Advanced Materials Research Vols. 915-916

Abstract: Soil as a special material featured with nonlinear stress-strain relationship plays a critical role in determining the magnitude of hazards in an earthquake. For a unique capability of simulating a combined environment of high gravity and shake loading, centrifugal shaking table provides an effective and advanced testing method to dynamic characteristics and failure mechanism of reduced scale soil models. From construction both at home and abroad, shaking tables often suffer waveform distortion and instability after installed on a centrifuge. The knowledge of this phenomenon is a dearth while relative theory is absolutely blank. Practically the construction of centrifugal shaking tables is still in an exploratory stage. This paper develops a transfer function of geotechnical shaking table with soil model and bucket to offer fundamental cognition of inherent mechanism, and establishes a theoretical procedure to evaluate the influence of bucket on shaking table.

Abstract: Two methods based on modal decomposition in circular cylinders are presented here. One is based on bi-orthogonality relation and the other is based on boundary discretization for mode matching. The two methods are comprised in numerical implementation and the efficiencies are evaluated.

Abstract: To control the pure electric vehicle motors vibration and noise, the dynamic characteristics of the motor are analyzed. Dynamic characteristic include the natural frequency and response characteristics of different parts of the motors structural member. This paper uses three-dimensional software Pro/E modeling of the motor: By making appropriate assumptions and equivalent treatment of the motors stator, rotor core and coil winding, establish the finite element simulation model of the various components .Using the finite element analysis software Workbench analyzes the windings and motor model modal analysis, to get natural frequency of each mode. To make a modal analysis test, we can use hammering method done on the motor. By using real-time signal analyzer AWA6291 make spectral analysis of the motor online, comprehensive comparative analysis of the results and used to guide motor design.

Abstract: The equivalent linearization program LSSRLI-1, proposed by Xiaojun Li in 1989, is the important content in seismic zoning work and seismic safety evaluation of engineering sites. It is necessary to check the applicability of LSSRLI-1 to all kinds of sites. The mainly elaboration of the paper is using exact solution to verify the applicability of seismic safety evaluation program LSSRLI-1 for medium soft soil. Previous research has already demonstrated that the shear strain in stiff and half-stiff sites calculated by LSSRLI-1 and the exact solution are about the same, have an almost identical shape. The distribution of shearing strain in different depths calculated by the two methods has the same set of characters, and the difference between the two methods is small, if any, can be ignored in an acceptable range. In this paper, however, the results calculated for the discrepancy of shear strain between LSSRLI-1 and exact solution in medium soft soil has a very significant impact on the surface response spectrum, leading to prominent diversity to the response spectrum.

Abstract: Shield construction will cause surface subsidence, and the presence of underground structures above the tunnel has an impact on surface subsidence. Based on this, with the engineering of undercross shield tunnel construction on railway station as background, used numerical simulation method to analyze the effect of surface subsidence of underground passage, and studied the influence of depth and width of underpasses on ground movement induced. The results show that: The impact of the underground passage to the wire surface subsidence caused by the shield cannot be ignored. Surface subsidence caused by double shield will be decreased because of the existence of the underground passage, and that related to the channel depth and width. The greater the depth of underground channel, the greater the surface subsidence; greater the underground channel width, the smaller surface subsidence. Meanwhile, the surface subsidence trough width and the largest settlement scope unrelated to the depth of underground tunnels but the underground channel width, and increases with the increasing of the underpass width.

Abstract: In this paper, with the help of the finite element software ADINA, an actual composite soil nailed wall was solved. The dynamic response of the composite soil nailed wall is analyzed and discussed under the EL-Centro and man-made Lanzhou accelerogram. And the variation principles of the soil nailed wall which subjected to the earthquake, and the earthquake coupled with pore pressure, are demonstrated respectively. The results of the FEM dynamic analysis can be a useful reference for engineers of the design and construction of the composite soil nailed wall.

Abstract: In order to test the applicable of the seismic response analysis procedures SHAKE2000 and LSSRLI-1 for class ІІ site, 17 stations and 35 underground strong motion records of KiK-net are selected from Class ІІ site. 210 working conditions are used to verify the applicability of the two soil seismic response analysis programs at Class ІІ site. These two programs are used to calculate the selected working conditions, giving the peak acceleration of the ground, the shear strain and the ground acceleration response spectra. By analyzing the results of the two programs and the measured results to assess the degree of difference between the two methods and which program is closer to the real situation. Studies have shown that in class ІІ site, in most cases, the results of SHAKE2000 and LSSRLI-1 differ little. While comparing with the actual records, SHAKE2000 is closer to the strong motion records.

Abstract: Computational Fluid Dynamic (CFD) was used to investigate gas-liquid two phase flow regimes for the inclined wells. The simulation results were compared with the Taitel chart. A good agreement between the prediction and the Taitel flow regimes shows that CFD method can reasonably predict flow regimes in the inclined well. Another further study was conducted to explore the influence of flow rates and inclination angle on flow regimes. The results show both of flow rates and inclination angle have a significant effect on flow regime transition.

Abstract: Construction of Fozhao intercity bridge in Guangzhou was a three-span prestressed concrete continuous beam bridge. The bridge adopted triangle hanging basket cantilever pouring construction method. The bridge mixed cable-stayed spans, H form tower and typical highway bridge elements. It spaned across the exiting transport hubs center, with modern and ethereal shape, and became a new landmark of the city.

Abstract: In order to study the bridge of a rail transit line in Guangzhou city, we use the finite element program Midas/FEA. Combining with the structure characteristics of the bridge, we establish space finite element model of piers. The linear and nonlinear analysis have been done respectively. In view of the nonlinear analysis, we analyze the left and right bearing under the most unfavorable load and dead load. The results show that as the ordinary reinforced concrete structure, bridge piers are bending crack under the design load. The width of crack controlled by force is less than the design value, so the bridge piers are in a safe state and it does not affect the normal operation. We noticed that the crack in piers appear a feature that width of crack become narrow in points under force controlling, but in other areas the crack in piers appear a feature that width of crack become wide. We have a preliminary judgment that the cause of this phenomenon may be the construction quality such as the actual reinforced protective layer are excessivecooling measures in the process of the construction of the pier head of mass concrete did not reach the designated positionmaintenance measures were in place and so on. The construction quality cause combined effects of mass concrete shrinkage crack and the structure of normal stress fracture.