condition andfunctional effect of a good pavements structure including sub-grade. Pavement must beprotected from any ingress of water. Otherwise over a period of time it may weaken the sub-grade by saturating it and cause distress in the pavement structure. The GSB layer shall extendthrough the full formation width and shall act as the drainage layer for effective subsurfacedrainage.

StoppingSightDistancem)13080

1.15 Surface Drainage

DesignSpeed (Kph)

8060

The surface drainage shall be effected by providing camber of 2.5 in the pavement and 3.5in the gravel shoulder on either side in straight alignment reaches. In the horizontal curveportions where super elevations are introduced, the outer carriageway slopes towards the centralmedian and so the collected water is to be discharged through concrete pipes embeddedunderneath in the manner indicated in the relevant drawin0.3 is considered adequate in most of the conditionshorizontal curves, median drainage system will be provide

Radius (m)

230130

Speed Change LaneAccelerationLane (m)

300400

DecelerationLane (m)130150


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(i) The Indian Road Congress (IRC) codes will be the basis of bridge designs, underpassesand flyoverl ROB S. For items not covered by latter, provisions of Special Publications andSpecification for Roads and Bridges published by IRC shall be followed.(ii) Grades of Concrete for superstructures will be as per MOST Specifications and IRCStandards. The Minimum grade shall be M40 for PSC and M30 T-Beamlslab respectively.

(iii) For substructures and foundations, the concrete grade will not be lower than M30 exceptfor well stoning and bottom plug where M25 concrete will be used. For PCC substructuresM20 grade will be adopted.

(iv) For all new 2-lane structures, live load to beconsidered shall be as per IRC-6.(v) Locations of new Minor Bridges will generally be guided by the alignment of the highway.

But, for major bridges, the bridge location and its alignment shall override the highwayrequirement in that portion.

(vi) On economic grounds and smooth-ride, wherever possible, for the new bridges the layoutof the existing bridges having a number of small spans will be modified by decreasing thenumber of spans, maintaining pier parallel and in line with those of the existing structure.

(vii) The deck will have 2.5 unidirectional camberlcross fall and the wearing course will be ofuniform thickness of 12 mm Mastic and 50 mm BC.

(viii) In general it has been observed during the preliminary study that the open type foundationsfor the existing bridges have not suffered any distress even after more that 30 years ofservice and accordingly open type foundations are proposed to be adopted for newstructures at these locations.

(ix) Open foundations have been proposed for flyovers and ROB structures, on the basis ofsub soil investigation reports.

1.17 Planning of New Structures1 17 1 Bridges and Structures

In general, while planning of new Bridges and Structures attention is required to be paid to thefollowing criteria:

Proper crossing of bridge and alignment and approaches.Linear waterways and minimum vertical clearances.Satisfactory foundation strata.Aligning the substructure of the new structure in line with that of the existing structure so thatthere is no obstruction to the flow.Minimum distance from the existing structure consistent with construction requirements andhydraulic consideration.

9 Modular approach in design for both superstructure and substructures.Economical, ease of construction, quality assurance, environmental and aestheticrequirements.Matching linear waterways and aligning substructures in line are the most important criteria,since existing and new corridors run parallel and adjacent to each other. It is important thatthe existing bridge does not experience any river flowlhydraulic problems. The existingeffective linear waterways and vertical clearances are found to be satisfactory. Hence, the

of the existing structure andnumber of spans would be suitably reviewed to

Final Detailed Project Report


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construction approach. Many existing structures have very small (4 to 8 m) multiple spans. Insuch cases efforts shall be made to reduce the number of spans.

Keeping in view the desire of a modular design approach, the types and spans length shallbe standardised to minimize variations. The types can be RCC slabs, and PSC beams andslabs. They will be in the simply supported system T-beam and slabs. Continuous andbalanced cantilever systems need un-yielding bearing strata and also extra construction timeschedules. These will be of limited application in a modular design approach. Hence, theseare not mooted. Similarly modular design approach will be attempted for piers andabutments. The proposals for new bridges are based on the criteria stated in the foregoingparagraphs. Economical design is of equal importance. Therefore, no standard formula isapplicable. But, it depends on the design quantities of the different structural elements, theirforms, construction techniques and time schedules. The design approach and designstandards have been discussed in detailed separately in Chapter 5.

1.17.2 Underpasses, ROB s and RUB sThere are no ROB s and RUB s in the project stretch under consideration. Two types ofunderpasses have been proposed. Type-l Underpasses with 6.5m width X 3.5 m verticalclearance are proposed at locations where cross road traftic is less important. Type-llUnderpasses with 8.5 m width X 5.0 m vertical clearance are proposed for the crossing of StateHighways and Major roads.

1.17.3 CulvertsFor culverts, guidelines stated below will be followed:(a) For culverts in new carriageway, minimum span and vent height will be kept equal to that ofthe existing carriageway; Raising, if required according to highway alignment will be made

wherever required.(b) Weak and non functional culverts to be dismantled and new culverts to be constructed withcarriageway and median matching with highway plan and profile.(c) For central widening three lane new PCC abutments to be provided on both the sides ofexisting culverts. Existing slab to be dismantled and new slab with specified camber to be

cast for the full length.(d) Culverts in service road locations to be extended up to the road side longitudinal drain.(e) In a number of cases where vent height is very small ~ 5 0 0 m, i.e. difference between

road formation level and adjacent ground level is very less and there is no water loggedarea in the close vicinity culverts are decided to be abandoned.(f) For Culverts with three lane carriageway width, have been designed for 3-lane class-A or 1lane Class 70R trackedlwheeled one lane class-A loading whichever is more severe. For

two lane carriageway width culverts have been designed for 2- lane Class A or one lane70R wheeled or tracked whichever is more severe.

T


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Chapter avement Design


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2 0 PAVEMENT DESIGN2 1 Review of pavement design methodology2 1 1 Introduction

Pavement design forms an integral part of detailed engineering study. Performance of pavementis critical as the economical returns are directly dependent on its performance. This chapterdeals with the design methodology adopted for the strengthening and rehabilitation of theexisting carriageway and the also suggests the design approach for both flexible and rigidpavement for the new carriageway. This chapter also brings out the present condition of theproject corridor, the pavement option study and suggests the best alternate design.The extension of the two lane national highway into 4 lane highway requires the design ofdifferent pavement structures:

Where the new road alignment will be eccentric against the existing one, one carriagewayrequires a new structure and the other one a part of strengthening of the existing road andlikely a widening part. Two types of construction have to coexist in the same cross sectionand the linklinterface between new construction and strengthening is to be carefully studiedto avoid longitudinal cracks at the junction.Where the existing centre line is kept in the new project, both carriageways can becomposed of strengthening and widening in new pavement. However, in many cases, itappears more economical and technically safer to build a new structure in full width for bothcarriageways.o New pavements are generally flexible, consisting of Granular Sub-base, Water MixMacadam, Bituminous Base course and wearing course in Bituminous Concrete. Howeverrigid pavement will also be studied and cost estimates will be compared with those offlexible structure.New pavement design is also required for service roads.Toll plaza pavement is generally constituted of concrete slab. Its life span is longer often30 years) and maintenance is supposed to be less than for flexible pavement.In case sensors have to be placed within the wearing course, for vehicles counting andweigh-in-motion, particular design should be taken to be sure that the measurements arereliable for a long time.

2 1 2 TOR RequirementsTOR prescribes that detailed pavement design should involve:

Strengthening of existing pavementDesign of new pavement for additional carriagewayPavement Design for bypass, Service roads, ramps for interchangesDesign of shouldersDesign of guard rails, Road furniture andDesign of drainage system

Amongst of above the last two items have been separately dealt in Miscellaneous Designs andDrainage Scheme chapters.TOR mentions about design of pavement primarily based on IRC publications.. TOR mentionsthat paved shoulders should be designed as an integral part of pavement for main carriageway.2 1 3 Pavement Design Methodology

Pavement design methodology includes two basic functions namely; design of strengtheningoverlay for exidng pavement and design of new crust for a d d i t p n q l ~ ss. ~ ~ ~ e a f ~ a v e i ito be adopted for additional two lanes shall also be decided ty yi on -. coy analysis as a


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part of pavement design methodology. Accordingly the following methodology has been adoptedin pavement design to achieve requirements of TOR.Step 1: Various Pavement investigations have been carried out on the project corridor toassess the adequacy of the existing pavement crust. These investigations include:Visual Pavement ConditionPavement Roughness SurveysBBD measurementsSubgrade lnvestigationslnvestigations on existing granular layerslnvestigations or quarry and Barrow areasDetails of these investigations have already been presented at feasibility stage. Gist of results ispresented below for ready reference. Based on these investigations locations for rehabilitationand reconstruction of existing pavement have been identified.

Step 2: Axle load surveys have been conducted on the corridor and VDF for different categoriesof vehicle established. Design traffic loading for pavement design has been estimated from VDFand projected traffic figures. Axle load spectrum for the rigid pavement design has also beenestablished.Step 3: Detailed material investigations have been conducted in the projected influence area andstrength characteristics and availability of construction material has been determined.Step 4: For the purpose of designing the overlay the project corridor has been divided intohomogeneous sections based on deflection measurements using Cumulative standardsapproach. Design thickness of overlay has been estimated from IRC-81-1997 using estimatedtraffic level and characteristic deflection of particular homogeneous section. Estimated BMthickness is then adjusted to equivalent thickness of AC DBM using conversion factors given inIRC 81-1997.Step : Homogeneous sections for pavement design have been established and design trafficloadings for each of them identified. Design of flexible pavement for additional two lanes hasbeen carried out in accordance with guidelines of IRC-37-2001.Step 6: Design of rigid pavement has been carried out in accordance with PCA method.Step 7: Design of flexible pavement for paved shoulders service roads interchange ramps hasbeen carried out in accordance with IRC 37-2001 guidelines.The above methodology has been presented in the form of a

Chapter 2: Pavement DesignContract pack age - N S s T N )


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New Cmst Designthickness fmmIRC 37 fmm PCmethod

Recommended

Figure2 1: Flow Chart for Pavement Design

2 1 4 Pavement condition EvaluationDetails of pavement investigations carried out have already been detailed out at previous stage ofproject preparation. Existing pavement details like Structure of the Existing Pavement and pavementCondition Evaluation are presented in Volume I:Main Report.

2 1 5 Crumbed Rubber Modified BitumenWith advancement in bitumen technology, rubber modified bitumen is available with provenrecord of durability for use in wearing course. So, it has been decided to use Crumbed RubberModified Bitumen with the Ministry specification. This has been kept in view while finalizing thebill of quantities.

2 1 6 Methodologies2 1 6 1 New Flexible Pavement

According to the terms of Reference, the flexible pavement life span should be of 5years.The first methodology for designing a new flexible pave


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and traffic expressed in cumulated number of equivalent standard axles driving on the mostloaded lane. Equivalent axle loads are calculated by using the following formula or the preparedtable in Annexure 2 of IRC:37-2001.Equivalency factor for single axle = [Load of axle in tonnesl8.160 t14Equivalency factor for tandem = [Load of tandem in tonnesl14.968 t14The second methodology could be the ASSHTO method from AASHTO Guide for Design ofPavement Structures 1993 or 1998. However, it must be kept in mind that AASHTO Method islimited to 50 msa. Moreover, as far as layer coefficients are concerned the Guide encourageseach road agency to develop their own relationships (layer coefficients vs CBR or ResilientModulus) for their specific materials and climate condition. Despite some studies conducted bydifferent Research Centres and Institutes of Technology, there are no official values of layercoefficients in India, probably because priority was given to develop proper Indian codes likeIRC:37, IRC:81 or IRC: 58 respectively for new flexible pavement, flexible overlay and rigidpavement.

2.1.6.2 Flexible StrengtheningSame design life of 15 years is to be taken up.IRC:81-1997 Guidelines for strengthening of flexible roads pavement using Benkelman beamdeflection techniques was used. True pavement deflection as defined in the Guidelines wasused as well as the same volume of traffic expressed in million of standard axles as for the newpavement design.This strengthening design was cross checked by AASHTO method combined with somerelationship given by HDM Manual (Highway Design and Maintenance Manual by World Bank). Itconsists to adjust the existing pavement parameters by using two formulas:Different kinds of Structural Number have to be calculated.SN cme ed = SN of existing pavement + SN of subgrade

=C i D i+3.52 x L O ~ C B R ) 0.85 x [ LO ~ C BR ) ] ~1.43And SN ,m = Function of Deflection (in mm) = 3.2 x DEF'.~.The SN for a new pavement is then calculated. The difference between this new SN and SN fromthe existing pavement gives the thickness required for overlay.Only some calculation samples have been taken for comparison purpose with the thicknessgiven by IRC:81-1997.

2.1.6.3 Rigid pavementPCA method is presented in 2001 Austroads pavement design guide. It is a simple and reliablemethod. This method requires to assess the expected number of axles during the life span (30years) distributed in different axle group categories:

Single axle with single wheel (SAST)o Single axle with dual wheel (SADT)o Tandem axle with dual wheel (TADT)Triaxle with dual wheel (TRDT)Only SADT and TADT were used for the design.The slab thickness obtained by this method could be crosgenerally the latter gives thicker concrete slabs.


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These two methods could also be used for overlay design by using the BBD results to get the k-value or resilient Modulus of the existing pavement considered as a sub-baselsubgrade aftercorrection of profile by means of a bituminous PCC.2 2 Design raffic2.2.1 Volume of equivalent standard axles

Retained vehicle categories are Bus, 2-Axle trucks, 3-Axle trucks and Multi-axles vehicles.Average annual daily traffic in each category and section along with annual growth rates havebeen assessed. Cumulated traffics in each category and section have been calculated for 15, 20and 30 years, assuming that the opening to traffic after construction will occur in the year 2008.Vehicle Damage Factors as defined after treatment of axle load survey data for each categoryand section have been applied to the cumulated traffics. The design traffic is the total traffic inboth directions divided by two for one direction and multiplied by a distribution factor of 75 .

Details of calculations can be seen on Tables 2.1.

I20 Years 137 msa

2.2.2 Expected number of axles by category of axle and load

30 Years

The expected number of vehicles in each category and section has been calculated by using thetotal cumulated number of vehicles multiplied by 50 for one direction and 75 for distribution in

326 msa

hvo lanes and applying the load distributions recorded during the axle load survey.The result of calculation is shown in Table 2.2 in the following page. These values are then inputin PCA method formulas to assess concrete slab thickness.

Table 2.1 Design Traffic data and msa calculations for Contract package- NS81 TN)

Final Detailed Project Report


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Total in millionof heavyTotal cumulated vehicles in num ber vehicles2008-2022 2,960,038 28,981,525 10,772,141 2,065,125 452008-2027 4,542,146 48,883,509 18,169,508 3,483,274 752008-2037 8,869,037 116,847,562 43,431,063 8,326,162 177VDF 1.77 4.24 5.97 11.85Total cumulated traffic in msa in bothdirections

15years 5.24 122.88 64.31 24.4720 years 8.04 207.27 108.47 41.2830 years 15.70 495.43 259.28 98.67

Design traffic for one lane = 75 of 50 of traffic in both d irections15years 8 1 msa20 years 137 msa30 years 326 msa

Final Detailed Project Report Chapter 2: Pavement Desi Page 6 of 15


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2.3 Flexible pavement design2.3.1 Design CBR

24 samples of soils collected from the sub-grade have been tested to determine Dry Density vsMoisture Content compaction curves and achieve MDD and OMC. CBRs at 95 of MDD wereassessed from CBR vs Compaction curves. Except for one sample that gives CBR less that 8, allCBRs are above 10 as shown in the following chart.

Locationof Trial Pits

2.3.2 Pavement Structure Design y IRC:37-2001After adjustment by interpolation on traffic, pavement structures according to the sectioning,given by IRC:37 would be the following:For a lifespan of 15 years :Note: For a traffic of 50 msa, IRC:37 proposes a BC thickness of 40 mm but for 100 msa a BCthickness of 50 mm is recommended. Both of solutions are shown hereafter, assuming that 10mm of DBM could be replaced by 10 mm of BC.

2.3.3 Comparison with Pavement Structure Designed yAASHTOAASHTO formula for flexible ~avement as aDDlied with the following parameters:o MR of Subgrade = 10CBR x 1500= 15000 psio Overall standard deviation So = 0.49o Reliability 90 Zr = -1.282o Design serviceability loss APSI = 4.5 - 2.5 = 2

Section

Km 345 381

For a lifespan of 15 years, Structural numbers have been obtained as follows:

DesignCBR

10

DesignTraffic81 msa

contract package'-NS ? TN)

Pavement Structure

~~Section

Km 345 381

BC40 mm50 mm

-':: ,\v2>Final Detailed Proiect Rewrt Chapter 2: Pavement Design \ --.A Page8 of 15

Design Traffic

81 msa

DBM125mm115 mm

Structural Nu

WMM250 mm250 mm

GSB200mm200 mm


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By applying the commonly used layer coefficients, the Structural Numbers of the proposedstructures are the following :

SN so calculated are very close to those given by AASHTO in case of a perfect drainage(Drainage Coefficient D=1.2 applied to both WMM and GSB layers) and about 0.5 below if amore common drainage coefficient D=l is used. However, more appropriate coefficients could beproposed :The modulus of Subgrade could be obtained by the formula given by IRC:37-2001Subgrade CBR = 10

0 64E = ~ ~ . ~ x c B R ) forCBR>5 E=77MPaFor the Subbase a modulus equal to two times that of the Subgrade can be taken up, say154 MPa or 23000 psi. Application of the following formula giving a relationship betweenmodulus of sub-base and layer coefficient (AASHTO Manual page 11-22), yields :a = 0.227 x (loglo Ese)-0.839 = 0.16For the WMM base a modulus equal to two times that of the Sub-base can be also taken up, say310 MPa or 45000 psi. Application of the following formula giving a relationship betweenmodulus of base and layer coefficient (AASHTO Manual page 11-22), yields :a = 0.249 x (logloEBS) 0.977 = 0.18For bituminous layer, IRC:37-2001 gives the same modulus for both BC and DBM at varioustemperatures: 2600 MPa and 1700 MPa respectively at 30C and 35C.We suggest to use the chart given by the AASHTO Guidelines in page 11-18 (Fig. 2.5). This chartis reproduced below after converting Elastic modulus from psi into MPa.

Layer coefficients for Bituminous Materials

Final Detailed Project Report Chapter 2: Pavement Design Page 9 of I 5


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From this chart we can deduce the layer coefficients for both BC and DBM 0.33 at 35C and0.40 at 30C.SNs of the previous table may be therefore recalculated with new layer coefficients:

The finding is quite satisfactory. By taking up the same drainage coefficients to WMM and GSB,say, D = I he structural numbers of the IRC structures are well above those required byAASHTO Manual.

2.4 Overlay Design2.4.1 Overlay Design by IRC:81-1997

The overlay design method of IRC:81-1997 is based on characteristic deflection of eachhomogeneous section defined on the project road. A chart gives the thickness of BM to be laidon the existing pavement according to the traffic expressed in msa and the characteristicdeflection. An extract of this chart with a slight different presentation to make easier its use, isreproduced hereafter.BM Overlay Thickness Design Curves(from Fig. 9 in IRC:81-1997)

lolo


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The following thicknesses of BM have been obtained and converted into BC and DBM, with theassumption that 1 cm of BM 0.7 cm of BC or DBM. The thickness of 50 mm or 40mm for BChas been selected to avoid too thin layer of DBM.Section Km 345 000 to Km 381 000

can be noticed that the DBM thickness is much less than (Two third) than that obtained for newpavement structure.2.4.2 Comparlson with AASHTO method

The number of CBR tests being short at this stage of the study, it is not possible to calculateSNeXistrom deflection (SNC) and in situ CBR (SNSG), SNe*, SNC SNSG in all locationswhere the deflection has been measured. We can however get a general idea by calculatingSN,,, for different values of CBR and deflections:

Then assessment of SN by New Pavement AASHTO formula for different values of CBR andtraffic can be done :

Eventually the SN overlay will be combination of differences between SN and SNexlst s shown inthe following table: SN= SN SNea


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Both assumptions: with or without shoulder have been tested.

To summarize, a slab thickness of 320 mm is acceptable without shoulder and 260 mm with

The results of calculation are displayed in the following table:

shoulder.The same thickness could be used for overlay. CBR 10% is equivalent to 15000 psi of resilientmodulus. Deflection on a layer of infinite depth and a resilient modulus of 15000 psi is about 1.2mm. After placing a profile correcting course on the existing pavement, the same strength as fornew pavement will be obtained. Therefore the same slab thickness can be designed.2 5 2 SHTO Method for Rigid Pavement Design

With ShoulderThickness IFatigue IErosion253 mm 56.4% 96.0%

SectionsKm 345 381

The method requires defining the k-value that is the bearing capacity of the subgrade. This k-value is increased if a sub-base layer is laid between the subgrade and the concrete slab. Acomposite k-value is then to be assessed.As the design CBR is assumed to be 10% the roadbed resilient modulus can be taken as10x1500 15000 psi.The sub-base is assumed to be a DLC, the Elastic Modulus of which is 2 000 000 psi. Itsthickness is 150 mm or 6 inches.By using the chart of Fig. 3.3 in AASHTO Manual (1993) Chart for estimating compositemodulus of subgrade reaction k , assuming a semi-infinite subgrade depth , a CompositeModulus of Subgrade Reaction of 1500 pci is obtained.Another factor is included in the design of rigid pavements to account for the potential loss ofsupport arising from sub-base erosion andlor differential vertical soil movements.For Cement Treated Granular Base with an elastic modulus between 1,000,000 and 2,000,000psi the Loss of Support LS is recommended to be between 0 to 1. A value of 0.5 can be taken

Without ShoulderThickness Fatigue Erosion316 mm 0.3% 99.8%

UP.By using the chart of Fig. 3.6 Correction of Effective Modulus of Subgrade Reaction for PotentialLoss of Subgrade Support , and inputting the value of 1500 pci and LS 0.5, a value of 1000 pciis obtained for effective modulus of roadbed reaction.The design traffic recommended by AASHTO Guidelines is the traffic for design of flexiblepavement (30 years life span):

Km 345 to km 381 : 84msaThe parameters required for the thickness design are the following:

Effective Modulus of Subgrade ReactionConcrete Elastic ModulusMean Concrete Modulus of RuptureLoad Transfer CoefficientDrainage CoefficientOverall standard deviationReliability 90%Design serviceability loss

And of course the slab thickness.

k 1000 pciEc 5,000,000 psiS'c 650 psiJ 3.2 (without shoulder)J 2.8 (with shoulder)Cd 1So 0.39Zr -1.282APSI 4.5 2.5 2

After calculations, it yields:I Section Traffic Thickness with Thickn ess withou t shoulder


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2.6 R e c o m m e n d e d P a v e m e n t C o m p o s i t io n I

Thicknesses are very high compared with those given by PCA method as shown in the followingtable.

2.6.1 Flexible Option

SectionKm 306 345Km 345 381Km 381 426

A primer is to be spread between DBM and WMM. Particular care must be taken for this layer toconstitute a good support while spreading and compacting DB M. Otherwise the bottom of DBMcourse will be spoiled by W MM materials and its efficient thickness w ill be less than required.

Traffic229 msa284 msa312 msa

The PCC to be spread before overlay will be made of BM materials as per MORTHSpecifications.

Overlay (mm)DBM I BC125m m 50 mmSection

Km 345- 381

For service roads, the following structure could be adopted, corresponding to a traffic of 10 MSA,namely between 9 and 13 of the traffic in one direction. Most of the service roads will be usedby heavy trucks manoeuvring at entrance or exit of spinning m ills. For traffic of 10 MSA, IRC willnot recommend SDBC. However, in order to maintain uniformity with adjacent contractpackages, as per NHAl directions during review meeting held at Hyderabad and Draft DPRpresentation, the following pavement composition has been recom mended for service roads.

Thickness withshoulderA = 115 mmA = 123 mmA = 128 mm

Thickness50 mm250 mm200 mm

Thickness witho ut shoulderA = 8 0 m mA = 8 8 m mA = 9 2 m m

New Pavement (mm)

2.6.2 Rigid OptionFor comparison purpose the following concrete slab thickness PQC are proposed:

GSB WMM I DBM BC

Shoulders if provided, must be tied concrete shoulders or 3 foot monolithic widening of theoutside cement concrete lane.

200 mm 250 mm 125 mm 50 mm

Length of slab is recommended to be 4.50 mBetween subgrade and concrete slab a drainage layer will be first laid (coarse graded GSB in150 mm depth) followed by a dry lean concrete (DLC 150 mm).The same thickness w ill be adopted for overlay. The existing surface will be first scarified and aPCC of BM will be laid.

Thickness withoutshoulder360 mmSection

Km 345 381

This structure could also be adopted for Toll P laza pavement.As far as Tie b ars are concerned, IRC:58-2002 gives the foll350 mm

Final Detailed Project Report Chapter 2: Pavement DesignContract Package NS 81 TN)Volume II : Design Report (Highway Structures)

Thickness withshoulder320 mm


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3.0 Drainage Scheme3.1 General

A good drainage system is vital for the safety and longer life of any structure. This is more relevantin the case of highways. Proper drainage of road surface, pavement and the foundation layers isbasic requirement for maintaining the structural soundness and functional efficiency of a road.Pavement structure including sub grade must be protected from any ingress of water. For thispurpose, the following conditions have to be ensured:. Interception of the surface runoff,Keeping the water flow duration on the pavement to a minimum,Saving the pavement structure from stagnation of water,Efficient dispersal and disposal of water. and. Quick disposal of sub-surface water away from the pavement.Drainage management is a necessity all along the road. However, special attention has been paidto the water drainage and disposal scheme at following nodal points along the project road:

Bridges, both minor and major,Culverts and all other cross drainage structure,Side drains, open and covered type,Built-up urban areas, and. Junctions, intersections, flyovers, ROB, RUB and Level crossings etc.3.2 Present Scenario

The project road is a part of the National Highway No. 7. The existing road runs on a lowembankment. As such there is no well defined drainage facility for the existing road. In cut sectionin plains olling terrain, side drains exist in some of the location but have not been maintainedproperly and were found choked at places. Drainage condition is found to be poor to very poor incity illage areas.3.3 Design Parameter3.3.1 Longitudinal GradientGradients are provided on roads according to the road profile designed on the basis of designspeed and to match the surrounding terrain. In any case, a slight longitudinal gradient in the roadalignment helps improve internal drainage of pavement layers. A minimum longitudinal gradient of0.3% is provided in most conditions except on existing road for which in few sections flattergradients have been adopted to minimise the overlay.

All valley curves have been designed to have large radius and low points have been adjusted nearto cross drainage structures. In cut sections, as far as possible valley curves have been avoided orelse proper drains are proposed. Drainage for the project road has been designed as per IRC-SP:42 Guide lines on Road Drainage IRC-SP: 50 Guide lines on Urban Drainage.

3.3.2 Cross Slope CamberIf a steep cross slope is provided, it helps in quick dispersal of water from the pavement surface,but it may be objectionable from considerations of comfort to the traffic. Therefore cross slope isoften a compromise between the requirements of drainage and those of vehicular traffic. But fromdrainage point of view a reasonably steep cross slope will be helpful in minimising ponding ofwater on flat grades. Flat slopes are major contributors to the condition which produces thephenomena of hydroplaning and accidents on high speed roads.IRC: 73-1980 Geometric Design Standards for Rural (non-urcamber or cross slope on straight section of roads. In keeping WIafter consultations with officials of NHAI, the Consultants have


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of 2.5 for main carriageway. This is considered enough to drain out the water from top of thepavement surface as even for steepest adopted longitudinal gradient of 3.33 .Following values for cross fall I amber have been adopted for drainage of water from theshoulders:

Paved Shoulders: 2.5 (same as main carriageway). Unpaved (gravel) Shoulders: 3.5 %3 3 2 1 Minimum Section of Drain

Section is to be chosen such a way so that the drain would be able to be cleared periodically usinga spade. Accordingly, it is recommended that minimum width of a drain would be 600 mm. in caseof pipes the minimum diameter should not be less than 450 mm. For earthen drain 600 mmminimum bed width is proposed.3 3 2 2 Channel Shapes

The usual channel shapes are:Parabolic. Trapezoidal

RectangularTriangular or V shaped

The parabolic section is the best from hydraulic consideration but it is very difficult to construct andsubsequently maintain. The V-shaped drains are also very difficult to maintain as its desilting isdifficult. The trapezoidal and rectangular sections are easier to construct and maintain, thus isconsidered the most suitable. Trapezoidal section is recommended to adopt for the projectroad3 3 2 3 Side Slopes

The economical sections can be obtained by adopting drain section based on the following relationbetween bed width and depth:. Rectangular drain b = 2dTrapezoidal b = 0.82d (1 1 side slope)= 1.24d (112:l side slope)Side slope of 2 (H):l(V) is recommended for earthen drain considering angle of repose of availablematerial which is generally clayey gravel. For lined drain with brick or stone or concrete paving,side slope of 1H): 1 V) is preferred for trapezoidal section.

3 3 3 Pavement Internal DrainageDrainage of pavement layers across the earth shoulders has an important bearing on theperformance of the pavement. In case of new carriageway and reconstruction of existing road,bottom most granular sub-base layer is to be extended upto to the edge of embankment slope. Incase of widening with existing road on one-side, continuous drainage layer is not possible andextension is to be limited till existing crust.The sub-base layer is to have following capacity to carry the design discharge. Flow through sub-base layer is considered as saturated laminar flow and calculated using Darcy's Law as under;Q = K i AWhere,Q = discharge in cumlsec cK = Coefficient of permeability in mlsec . . .i = Hydraulic gradientA = cross section area in sqm perpendicular to the direction


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3.3.4 Drainage of Subsurface WaterTwo main objectives of subsurface drains are to lower the level of wpter table and to intercept ordrain out underground water. The subsurface drains in cut slope a r w o useful as these carryaway underground water which otherwise responsible for sloughing of the slope.

3.4 Strom Water Drainage DesignThe design of drainage system involves (a) calculating the total discharge that the system willrequire to drain off and (b) fixing the slope and dimensions of the drain to have adequate capacityto carry the discharge and afford maintenance.

3.4.1 Hydrological DesignHydrological study is an important step prior to the design of road drainage system. Such analysisis necessary to determine the magnitude of flow and the duration for which it would last.Hydrological data required for design includes drainage area map, water shed delineation, arrowindicating direction of flow, outfalls, ditches, other surface drainage facilities, ground surfaceconditions, rainfall and flood frequencies.To estimate the amount of runoff requiring disposal at given instant, information regarding rainfallintensities within the catchment area and the frequency with which this precipitation to assesspeak run-off is essential. The Rational Method is universally accepted empirical formula relatingrainfall to run-off and is applicable to small catchment areas not exceeding 50 sqkm. Thedischarge is calculated by,Q+0.028 P A IcWhere;Q = Discharge (Peak run-off) in cum/ secP = Coefficient of run-off for the catchment characteristicsA = Area of catchment in HectaresIc = Critical intensity of rainfall in cm per hour for the selected frequency and for duration equal tothe time of concentrationCoefficient of run-off P for a given area is not constant but depends on a large number of factorssuch as porosity of soil, type of ground cover, catchment area, slope and initial state of wetnessand duration of storm. For specific site conditions, the following values of P given in IRC: SP 42-1994, Guidelines on Road Drainage have been adopted.The primary component in designing storm water drains is the design storm i.e. rainfall value ofspecified duration and return period. For the project road a return period of 25 years is consideredto be adequate. As the extent of drainage system for the project road is small, even an intenserainfall of short duration may cause heavy oufflows. The s tom duration chosen for designpurposes is equal to time of concentration. It has two components- (a) entry time and (b) time offlow. Because of lack of data for small duration peak rainfall for small catchments in projectinfluence area, the following equation has been used to estimate the rainfall intensity for theshorter durations:

where,i= Intensity of rainfall within a shorter period of t hrs within a sF= Total rainfall in a storm in cm falling in duration of storm oft= Smaller time interval in hrs within the storm duration in T h


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For the purpose of design storm, one hour maps available from Directorate of Hydrology (smallcatchments), Central Water and Commission, New Delhi have been used. I-hr rainfall for returnperiod of 25 years for the project influence area has been taken as 60 mm.3 4 2 Design of Drain Section

For uniform flow in open channels, the basic relationships are expressed by the Manning sFormula:1Q = - A R ~ ~innWhere,

Q discharge in cumlsecn= Manning s roughness coefficientR= hydraulic radius in m which is flow cross section divided by wetted perimeterS= energy slope of the channel which is roughly taken as slope of drain bedA= Area of flow cross section in sqmIn design, the flow is assumed to besub-critical. The slope and velocity are kept below the criticallevel. If design depth is less than critical depth, the section is to be redesigned to avoid critical flowsituation. Detailed design calculations are presented in Annexure 3.1.

3 5 Drainage System and AppurtenancesThe rain water from the right of way of the road is ultimately required to be transported awaybefore it can cause nuisance or damage. First of all, water has to be transported over the surface.This aspect has been well looked after by providing adequate cross-slope and compatiblelongitudinal profile. After running over the surface, most of the runoff is collected in the coveredopen drain along the road. Open drains are preferred over covered ones as these are easier tomaintain and allow removal of silt and other solids easily. Also, for a given cross section opendrains can carry much larger discharge particularly in flood conditions where drain is surcharged.To improve the present drainage network, unlined drain is proposed for rural sections. Open lineddrain is proposed anticipating the low level maintenance for urban sections. In order to furtherimprove the drainage, special attention has been paid to disposal of oufflow from drains to eithervacant land or nearby culvert. As the cross drainage structures are located very often, longitudinaldrains have been connected to the nearest cross drainage structure. The types of drainprovisioned are discussed in subsequent paragraphs.

3.5.1 Unlined Open Drain in Rural SectionIn rural stretches of road where embankment height is less than 1.5 m, unlined toe drains areproposed. It is necessitated as in the low embankment stretches, the pavement drainage layersand sub grade would be buried under ground. Unless exposed to the atmosphere by a cut faceintra-pavement drainage can not be achieved.Intra-pavement drainage being the primary consideration, the longitudinal gradient of the toe drainhas secondary importance. However, attempt has been made to provide a nominal gradient whileextending the drains to nearest outfall. For this type of drain, trapezoidal section of side slope 2(H):l V ) with base width of 60 cm and average depth of 35 cm (depth varies) has been consideredadequate. The drain base should be minimum 150 mm below the subgrade.

3 5 2 Unlined Drain in Urban AreasUnlined drain between main carriageway and service road hguidelines from NHAl to act as water harvesting medium apartbe constructed at interval of 500m alternatively on left and right


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service road or any side road is joining with main carriageway 450mm dia pipe will be put in placeof open unlined drain. The design runoff has been considered for area between main carriagewaykerb and extreme edge of service road. At every 500m water harvesting structure will beconstructed alternatively on left and right of the highway and unlined drain will be joined with thesestructures.The depth of drain can be varied to facilitate the minimum longitudinal gradient if terrain is flathowever, it should not be less than 60 cm at any place.The section of drains will remain same even in super-elevated reaches.

3 5 3 Median DrainageThe top level of earth in median of 4.5 m width has to be kept minimum 25 mm below the top levelof the kerb to prevent its washing away to the road surface. In this type of median, water is allowedto percolate down till the pavement drainage layer which will intercept the water and take it toembankment toe drain. On concentric widening sections, median is to be built only afler removingthe existing bituminous crust in order to obviate the stagnation of water within median.In locations where carriageway is sloping towards the median i.e. on curved alignments, there aretwo possibilities to have two different proposals for the disposal of rain water as discussed below:a) Where inner carriageway is lower or at level with outer carriageway, water is to becollected through 200mm vide median openings spaced at lorn clc. Water is allowed toflow across the entire formation width which will not cause any detrimental effect onpavement considering the quantum of rainfall in the project area.b) Where inner carriageway is higher than the outer carriageway, water is collected throughroad gully as shown in the drawing and then taken to suitable place of disposal throughconcrete channel. Disposal point can either be

Slab Culvert / minor bridge; or600 mm diameter NP-4 RCC pipe across the carriageway.Typical arrangement of median drain have been shown in the drawing Volume IX A):Drawings Highway)

3 5 4 Drainage of High EmbankmentsIn high embankment and bridge approaches if water is allowed to leave the carriageway atundefined spots, it may cause serious damage to embankment and pavement crust. This problemof erosion of slopes and shoulders is more pronounced in more than 6 m high embankments. Theproblem becomes more severe if the slopes of the embankment are steeper along the longitudinaldirection such as in approaches to bridges.In such location, both longitudinal and cross drains are required. Longitudinal drains have beenprovided at the edges of roadway. Rainwater is led down the side slopes through chutes of half cutpipes 300mm) placed at 15 m interval. Water from chutes will also be discharged into sidechannel. Typical details of High Embankment drainage have been show in the drawing Volume IXA): Drawings Highway).

3 5 5 Drainage at IntersectionsAny stagnation of water at intersections would reduce the capacity of junction resulting in queuingup of traffic. No covered drain is provisioned as these are likely to be choked due to sweepingsthe cross roads till the


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L

INLET

BAFFLE WALL 225x300 1 Om 0 FOR INSPECTION5 0 m m R CC SLAB M I 5

OUTLET TO DRAIN2 2 5 mm THK BRICK WALL

1 0 0 m m THK CC SLABFILTER MEDIA

PVC PIPE 2M LONG

3 6 AGGREGATE

GEOSYNTHETIC FILTER FABRIC


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Unlined draln In urban\semi-urban section between main carriageway and sewice road1 Runoff Coefficient

etation cover and uneven

turfe I Ih) Sandy soil light growth. 12.25 0.2 2.45parks gradens, lawnsmeadows Ii) Sandy soil covered with 0.1

heavy bush or wooded forestarea ITotal 28 16.625Average Runoff Coefficient 0.59P,)

2 Time of ConcentrationAssuming runoff velocitya) Over Adjoining land 0.06 mlsecb) In the drain 0.30 mlsec

3 Catchment Area /W 43 x LH0000 hawhere L is Length of madunder consideration n f

Flnal Delailad Project Report


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4 Hydraulic DesignCritical Rainfall Intensity I,) for 10 cmlhr1 hr -25 year return periodDuralion 1 hrChannel Slope s) 1 in 100Width b) 1 rnRugosity Coefficient n) 0.023 Sandy Clayside slope I n 2

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provide drain of depth 0.5 rn

1 . .; .\,Final Detailed Project RepoltContract Package NS81 ITNVolume Ii Design Report Highway. Structures) Chapter 3: Drainage Scheme Page o 9


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Chapter Miscellaneous Designs


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4 6 Laning of Karur Madurai Section ofNH-7Consulfancy Setvices for Feasibility study and Preparation of DPR

ADNxDHxPFxP,Parking Spaces = VHS,where:A D N the average daily traffic by vehicle less the traffic generafeddestinedDH -Design HourPF - Peak Factorv - Percentage mainline traffic stopping at wayside amenity center or at theparking complexVHS - Vehicle parked per hour per parking space

c) DormitoryThe number of cots and rooms are arrived using the formula given blow assuming 3 beds perroom.Number of rooms NPV A0 x 0.1NBEDNumber of rooms 53 x 3 xo . l = 5year 2017) 3Number of rooms - 1 1 8 ~ 3 ~ 0 . 1 = 12Year 2028) 3Where, NPV = Number of parking spaces for goods vehiclesA 0 = Average occupancyNEED = Number of beds per roomFive rooms with three beds in each room with common toilets are required to meet the demandup to the year 2017 and another seven rooms have to be added to meet the demand of the year2028.

d) Eating PlacesEating Places for Goods Vehicles Crew :The approximate numbers of seats required are arrived using the model;Number of Seats NP, x Ao x ASTAPD x 1-PVS) x VHSVNumber of Seats - 5 3 x 3 ~ 2 0 = -Year 2017) 60 x 0.8 x I

Number of Seats 1 1 8 x 3 ~ 2 0 = /

Final Detailed Project Report Chapter4: Miscellaneous Designs Page2 of 36


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Year 2028) 60 x 0.8Where,

Npg Number ofparking spaces of goods vehicleA 0 Average OccupancyAST Average Service TimeAPD Average Parking DurationPVS Percentage Vacant SeatsVHSV - Vehicles parked per hour per parking space.

Eating Places for Passenger VehiclesFor estimating the number of seats in eating places, the following model is used:Number of seats - [ NPc x AOc NPB)]x ASTAPD x 1-PVS) x VHSVNumber of seats - 22x5 9x30) x 20 = 159Year 2017 4 5 ~ 0 . 8 ~.33Number of seats - 63x5 14x30) x 20 = 307Year 2028) 4 5 ~ 0 . 8 ~.33Where,NPc,NPB- Numberofparking spaces for cars and buses

AOc, AOB Average Occupancy for cars and busesAST Average Service TimeAPD Average Parking DurationPVS Percentage Vacant SeatsVHSV Vehicles parked per hour per parking space.e) Mechanical Repair Shop

One shop equipped with lathe, welding machine, drilling machine tools and equipment, etc., toprovide services like minor mechanical repair, lubrication, adjustments, etc., have to be providedin amenity complex.f Tyre Repair Shop

One shop equipped with air compressor, vulcanizing equipment, air gauge, tools and equipment.etc., to provide services like vulcanizing, checking and filling air pressure, etc, have to beprovided in amenity complex.g) Toilets

Minimum of two blocks each one of them consisting of water closets, bath, washbasins andurinals have to be provided one each to goods vehicles crews and passengers in amenitycomplex.h) Area requirements of Comprehensive Wayside Amenity Complex

Approximate area required for the development of integrated complex is worked out aspresented below :

Final Detailed Projed Report Chapter 4: Page 3 of 36Contract Package NS81 TN)Volume : Design Report Highways Structures)


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Sub Total la 10.075 21.930

5ource: Evolving Guidelines on the Infrastructure Facilities for Freight Traftic Movement of MuMi

DescriptionLCVTruckMAV

Axle Vehicle along Arterial Highways, MOST, f 996. -

Total Area (sqm

An area of 3.05 hectares is required to meet the design year 2028 needs on developing anintegrated wayside amenity complex. However this integrated complex has been phased out foreffective utilisation and on economic considerations:

201781 0

6,300600

Phase 1: An area of 1.55 hectares has to be developed to meet the demand up to theyear 2017.

Area (sqm)90150300

Nos. -20281,80014,1001,200 -

Phase 2: An additional area of 1.50 hectares has to be developed to meet the design yeardemand.

20179422

However as per the circular of NHAI, a total of 2 hectares has been considered in the feasibilitystudy for developing the comprehensive wayside amenity.

2028209

Based on assessment of parking facilities, wayside dhabas along the project section andMORTH guide lines1 circulars truck laby's have been proposed in the following locations.

4.4 Traffic Control and Safety MeasuresTo enhance the safety of road users adequate provisions for roadway width, geometric elementsand junction improvements, have been proposed. In addition due consideration has been givento the provisions contained in IRC: SP 44-1994, 'Highway Safety Code . Various measures havealso been proposed to enhance traffic control for the high-speed highway.

4.4.1 Crash BarriersMetal beam crash barrier or precast concrete roadside barriers have been proposed to beinstalled along the roadway edge on either side if road stretch falls under the following category:

. Embankment height> m. Approaches of UnderpassI lyoverI OBS, /

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4 4 2 Road SignsAdequate road signs have been proposed for the project road in order to provide advanceinformation to regulate control traffic flow and ensure safety of operations. Road signs willeither be ground mounted or displayed as overhead gantry signs. The signs will be of retro-reflective sheeting of encapsulated type as per the MORT&H specifications for Road and BridgeWorks, 2001. Two overhead gantry signs will be installed near each terminal ends of thecontract package(s). Detailed instruction set and drawings will be issued for major and minorintersection showing position and type of road sign. Road signs are to be installed at 2.0 rn fromthe extreme edge of carriageway to ensure a safe clear zone and bottom edge of the lowestsign is not be less than 1.5 m above the crown of the pavement. On kerbed sections it is to beinstalled 60 cm away from the edge of the kerb and bottom edge of the lowest sign is not beless than 2.0 m above the kerb.Generally all signs are to be placed on the left side of the project road except at few locationswhere duplicate signs are to be placed on right side as well.

4 4 3 Pavement MarkingsMarkings to guide and assist the road users to negotiate conflict points and to be positioned atprecisely the right location to make his manoeuvre in the safest and quickest way so that the timehe is exposed to risk is minimised.Pavement markings on the project road have been proposed as per IRC: 35-1997, Code ofPractice for Road Marking with centre-line, shyness and edge strip. The pavement marking willbe in thermo-plastic paint with glass beads as per the MORT&H specification for Road andBridge Works, 2001. Detailed instruction has been provided in the drawings for major and minorintersections showing lane markings, pedestrian crossings, directional arrows etc.

4 4 4 LightingAs suggested by NHAl officials, solar lights have been provided at important locations.However, operation and maintenance cost of street lights is recommended to maintain by localcivic bodiesIAuthorities. Lighting arrangement shall be provided as per the technicalspecification given in Volume V: Technical Specifications.

Lamps are to be chosen to match as many of the following criteria as possible:1) High efficacy and low energy consumption11) Long lifeIl l) Resistance to fluctuations in the electricity supplyIV) Low capital costsV) Good colour rendition

4 4 5 Kilometre stonesStandard kilometre, 5Ih kilometre and hectometre stones have been proposed as per provision ofIRC: 8-1980 and IRC: 26-1967. These are to be made of precast M-20 grade reinforced cementconcrete, and lettering I umbering as per the respective IRC codes.In addition, boundary stones at 100 m interval staggered on each side have been proposed asper the provision of IRC: 25-1967.

4 4 6 DelineatorsDelineators provide visual assistance to drivers about the alignment of road ahead, particularly atright side. Three types of delineatorsprovision contained in IRC: 79-1981

Roadway indicators with rectangularhorizontal curves with deflection angle >Final Detailed Project Report Chapter 4: ~iscellankbs, Page 5 of 36Contract Package NS 81 (TN)


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of I m long and 10 cm square section painted alternatively black and white in 15cm widestrips. Delineator posts are to be erected at the edge of hard shoulder. The overall line ofposts should be parallel to centre line of the road. These are to be placed at outer and innerside of curves with the spacing defined in IRC: 79-1981 'Recommended Practice for RoadDelineators'.Striped retro-reflectorised hazard markers (30 cm x 90 cm) consisting of alternative blackand yellow stripes sloping downwards at an angle of 45'towards the side of obstruction.These are to be erected immediately ahead of bridge railing1 crash barrier. The insideedge of markers is to be in line with the inner edge of the obstruction.Cluster of red reflectors arranged on triangular panel as object markers provided at theheads of medians and directional islands. The object markers are to be setback by 50cm from the face of the kerb. Height of the post will be 50 cm. Size of equilateraltriangular panel will be 30 cm and there will be four red reflectors of 75 mm diameter.Triangular panel and post will be painted white.

4 5 Traffic Management and Safety During Construction4 5 1 introductionConstruction zones are an integral part of any road system. Road construction and maintenancework is hazardous for both the site operatives and the road users. In addition, speeding vehiclescreate a whirlwind of dust around the work place and noise from the traffic and maintenanceequipment often masks the sound of an impeding accident. Under the present system, the trafficoperations and safety provisions during improvement / maintenance works depend entirely uponthe expertise of the engineer. In the part this has not proved to be very efficient. Besides, non-uniformity in the methods of traffic control and placement of signs and other traffic controldevices at various locations increases confusion for road users.The current techniques of road improvement wherein traffic is allowed to use part of the existingcarriageway create considerable problems for traffic. Sometimes delays can leads to driver'sfrustration and then tendency of over speeding to make up time. All this is detrimental to roadsafety.Proper education, training programme and clear specifications equirements in the contract forthe site operatives would assist in creating and maintaining a safer environment for constructionworkers and for road users. Training could cover the personal safety of workers, safe use ofconstruction equipment in confined spaces and on 'live roads and the correct use of traffic signsand other control devices. The construction workers should be provided with high visibility use oftraffic signs and other control devices. The construction workers should be provided with highvisibility jackets with reflective tapes especially during night time working. The alertness of thesite operatives would also be improved if they were properly equipped for the work with safetyhelmets, gloves, boots and safety spectacles. A greater safety consciousness can also beensured if some of the supervisors and senior site operatives have first aid training. Theguidelines of safety at construction zones shall be as per IRC: SP: 552001

4 5 2 Traffic Management PlanA detailed traffic management plan shall be worked out by the Contractor in consultation with theEngineer and got approved prior to implementation.

4 5 3 Guiding PrinciplesThe guiding principles for safety in road construction zones are to:_---

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4.5.4 Components of the Construction Zone4 5 4 1 Traffic Control Zone

It includes all those areas of carriageway in advance of the actual work site which are requiredfor advanced warning of the hazard as well as safety zones, the transition zones and the workingzone itself.The Traffic Control Zone can be divided into three components, which are the Advance WarningZone, the Transition Zone, and Working Zone. Figure No. 4 1 shows the elements of trafficcontrol zone. All construction zones will have a working zone, which is flanked by a TransitionZone for each direction of approaching traffic, and an advance warning zone will precede thesein turn.

4 5 4 2 Advance Warning ZoneThe advance warning zone , is the area to warn the road user of the approaching hazard and toprepare them for the change in driving conditions. It is essential for traffic control in theconstruction zone. It should provide information on:1) The presence of the hazard through the 'Men at Work sign, accompanied by thedistance to the hazard:i) Any changes affecting traffic arrangements (such as a reduction in the number of lanesand r in the speed limit) within the traffic control zone;ii) Extent of the hazard (for example; the length of restriction); and for general information;iii) The type of hazard.The advance warning zone is also where the reduction in speed of vehicles should be notified.The drivers should be advised to reduce their speed so as to achieve the desired approachspeed before reaching the approach transition zone. The information in this zone is conveyedthrough a series of traffic signs along the length of the zone.

4 5 4 3 Transition ZoneThe transition zone is the area in which the traffic is guided into the altered traffic flow patternaround the working zone. This is one of the most crucial zones as far as traffic safety aspects areconcerned because most of the movements involved are merging / turning in nature. Thetransition zone has two components; The Approach Transition Zone and Terminal TransitionZone.The initial part of the transition zone called Approach Transition Zone should further reduce theapproach speed of vehicles and channelise them into the narrower and /or restricted number oflanes, if this is necessary.At other construction zones, it may be necessary to divert traffic away from the originalcarriageway and the design of the temporary road geometry through the transition zone shouldtake into account the following factors:1) The turning radius of the longest vehicle that generally uses the road should be the rulingradius for curves;11 Where changes in vertical profile are required these should be shallow enough to allowsafe passage of animal drawn vehicles if these are present in significant numbers);Ill) The zone should have a good drainage to avoid any stagnation of water on the roadsurface.IV) Sources of dust should be minimized. This is not only essential for good visibility but alsofor proper maintenance of signs and barricades in the zone.The traffic is taken across the transition zone mostly witchannelisers and pavement markings.

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4.5.4.4 Working ZoneThe working zone is the zone where actual construction s being undertaken. It contains the workarea and a working space, as well as lateral and longitudinal buffer zones to create the safetyzone to protect both the workforce from wayward vehicles entering the area of actual work andthe road users from construction equipment areas.Speeds should continue to be controlled in this zone because of the close proximity of movingconstruction plant and site operatives. Further, there may also be a difference in the elevation ofthe road and the diverted path in the zone.The path of the traffic must be very clearly delineated through the traffic control zone to avoid .vehicle intruding into the work area. Delineators and channelisers discussed further below mustbe used effectively for this purpose. Where the work site uses machinery with revolving boomslike cranes or excavators the intrusion of moving parts must be taken into account whendetermining the lateral clearances for the buffer or safety zone.

4.5.4.5 TerminalTransition ZoneThe Terminal Transition Zone TTZ) provides a short distance to clear the work area and toretum to normal traffic lanes. It extends from the downstream end of the work area.to the signindicating the end of works.A downstream or closing taper may be placed in the TTZ. It may be useful in smoothening of theflow of traffic. However, it may not be advisable when the trucks carrying material move into thework area by reversing from the downstream end of working zone. The length of the downstream taper may be 25-30 m.

4.5.5 Other AspectsThe distance between two traffic control zones should be such that the flow of traffic can return tonormal stream between them. Separation should permit fast moving traffic to overtake slowvehicles so that platoons can be dissipated and traffic normalised. These distances could varyfrom 2 Kms on urban roads to 5 Kms or 10 Kms on rural roads according to gradients, trafficlevels or traffic operation schemes.

4.5.6 Traffic Control Devices

Recommended Length of Traffic Control Zones

4.5.6.1 General

Average ApproachSpeed Kmlh)50 or less51- 8081- 100Over I00

Traffic control devices are the equipment and installations over and on the road, whichindividually and collectively perform the following tasks:1) Warn the road user;II) Inform the road user;Ill) Guide the road user;IV) Modify road user behaviour;V) Protect the road user and the vehicle;VI) Ensure safe passage to the road user; and .VII) Provide a safe working area. .

Length ofWorking Zone m)2 Km Urban5 Km Rural

Length of AdvanceWarning Zone m)I00100- 300300 - 5001000

Length of ApproachTransition Zone m)5050- 100300- 5001000


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The primary traffic control devices used in work zones are signs, delineators, barricades, cones,pylons, pavement markings and flashing lights.4.5.6.2 Signs

The road construction and maintenance signs fall into the same three major categories as doother traffic signs, that is Regulatory signs, Warning Signs and Direction (or Guidance) Signs.The IRC: 67: 2001 (Code of Practice for Road Signs) provides a list of traffic signs. Size, coloursand placement of signs shall conform to IRC: 67:2001. Each sign should be well located so thatits message is seen and is clear, which will be assisted if the surroundings are devoid ofunnecessary sign and other clutter. These signs should be of retro-reflective sheeting of highintensity grade or engineering grade depending upon the importance of the road as directed bythe engineer.The correct positioning and size of sign will ensure that it can be observed and recognized,thereby providing the driver with more time to react and take action.The following principles should govern the positioning of sign:1) Location should have clear visibility;II) They should be so placed that driver would have adequate time for responses;Ill) as a general rule, signs should be placed on the left-hand side of the road. Wherespecial emphasis is required, duplicate signs should be installed on the left and right sideof roadway. In case of hill roads, the signs shall generally be fixed on the valley side ofthe road unless traffic and road conditions warrant these to be placed on the hill side;andIV) The signs should be covered or removed when they are not required.On the kerbed roads, the extreme edge of the sign adjacent to the road shall not be less than600 mm away from the edge of the kerb. On the un-kerbed roads, the extreme edge of the signadjacent to the road shall be at a distance of two to three meters away from the edge of thecarriageway aved shoulder depending on local conditions but in no case, shall any part of thesign come in the way of vehicular traffic.. Regulatory Signs

Regulatory signs impose legal restriction on all traffic. It is essential, therefore, that theyare used only after consulting the

Dindigul Bypass to Samyanallore on Nh 7 in the State of Tamil Nadu Vol - II

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