Applied Mechanics and Materials Vols. 204-208

Abstract: At present, structural designers have many different views on determination of torsional mode. This paper adopts the structural mode factor and the mass participation factor method to determine structure torsional mode. Use the shear correction to simplify the calculation of structure torsion, derivate the relevant formulas of torsional effect, it has guide significance for manual calculation of structural torsion; Analysis of structural torsion resistant measures finally.

Abstract: In China recent accidents of sudden collapses of in-service bridges have aroused great concern about the real traffic load and bearing capacity of existing bridges. The proper management of existing bridges relies on accurate information of bridge operating load which is essential for correct assessment of operation and safety of bridges. An integrated load identification system for operating traffic which is built on characteristics of orthotropic steel deck, that is, the locality of stress influence line of orthotropic steel deck, and is based upon BWIM technique to establish functional relation between axle load and stress history, Case study of stress monitoring was carried out on two truss bridges with orthotropic steel deck under both controlled and normal traffic conditions to verify the system. In the case of controlled traffic, monitored information was used to back calculate axle load. The load information was compared with synchronous video recording of the traffic to check inversely calculated data about wheel weight and its lateral deviation between actual condition, The results show that the established identification system is accurate and valid. In the case of normal traffic, monitored stress data were used to back calculate axle load and wheel lateral distribution. From the results, axle load spectrum is abstracted and can directly help assessment of real load capacity and fatigue life of the bridge.

Abstract: This article deduced the debonding in the whole process of modification of CFST under axial compression through the spatial elastic incremental theory, then found the debonding conditions and laws of CFST with different sizes and materials, and decided the different design concepts of CFST structures at the elastic working stage and at the ultimate state.

Abstract: The initial geometric imperfections and the contact problem between sheets and skeletons are two key issues of the stability analysis of sheet space structures. In this paper ,the distribution law of the critical load is found out, the appropriate sample number and the critical load value formula are chosen for stochastic imperfection method, while the value of probability reliability is ensured. The results of contact model and fully coordinated model are compared to indicate that the effect of contact must be considered in the imperfection sensitive analysis of the structure after stochastic imperfection sensitivity analysis of sheet space structures. The paper also raises the quantitative indicators to characterize the imperfection sensitivity of sheet space structure, and it is the necessary preparation to quantify the sensitivity of structures.

Abstract: To predict the behavior of steel structure under fire effect, the material property is very important in the analysis of steel structure at high temperature. This paper adopted finite element method to investigate the nonlinear behavior of steel structures under high temperature and creep conditions. We studied the creep strains with different models of creep. Differences between these models are highlighted. Furthermore, the importance of creep effect in fire is discussed.

Abstract: Today, by the diversity of advanced structural systems, structures are guided to lighter designs, more efficient and stunning, tensile fabric structures are getting popular more and more everyday because of their lightness, quickly and easily installation, cheapness and also durability improvement of materials. Due to the necessity of recognizing the types of these structures, in this paper authors have tried to present a comprehensive review and appropriate analysis for these kinds of structures. In the first phase, after describing the desired topic, 52 case studies of Tensile Fabric Structures and their general features have been deliberated. At last all case studies were classified based on location, year of construction, base structure, material and form. Assessing these items, classified case studies could have been analysed. In this article, with focus on structural form, Tensile Fabric Structures were analysed in 3 categories: Hypar, Conic and Barrel. The method and results of analysis based on the structural information will be presented and discussed.

Abstract: The study gives an example of the sinking pier case at Takeda Interchange of National Highway NO.3 in Taiwan. We got the monitoring data, explored the impact on the consolidation settlement of piled-raft foundation from construction procedure and soil improvement by finite element method「Plaxis8.2」and predicted the degree of post-settlement. Analytic results are shown as follows：Firstly, the soil consolidation settlement model is built by the estimated soil parameters using the data of soil exploration. The calculation value of settlement and the measured value are identical. Secondly, soil improvement only shows effective in initial stage. The pre-consolidation settlement is smaller when building embankment is before pier than when building pier is before embankment.

Abstract: Cable net is a typical kind of flexible space structure, the effective stiffness forming need be through the prestress. The distribution of the prestressed need be through morphological analysis to find in finish. Based on the analysis of two methods: force reduction equilibrium method and inverse iteration method, the basic thought and algorithm of the two methods were analyzed. The numerical results indicate that the large cable network structure can be obtained through analysis for force satisfies given shape of prestress distribution.

Abstract: In this study, a push down analysis was performed for reinforced concrete (RC) frame building with collapsed column at lower floor by shock due to abnormal load in order to find progressive collapse process of building. The nonlinear flexural behavior of each structural element was defined from sectional analysis by using X-tract program. For push-down analysis of frame structure, Zeus-NL program was used. Main parameters in the analysis are location of damaged column and story of building. As a result, the deflection at the time of collapse of internal column was lower than one at the time of collapse of external column. In the frame structure with severely damaged column at lower floor, the higher the story was, the smaller the change of moment in beams at upper floors was. And, deflections of beams were found to appear evenly. This can be judged to be caused by a beam's suspension action.

Abstract: This paper based on a highway reconstruction projects. It puts forward the construction control measures of over-excavation and undercut in process of construction with Drilling and Blasting Method of multi-arch Tunnel, and analyzed the effect of the blasting vibration to middle wall and supporting structure. It also points out that shock absorption should be adopted in the construction. At last, it discussed the problems needing attention in the construction process of the middle wall.