Bu Yu Jia

Full-Scale Model Test for Anchorage Zone of Pylon of Cable-Stayed Bridge

In this paper, the construction technology for main pylon of cable-stayed bridge is researched through test of full-scale model of anchorage zone of pylon of Guangzhou Bridge. Stress distribution and deformation condition of model under prestressed tendons and cable force are analyzed. Numerical simulation on this anchorage zone model is carried out. By comparing FEM results to the test results, some important conclusions are drawn out and give some advices to the optimum design of the bridge pylon. Parts of the achievements have been applied to actual bridge work and obtained successful engineering experience.

Study on Dynamic Behavior and Seismic Performance of Cable-Stayed Bridge with Different Auxiliary Pier Positions

Choosing the Panzhong Bridge of the Guangzhongjiang highway as the research object, the dynamic behavior and seismic performance of cable-stayed bridge with different auxiliary pier positions were studied. The results show that the position of the auxiliary pier has limited influence on dynamic behavior. Under the action of the earthquake, auxiliary pier restricts the deformation of side span effectively and reduces the bending moment at bottom of the pile caps.

Study on the Prestressed Arrangement in Cable-Pylon Anchorage Zone of Cable-Stayed Bridge

According to the study on the practical Chaolianxijiang bridge, the stress state of cable-pylon anchorage zone of cable-stayed bridge under two kinds of prestressed arrangements (that is, U-shaped arrangement and parallel arrangement) were calculated and compared. The results suggested that parallel prestressed arrangement could avoid the difficulty caused by other arrangements in the construction. Parallel prestressed arrangement with clear concept, simple structure, clear stress and small amount of work is suitable for the thick walled cable-pylon.

The Key Technologies Research in Demolition Construction of Liuxi River Bridge

Because the flow of river bridge was not suitable for bearing existing vehicle load, it is needed to be dismantled, and a new bridge will build on the original site. The overall construction plan is using double bridge girder erection machines to remove box girder and the suspended beam of the main bridge. In order to guarantee the security of assembling the bridge girder erection machines and lifting the beam, we did some research in assembling technology, using the finite element software MIDAS to establish model of sling equipment, and analyses whether the sling equipment can bear the design load . With the purpose of ensuring the stability and safety of the suspended beam in the process of hoisting, the suitable order of hoisting suspended beam and risk control of slipping the suspended beam were analyzed. For purpose of guaranteeing the stability of the hoisting box girder, the construction team designed the stabilization system. Due to the complexity of the stress of the girder in the demolition process, we use the finite element software ANSYS to establish the model of e box girder in the process of hoisting, and analyze its stress and deformation. According to the practical engineering, we draw a conclusion: the box girder, suspended beam remained stable in the process of hoisting, and their internal forces conform to the requirements of the specification. The overall construction plan can provide a reference for other similar projects.

Key Technologies Research in Incremental Launching Demolition Construction of Beijiang Bridge

Because of dredging waterways, navigable rank of Beijiang Bridge needed to improve to National III level,it was necessary to remove the old Beijiang Bridge, building a new Beijiang Bridge at the same time and the same position. In view of problems as difficult to install launching nose, not enough space to remove beams,stability of the last removed box beam emerging in the process of removing, desiging and installation platform, cutting beams platforms, last-hole assisted platforms,in order to analyse force situation of the guiding beam in the process of push, using finite element software ANSYS to establish launching nose model, by simulating guiding beam at the bottom position by adding reverse force. At last, study guide beams in the up-push limit deviation technology, there was a conclusion: the building of a launching platform, cut beams platforms, last-hole assisted platforms improves the security and the stability of the construction, saves the construction space without damages in the guiding beams, forces conforming to real situation, pushing the limit deviation correction system, ensures box girder deviation in the allowed range. Key technology research in main up-push remove of Beijiang Bridge can be used for other similar bridge engineering.

The Reliability Sensitivity Analysis of Composite Beam Cable-Stayed Bridge during Construction Stage

A 10DOF composite beam element was developed, which had taken the interface slip effect and geometric nonlinearity into consideration. The method to obtain structural response gradients of composite beam was analyzed, meanwhile the reliability index was achieved by using the FORM method and on this basis, and the sensitivity of random variable parameters could be finished. At last the control of target elevation was took as state performance function, the sensitivity analysis of random variable parameters which might have an effect on the elevation control reliability was effectively completed, and some useful conclusions which were be beneficial to construction control of composite beam cable-stayed bridge obtained.

Large Span Continuous Girder Bridge Jacking Steel Hoop Stress Analysis

Bridge jacking technology is a new technology in the field of old bridge reconstruction. Based on the case of Beijiang River Bridge jacking of Fokai highway extension engineering, the paper designs steel hoop as jacking force platform. By using ANSYS software, it makes finite element analysis and calculation as well as compares with the experimental data to check the reliability of models. In addition, the paper puts forward the optimization methods of steel hoop based on the analysis of the results. At last, it achieves the objective of saving materials and simplifying installation and use as well as provides guidance for the similar engineering.

Application of Improved Response Surface Method Based on Kriging Model to Structural Reliability Analysis

The paper aims to do the reliability analysis by the Kriging model. Its excellent approximating capability is taken into consideration, which is superior to traditional response surface method. An improved response surface method has been proposed based on the Kriging model. The seismic response of structure is characterized by nonlinear and complexity, more difficulties in the reliability analysis have been found as well. Compared to other methods of reliability analysis, the response surface method is regarded as an effective way to solve such problems. Thus the improved response surface method based on the Kriging is utilized to analyze the structural first excursion dynamic reliability problem under random seismic excitation. Meanwhile, the influence on the reliability due to the randomness of structural parameters is analyzed.

Construction Monitoring of Dukeng Bridge

In this paper, a continuous beam arch bridge Dukeng bridge was introduced. Its construction process and its construction monitoring were discussed. In the construction process, the elevations of the box girders measured were closer to the values theoretical calculated. Though construction monitoring, although there were some construction errors, they can be timely adjusted and rectified and the main beam was ensure to smoothly closure.

Seismic Reliability of Long-Span Bridges Based on the First Order Reliability Method

In this paper, first order reliability method (FORM) is generalized to the seismic reliability analysis of long-span bridges and the first excursion probability of a single tower cable-stayed bridge is studied. The seismic motivation is firstly dispersed as a series of random variables. Then the cross velocities on the dispersed time points can be obtained by solving the motivation of the design checking points with FORM. The upper bound of first excursion probability is also obtained by integrating the cross velocities at different time. The results show that the seismic reliability analysis method based on the FORM is feasible and effective to solve the first excursion probability problem. The single tower cable-stayed bridge studied in this paper has a higher reliability under strong seismic.