Influence of Segmented Construction Methods on the Prestressed State of Truss String Structure Roof of Xinjiang Exhibition Center

2010 ◽  
Vol 163-167 ◽  
pp. 85-89
Author(s):  
Jin Zhang ◽  
Xin Chang Luo ◽  
Jian Guo Cai ◽  
Jian Feng ◽  
Xiao Jing Yang
Keyword(s):  
Control Force ◽  
Stage Model ◽  
Ground Model ◽  
Construction Stage ◽  
Construction Methods ◽  
Long Span ◽  
Cable Force ◽  
Maximal Displacement ◽  
Set Up ◽  
Prestressed State

Taking Xinjiang Exhibition Center Roof as an example, three models ("No construction stage" model, "Stretching on the ground" model and "Flow construction stage" model) were set up and analyzed with consideration of different segmented construction methods. The results show that the effect of the segmented construction method on the prestressed state of long-span truss string structures is significant. For the "No construction stage" model, the maximal cable force during construction is the largest among three models, while there are great differences between each cable force. However, the maximal displacement of sliding ends is the smallest among three models. For the "Stretching on the ground" model, the tension control force is the most uniform. This is because the cable of every truss is pre-tensioned independently, which causes no influence on other cables. For the "Flow construction stage" model, the maximal displacement of sliding ends and the uniformity of cable forces of the truss string structures are between those given by the other two models.

scholarly journals Numerical Analysis of Long-Span Cable-Stayed Bridge in the Construction Phase

2015 ◽  
Vol 9 (1) ◽  
pp. 896-905 ◽  
Author(s):  
Xue Chengfeng ◽  
Liu Laijun ◽  
Wu Fangwen ◽  
Yang Caofang
Keyword(s):  
Parametric Design ◽  
Tension Stress ◽  
Construction Stage ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Fea Model ◽  
Temperature Method ◽  
Cable Force ◽  
Sutong Bridge ◽  
Stage Analysis

The fabrication and erection of cable-stayed bridges involve major changes in structure configuration through the addition and removal of structure components. In every stage of the construction process, adequate information on the constructed structure is important to determine the real structure situation for the analysis of errors and to verify construction requirements. The ultimate goals are to meet construction needs and identify the effects of modification in subsequent construction procedures. The final configuration of the structure is strongly dependent on the construction and fabrication procedures. In this regard, developing an FEA model to simulate the actual construction processes is necessary to determine the performance of a bridge under external loads. In this study, a general methodology for construction processes is presented to simulate a cable-stayed bridge. The stage-by-stage construction of the Sutong Bridge is simulated with ANSYS software package. The tensions of cables are realized with ANSYS parametric design language, element birth and death function, and mutliframe restart function. The objective of the construction stage simulation is to identify stresses and deformations of the steel box girder and the concrete towers, as well as the cable tension stress, to meet the design requirements. Results of the construction stage analysis showed that the temperature method could simulate the adjustment of the inclined cable force successfully, and the global stiffness of the Sutong Bridge was very small before closure. These findings served as the initial data for a dynamic research on the Sutong cable-stayed bridge.

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

Analysis of Technical Characteristics and Construction Focus of Long-Span Continuous Rigid Frame Bridge with High-Rise Piers

2014 ◽  
Vol 587-589 ◽  
pp. 1637-1641
Author(s):  
Yao Cui ◽  
We Nang Hou ◽  
Fei Ying Liu
Keyword(s):  
Deep Water ◽  
Water Reservoir ◽  
Bridge Pier ◽  
Reservoir Area ◽  
High Rise ◽  
Construction Methods ◽  
Long Span ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Rigid Frame Bridge

Under the condition of the deep water reservoir area, the choice of bridge pier and long span continuous rigid frame beam construction methods are quite various. And the analysis of destruction of bridge depends mostly on the beam and piers. The paper cares mostly about these two parts.

scholarly journals Layout Optimization of Rail Expansion Joint on Long-Span Cable-Stayed Bridge for High-Speed Railway

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaopei Cai ◽  
Wanli Liu ◽  
Kaize Xie ◽  
Wenjun Zhu ◽  
Xiyuan Tan ◽  
...  
Keyword(s):  
High Speed ◽  
Field Tests ◽  
Element Model ◽  
Longitudinal Force ◽  
Main Beam ◽  
Expansion Joint ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Small Resistance ◽  
Set Up

Continuous welded rail (CWR) has been widely applied to the Chinese high-speed railways. It is interesting to reduce the effect of rail longitudinal force on the long-span cable-stayed bridges. Taking the pile-soil interaction into account, the finite element model of CWR on the long-span cable-stayed bridge is established based on the bridge-track interaction theory. The rail longitudinal force can be reduced and the track stability can be improved significantly by installing Rail Expansion Joint (REJ). The layout scheme of REJ plays a controlling role on designing CWR on bridges. Results show that the unidirectional REJ should be laid on both ends of the long-span cable-stayed bridge. Switch rails of REJ are set up on the main beam, stock rails are laid on the simply supported beams and crossing over beam joints, and several-meter long small resistance fasteners need to be laid on the sides of stock rails to reduce the fixed pier longitudinal force near the main beam. The range of REJ laid on cable-stayed bridge is mainly determined by temperature, rail breaking, and seismic condition; the bending and braking loads have little influence on it. Multiple field tests are carried out to prove the validity of the numerical model and the design methodology.

Calculation of Cable Force for Long-Span Rib Arch Bridge Construction under Seasonal Ambient Temperature

2011 ◽  
Vol 378-379 ◽  
pp. 341-344
Author(s):  
Wei Feng Tian ◽  
Shui Xing Zhou ◽  
Ayad Thabet Saeed Alghabsha
Keyword(s):  
Ambient Temperature ◽  
Control Method ◽  
Difficult Problem ◽  
State Control ◽  
Optimization Analysis ◽  
Arch Bridge ◽  
Long Span ◽  
Unstressed State ◽  
Cable Force ◽  
Cable Forces

Calculation of cable force under seasonal ambient temperature is the key and difficult problem in the construction of long-span rib arch bridge. It affects the final cable forces and deformations of arch rib after arch closure. Unstressed state control method is introduced in the construction of Daning River Bridge; unstressed qualities of ribs and unstressed length of cables can be obtained by optimization analysis of the maximum cantilever state in construction. According to unstressed state control method, the cable forces of each segment were calculated using the forward-iteration method. These results offer the basis for construction control, and guarantee the arch rib line and cable forces to meet the design requirements, and an arch closure with high precision.

Singular Perturbation Method for Solving Non-Linear Vibration of Stay Cable (I) - Theory Research

2011 ◽  
Vol 147 ◽  
pp. 112-116
Author(s):  
Zhi Hong Ran ◽  
Jun Tong Qu ◽  
Fei He ◽  
Sheng Miao
Keyword(s):  
Singular Perturbation ◽  
Perturbation Method ◽  
Stay Cable ◽  
Linear Vibration ◽  
Singular Perturbation Method ◽  
Cable Structure ◽  
Non Linear ◽  
Cable Force ◽  
Set Up ◽  
Theory Research

In order to solve the difficult in calculating cable vibration, the non-linear dynamic model of cable was set up with geometrical non-linearity. The differential equation was solved using the singular perturbation method. The analytical expression of frequency and form function was deduced. The expression can be widely used for the field of measurement of cable force and identification of parameter in cable structure.

Semi-Active Direct Velocity Control Method of Dynamic Response of Spatial Reticulated Structures Based on MR Dampers

2009 ◽  
Vol 12 (4) ◽  
pp. 547-558 ◽  
Author(s):  
Yan Bao ◽  
Cheng Huang ◽  
Dai Zhou ◽  
Yao-Jun Zhao
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Control Method ◽  
Optimal Placement ◽  
Feedback Gain ◽  
Control Force ◽  
Optimal Control Strategy ◽  
Integrated Method ◽  
Mr Dampers ◽  
Set Up

In this paper, a semi-active optimal control strategy for spatial reticulated structures (SRS) with MR dampers subjected to dynamic actions was proposed. The motion equation of SRS embedded with MR dampers was set up. The performance function of the optimal control strategy including both the structural responses and the control efforts was constituted for the optimization of feedback gain and MR damper placement in SRS, and an integrated method of genetic-gradient based algorithm was developed to solve this optimization problem. The clipped-optimal semi-active control strategy in the conjunction of velocity output feedback was applied to compute the desired control force from the MR dampers. Finally, a numerical example of SRS dealing with optimal placement of MR dampers and feedback gains of control system demonstrates the validity of the present semi-active optimal control strategy.

Construction Methods for Long-Span and Bifurcation Tunnel Structure

2014 ◽  
Vol 580-583 ◽  
pp. 983-986
Author(s):  
Chun Lei Xin ◽  
Bo Gao
Keyword(s):  
Surrounding Rock ◽  
Tunnel Engineering ◽  
Small Interval ◽  
Complicated Structure ◽  
Underground Engineering ◽  
Construction Methods ◽  
Long Span ◽  
Crucial Part ◽  
Optimum Construction ◽  
Preliminary Support

Long-span and bifurcation tunnel engineering is not very common in underground engineering field. It is difficult to construct this complicated structure because of the numerous influencing factors. In order to find out the optimum construction method for long-span and bifurcation tunnel to guarantee construction security and stabilization of this project, six construction methods were compared and analyzed by using numerical simulation. The results show that: (1) The excavation of confluence segment and small interval tunnel can affect each other but the confluence segment is the crucial part of the whole project. (2) The vertical brace determines surrounding rock and preliminary support stabilization in confluence segment. (3) The central concrete between main tunnel and ramp tunnel is the key point to guarantee the construction security and stabilization of small interval tunnel. The above results certainly contribute to research and develop new types of construction methods for long-span and bifurcation tunnel engineering.

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