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DESIGN TASK PROTOCOL Design Task Protocol No.: DRSR - 001 Revision No.: 0 Project: I-91 over Deerfield River Job No.: 60132040 / 62146 Design Task Element: DF (D-06-044) – Superstructure-Steel Deck Design Substructure Bob Hajjar John Smith Originator / 3/4/2009 Reviewer / 3/7/2009 Objective The purpose of this task is to design the superstructure elements of the replacement

bridge which carries Interstate 91 (I-91) over the Deerfield River and Stillwater Road. The project consists of replacing the existing 6-span Northbound and Southbound bridges with new 5-span steel plate-girder bridges.

This work includes, but is not limited to: o Superstructure – design of steel plate girders, diaphragms, utility supports, splices,

bearing stiffeners, shear connectors, and the calculation of cambers and top of form elevations.

o Deck Design – selection of reinforcement and concrete deck thickness as well as selection of additional reinforcement in deck overhangs.

o Substructure – design of the abutment, reinforcement and geometry; calculation of beam seat elevations at abutments and piers; pier wall design including reinforcing in the wall and pile cap, selection of pipe piles at the piers, and design of the cofferdam and tremie seal at the piers.

Prerequisites (Input)

Required Formats:

o All calculations and drawings will be in English units. o Two independent sets of calculations will be performed for the design, with the

exception of the steel plate girder design, which will be designed using Merlin-Dash and independently verifying the input. All detailing work computed using Merlin-Dash shall be verified by equivalent hand calculations.

o Computations should be performed in accordance with current Design Control Procedures for the Preparation and Review of Calculations.

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o Contract Drawings should be produced in accordance with current Design Control Procedures for the Preparation and Review of Drawings and MassDOT Bridge Manual.

Design results from other disciplines: Alignment, Horizontal and Vertical Geometry and construction phasing will be coordinated with the Civil Department of AECOM Technical Services. Survey information also exists.

Existing test data or analyses: Existing borings. Required test data: No additional test data is required.

Design

Design Criteria: All design is in accordance with the 5th Edition of AASHTO LRFD

Bridge Design Specifications 2010, the 1st Edition of AASHTO Guide Specifications for LRFD Seismic Bridge Design 2009, and the Massachusetts Department of Transportation (MassDOT) LRFD Bridge Manual (2009) Part I and II. All steel design shall be designed by the Load and Resistance Factor Design Method (LRFD).

Client Specifications: See above.

Design Manuals: o MassDOT Highway Division LRFD Bridge Manual (2009)

Design Codes and Standards:

o AASHTO LRFD Bridge Design Specifications 5th Edition 2010, AASHTO Guide Specifications for LRFD Seismic Bridge Design 1st Edition 2009

Design Loads: This structure will be designed for AASHTO group loadings, including:

dead load, live load, wind, seismic, and all other loads as directed by the Codes and Standards above, with minimum values as specified below:

o Dead Load

Soil 120 pcf Concrete 150 pcf Steel 490 pcf Water 62.4 pcf Pavement 150 pcf – a 3” HMA wearing surface shall

be taken into account Utility loads 250 plf (B.M. section 3.5.4.2)

o Live Load

Each bridge shall be designed for HL93 truck loading. Appropriate distribution factors will be calculated by AASHTO and dynamic load allowance shall be included. Two 12’ lanes, one 10’-0” shoulder, and one 8’-0” shoulder will be carried over each bridge (D-06-044). Staged construction need not be considered in the superstructure design as a temporary bridge will be provided.

o Wind Load

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A wind load of 50 psf shall be applied horizontally and at right angles for groups II and V. Groups III and VI loadings shall comprise the loads used in group II and V reduced by 70%.

o Seismic Load

25 percent of tributary dead load is considered for seismic design of substructure. Per Section 3.10.8 of AASHTO LRFD Bridge Design Specifications 2010, 100 percent of the absolute value of the force effects in one of the perpendicular directions will be combined with 30 percent of the absolute value of the force effects in the second perpendicular direction and vice versa.

Materials:

o Superstructure o Concrete: 4000 psi, ¾” 585 HP Cement Concrete for deck, o Reinforcement: AASHTO M31, GRADE 60 Stainless Steel o Structural Steel: Uncoated weathering steel, AASHTO M270, Grade 50W o High Strength Bolts:

All field connections shall be made with AASHTO M164 (A325) o Anchor Rods: ASTM F1554 Grade 50

o Substructure o Concrete:

4000 psi, 1½” 565 Cement Concrete for pier footing, lower half of abutment, and approach slab

4000 psi, ¾”, 610 Cement Concrete for pier wall, pier diaphragms, keeper blocks, and the upper half of abutment

4000 psi, 3/8”, 705 Cement Concrete for pier pipe piles 5000 psi, ¾”, 685 HP Cement Concrete for retaining wall barriers

o Reinforcement: AASHTO M31, GRADE 60, epoxy coated o Structural Steel: Uncoated weathering steel, AASHTO M270, Grade 50W o High Strength Bolts:

All field connections shall be made with AASHTO M164 (A325) o Anchor Rods: ASTM F1554 Grade 36

Preferred analysis methods and design approaches: All analysis and design will be

completed using the software listed below following guidelines from AASHTO. Load and Resistance Factor Design shall be used for all superstructure, deck, and substructure elements. The following elements have specific design criteria:

o Steel Plate-girder Design

Plate-girders will be designed using Merlin-Dash software. Plate-girders shall be designed considering composite design, following

the steps outlined in the MassDOT Bridge Manual Chapter 3. Load Distribution

Distribution of loads will be per MassDOT Bridge Manual Section 3.5.3

Shear connectors

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Shear connectors will be used for composite design following MassDOT Bridge Manual section 3.5.1.

Bolted Field Splices Splices shall be designed following standards set by MassDOT

Bridge Manual section 3.6.5 and Standard detail 5.2.12. Utility provisions

Non-composite sections carry the total dead load of utilities. See framing plans for location of utility bay.

Dead load of utility is carried by the two stringers comprising the bay

Top of Form Calculations: Top of form will be calculated as follows Calculate the theoretical top of roadway elevation directly over the

beam at the required points along the span using a spreadsheet. From this elevation, subtract the thickness of the wearing surface

and deck to obtain the in-place bottom of deck elevation. Include ¼” for the thickness of the membrane if used.

To the in-place bottom of deck elevation, add the total dead load deflection of the beam, excluding the deflection due to the beam’s self-weight, calculated for the particular point along the beam under consideration. The result is the top-of-form elevation.

Deflection and Camber Calculations Live load deflection shall preferably be limited to 1/1000, but no

more than 1/800. Camber will be calculated at 10th points. Camber and Deflection will be calculated per MassDOT Bridge

Manual Section 3.5.5

o Elastomeric bridge Bearing The Elastomeric bearings will be designed per MassDOT Bridge Manual

Section 3.5.6 o Cast-in-place concrete deck

Cover distances from AASHTO Table 5.12.3-1 will be used. Design shall be in accordance with the following standard details from the

MassDOT Bridge Manual (2009): 7.1.1 Typical Deck Reinforcement 7.1.5 Deck Slab Reinforcement – Steel Stringers w/ HMA 7.1.13 Addl. Overhang Reinforcement: CF-PL3 Rail (w/ HMA) 7.1.21 Addl. Overhang Reinforcement Assumptions

o Abutment geometry and reinforcement: An active earth pressure coefficient of Ka will be used to account for the

horizontal earth pressures per MassDOT Bridge Manual Section 3.1.5. The non-seismic longitudinal forces for abutment design will be

determined per Section 3.3.1.3 of the MassDOT Bridge Manual. o Pier geometry and reinforcement:

Live loads on the piers will be generated using a STAAD model. The pier geometry and reinforcement design will be completed using the

LEAP Bridge Suite software RC Pier. o Wingwall design

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An active earth pressure coefficient of Ka will be used to account for horizontal earth pressures per MassDOT Bridge Manual Section 3.1.5.

A 10 kip horizontal collision force (2 kips per foot uniform load over a 5 foot length) will be considered under Extreme Event II limit state per MassDOT Bridge Manual Section 3.3.2.2.

o Selection of piles All dead and live loads, including impact, from the superstructure,

abutment, wingwalls, and half of the approach slab will be applied to the piles. The capacity will be taken as the minimum of the structural or geotechnical capacity of the piles.

Assumptions:

o See those stated above

Appropriate Validated Software: Merlin-Dash, STAAD, LEAP Bridge Suite RC Pier, L-Pile Group, MathCad, validated Microsoft Excel spreadsheets.

Construction Specifications: Designer should review Construction Specifications to ensure consistency of material properties specified and construction methods to be used.

Interdisciplinary Coordination

Significant coordination with the Civil Department is required for geometry, utilities, obstructions, and construction phasing.

END OF PROTOCOL