Advanced Materials Research Vols. 594-597

Abstract: Based on the theory of vehicle-bridge coupled vibrations, the influence of transverse linear stiffness of double column piers on dynamic response of the train and bridge is investigated. A dynamic model of vehicle-bridge coupled system is established to analyze a high-speed railway bridge by BDAP software (Bridge Dynamic Analysis Program). By comparing the dynamic responses of piers which have different transverse linear stiffness, the characteristics of the relationship between the transverse linear stiffness of pier, the height of pier and transverse dynamic response are summarized, additionally some suggested values for transverse linear stiffness of piers are given to offer guidance for the design and construction of high-speed railway bridge.

Abstract: Based on the Chong He Bridge as research object, this paper expounds the purposes, methods and analysis results of prestressed concrete continuous thin-walled box girder bridge in the process of cantilever construction. The purpose of the research is to make a reasonable structure which meets the designed stress monitoring and to ensure the quality of construction. The method is to layout stress control points in the main control section and conduct real-time control. The result shows that the beam stress is within the safety range and can predict that the structure meets strength requirements in next stage. The conclusion is that through the data analysis, the results guide the whole process of bridge construction as well as fit the design plan.

Abstract: In this paper, using the universal finite element analysis software SAP2000 to build a large span cable-stayed bridge with finite element model, using a stepwise analysis finite element method to study the concrete shrinkage and creep efforts on the main beam inner force and deformation, cable tension during the cable-stayed bridge construction process and after the bridge. Research results show that the effects of shrinkage and creep in the finished bridge cannot be ignored, and the results can be used as reference for the design of similar projects.

Abstract: This paper introduces the numerical analysis method to analyze the dynamic characteristics of pier in water. The method comes to realize by the software ANSYS. By the calculating of ANSYS, the 1~3 order frequency can be found regular when the pier in full of water and anhydrous conditions. Water has a strong impact on natural vibration frequency of structures, as the water level rises, the natural vibration frequency decreases gradually, the value of the reducing is about 13%. At the same time, the frequency decreases as an increasing rate. So the natural frequency effect which the water acting on the structure can not be ignored.

Abstract: Based on the experimental study into the temperature control scheme for mass concrete pile caps of the Zhenyuling Bridge, this paper did comprehensive research on effective ways to reducing massive concrete temperature caused by hydration heat, and preventing concrete cracks caused by thermal stress. The paper analyzed the effects of cooling pipe, concrete thickness and surface insulation materials on the temperature-stress field of massive concrete. By theoretical analysis and simulation research, the temperature control scheme was developed to guide the construction of massive concrete. Temperature-controlling techniques and precaution measures of early thermal cracks are introduced, which can provide reference to construction similar structure.

Abstract: This article simulates prestressed concrete continuous girder bridge reinforced many times and evaluates carrying capacity after reinforcement. Taking the FuFeng bridge for an example, we analyze the bridge’s stress state in using by Midas software, evaluate the concrete ability of crack resistance, check the reinforced concrete structure ultimate carrying capacity, the cracking resistance and the stiffness, assess reinforcement effect and verify the accuracy and reliability of the simulation results. The maximum main compressive stress, maximum compressive stress, maximal main tensile stress and maximum tension stress of mid-span cross-section of the bridge are 1.6Mpa, 1.6Mpa, 0.3~0.5Mpa, and -1.2Mpa respectively, the mid-span center cross-section of deflection is 2.89cm. Reinforcement suppresses the development and expansion of the crack; the mid-span deflection tends to stabilize; the ultimate bearing capacity meets the Standard requirement basically; the emergency capacity is not enough; and the car whose weight over 55 tons is prohibited from passing.

Abstract: The objective of this paper is to find the appropriate stressing and monitoring method of the horizontal steel tie rod which is installed in RC inclined-column bridge. Taking Dongxulu Expressway Bridge as study objective, based on the FEM simulation, pulling+electrometry method is selected as stressing and monitoring scheme. The monitoring data show that the selected stressing method is reasonable and the final tensile forces in the steel tie rods can meet the requirements of design documents. The stressing and monitoring techniques ensured the construction quality and safety which provides reference for similar works.

Abstract: Based on mark points on the surface of bridge pneumatic model, adopting the DIC-Digital image correlation method to handle the pictures captured by CCD Video Camera in the high frequency get the displacement values of the mark points in the time series and thus obtaining the vibration forms of the bridge. The fundamental principles of the DIC-Digital image correlation method and its application were introduced in this paper and the reliability and stability of the method was testified by the comparison to the results measured by the laser displacement sensor

Abstract: Take one long span double-curved arch bridge as the example, built the finite element model of bridge structure and analyzed the modeling method, dynamic features and response under ground motion. It demonstrates that response spectrum method could meet the calculation requirement in seismic analysis of the double-curved arch bridge, and the result accords with time-history analysis method. Bridge vibration type is dispersing in quality distribution of double-curved arch bridge; it should take adequate vibration types in bridge combination. At frequent earthquake, it is actual to considerate the coalition function between arch crown structure and the main arch ring. But at rare earthquake, the arch crown buildings of masonry structure is easy to be damaged, it is not suitable to considerate the coalition function in bridge reinforcement.

Abstract: The carbon fiber is applied to the bridge reinforcement as the intelligent material because of the electrocaloric effect, which can improve the bearing capacity and the deformation capacity of the bridge. This paper investigated the application of the carbon fiber concrete in the maintenance of Guan Yin Dang bridge. With the combination of the analytical and experimental methods, we can obtain the calibration coefficient for the structure. The maximum calibration coefficient of the stress at the mid-span is less than 1, and meets the requirement of the criterion. The results demonstrate that applying the carbon fiber concrete in the bridge reinforcement is an effective method, which may provide a basis for the bridge intelligence of reinforcement and health inspection.