scholarly journals Modeling and analysis of a prestressed girder bridge prior to diagnostic load testing

2021 ◽  
Vol 13 (2) ◽  
pp. 23
Author(s):  
Emilia Andrade Borges ◽  
Eva O. L. Lantsoght ◽  
Sebastián Castellanos-Toro ◽  
Johannio Marulanda Casas

Progressive deterioration is a problem that affects road infrastructure, especially bridges. This requires the development of methods for its adequate detection and revision, one of them being load testing. Within load testing, finite element analysis (FEA) models provide initial information to understand the behavior of a structure and plan accordingly, which represents a fundamental step towards a precise structural evaluation of a bridge. This study focused on the modeling and analysis of the static response of the bridge over the river Lili in Cali, Colombia, a prestressed girder bridge programmed to undergo a diagnostic load test. A linear FEA model was created with information from a manual survey and from other bridges’ plans designed and built under the regulations in force at the time. Due to the absence of plans and design specifications for the bridge, variations were applied to certain model parameters (stiffness of diaphragms and elastomeric bearings), to quantify their effect on the overall behavior of the bridge. The analysis included obtaining the critical position for the design vehicles, the transversal distribution of stresses and determining the influence of the variation parameters in the response of the structure. Results showed that the critical combinations for bending moment and shear were when the loads were the closest to the exterior girders, being these elements the most affected. The variation on the modulus of elasticity for the diaphragms and the stiffness of the elastomeric bearings did not significantly influence the results for bending moment and shear, nor the critical position. Girder distribution factors (GDF) from the model were compared to previous research, finding similarities in shape and value with other FEA models and experimental results. Finally, an instrumentation plan focused on the girders of the bridge was proposed based on the zones where the maximum effects are expected. The findings in this study show how linear FEA models provide initial but relevant information regarding the critical position of design vehicles, the distribution of stresses and the expected values for bending moment and shear under design loads.

2010 ◽  
Vol 163-167 ◽  
pp. 3551-3554
Author(s):  
Wei Peng ◽  
Zhi Xiang Zha

This template Based on cracks observation and finite element analysis of real engineering projects as well as bridge load test after reinforcement, causes and types of cracks in prestressed concrete box girder bridges and treating measurements are systematically studied. The results obtained from the calculation are presented to demonstrate the effect of sensitive factors, such as arrangement of longitudinal prestressed tendons, the magnitude of vertical prestressed force, temperature gradient, etc. The results show that the arrangement of longitudinal prestressed tendons and the magnitude of vertical prestressed force take key roles in cracks control of box girder webs. Lots of treating measurements are presented in accordance with different types of cracks, some of them are applied to a reinforcement engineering of a long span pretressed concrete continuous box girder bridge with cracks. Load test after reinforcement of the bridge demonstrates the reasonability of the treating measurements. Several design recommendations and construction measures about reinforcements and some sensitive factors mentioned above are proposed to control cracks.


2015 ◽  
Vol 744-746 ◽  
pp. 827-831
Author(s):  
Hu Wang ◽  
Fei Han

In order to study the stress distribution law of simply-supported box girder bridge deck pavement under the effect of triangular concrete cushion, finite element analysis program is used to analyze distribution regularity of stress among asphalt and cement concrete cushion at the thinnest thickness of concrete cushion and transverse slope degree under the action of eccentric load which is applied in the most critical position. The result indicates that the first principal stress in asphalt pavement, the interface normal tensile stress and interface shear stress will reduce when the cushion layer thickness and transverse slope degree increase, however, the thinnest thickness of cushion should not be less than 3 cm. Considering the total weight of structure, cushion thickness should not be too large either. The thinnest cushion thickness of simply supported box girder bridge pavement layer is recommended for 3-4cm while transverse slope for 2-3%.


2021 ◽  
Vol 30 (3) ◽  
Author(s):  
Honglei Zhang

In order to study the influence of spatial stress effect and shear lag effect on the cracking of PC continuous thin-walled box girder bridge, a spatial model was established by using ANSYS finite element software to analyze the internal stress distribution of the bridge. The test results are compared with the analysis results of spatial model and plane link system model through the load test of real bridge. The results show that the longitudinal stress is evenly distributed along the width direction, which means that the spatial stress effect and the shear lag effect have little influence on the downdeflection of the bridge. The shear lag coefficient at the longitudinal axis of midspan bottom plate and the intersection of bottom plate and web are larger than other positions, which is most likely to produce cracks caused by stress concentration, and should be strengthened here in practical engineering. The results of load test show that the results of spatial finite element analysis are more reliable than those of plane link system calculation, and the design and construction based on the results of spatial finite element analysis is safer.


2014 ◽  
Vol 638-640 ◽  
pp. 937-941
Author(s):  
Jie Jun Wang ◽  
Peng Tan ◽  
Jiang Ya Yuan ◽  
Hai Qing Yuan ◽  
Gui Ming Zhang

This paper simulates the practical engineering, using plexiglass to make a three-span continuous wide curved box girder model by the geometry scale ratio 1:30. With the model load test, measured the strain and deflection of the control cross-sections, got the distribution about the stress and deflection of the wide curved continuous box girder; And we proposed the “uniformity coefficient” to express the uneven force of the curved bridge. Compared the finite element analysis results and experimental data, the results show both are in good agreement.


2008 ◽  
Vol 45 (3) ◽  
pp. 377-392 ◽  
Author(s):  
M. Kamran Khan ◽  
M. Hesham El Naggar ◽  
Mohamed Elkasabgy

When pile driving is difficult and (or) economically not viable, cast-in-place piles are indispensable. Tapered piles, which have top cross-sections larger than the bottom cross-sections, have the potential for substantial advantages over conventional straight-sided piles. This paper investigates the construction and performance of innovative drilled concrete tapered piles. A full-scale pile load-testing program was conducted to evaluate the axial compressive capacity of drilled concrete tapered piles in frictional soil. One straight and three tapered augers were designed and manufactured to produce six piles. The piles that were constructed and tested included four tapered and two straight piles. The testing results showed that tapered piles with a taper angle varying between 0.95° and 1.91° had a load carrying capacity up to 50% higher than the straight-sided piles with equal volume. It should be noted, however, that the experimental results are site specific. Moreover, an analytical expression was developed to evaluate the pile taper effect on its shaft capacity in terms of a taper coefficient, Kt. The value of Kt evaluated from the analytical expression compared well with experimentally measured values. Finally, a two dimensional nonlinear finite element analysis was conducted to simulate the load test conditions, and it proved to be successful.


2014 ◽  
Vol 638-640 ◽  
pp. 1092-1098 ◽  
Author(s):  
Rui Juan Jiang ◽  
Qi Ming Wu ◽  
Yu Feng Xiao ◽  
Xiao Wei Yi ◽  
Wei Ming Gai

In the present paper, based on the three-dimensional finite element analysis for a three-span continuous PC box girder bridge with corrugated steel webs and the corresponding conventional box girder bridge with concrete webs, a comparative study on the shear lag effect under self-weight is carryied out together with the analyslis on the coefficient of the effective flange width. The results show that At the sections in the negative bending moment near the intermediate piers, the shear lag effect in the bridge with corrugated steel webs is more obvious than that in the bridge with concrete webs by 8%; and the corresponding effective flange width coefficient in the bridge with corrugated steel webs is even smaller than 0.9, so the shear lag effect at these sections should be considered in the design of this type of bridges. At the mid-span section of the middle span of a three-span continuous bridge either with corrugated steel webs or concrete webs, the shear lag effect can be omitted since the corresponding effective flange width coefficient there is close to 1.0.


2012 ◽  
Vol 530 ◽  
pp. 122-129
Author(s):  
Hong Kai Chen ◽  
Hong Mei Tang ◽  
Ting Hu ◽  
Yi Hu ◽  
Xiao Ying He

Based on the finite element analysis software Midas, it takes response spectrum analysis, and posts the failure mechanism and characteristics of Girder Bridge under intense earthquake. Through the seismic response spectrum displacement maps of Girder Bridge, it finds out that the abutment and foundation deformation is in evidence, especially the top of abutment foundation. Through the study of seismic internal force variation on girder and pier, it indicates that the longitudinal earthquake controls axial force, vertical shearing force and in-plane bending moment, transversal earthquake dominates transversal shearing force and out-planes bending moment. And it shows that the pier and mid-span section are seismic response sensitivity parts. The three parts, axial force, longitudinal shearing force and in-plane bending moment, becomes the controlling index of pier intensity. According to the seismic response spectrum displacement for pier and abutment, the transversal anti-seismic stiffness of pier is smaller than longitudinal one, longitudinal seismic force shows no effect on transversal displacement, and the transversal seismic force can augments longitudinal displacement. At the same condition, longitudinal seismic force changes the longitudinal distributing form of abutment and concaves it deeply, and the transversal seismic force can not change its shape, but augment its value.


Author(s):  
Eva O.L. Lantsoght ◽  
Yuguang Yang ◽  
Ane de Boer

As the existing bridge stock is aging, improved assessment methods such as proof load testing become increasingly important. Proof load testing involves large loads, and as such the risk for the structure and personnel can be significant. To capture the structural response, extensive measurements are applied to proof load tests. Stop criteria, based on the measured quantities, are used to identify when further loading in a proof load test is not permitted. For proof load testing of buildings, stop criteria are available in existing codes. For bridges, recently stop criteria based on laboratory tests on beams reinforced with plain bars have been proposed. Subsequently, improved stop criteria were developed based on theoretical considerations for bending moment and shear. The stop criteria from the codes and the proposed stop criteria are compared to the results from field testing to collapse on the Ruytenschildt Bridge, and to the results from laboratory tests on beams sawn from the Ruytenschildt Bridge. This comparison shows that only a small change to the stop criteria derived from laboratory testing is necessary. The experimental evidence strengthens the recommendation for using the proposed stop criteria in proof load tests on bridges for bending moment, whereas further testing to confirm the stop criteria for shear is necessary.


2011 ◽  
Vol 243-249 ◽  
pp. 1767-1773 ◽  
Author(s):  
Jin Quan Zhang ◽  
Hong Wei Ren ◽  
Bo Yu

As a common type of bridge, the reinforced concrete simply supported T-girder bridges have some usual disease problems such as web vertical cracks, incline cracks near the supports and diaphragm damage, and so on injured by transportation loads. In Shanxi province most of T-girder bridges appear to be under strength for current vehicle loads because most of which are designed by conventional methods and the old codes so it is important to evaluate how the existing damage influence the ultimate bearing capacity of the bridge. The destructive test is a directive mean of verifying the ultimate bearing capacity of bridges. This paper provides details of a destructive load test of a T-girder bridge called Zuojiabao Bridge. It describes the analysis performed prior to testing, aimed at predicting the response of the structure at both serviceability and ultimate states, and discusses the results obtained.The development rule of strain, deflection and crack and the ultimate bearing capacity of the bridge were obtained through the destructive test process. The results showthat although the old T-girder bridge has enough bearing capacity to satisfy the new vehicle standard, it is strongly recommended to strengthen or retrofit the bridge. And the finite element analysis can be effectively applied to the failure analysis of the reinforced concrete T-girder bridge subjected to destructive load.


1987 ◽  
Vol 14 (1) ◽  
pp. 103-110
Author(s):  
W. J. McCulloch ◽  
C. Militano ◽  
S. Rizkalla

The Disraeli facility, which was completed in 1960, consists of several overpasses utilizing rolled steel beam construction and a riveted steel plate girder bridge crossing the Red River in Winnipeg, Manitoba. The total length of the facility is approximately 707 m (2320 ft). In 1984, the City of Winnipeg commissioned Reid Crowther and Partners Limited to perform a load test on the facility to ascertain the possibility of increasing the maximum gross vehicle weight limit. The tests were performed on three consecutive Sundays, from September 23 to October 7, 1984.Three spans were tested. One normal and one skewed span were selected for the overpasses to study possible differences in their behavior along the exterior span of a three-span continuous riveted plate girder bridge over the Red River. The test was designed to determine the structural response of the bridges at different load levels, to determine the load distribution characteristics, and to investigate dynamic impact values for the test vehicles.This paper describes the instrumentation layout, data acquisition system, test vehicles, and testing procedures. Test results and comparisons with the predicted values utilizing conventional analysis are included.


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