Applied Mechanics and Materials Vols. 587-589

Abstract: Fiber reinforced polymer (FRP) has widely used in civil engineering due to their high strength-to-weight, high stiffness-to-weight ratios, and corrosion resistance. To solve the corrosion of the reinforcing steel in the bridge engineering and reduce the initial cost, FRP-concrete composite structure has been considered as the most effective composite form. A detailed research status survey of FRP-concrete composite beam/deck systems and their construction applications in civil engineering is presented. Several problems in future research are put forward.

Abstract: Prestressed concrete continuous rigid frame bridge is widely used in bridge engineering. Its closure is one of very important working procedure in the bridge construction. In this paper, taking Liangjiang Great Bridge in Xinxu Highway as an example, the methods for determining the Jacking force and displacement are discussed. The implementation of the process and construction technology of closure jacking scheme is introduced in detail. Through the finite element simulation, the stress state of on the structural pusher is analyzed. And the maximum stress of the pier bottom and the displacement of the pier top are obtained. They can verify the feasibility of the scheme. Monitoring results from the site construction verify the safety of the scheme. The method has a certain reference value on jacking closure construction for the similar bridge.

Abstract:

This paper mainly discusses on what should be paid attention to when innovative ideas in bridge construction are put into practice through analyzing the achievements of China’s modern suspension bridge construction since the initiation of China’s reform and opening up to the outside world. In recent years, some new concepts have been put forward in stiffening beams, cable saddles, cable bent towers and other aspects of the suspension bridge during its development. Among them, some are innovative and useful indeed while some merely meaningless. Analyzing the innovations of suspension bridge has a guiding significance for China’s bridge construction in the future.

Abstract: Based on the working principle of vibration wire strain gauge, two influence factors were analyzed and the temperature correcting equation was given. Furthermore combined with the anchorage zones model test of Xiaoshawan Yellow River Bridge in Inner Mongolia, temperature correction coefficients of test dates were found by linear fitting function of MATLAB, and then the test datum were corrected that achieved very good effects.

Abstract: This article based on bridge structural dynamics, vehicle dynamics and soil dynamics theory, set up the practical space mode, with an example of a dual-line 32 m single box section beam on Beijing-Shanghai Railway Line. According to the typical soft soil sites of Shanghai, the dynamic response of the bridge was analyzed by the large finite element software ANSYS under seismic action. Moreover the impact about the dynamic interaction of pile-soil-structure affecting on the design of high-speed railway bridges was got which will provide reference and basis for the construction and design similar project.

Abstract: The combinative bridge with V-type rigid frame continuous concrete beams and concrete filled steel arch bridge is a hyperstatic structure at internal and external, the construction process is complex, the structure is occurring system transformation with construction process. The tensioning process of hangers has a direct impact on the force of suspender final bridge and the stress state of the structure. The influence of deformation and stress of structure are studied with one-step tensioning and multi-step tensioning, Based on finite element simulation of construction process for the combinative structure with V-type rigid frame and arch of Nianchu River Bridge. The tensioning construction process of suspenders is forward on considering the actual situation of the bridge.

Abstract: Elasto-plastic seismic response analysis of complex bridge requires large computation, thus in practical engineering design this method can be simplified according to finite energy principle, finite displacement principle and Pushover method or other approximation algorithms. Finite energy principle and finite displacement principle are applied to piers with simple damage mode, and the two principles differ in structure’s natural mode of vibration. Pushover applied to complex structures which can’t be analyzed as single pier. Pushover gives maximum seismic response by static nonlinear analysis, and current Japanese specification adopts Pushover for complex bridge seismic design such as continuous rigid bridges.

Abstract: Taking Guizhou Hezhang Bridge as the engineering background, this paper used Midas/Civil FEM platform to study the pre-stress loss and deformation of main girder in bridge construction stage and completion stage on the basis of concrete creep and shrinkage formulas provided by “Highway reinforced concrete and pre-stressed concrete bridge design code (JTG D62-2004)” and the US bridge standard – AASHTO LRFD – published in 2005. The results showed that the pre-stress pipeline friction losses calculated according to the two standards are basically the same. The loss of the anchor deformation, elastic compression and tendon relaxation obtained by AASHTO LRFD is slightly greater than that obtained by JTG D62-2004. However, due to the different computing models, both pre-stress loss and the main beam deflection caused by concrete creep and shrinkage obtained by AASHTO LRFD are larger than that by JTG D60-2004.

Abstract: With the help of the commercial FE package ANSYS, this paper presents a finite element (FE) model for analyzing coupled flutter of long-span bridges. This model models the aero-elastic forces acting on the bridge utilizing a specific user-defined element Matrix27 in ANSYS, by which stiffness and damping matrices can be expressed in terms of the reduced wind velocity and flutter derivatives. Taking advantage of this FE model, Transient dynamic analysis is carried out to determine the dynamic response of a structure under the action of pulse load, of which the damping ratio can be obtained by considering response peaks which are several cycles apart. The condition for onset of flutter instability turns into that, at a certain wind velocity, the structural system incorporating fictitious Matrix27 elements does simple harmonic vibration with zero damping ratios or near zero one. The damping ratio is completely calculated in post-analysis of ANSYS and the initial frequency is given by any value and the last frequency can be got by iterating several times. In order to validate the developed procedure, a classical case study on three hundred meter simple supported beam is provided.

Abstract: Based on the material strength limit conditions of cable and stiffening girder, the static analysis of self-anchored suspension bridge was calculated. The stiffening girder of self-anchored suspension bridge was assimilated with elastic foundation girder. Considering of the action of both axial force and bending moment, the limit span of self-anchored suspension bridge was discussed. The limit span equation of three-span self-anchored suspension bridge with two towers was deduced. The influencing factors, such as ratio of rise to span of main cable, cross-sectional area and spacing of hangers, are studied, and the corresponding limit spans were given. It can provide valuable reference for the primary design of self-anchored suspension bridge.