Advanced Materials Research Vols. 368-373

Abstract: The complex tower structure appears as modeling of palms together, which is designed as steel frame-core tube structure. This paper uses SAP2000 to analysis seismic response respectively on the linear and elastic-plastic stage, and puts forward some specific suggestions for seismic design according to the analysis and calculation.

Abstract: In this paper, the deformations and the stresses of surrounding rock of Jijiata tunnel, Liulin County, Shanxi Province, are all computed before reinforcement and after reinforcement, through the 3D numerical simulation. According to the computing result, before reinforcement, the computing result of the lateral displacements of the surrounding rock is consistent with the field measurement result. The maximum principle stress and the minimum principle stress are all less than the strength of the surrounding rock supporting, and this will not cause material damage so as to structural damage. But, since the tension stress is higher than the strength of the junction of tunnel arch and tunnel upright wall, this leads the larger deformation and the failure of the junction. After reinforcement, through the steel arch and the lock pin bolt’s enhanced role, the lateral displacement of the tunnel can be constrained effectively, the maximum principle stress and the minimum principle stress can be less than the strength of the surrounding rock supporting, and the tension stress can also be less than the strength of the junction. All the structures are all stable after reinforcement. Thus, this method should be selected as the proper method to reinforce the tunnel.

Abstract: Using the finite element method to establish refined finite element model and the simplified mode of cross line cable-stayed bridge "yan Hong qiao" of the yanshan university. And using ANSYS structure analysis procedures to analysis the vibration characteristic, the first10 order natural frequency and the correspo- nding vibration mode were given. Then, compared and analysis the refined model and the simplified model, the establishment of finite element model in general engineering analysis, correction method and validation suggestions.

Abstract: Based on coupled thermal-mechanical method, rust bilge cracking of reinforced concrete pier in marine environment has been studied in this paper. Because of the similarity of differential equations of chloride diffusion and transient heat transfer, chloride diffusion is completed by using the transient heat transfer method. The chloride ion concentration at the reinforcement surface is obtained and is taken as temperature load at each time step. After introducing the equivalent time-varying coefficient of thermal expansion, the corrosion-induced reinforcement expansion and concrete cracking are simulated by the thermal expansion method. Numerical results show that the method is reasonable and feasible.

Abstract: This paper is basis on previous studies, taking The main haulage roadway of the western district of Zhaogu No.1 mine ,which belongs to Jiaomei group, as the background of study. On the basis of understanding the mechanical properties and engineering characteristics of soft rock, proposing the stability control mechanism and supporting scheme design countermeasure of fractured soft rock roadway. Numerical analysis was made to the stability of roadway surroundings used the FLAC-3D finite element analysis software, and a set of reasonable supporting technology schemes and parameters were proposed.

Abstract: As a part of lifeline system, the LNG tanks seismic design is very important because of the increasing danger caused by the rapid economic development. However, the LNG tanks design codes are absent in China. The application of the double-layer spherical tank should be promoted, because of its advantages including better mechanical behavior, less maintenance cost etc. The state of the art about the design aspect is reviewed, especially the low temperature material properties, the liquid-structure interaction analysis techniques, the isolation and damping of tanks. The potential aspects for the future design are also discussed.

Abstract: It is important and necessary to establish fire-resisting design approach for large-space grid structures. In terms of establishing finite element analysis models, main influencing factors on mechanical performances of grid structure under fire conditions were determined. Based on numerical calculation and comparison analysis on ordinary sandwich plate analogy method considering the effect of fire, a simplified design approach named modified sandwich plate analogy method for calculating maximum displacement of grid structures under fire conditions is given. It gives guidance for structural fire-resisting designers.

Abstract: In order to study the displacement ductility coefficient of steel reinforced high-strength concrete column, 23 groups of components with various design parameters were tested and related factors that affect the displacement ductility coefficient of SRHSC column were presented in this paper. The proposed formula for calculating the displacement ductility coefficient of SRHSC column can be obtained from the multivariate nonlinear regression of test results by using SPSS. The calculation results agree well with the test conclusions, and it shown that the proposed formulas own high accurateness and can be objectively reflect the mechanical behavior of SRHSC column root. The research achievements will provide a theoretical support for the design of SRHSC column.

Abstract: With the developments of the design theories and the researches, the quantity and the technology of space truss systems in our country have reached the international leading level. In the meantime, the construction methods need to achieve even higher standard. In the article, the rhombic space truss roof of the north station building of Suzhou is selected as the research object. Each step of the sliding and unloading construction is simulated by FEM. The stability and rigidity of the truss are checked in detail. It gives an representative exsample for complicated construction design of large-span space trusses.

Abstract: In this paper, the influence of tie beams for piers is investigated on the dynamic characteristics and the seismic performance of a continuous rigid frame bridge with twin-legged piers. Modal analyses and the linear seismic response analyses are performed on a practical continuous rigid frame bridge with twin-legged piers with no tie beam, one tie beam and three tie beams of pier, using software Midas/civil. The findings indicate that installing tie beams of pier can increase the natural frequencies of this kind of bridge. Setting tie beams of pier is disadvantageous to the seismic performance of the bridge beam, but advantageous to improving the seismic performance of the twin-legged piers. The influence of tie beams of pier on the seismic performance on the whole structure is relevant to the pier height. These analytical results provide a reference for the seismic design and analysis of similar structures.