scholarly journals Thermo-Hydro-Mechanical Combined Effect Analysis Model for Early-Age Concrete Bridges and Its Application

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Shiwei Li ◽  
Yongqing Yang ◽  
Qianhui Pu ◽  
Wangqing Wen ◽  
Aiguo Yan
Keyword(s):  
Prestressed Concrete ◽  
Coupling Model ◽  
Concrete Bridges ◽  
Combined Effect ◽  
Analysis Model ◽  
Effect Analysis ◽  
Long Span ◽  
Girder Bridge ◽  
Cantilever Construction ◽  
Early Age Concrete

The early cracking of concrete beam bridges remains a concern in civil engineering. An analytical model considering the combined effect of thermo-hydro-mechanical processes forms the basis for assessing the cracking risk of girders during construction. Based on the equivalent hydration theory, the temperature and moisture conduction processes and the evolution of the mechanical properties of concrete were modeled as a function of the equivalent age. A coupling model for the temperature and moisture fields was established, and a theoretical framework for analyzing the thermo-hydro-mechanical combined effect was presented. Based on this, a numerical analysis method was proposed and implemented into ABAQUS; the results were validated with some typical tests. Finally, a long-span prestressed concrete (PC) box girder bridge with balanced cantilever construction was taken as an example, and the causes of web cracking and its impact degree were analyzed. The results show that the rate of moisture conduction is significantly lower than the rate of temperature conduction; even for thin-walled components, there exists a significant humidity gradient on the surface layer. The humidity-induced shrinkage and restraint of the precast members are the main causes of web cracking.

Study on Crack Causes and Strengthening Measures of Large Span PC Continuous Box Girder Bridges

2010 ◽  
Vol 163-167 ◽  
pp. 3551-3554
Author(s):  
Wei Peng ◽  
Zhi Xiang Zha
Keyword(s):  
Prestressed Concrete ◽  
Load Test ◽  
Box Girder Bridges ◽  
Element Analysis ◽  
Box Girder ◽  
Girder Bridges ◽  
Long Span ◽  
Concrete Box Girder Bridges ◽  
Girder Bridge ◽  
Engineering Projects

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.

Optimization on Closure Scheme of Multi-Span Prestressed Concrete Box-Girder Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 2369-2375 ◽  
Author(s):  
Ming Yuan ◽  
Dong Huang Yan
Keyword(s):  
Stress State ◽  
Prestressed Concrete ◽  
Box Girder ◽  
Rigid Frame ◽  
Closure Scheme ◽  
Concrete Box Girder ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Cantilever Construction ◽  
Rigid Frame Bridge

The stress state of finished bridge and service stage is influenced by various closure schemes in cantilever construction of multi-span prestressed concrete box-girder bridge. Two typical bridges—multi-span prestressed concrete continuous rigid frame bridge and girder bridge are investigated, The stress state in different closure schemes are analyzed using finite element(FE) analysis. Meanwhile, compared the healthy monitoring data, it has been found that taking the closure sequence from side span to middle span in cantilever construction of multi-span prestressed concrete box-girder bridge can lower stress of girder and pier in finished bridge stage, as well as reducing deformation of girder in service stage. Hence, the closure sequence from side span to middle span is more suitable for cantilever construction of multi-span prestressed concrete box-girder bridge.

Load Test Analysis of Long-Span Prestressed Concrete Continuous Beam Bridge

2014 ◽  
Vol 1030-1032 ◽  
pp. 798-801
Author(s):  
Hua Su
Keyword(s):  
Bearing Capacity ◽  
Prestressed Concrete ◽  
Highway Bridges ◽  
Load Test ◽  
Beam Model ◽  
Test Analysis ◽  
Single Beam ◽  
Long Span ◽  
Continuous Beam Bridge ◽  
Girder Bridge

This paper takes a 45+60+45m prestressed concrete continuous box Girder Bridge as background, based on “Specification for Inspection and Evaluation of Load-bearing Capacity of Highway Bridges” (JTG/T J21-2011), single beam model and solid model are built for schematic design of load test. Compare the measured value and the theoretical value, and evaluate the bridge bearing capacity, finally provide technical base for project checking and accepting.

Behaviour Analysis of Prestressed Concrete Deck-Tied Arch Bridge

2013 ◽  
Vol 671-674 ◽  
pp. 952-956 ◽  
Author(s):  
Yi Qiang Xiang ◽  
Li Chang Zhang ◽  
Qiang Qiang Wu
Keyword(s):  
Prestressed Concrete ◽  
Internal Force ◽  
Analysis Model ◽  
Box Girder ◽  
Arch Bridge ◽  
Long Span ◽  
Prestressing Force ◽  
Horizontal Thrust ◽  
Tied Arch Bridge ◽  
Concrete Deck

The prestressed concrete deck-tied arch bridge doesn’t only have a long span, good appearance and economy, but also have the characteristics of low requirements to the foundation. It changes traditional tied arch bridge into deck-tied arch bridge, which looks like sunflower-shaped arch and prestressed steel strands are embedded in box girder on the top of the arch. Taking Yingbin Bridge as engineering background, the reasonable analysis model was established and behaviour of the bridge under design load was analyzed. The results shown that the design project is reasonable, prestressing force embedded in box girder can balance horizontal thrust in arch bridge effectively, improving the internal force of the main arch ring.

Sign in / Sign up

Export Citation Format

Share Document