Applied Mechanics and Materials Vols. 438-439

Abstract: Combined with the design of Tiantang Site Protection Exhibition Project in Luoyang, China, the seismic performance of an archaized steel tower is studied in this paper. Firstly, a finite element model of whole structure is built accurately with ANSYS software. Then the dynamic behaviors of steel tower are analyzed. The natural vibration frequency and mode shape are obtained. Compared with dynamic test at site, the theoretical values are verified and it is reasonable about adopted loads and boundary conditions in the finite element model. After that, the seismic behaviors of steel tower are calculated and analyzed under seismic intensity 7 degree with methods of spectrum analysis and time-history analysis. The distribution characteristics of displacements and stresses are revealed. The results prove that the seismic performance of the given archaized steel tower can meet the code requirements. It is believed that the results in this paper would give some reference for the design of similar steel tower structures.

Abstract: Concrete filled steel tube (CFST) got a good application in actual project. In order to further the seismic performance of the CFST, experiment was carried on two 1/5 scale models, which included one CFST frame, one CFST truss. Based on the experimental study, load-carrying capacity, stiffness, ductility, hysteretic property, energy dissipation and failure phenomena of each model were analyzed. The study shows that the seismic performance of CFST truss has high bearing capacity, stiffness, energy dissipation capacity and good ductility.

Abstract: In this paper, the finite element analysis software ANSYS is used for modal analysis and dynamic analysis of a cold-formed steel villa to calculate its natural frequency, vibration period and dynamic time history curves. The analysis provides a basis for cold-formed steel villas design and has a certain reference value for similar projects.

Abstract: This paper studies on the ultimate failure modes and bearing capacity of high intake tower under the action of seismic load based on nonlinear concrete model. By monitoring the way of crack development and failure process of the tower to study failure mode under the action of various seismic wave, we can conclud that the regional distributions of the structural crack of tower body vary with the duration of an earthquake. In the early period of earthquake, the crack has little effect on the whole structure. After duration of the earthquake, the structure forms penetrable cracks. By studying the cracks development and distribution on the structure of tower body under the action of various seismic waves, we know the failure process and failure mode of high intake tower. The conclusions provide evidence for engineering design and seismic analysis of pertinent engineering.

Abstract: A three-dimensional model of dam-water-interaction system was built. Three different materials were used to model the dam, and the acceleration response of arch dam under the observed seismic waves was simulated. The results show that the dynamic reactions of the arch dam under observed earthquakes can well match the monitoring values, which means the established model of the arch dam is reliable. In the future, when great earthquakes happen, the stress strain situation of the key positions can be quickly obtained by the finite element calculation, which could provide scientific support for post-earthquake safety evaluation and decision-making.

Abstract: The vibrant-type-disintegration method is applied to calculate structure seismic action of a weir dam. Based on calculation and analysis of the weir dam, special attention is paid to the stress state of key parts. The results show that the displacement and stress of weir dam are affected by earthquake excitation direction. Since large principal tensile stress appears in the joint of girder and pier, and the zone of principal tensile stress is large because of the thrust of radial gate and steep changes of geometry shape, we should pay special attention when calculating anti-seismic checking and reinforcement arrangement.

Abstract: Conventional demand-driven models of water supply system are formulated under the assumption that nodal demands are statistic constants, which is not suitable for the cases where nodal pressure is not sufficient for supplying the required demand. An efficient approach for pressure-dependent demand analysis was developed to simulate the hydraulic states of the network for low pressure scenarios, and the mean-first-order-second-moment method was introduced to do the functional reliability analysis of post-earthquake water supply system, which can be applied to further study for seismic performance control analysis of water distribution system.

Abstract: The response spectrum method was applied to calculate the seismic behavior analysis of a spillway weir gate. Based on the analysis of the structure performance, special attentions were paid to the stress state of the key parts on the surface and root of the pier. The results showed that the displacement and stress of the whole structure were related to the direction of earthquake excitation; large principal tensile stress and principal tensile stress area appeared in steep change points of geometry shape, special attention should be paid when calculating anti-seismic checking and reinforcement arrangement; the displacement and stress of the weir section met the standard requirements.

Abstract: This paper presents nonlinear seismic response analysis of canyons in layered sites. The equivalent linear method is used in the dynamic analysis and Lysmer-Kuhlemeyer transmitting boundary is added at the left and right boundaries of the computation region. It is shown through numerical examples that, soil nonlinearity has significant effect on seismic ground motion around canyons. There are differences between seismic response amplitudes in nonlinear analysis and those in linear analysis, but the differences are smaller for observation points inside canyons. There are shifts between response spectra in nonlinear analysis and those in linear analysis, but the differences are much larger for observation points inside canyons.

Abstract: The paper is combined by the 2^nd phase engineering of Dahuofang water-conveyance tunnel. The 3D finite element models of the circular tunnel were built to analyze the seismic responses of the concrete lining under homogeneous rocks and nonhomogeneous rocks. The stress distribution of the concrete lining was studied under different buried depths. The results show that the seismic responses of the concrete lining magnify first and then reduce with the increase of the buried depth. The maximum stresses appear when the buried depth is up to 25m. It affords an important engineering reference for tunnel site selection, design and construction.