Advanced Materials Research Vols. 368-373

Abstract: The retaining wall structure reliability calculation model was established by identifying the stability reliability analysis function of retaining wall according to the geotechnical mechanics parameters’ interval characteristic. The method in this paper has been applied to the engineering examples, the results shows it is reasonable and practicable. The influence of geotechnical mechanics parameters on the retaining wall stability reliability index that was discussed in this paper has a certain reference value for engineering.

Abstract: Based on the previous experiments and theoretical analyses, finite element analyses (FEA) and parametric study on seismic behavior of Cover Plate Strengthen-Beam Flange Weaken Beam-to-Column (CPSBFW) connection are executed by using ABAQUS. Suggestions on design conceptions and details of the cover plate strengthen-beam flange weaken beam-to-column connection are presented in this paper, and that provide valuable reference for design of beam-to-column connections in steel structures.

Abstract: Taking a double span- swallows-type CFST (concrete-filled steel tubular) trussed arch bridge as an engineering example; a spatial finite element analysis model is established to calculate its dynamic characteristic. The seismic responses in different earthquake input directions are calculated based on the elastic dynamic time history method. Results show that: the out-plane stability of the bridge is weaker than that of the in-plane; the torsion resistance ability of the bridge deck is smaller than that of the arch ribs; the axial force-Fx, shear force-Fz and bending moment-My of the bridge are mainly controlled by longitudinal seismic forces, whereas the shear forces-Fy, bending moment-Mz and torque-Mx are mainly controlled by transverse seismic forces; vertical seismic force has a considerable effect on internal forces of the bridge, so it can not be ignored in seismic design.

Abstract: The formulas to define the minimum ratio of length-to-thickness of the pier cross section of short-pier shear wall is presented, by which the short pier shear wall is distinguished from the irregular cross-section column frame numerically. According to the results of finite element analysis of typical short-pier shear walls, the elastic mechanical performances of them were investigated. Conclusions were achieved that the flange width hardly influence on the moment of piers but significantly influence on the magnitude of stresses in the horizontal section and the top displacements of walls; the deflection curve of short-pier shear wall is flexural-shearing type, equations and diagrams to define the position of the contra-flexural point in the curve are provided.

Abstract: Records from 56 stations on free-field within 150km to causative fault surface are used as database during the Mw7.9 Wenchuan earthquake in china. According to this study, the duration of ground motion is strongly affected by rupture distance, site conditions, fault rupture directory and thrust of hanging wall. Duration is obtained based on the time between 10 and 80 per cent of Arias intensity. A simple attenuation relation in terms of rupture distance is proposed and compared with some available predictions. The durations of tri-component ground motions on hanging wall are smaller than those on the foot wall in the same range of rupture distance. Durations of ground motions close to rupture fault resulting from directivity effects are significantly different between the forward and backward direction, and this difference reaches nearly 2 times on average.

Abstract: For the purpose of providing useful reference for optimizing the design of Collision-Prevention Device of Bridge Pier, analyzing the collision parameters and putting forward the ideal size of the circular steel tube and angle steel in absorbing energy,the ship impacting the steel tubular truss,which belongs to the Collision-Prevention Device of Bridge Pier, is simulated.The water level of ship and the size of circular steel tube and angle steel are discussed respectively with the ANSYS/LS-DYNA program，which is the nonlinear dynamic analysis software,to study the impact of change of the single collision parameter to the equipment for anti-collision which is the steel tubular truss.when the ship impacts the steel tubular truss under the ideal level,the circular steel tube and the angle steel could play fully in resisting the collision of ship, achieved a better absorbing effect.The circular steel tube can play a chief absorption effect through the bending deformation, while the relatively small energy is absorbed by the angle steel through the buckling deformation. The best sizes selected through the optimum structural design are shown as follows: the diameter of circular steel tube is 800mm; the thickness of tubular wall is 12mm; the size of angle steel is 100mm×100mm×12mm.

Abstract: Based on the current situation of the Lower Yellow River channel, this paper analyses the factors affecting river health, points out that river channel health is the foundation and key to river health. It evaluates the Yellow River's downstream channel health using fuzzy comprehensive evaluation method and gets the conclusion that the Yellow River's downstream channel health has deteriorated in 50 years and has improved in the beginning of this century. This paper analyses and points out that the reservoir to regulate natural flow-sediment process is the primary means that the human impact on river health. The regulation of reservoir has duality that "excessive" regulation will seriously damage river health and "moderate" regulation can better maintain and restore river health. Coordination of flow-sediment relationship is the key to maintaining the health of the Lower Yellow River.

Abstract: As Steel reinforced concrete (SRC) structure has a good prospect in Practical engineering, large number of studies carried out home and abroad, as for the study of the Steel reinforced concrete composite torsion , research data is not mature at present time. This paper analyzed the steel reinforced concrete members’ Torsion properties under combined force by method of the finite element analysis. Considering the main affecting factors like compression ratio to reveal the SRC structures under the force of monotonic torque’s characteristics of the damage and capacity, etc.

Abstract: This With the deepening of sustainable development strategy, groundwater environmental problems caused by tunnel projects are becoming more and more outstanding. This paper estimate the groundwater resources loss of fractured rock tunnel adopting equivalent flow models. In order to increase the model fidelity, the author considers the nonhomogeneous and anisotropic characteristics of fractured rock. Based on Shibanshan tunnel in Shijiazhuang-Taiyuan passenger line, this paper estimated the groundwater resources loss of fractured rock tunnel in construction stage and operation stage, which provides technical support for decreasing loss of groundwater resources.

Abstract: A model is proposed to simulate multivariate weakly stationary Gaussian stochastic processes based on the spectral representation theorem. In this model, the amplitude, phase angle, and frequency involved in the harmonic function are random so that the generated samples are real stochastic processes. Three algorithms are then adopted to improve the simulation efficiency. A uniform cubic B-spline interpolation method is employed to fit the target factorized power spectral density function curves. A recursive algorithm for the Cholesky factorization is utilized to decompose the cross-power spectral density matrices. Some redundant cosine terms are cut off to decrease the computation quantity of superposition. Finally, an example involving simulation of turbulent wind velocity fluctuations is given to validate the capability and accuracy of the proposed model as well as the efficiency of the optimal algorithms.