Applied Mechanics and Materials Vols. 501-504

Abstract: Since the 21st century, Beijing accelerate the process of internationalization. The level of the construction of Beijing city also faced a new challenge. The city traffic problems in Beijing is badly in need of improving. The stiffness of pedestrian bridge is so low that produce large vibration in the influence of ground traffic, which has a psychological effect on the pedestrian, even may cause psychological panic, anxiety and other adverse reactions. This study by monitoring the footbridge vibration at Beijing City Garden Road ,establishing finite element model to know about its severity under Motor vehicle traffic loads to get Vibration mechanics parameters. Use ISO, UK, Japan bridge design specifications and standard to check to make a scientific and reasonable evaluation on the vibration comfort about it.

Abstract: Ji'an Bridge is a newly built bridge. In order to understand the bearing capacity and actual working conditions of the bridge, the static and dynamic tests were carried out. This paper mainly describe the methods and principles of the load test. Through static and dynamic load test, we can detect and analyze the bridges action of stress, deflection and dynamic characteristics, then evaluate the bearing capacity of the bridge, which can provide reference for other similar bridges.

Abstract: In the modern urban bridge projects,especially the urban interchange projects and the urban viaduct projects,the long-span curved bridge with the small radius is often inevitably used,considering the transportation under bridges,pipelines and aesthetic factors.This kind of long-span curved bridge with small radius was adopted on the south of Second Ring Road in Chendu of the project of "Two Expressways,Two Extended Roads,Two Ring Roads".The influence,which the change of the parameters on the structure had,was analyzed by using the finite element software of Midas Civil 2010.Then,the parameter which had greatest impact on the inner force of the structure was found.The girder depth is the key parameter in design.

Abstract: The fabrication precision of steel box girder segments is critical to ensure the erection of girder segments is smooth. Taken Jiashao bridge as the research subject, based on geometry control theory, control elements of a steel box girder and control method were introduced, and measured data in the fabrication control of Jiashao bridge girder was given. Control practice shows the erection of the girder is smooth due to the precise control of steel box girder segments at the fabrication stage, and the profile of main girder at completion stage can achieve smoothly the design profile.

Abstract: The superstructure of H-bridge is prestressed concrete composite box-girder with corrugated steel webs with a main span of 90m, and the span arrangement is 52m+90m+52m. In this paper, the finite element method is used to model H-bridges superstructure and do analysis of construction stage and completed bridge stage, and the analysis is checked with the current corresponding regulatory of bridge design and construction. Checking results show that under the existing highway-level loads, the main beams carrying capacity, stress, crack resistance, deformation and corrugated steel webs shear strength and shear stability meet the regulatory requirements. The checking process also reflects the mechanical properties of corrugated steel web.

Abstract: In this paper, vibration of a steel truss bridge under moving train and earthquake action is analyzed. The following conclusions are drawn by modal analysis and time-history analysis. 1) Lateral dynamic response of this structure is more obvious under earthquake action and lateral dynamic effect of train running load; 2) seismic response in the directions different from train load is small, and dynamic response becomes larger obviously when they are considered together.

Abstract: Using the viscouselastic artificial boundary, three conditions of long-span cable-stayed bridge are analyzed,such as pile cap consolidation, pile - structure and pile soil structure interaction. Natural frequency of bridge of pile - soil - structure coupling becomes small and cycle becomes long. The pile bottom reaction force decreased obviously, at the same time, the axial force , bending moment, axial force of cable, tower of axial force and bending moment is also reduced significantly. Cable-stayed bridge is a special flexible structure, so, static internal force calculation in the tower bottom consolidation pattern is safe, but the value is too large.

Abstract: Jiu-Jiang Yangtze River Highway Bridge, with a main span of 818m, is another long span hybrid girder cable-stayed bridge which connects Jiang Xi province and Hu Bei province in China. Steel box girder is adopted in main span and north side span, and main girder of south side span and south tower nearby is designed of concrete box girder. The pylon is concrete structure, with the height of 242.3m and H-shape. There are 216 cables used in this bridge, of which are assembled by parallel strands. Jiu-Jiang Yangtze River Highway Bridge began to construct in 2009, and was closed in December, 2012. The bridge opened to traffic officially in the next year. Design concept, construction method and vibration control measures about Jiu-Jiang Yangtze River Highway Bridge are introduced in this article.

Abstract: The essay was initiated by Hubei Provincial Communications Department, endorsed by Traffic Planning and Design Institute of Hubei Province, Bridge Science Research Institute (China Zhongtie Major Bridge Engineering Group), Huazhong University of Science and Technology, Wuhan University of Science and Technology. 6 kinds of common bridge diseases and 6 kinds of effective improvement measures were ranked and graded using questionnaire, and counted and calculated the weight using dual contrast fuzzy decision method. The calculation result shows that the concrete crack, bridge damage and main girder downwarping were accounted for larger proportion in the current common bridge diseases. In improvement measures, strengthening bridge linear control, mastering the concrete ages and strengthening dual control of prestressed reinforcement are particularly important.

Abstract: In order to reduce loss of terrorist attacks or accidental explosion accidents to traffic facilities of the state and society, antiknock safety of long-span bridge needs to be further studied. A deck arch bridge calculation model of fluid-structure interaction was established, and explicit dynamic analysis was presented to study the dynamic response of long-span arch bridge under blast loading, and the explosion effect to the overall structure of the bridge was analysed. The results show that the area around explosion center, has local large deformation and heavy damage degree, while a little far region has low deformation and damage degree; When explosives is located on the deck, the damage of blast-impact load on the main arch ring can be neglected, which is advantageous to the late bridge repair work. The results of this article can be provided as important theoretical reference to antiknock and explosion-proof of bridges in the future work.