BEHAVIOUR AND ANALYSIS OF AN INSTRUMENTED SLAB BRIDGE · 4 F. Sawko, Ultimate Load Analysis of...

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Abstract— Because of quick construction and cost effectiveness, adjacent precast, pre-stressed box girder bridges have been used

nowadays more often for short-span bridges, and the standardization of this modular bridge is highly desired.

The new design of using high strength rods will provide a more tightly integrated modular slab bridge system with higher

post-tensioning forces. With the new design, the Highway Administration is highly increases the efficiency by interested in the

performance of the new design, especially compared with the old design. This study presents the procedure of test, live load test results

and analysis results in association with the finite-element model simulated in a newly-built bridge.

Key Words—deck slab, link slab, ANSYS, hardness, load.

I. INTRODUCTION

Many highway bridges are composed of multiple spans steel or pre-stressed concrete girders simply supported at piers or bents. The

girders support cast-in-place concrete decks. A mechanical joint is typically employed at the end of the simple span deck to allow

deck deformations imposed by girder deflection, concrete shrinkage, and temperature variations. It is well known that bridge deck

joints are expensive to install and maintain. Deterioration of joint functionality due to debris accumulation can lead to severe

damage in the bridge deck and substructure. The durability of beam ends, girder bearings, and supporting structures can be

compromised by water leakage and flow of deicing chemicals through the joints. A significant negative economic impact of

mechanical joints in all phases of bridge service life, from design to construction and maintenance, was documented by Wolde-

Tinsae and Klinger. A possible approach to alleviate this problem is the elimination of mechanical deck joints in multi-span bridges.

1.1 scope of the study

There is always having a problem about the sustainability of bridge due to the cracks or de-rating of the joint because o the

leakage in the joint cracks in the bridge, to overcome these drawbacks, it is necessary to work over the joint parameters of bridge.

This project deals with the bridge link slab load analysis at the joint and study over the experimental and software validation to

improve the efficiency of the bridge. This technology can be applicable to the construction of bridge and it will be beneficial to get

the improvement of joint.

1.2 Problem statement

Bridge deck joints are a persistent and costly maintenance problem. Water leaking through the joints is a major cause for the

deterioration of bridge girder bearings and supporting structures. Debris accumulation in the joints restrains deck expansion and

causes damage to the bridge. Joints and bearings are expensive to install and maintain. Therefore, the cost of construction and

maintenance for a bridge can be greatly reduced if the number of deck joints in multi-span bridges can be minimized. It should be

noted that when the deck joints are removed and replaced by a joint less deck, fine cracks can be expected to develop in the joistless

deck and in many cases water may still leak through the fine cracks. However, the situation is preferable to that of jointed decks.

G. N. Bhange1, Prof. G. J. Kumbhar2, Prof. M. N. Shirsath3.

M. E. structural engineering, G. H. raisoni college of Engg. & management CHAS, Ahmednagar,

BEHAVIOUR AND ANALYSIS OF AN

INSTRUMENTED SLAB BRIDGE

JASC: Journal of Applied Science and Computations

Volume VI, Issue VI, JUNE/2019

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Fig. 1.2 damaged bridge joint

1.3 AIM: to study the bridge joint structure and comparative experimental and load analysis of link slab and deck joint slab used

for the joint of bridge.

1.4 Project Objectives

There are three major objectives of this research, which include the following:

1) Design and analysis of the bridge model with and without joint bridge.

2) Experimental validation of the bridge with and without joint i. e. with and with link Slab Bridge.

Validate analysis and design assumptions, investigate limit-states design parameters and simplified design procedure, and In

order to accomplish all of the research objectives, several tasks have been identified. These tasks include the following: live load

testing and data collection, collection of data under random loading, live load test analysis, and random and thermal loading

analysis. The instrumentation on the bridge will be used to obtain data from loading, service loading and live load testing. Each one

of these loadings will provide different results, which can then be used to accomplish objectives one and two (validate analysis and

design assumptions and investigate limit-states design methods). Also, the on-going data collection will be useful in developing a

long-term monitoring strategy, which is object three.

2. LITERATURE REVIEW

Cheung (1978) studied analytically and experimentally the behavior of simply supported curved bridge decks with intermediate

column supports. His analytical study was based on the finite-strip method, the results of which compared favorably with

experimental values obtained from testing thirty 1:60 scale asbestos cement curved slab decks. He conducted a static analysis of

orthotropic curved bridge decks with two radial edges simply supported and the other two curved edges free, using a combination of

Fourier series and the finite-difference technique. The governing fourth-order partial differential equation of orthotropic plates was

converted to an ordinary differential equation and solved by the finite-difference method.

Miah and Kabir (2005) studied the behavior on reinforced concrete skew slab. They tested six skewed slab of concrete in the

laboratory where the entire tested slab scaled to 1/6 model of prototype skew slabs, with using the same steel arrangement for all.

The experimental observations were limited to measurement of deflection at different nodal points, concrete fiber strains at some

top and bottom points of the slabs, steel strains, cracking patterns and observing the cracking and ultimate loads. They observed that

the load carrying capacity of skew slabs significantly depends on the skew angle. As can be expected, with the increase in skew

angle stiffness of slab decrease and so is load carrying capacity.

Alp Caner, 1995, Maintenance of bridge deck joints is a costly problem. Debris accumulation in the joints can restrain deck

expansion, causing undesirable forces in the deck and damage to the structure. Water leaking through the joints is a major cause for

the deterioration of bridge girder bearings and supporting structures. Therefore, elimination of deck joints at the supports of multi-

span bridges will reduce the cost of construction and maintenance. This paper presents the results of a test program to investigate

the behaviour of link slabs connecting two adjacent simple-span girders, and proposes a simple method for designing the link slab.

To illustrate the proposed design method, three design examples are included.



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Fig.2.1 link slab

Fig.2.2 Deck joint

Fam, Huitema and Meyer (2006) designed a highly curved concrete ramp bridge, which presented a challenge to bridge engineers

due to the problems imposed by the complex environmental and geometric constraints. They maintain the stability of the structure

by balancing the dead, pre-stressing and live loads with the reactive forces at supports which is of particular important. They proved

that these bridges could be designed and constructed economically. By respecting the geometry of the curved road and the

constraints of the underlying elements, these bridges provided both functionality as well as balance of visual elements.

Massimo Fragiacomo, 2018, Timber-concrete composite bridges: Three case studies, During the last years, timber-concrete

composite (TCC) structures have been extensively used in Europe both in new and existing buildings. Generally speaking, a

composite structure combines the advantages of both materials employed: the strength and stiffness of the concrete in compression

and the tensile strength, lightweight, low embodied energy, and aesthetical appearance of the timber. The concrete slab provides

protection of the timber beams from direct contact with water, which is crucial to ensure the durability of the timber beams,

particularly when used for bridges. Different types of connectors can be used to provide force exchange between the concrete slab

and the timber beam.

Junqing Xue, 2018, Design and field tests of a deck-extension bridge with small box girder, A joint less bridge could

fundamentally eliminate vulnerable deck joints, thereby meeting the need for sustainable development of bridges, especially for an

expressway with high-speed traffic. In this paper, one joint less bridge (deck-extension bridge) with a small box girder in an

expressway was chosen as a case study to examine the structural design, construction and field test. The field tests of the bridge

indicated that the designed and constructed structures can satisfy the requirement for service performance of the deck extension

bridge. Some key technologies, such as the position of longitudinal reinforcements in the superstructure-approach slab connections

and the arrangement of the sliding material layers, were introduced.

Khanh Nguyen Gia, 2017, Vibration analysis of short skew bridges due to railway traffic using analytical and simplified models,

Skew bridges are common in highways and railway lines when non-perpendicular crossings are encountered. The structural effect

of skewers is an additional torsion on the bridge deck which may have a considerable effect, making its analysis and design more

complex In this paper, the dynamic vibration of skew bridges due to railway traffic including the vehicle-bridge interaction is

analysed and studied.

In this paper, an analytical model for determining the dynamic response of the simply-supported skew bridge under

the moving loads is presented and a simplified model is also proposed. The modal superposition technique is used in both models to

decompose the differential equation of motions.



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F. Sawko, Ultimate Load Analysis of Bridge Decks, The yield line method for ultimate load analysis of slabs has been applied to

simply supported, edge stiffened, and continuous bridge decks. The importance of punching shear failure has been emphasized. An

extension of the basic yield line approach to beam and slab type decks are suggested.

The authors have attempted to present a comprehensive treatment of the ultimate load analysis of bridge decks. The

punching shear failure is seen to be an important criterion in the behaviour of beam and slab decks, and one which determines the

true load factor against collapse. It was further demonstrated how the yield line approach can be extended to cover the ultimate load

behaviour of grillages. The outlined procedure eliminates many of the tedious calculations involved in the plastic hinge approach

used for grillage analysis.

Katarína Serdelova, 2015, Analysis and design of steel bridges with ballastless track, Currently the modernisation of railways is

in progress in a large global scale. While classic ballast is verified in the long term and quite popular, the structural solutions using

more quality materials (concrete, asphalt) are more and more preferred. Therefore, the slab track system (STS) was developed that is

characterized as relatively maintenance-free structure of the railway superstructure where the reinforced concrete slab accepts the

load distribution function of the ballast [1][4]. In the case of bridge structures, the slab tracks are built mainly on concrete bridges

where the rigid connection between the STS and the bridge deck is solved using the cross-shaped slab directly concreted on the

bridge deck. Application of STS on steel bridges is rarer and therefore the design is not entirely clear. Therefore, the main purpose

of this work is to analyse the possibilities of utilizations of STS on steel bridges.

Application of the STS on steel bridges is less frequent and therefore the design solutions are not quite worked up and

known. Therefore, the main objective of the paper was to analyse the possibilities and structural solutions of the connection of the

STS with the steel bridge deck. The research will continue by the parametric studies to verify the optimal type of connection and to

prove actual possibilities of application of the STS for steel bridges.

3. METHODOLOGY

The project methodology is as follows,

Fig. 3.1 methodology of project

The methodology of the project contains the following contents, the project contains the software simulation validation &

experimental validation, out of the two validations the software validation and experimental validation are as explained bellow, and

it shows in the form of the flow chart as following,

3.2 Design data collection

The design procedure of the link slab bridge is as follows,

Currently, there is no formal design procedure for joint less bridge decks with deboned link slabs. Based on the results of

available analytical studies and the test program presented herein, a simple design method can be developed as follows:

1. Each span of a bridge with a joint less bridge deck may be designed independently as a simply-supported span using standard

design procedures without considering the effect of the link slab because the stiffness of the link slab is much smaller when

compared to that of the composite girders.

2. Provide deboning of 5 present of each girder span for the link slab to further reduce its stiffness. El-Safty's studies8 indicated that

the load-deflection behaviour of joint less bridge decks supported by simple-span girders is not affected by deboning up to 5

present of the span length.



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3. Determine the maximum end rotations of the girders as simply supported under service load and impose the end rotations to the

ends of the link slab. Determine the moment Ma in the link slab due to the imposed end rotations, using the gross section

property of the link slab (which is conservative because the link slab will develop small cracks causing a reduction in its

stiffness). Design the reinforcement for the link slab using a conservative working stress such as 40 % of the yield strength of

the reinforcing bar.

3.3 Modelling of project

In this chapter, the general description of how the finite element model is built is noted, and the calibration of the generated Finite

Element Analysis (FEA) model is introduced. Finite element analysis proposes substantial benefits in accurateness over alternative

methods of analysis such as grillage analysis or analytical methods in many specific types of structures. (O'Brien 1999, p. 185) For

instance, FEA enables membrane forces to be modelled accurately in structures such as arch, box girder, folded plate or shell

structures. In addition, FEA modelling allows greater analytical flexibility enabling the model to be manipulated by material

characteristics, which can allow further study.

Deck bridge

Isometric view of deck slab bridge

Dimensions of conventional bridge



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Parts of bridge

I section girder

Fig. I section and shear bolts



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Link slab bridge



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3.4 Modelling Method

Measuring strain from the live load test can be utilized in understanding the bridge behaviour. In addition, it can also become a

good developmental tool of the accurate finite element model of the bridge, especially in the calibration process. In performing a

comparison of in-field measured data and calculated data by a finite element analysis program, it is essential that the created finite

element model represents the identical strain response as the actual bridge behaviour. Therefore, creating the same geometry of

actual bridge and boundary conditions was required.

ANALYSIS OF BRIDGE JOINT

1. Conventional Bridge

2. Link Slab Bridge

1. Conventional Bridge



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Modeling Of Bridge

Meshing

ANSYS ANALYSIS

1. AT 250 N



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2. AT 500 N

3. AT 750 N

2. Link slab bridge

Modeling of bridge



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Meshing of bridge

ANSYS ANALYSIS

1. AT 250 N

2. AT 500 N



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3. AT 750 N

RESULT

Deck joint

Sr. no. Load N STRAIN (10-7)

1. 250 7.8414

2. 500 15.68

3. 750 23.52

Link Slab Bridge

Sr.

no.

Load N STRAIN

1. 250 4.005

2. 500 8.01

3. 750 12.91

Graphical analysis

1. Deck joint of a slab

0

10

20

30

250 500 750

stra

in

load (N)

Load Vs Strain



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Link Slab

COMPARATIVE STRAIN GRAPHICAL ANALYSIS

Conclusion,

From the above results and analysis, it showed that, the analysis results of the link slab joint and deck slab joint comparative

analysis. Above analysis results shows the strain measurement of the model at different load, the strain of the link slab joint

is less than the deck slab joint.

References 1. A. Caner and P. Zia, "Behavior and Design of Link Slabs for Jointless Bridge Deck," PCI Journal, vol. 43, no. 3, pp. 68-80,

1998.

2. Anusreebai S.K, Effect of Reinforcement Pattern on the Behaviour of Skew Slab, ternational Research Journal of

Engineering and Technology (IRJET) e, Volume: 03 Issue: 08 | Aug-2016

3. Kanhaiya Lal Pandey Behavior of Reinforced Concrete Skew Slab under Different Loading Conditions, GJESR

RESEARCH PAPER VOL. 1 [ISSUE 1] FEBRUARY, 2014

4. Naresh Reddy G N, Experimental Investigation of Simply Supported Skew Slabs Subjected to Uniformly Distributed

Loading, International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 7 (2018) pp. 274-27

5. Alp Caner Behavior and Design of Link Slabs for Jointless Bridge Decks, May-June, 1998, 68-80

6. E. Ulku, U. Attanayake, and H. Aktan, "Jointless Bridge Deck with Link Slabs," Journal of Transportation Research Board,

vol. 2131, pp. 68-78, 2009.

7. V. C. Li and M. D. Lepech, "Application of ECC for bridge deck link slabs," Materials and Structures, vol. 42, pp. 1185-

1195, 2009.

8. El-Safty, A. K., "Analysis of Jointless Bridge Decks with Partially Debonded Simple Span Beams," Ph.D. Dissertation,

North Carolina State University, Raleigh, NC, 1994.

9. Katarína Serdelová, Analysis and design of steel bridges with ballastless track, Procedia Engineering 111 ( 2015 ) 702 – 708.

10. Ilze Paeglite, Dynamic behavior of pre-stressed slab bridges, Procedia Engineering 172 ( 2017 ) 831 – 838.



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