Pre-Camber Analysis for Hanging Cradle Construction of Qinhe Bridge

2013 ◽  
Vol 438-439 ◽  
pp. 923-925
Author(s):  
Ji Hao Chen ◽  
Sen Liu ◽  
Yu Jia Gao ◽  
Yong Peng Sun

In order to ensure the safety of long-span continuous prestressed concrete girder bridge constructed by hanging cradle method, a pre-camber is always made to reduce shrinkage and creep in the process of post-operation, the late loss of pre-stressed, deformation produced by live load and so on. Combining with Qinhe Bridge, how to install the pre-camber is studied in this paper. The maximum pre-cambers and their locations of every span of Qinhe Bridge are determined by the method of standard JTG D62-2004 with the finite element analysis software MIDAS/CIVIL. The results show that the final pre-camber curves calculated by the method of standard JTG D62-2004 and quadratic parabolic method have cusps, which cannot meet the standard requirements for the smooth of the bridge. But the slop of the final pre-camber curve calculated by cosine curve at the maximum pre-cambers and the pier top is zero, and the slop of curve from pier top to the mid-span is small, which satisfy the standard requirements for the smooth of bridge. Therefore, the final pre-camber curve should be calculated by cosine curve.

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.


2011 ◽  
Vol 255-260 ◽  
pp. 821-825 ◽  
Author(s):  
Yun Bo Zhang ◽  
Da Peng Liu

In the design of continuous rigid frame bridge setting reasonable pre-camber can eliminate the impact of various loads on the linear in construction process, reduce shrinkage and creep in the process of post-operation, the late loss of pre-stressed, deformation produced by live load and so on ,resulting in deflection phenomenon. Based on the current specifications of the continuous rigid frame bridge camber setting methods, this thesis proposes the reasonable setting suggestions of pre-camber and sets examples to illustrate this.


Author(s):  
Jianqing Bu ◽  
Jincan Cui

In order to analyze the impacts of pre-stress loss on the long-term deflection for long-span PC continuous girder bridges, this paper presents a numerical analysis using the finite element analysis software MIDAS/Civil based on a long-span PC continuous box-section girder bridge in Shijiazhuang. Once the 3-D finite element model was established, the influences of different pre-stress loss levels and locations were analyzed in a numerical simulation. Pre-stress loss is often the key reason for long-term deflection in long-span PC continuous girder bridges, so we can estimate the development of deflection by considering these factors during the operation.


2014 ◽  
Vol 1030-1032 ◽  
pp. 798-801
Author(s):  
Hua Su

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.


Author(s):  
Jian-Qing Bu ◽  
Shuo Li

In order to analyze the distortion effects of the skewed PC box-section girder bridge, a simply-supported and three-span continuous skewed PC box-section girder bridge models are built by using the finite element analysis software ANSYS in this paper. First of all, the distortion effects in the longitudinal direction are analyzed for the bridge models and the most disadvantage section are found. Then the longitudinal distortion effects how to vary with the slope is discussed. The results show that the influence of slope is remarkable, with the increase of slope, distortion is becoming more and more large, and it is proportional to the slope degree, the distortion angle of 1/4 span and 3/4 cross section of the bridge is the largest. Therefore, in the process of design, construction and maintenance, the deformation of unfavorable cross section should be paid special attention.


2011 ◽  
Vol 255-260 ◽  
pp. 1261-1265 ◽  
Author(s):  
Bo Wang ◽  
Yu Xiang Liu

A four span curved HcontinuousH HboxH-girder bridge is used as an engineering example to investigate the effect of radius of curvature on the seismic response of curved bridge. Numerical models with different radii of curvature are created using the finite element analysis program Midas/Civil. The calculation results obtained from response spectrum method show that radius of curvature is an important parameter to curved bridge. When the radius of curvature is large enough, the relationship between seismic response of main girder and radius is approximately linearity, while nonlinear variation is obtained when theradius is not too large. Finally, conclusions are made that seismic design of Hstraight bridgeH unHfoldHed from curved bridge which radius of curvature is specified could Hsatisfy the engineering Hrequirement.


2021 ◽  
Author(s):  
Yao Wang ◽  
Mirela D. Tumbeva ◽  
Ashley P. Thrall

This research experimentally and numerically evaluated the reserve strength of girder bridges due to bridge rail load shedding. The investigation included: (1) performing non-destructive field testing on two steel girder bridges and one prestressed concrete girder bridge, (2) developing validated finite element numerical models, and (3) performing parametric numerical investigations using the validated numerical modeling approach. Measured data indicated that intact, integral, reinforced concrete rails participate in carrying live load. Research results culminated in recommendations to evaluate the reserve strength of girder bridges due to the participation of the rail, as well as recommendations for bridge inspectors for evaluating steel girder bridges subjected to vehicular collision.


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