A Study on Live Load Effects in Railway Backfilled Arch Bridges

2021 ◽  
pp. 759-766
Author(s):  
Tomasz Kamiński ◽  
Czesław Machelski
Keyword(s):  
Live Load ◽  
Load Effects ◽  
Arch Bridges

Modeling maximum live load effects on highway bridges

2008 ◽  
pp. 335-341 ◽  
Author(s):  
Bala Sivakumar ◽  
Fred Moses ◽  
Michel Ghosn
Keyword(s):  
Highway Bridges ◽  
Live Load ◽  
Load Effects

Structural Behavior of Three-Sided Arch Span Bridge

1996 ◽  
Vol 1541 (1) ◽  
pp. 112-119 ◽  
Author(s):  
Timothy J. McGrath ◽  
Ernest T. Selig ◽  
Timothy J. Beach
Keyword(s):  
Structural Design ◽  
Load Test ◽  
Structural Performance ◽  
Live Load ◽  
Element Analysis ◽  
Annual Basis ◽  
Soil Stress ◽  
Load Effects ◽  
Live Loads ◽  
Adjacent Segments

A study was undertaken to evaluate the methodology used for the structural design of three-sided culverts with arched top slabs. An 11-m span by 3.4-m rise bridge was instrumented and monitored during installation, under an HS-25 + 30 percent live load and at 6-month intervals for 2 years after installation. The bridge consisted of ten 1.6-m-wide precast segments. Three of the interior segments were instrumented with soil stress cells mounted on the legs of the bridge and with anchor pins for use with a tape extensometer to determine change in shape of the bridge. Survey data were taken on the same three segments and the two adjacent segments. Visual observations were also made to monitor cracking. The live load test was conducted with 0.3 m of cover. Final cover was 0.9 m. The bridge showed less movement under the live load than under the 0.9 m of earth load. The 2-year data show that the shape of the bridge and the soil stresses at the sides of the bridge cycle on an annual basis and that the spans have increased 4 to 8 mm over the 2 years since the completion of construction and appear to be still increasing. Overall, the structural performance of the bridge under earth and live loads was excellent. The correlation between the measured behavior and the computer analysis was good except that the actual live load effects were much smaller than assumed for design. The results of the project support the use of finite-element analysis to design such structures.

Field Performance of Integral Abutment Bridge

2000 ◽  
Vol 1740 (1) ◽  
pp. 108-117 ◽  
Author(s):  
Andrew Lawver ◽  
Catherine French ◽  
Carol K. Shield
Keyword(s):  
Earth Pressure ◽  
Field Performance ◽  
Design Parameters ◽  
Live Load ◽  
Integral Abutment ◽  
Double Curvature ◽  
Integral Abutment Bridge ◽  
Frost Depth ◽  
Load Effects ◽  
Load Tests

The behavior of an integral abutment bridge near Rochester, Minnesota, was investigated from the beginning of construction through several years of service by monitoring more than 180 instruments that were installed in the bridge during construction. The instrumentation was used to measure abutment horizontal movement, abutment rotation, abutment pile strains, earth pressure behind abutments, pier pile strains, prestressed girder strains, concrete deck strains, thermal gradients, steel reinforcement strains, girder displacements, approach panel settlement, frost depth, and weather. In addition to determining the seasonal and daily trends of bridge behavior, live-load tests were conducted. All of the bridge components performed within the design parameters. The effects from the environmental loading of solar radiation and changing ambient temperature were found to be as large as or larger than live-load effects. The abutment was found to accommodate superstructure expansion and contraction through horizontal translation instead of rotation. The abutment piles appeared to be deforming in double curvature, with measured pile strains on the approach panel side of the piles indicating the onset of yielding.

Optimization of hanger arrangement in pedestrian tied arch bridge with sparse hanger system

2019 ◽  
Vol 22 (12) ◽  
pp. 2594-2604 ◽  
Author(s):  
Yonggang Tan ◽  
Yuanbin Yao
Keyword(s):  
Mechanical Properties ◽  
Genetic Algorithm ◽  
Numerical Analysis ◽  
Mechanical Behavior ◽  
Live Load ◽  
Optimization Approach ◽  
Dense Network ◽  
Arch Bridge ◽  
Arch Bridges ◽  
Tied Arch Bridge

The hanger arrangement has a decisive influence on the mechanical behavior of the tied arch bridge with network hanger system. Many investigations on highway or railway tied arch bridges show that the arch bridges with dense network hangers are superior to those with vertical hangers under larger live load. However, numerous dense inclined hangers lower the esthetic effect of the bridge, especially for pedestrian tied arch bridges. Consequently, the sparse inclined hanger system is recommended in the design of pedestrian tied arch bridges. However, the amount of possible schemes of the hanger arrangement grows rapidly with the number of hangers increasing beyond 10, rendering great difficulties in searching for proper schemes. In this article, a dimensionless optimization approach based on genetic algorithm is proposed in searching for hanger arrangement schemes. Numerical analysis indicates that the proposed method is effective in the optimization of pedestrian tied arch bridge with sparse inclined hanger system, and some of the feasible hanger arrangement solutions show more excellent mechanical properties.

Control of Live Load on Bridges

2000 ◽  
Vol 1696 (1) ◽  
pp. 136-143 ◽  
Author(s):  
Andrzej S. Nowak ◽  
Junsik Eom ◽  
Ahmet Sanli
Keyword(s):  
Dynamic Load ◽  
Carrying Capacity ◽  
Load Test ◽  
Load Factor ◽  
Live Load ◽  
Load Carrying Capacity ◽  
Load Effect ◽  
Vehicle Weight ◽  
Load Carrying ◽  
Load Effects

Application of field testing for an efficient evaluation and control of live-load effects on bridges is described. A system is considered that involves monitoring of various parameters, including vehicle weight, dynamic load component, and load effects (moment, shear force, stress, strain) in bridge components, and verification of the minimum load-carrying capacity of the bridge. Therefore, an important part of the study is development of a procedure for measuring live-load spectra on bridges. Truck weight, including gross vehicle weight, axle loads, and spacing, is measured to determine the statistical parameters of the actual live load. Strain and stress are measured in various components of girder bridges to determine component-specific load. Minimum load-carrying capacity is verified by proof load tests. It has been confirmed that live-load effects are strongly site specific and component specific. The measured strains were relatively low and considerably lower than predicted by analysis. Dynamic load factor decreases with increasing static load effect. For fully loaded trucks, it is lower than the code-specified value. Girder distribution factors observed in the tests are also lower than the values specified by the design code. The proof load test results indicated that the structural response is linear with the absolute value of measured strain considerably lower than expected. Field tests confirmed that the tested bridges are adequate to carry normal truck traffic.

Soil–steel structure design by the Ontario Code: Part 2. Structural considerations

1981 ◽  
Vol 8 (3) ◽  
pp. 331-341 ◽  
Author(s):  
G. Abdel-Sayed ◽  
Baidar Bakht
Keyword(s):  
Steel Structure ◽  
Steel Structures ◽  
Empirical Method ◽  
Structure Design ◽  
Live Load ◽  
Finite Element Program ◽  
Worked Example ◽  
Metallic Shell ◽  
Element Program ◽  
Load Effects

The paper presents provisions of the Ontario Bridge Design Code for the structural design of the metallic shell of soil–steel structures, and also discusses the development background of these provisions. A simplified method of determining live load effects in the metallic shell is presented. The method is based on results of a well-tested plane strain finite element program. An empirical method for determining live load effects, which is based on tests of full-size structures, is also given. A worked example is given to illustrate the usage of the design provisions.

Reliability Assessment of Steel Bridges for Specialized Hauling Vehicles

2019 ◽  
Vol 2673 (12) ◽  
pp. 391-403
Author(s):  
Peng Lou ◽  
Dongjian Gao ◽  
Hani Nassif ◽  
Mula Reddy
Keyword(s):  
Safety Margin ◽  
Steel Bridges ◽  
Live Load ◽  
Load Rating ◽  
Truck Traffic ◽  
Reliability Indices ◽  
Weigh In Motion ◽  
Load Factors ◽  
Load Effects ◽  
Existing Bridges

Specialized hauling vehicles (SHVs) are short heavy trucks within the legal weight limits but induce higher load effects than routine commercial loads. The Manual for Bridge Evaluation (MBE) adopted a series of single-unit trucks (SUs) to represent this type of vehicle. However, the SUs were introduced without rigorous reliability-based analysis due to the lack of data on SHVs. With the availability of vast amounts of data on weigh-in-motion (WIM) truck weights and configurations, the reliability of steel bridges under the SHVs should be evaluated in a more robust and quantitative manner. Through the utilization of WIM data, the authors quantified the SHVs in terms of percentages of SHVs among all truck traffic, daily average counts of SHVs, and number of axles. The gross vehicle weights (GVWs) and typical configurations of SHVs were investigated. In addition, their load effects were determined and normalized by the corresponding SUs. The maximum live loads corresponding to a return period of 5 years were also extrapolated using normal probability paper (NPP). To evaluate the effectiveness of current load-rating procedures for SHVs, the authors investigated the relationship between the load-rating factors and the corresponding reliability indices for existing bridges using the developed live load parameters based on the WIM data. Results indicated that the current live load factors were not able to provide a uniform and appropriate reliability index at different average daily truck traffic (ADTT) scenarios. This paper thus proposes new live load factors and weight adjustments of SU trucks to provide an adequate and uniform safety margin for the evaluation of steel bridges.

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