Advanced Materials Research Vols. 243-249

Abstract: Making use of the numerical analysis method, the bearing capacity of reinforced concrete column with Z-shaped cross-section subjected to biaxial eccentric compression was analyzed in this paper. Some factors affecting the ultimate bearing capacity of Z-shaped reinforced concrete column were studied, such as loading angle, ratio of axial compression, reinforced ratio, concrete strength and reinforcement arrangement in the limb. It is shown that the worst loading angle was near the second center bisector, the bearing capacity can be improved by enhance reinforced ratio, rebar strength or concrete strength, and the reinforcement arrangement in the limb had little effect on the bearing capacity.

Abstract: A full-scale experiment on two kinds of rectangular CFST column and H-section steel beam diaphragm through connections which under low cyclic loading was been carried out. Through the analysis of the destruction shapes, hysteresis curves, ductility indicators, we obtained some practical conclusions.

Abstract: Structural additional force and deformation of a single-level, single span steel frame with cantilever beam spliced joints under the horizontal deformation and vertical deformation were researched by a physical simulation experiment. The results showed that the horizontal tensile-compression deformation is the most unfavorable to the frame. However, the frame was still in elastic stage and can resume normal work status after unloading, which make it a good anti-deformation performance.

Abstract: The paper analyses the damages of the frame structure with bottom weak layer considering of Wenchuan earthquake. The analysis result indicates the current design method "pure frame" is imperfect. The related research shows that important reason for the bottom weak layer’s breakage is the stiffness mutation which is caused by the filler wall. If we arranged partial shear wall structure in the bottom weak layer, the adverse effects of stiffness mutation will be decreased, and improve the seismic performance of the frame structure with bottom weak layer.

Abstract: Knowledge about the dynamic properties of concrete is vital to the design and safety evaluation of large-scale concrete structures subjected to seismic excitation. There are many factors affecting the dynamic properties of concrete such as moisture content and temperature. Though a lot of concrete structures have been designed to withstand low temperature, research on the strain-rate sensitivity of concrete under low temperature condition is still very limited so far. In this study, both tensile and compressive experiments were carried out to investigate the influence of temperature on the rate-dependent characteristics of concrete. Tensile experiments of dumbbell-shaped specimens were carried out on a MTS810 testing machine and compressive tests on cubic specimens were performed using a servo-hydraulic testing machine. Specimens at two types of temperature, room temperature 20oC and low temperature -30oC, were characterized. The strain rate varied over a wide range. It was concluded from the test data that the strengths of specimens at both types of temperature tended to increase as strain rate increased. Temperature had slight influence on the rate-sensitive behavior of concrete when concrete specimens were dry; however, test on saturated specimens indicated that the role of temperature on the mechanical behavior of concrete subject to dynamic loading was very significant. This phenomenon may be attributed to the state of free water in concrete.

Abstract: Combined with the pile foundation engineering of a super-large highway bridge, vertical static loading test of pile with expanded diameter was carried out. The pile’s load-settlement curves, axial forces of the different pile’s section and the pile-soil interaction friction were obtained from the test. The load transfer mechanism and bearing behavior of the pile with expanded diameter under vertical load were studied. The results show that the ultimate load of the testing pile is more than 6000kN. The pile-soil interaction of the pile with expanded diameter behaviors as friction pile, and the bearing capacity of the segment with expanded diameter accounts for 40% of the ultimate load. These studies provide important references for similar projects.

Abstract: By mean of potential energy various principles,the governing differential equations of the steel and concrete composite girder in considering relative slips between steel girders and concrete slabs and shear lag effects of the flanges and the concrete slab are derived. The equations are solved by Galerkin method. It is shown from the calculating example that the proposed method not only is easy to calculate, but also has high convergent speed

Abstract: Based on the analysis for damages of masonry structure from Wenchuan earthquake, the seismic behavior of multi-story masonry school building is analyzed, and the seismic behavior with load-bearing structural system of longitudinal wall is mainly discussed. Based on the analysis and study, several problems which need more attention to the seismic appraisal and reinforcing design are pointed out, and finally the differences and correlation of seismic appraisal, as well as seismic design are discussed.

Abstract: In the paper, the protective equipments of the bridges were studied. The new type of protective devices, which was the rectangular column sandwich plate protective devices, and they were suggested. The ANSYS/LS-DYNA, which is non-linear dynamics finite element software, was applied to simulate the crashworthiness performance of the rectangular column steel sandwich plate, and analyzed the crashworthiness performance factors of the sandwich plate from the different structure parameters to optimize the overall crashworthiness sandwich plate. After structural optimization, it can be gotten that the rectangular column sandwich plates were better than traditional steel plates in crashworthiness performance. Then, the sandwich plate was used to replace the outside steel plates of the traditional box-protective device, from that obtained the overall crashworthiness performance of the rectangular column steel sandwich protective devices were better than the traditional box-protective device.

Abstract: Previous great earthquakes have performed serious structural damages to masonry structure, which also have caused great casualties and property damage, in order to enhance the structural anti-seismic class of civilian buildings, a new kind of combined structure form is introduced in the thesis, which is formed by two parts, masonry structure and special reinforced concrete shear wall structure. The reinforced concrete part can be effective in enhancing the anti-seismic performance of masonry residence, besides reinforced concrete tube structure can also become the nearest refuge when disaster occurred, even when the whole structure collapse, it can still remain relatively complete partial structures and a large space of survival. LS-DYNA, software of finite element, is used to study the structure, simulations of the response procedures of composite structure under earthquake load are made, as well as the destruction of composite structure. According to calculation and analysis, it can be known that this kind of composite structure can obviously improve seismic resistant capability, and the level of destruction is relative smaller, which can meet the requirements for fortification against earthquake that is "keeping intact in minor earthquakes, repairable in medium earthquakes, standing upright in major earthquakes"