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Objective The co-structure system of subway station (hereinafter referred to as 'co-structure system') realizes the connection and conversion between the box structure and the box frame structure through thick plates. Due to the unique structural form of the co-structural system, its seismic response law is currently unclear, further study on the characteristics of its seismic response is needed. Method Taking the co-structure system of a comprehensive utility tunnel and subway station as an example, the finite element simulation model of soil-co-structure system interaction is established. Considering one-way and two-way seismic waves (both horizontal and vertical) as inputs, three working conditions are selected. The acceleration response characteristics, displacement response characteristics, compressive and tensile damage situations, and the evolution process of the co-structure system under seismic action are analyzed. Taking the left column end of the co-structure system as an example, the internal force response characteristics of some structural parts are discussed. Result & Conclusion The vertical acceleration of the co-structure system is greatly affected by the bidirectional coupling ground motion. The maximum increase in acceleration at the joint between the side wall and the negative first floor slab reaches 158 % (compared with the vertical ground motion). Vertical ground motion may increase the relative horizontal and relative vertical displacements in the roof and floor of the co-structure system, and the internal force response of the column as well. Locations of the co-structure system such as the column ends, the lower part of the side wall, both ends of the bottom plate, the connection of the components, and the axillary angle are vulnerable to seismic damage, and should be strengthened accordingly.

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Urban Mass Transit is the property of Urban Mass Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on the ANSYS finite element software, the NREL 5 MW monopile offshore wind turbine tower system was modeled in 3D. The influence of different wind speeds on the dynamic characteristics of the tower structure was simulated and analyzed under the full consideration of the soil structure coupling effect and the impeller rotation. The six average wind speeds and the corresponding impeller speeds in the interval between the cut-in wind speed of 3 m/s and the cut-out wind speed of 25 m/s were selected as simulation conditions. The analysis results show that, with the increase of wind speed and impeller speed, the modal frequency of the tower structure gradually increases, and the first two modal frequencies change most obviously. Moreover, the peak value of the tower displacement increases as the wind speed and impeller speed increases, but the amplitude decreases. The displacement shows a non-linear growth trend. The equivalent stress value of the tower increases as the wind speed and impeller speed increases, but the change trend is different from the displacement, which is roughly linear. The fatigue life of the tower decreases sharply, but they are far more than the actual working hours, the fatigue damage and safety factor hazard values are mainly distributed at the bottom of the tower and at the single pile, consistent with the maximum equivalent stress distribution position.

Copyright of Power Generation Technology is the property of Power Generation Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study on the mechanical properties of soil-structure interface is the basis to solve the problem of soil-structure interaction, which involves many aspects of practical engineering. By modifying the conventional unsaturated direct shear apparatus and using the modified unsaturated direct shear apparatus, the shear tests of unsaturated sand-structure interface were carried out, and the effects of the matrix suction, the structural interface type and the net normal stress on the shear strength of the interface were studied. The experimental results show that the influence of matrix suction on the interface cohesion of unsaturated sand-structure interface is great, while that on the interface friction angle is small. With the increase of matrix suction, the shear strength of unsaturated sand-concrete interface increases first and then decreases, indicating a peak effect. The shear strength of unsaturated sand-steel interface was less affected by matrix suction. Under the condition of constant matrix suction, the shear strength of sand-steel interface increases nonlinearly with the increase of net normal stress. The influence of net normal stress on the friction angle (δb) corresponding to matrix suction is little. Finally, a shear strength formula of unsaturated sand-concrete interface was established based on peak effect. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Computational Mechanics / Jisuan Lixue Xuebao is the property of Chinese Journal of Computational Mechanics Editorial Office, Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

UHV(ultra high voltage) transformer is an important electrical facility in substation. In seismic calculation of transformer, the foundation is generally considered as rigid, and the influence of soil is ignored. To investigate the seismic performance of transformer considering soil-structure interaction, a seismic analysis model of soil-UHV transformer system was established based on finite element. The model considers the nonlinear mechanical behavior of soil under seismic load, and the effects of transformer stiffness and damping ratio change on the seismic performance of transformer were carried out. The results show that: the frequency error between the finite element numerical model and the test results is within 10%, and the stress and test error of high voltage bushing under 0. 2 g, 0. 4 g and 0. 8 g seismic excitation are 3. 3%, 2. 6% and 5. 6% respectively, which shows the effectiveness of the simulation analysis mechanical model. With the increase of transformer stiffness, as the weak link of transformer, the stress of high-voltage bushing decreases, the damping ratio increases, and the seismic response of equipment first increases and then decreases. The research results can provide guidance for the seismic design of UHV transformer. [ABSTRACT FROM AUTHOR]

The ambient vibration response of the isolated foundation has great influence on the stability of large laser facility. The method on the ambient vibration response of the simulation on the isolated foundation in the large laser facility is developed. TheSway of the artificialSboundary layer is adopted to simulate the influence of the infinite boundary. The finite element model of the isolated foundation of some laser facility is modeled then. The material parameters of the rock and the ambient vibration input are obtained by the modal and micro-vibration experiment. Then, the random vibration analysis based on modal superposition is carried out, and the acceleration power spectral density (PSD) curves on the isolated foundation of laser facility are obtained. At last, the comparison between the simulation results and the experimental results is carried out. The comparison results show that the simulation PSD curves agree well with the experimental results, and the maximum difference of the root mean square (RMS) acceleration response between the simulation results and the experimental results is less than 5%. The results indicate that the method is correct. And it can be used in the simulation on the isolated foundation of the similar large precise electron or optic facility. [ABSTRACT FROM AUTHOR]

Grapes can be cultivated in the cold areas of northern China. The cold-proof soil clearing has been the typical operation to prevent the freezing damage under the cold climate. Among them, the flexible roller is one of the most important components for the spring soil-clearing operation in northern grapes. The operating parameters have also posed a great impact on the performance of soil clearing. The numerical simulation can normally be used to optimize the operating parameters for the flexible soil-clearing roller. However, the overall modeling is confined to the harsh requirements so far, such as the large computational volume, long computation duration, and high configuration. In this study, a partial modeling of parameters was proposed to predict the whole one, in order to significantly reduce the cost of simulation calculation. Firstly, the minimum structure feature was extracted from the flexible soil-clearing roller. A prediction model of the overall performance was then constructed using the geometric similarity. Secondly, the minimum feature model of structure-soil interaction was established for the optimal operational performance using the coupled Discrete element method (DEM), and Multi-flexible-body dynamics (MFBD). Finally, the overall performance of the flexible soil clearing-roller was estimated using the prediction model. The results showed that a strong linear correlation was found in the linear fit R² values of 0.987, and 0.993 between the soil clearing rate and resistance torque of the flexible soil clearing-roller with the brush piece number, respectively. It infers that the linear model was used to accurately describe the relationship between the overall and partial performance. A series of finite element models (FEM) were established for the rubber sheet with the solid 10 cells and the damping ratio 0.005, while the brush wire with the solid 4 cells and damping ratio of 5×10-4, and the brush blade with the array density 90 of brush wire. The relative errors were 8.43%, and 1.52% for the simulation and physical measurements, respectively, for the minimum feature structure of the soil clearing rate and resistance torque in this case, indicating the excellent consistence with relatively small ones. Once different numbers of brush pieces were added, the maximum relative errors were 8.43%, and 10.53%, respectively, indicating the accurate and reliable model. Meanwhile, the contact calculation volume of the partial modeling was only about 8% of the overall modeling, which was effectively reduce the simulation calculation cost. Furthermore, an optimal combination was achieved, with the forward speed of 0.3m/s, the mounting angle of 30°, the axial length of 50mm, and the blade taper angle of 0°. The significant effects were also found on the operational performance of the minimum feature structure and brush piece. Specifically, the soil clearing rates of the whole and single brush piece were 36.87%, and 2.80%, respectively, whereas, the resistance torques were 18.91 and 2.78 N·m, respectively, for the minimum feature structure under the optimal condition. The relative errors were 3.74% and 10.15% between physical and simulation of the minimum feature structure under the same conditions, where the relative errors of brush piece were 10.36%, and 9.71%, indicating the accurate and reliable simulation optimization. Anyway, the soil clearing rate and resistance torque were 97.07%, and 78.68 N·m, respectively, for the flexible soil-clearing roller that estimated by the prediction model. The relative errors between the physical and the predicted were 7.84%, and 4.55%. The relative errors between the optimized by the overall modeling and the predicted were 10.66%, and 6.76%, indicating the partial modeling with the high feasibility and accuracy. The findings can also provide a new idea for the interaction modeling between the complex flexible bodies and bulk particles. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This work systematically summarized four types of methods for predicting tunnelling induced ground movements, namely analytical solution, empirical equation, numerical simulation and model test method. The theory of four types of analytical solutions was firstly presented. The widely-used empirical equations and determination methods for the key parameters were introduced. The development of numerical analysis methods with respect to soil constitutive model and simulation technique was discussed. The 1g model test and centrifuge model test were presented in brief as well. Some suggestions on predicting tunnelling induced ground movements in China were presented according to the advantages and disadvantages of various methods. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BackgroundThe floor response spectra of the nuclear reactor building is of great significance to the seismic analysis and design of the whole reactor system.PurposeThis study aims to get accurate floor response spectra of 2MW thorium molten salt reactor-liquid fuel 1 (TMSR-LF1).MethodsA three-dimensional finite element model coupling with beam, shell and solid was established by ANSYS finite element analysis (FEA) software. The results of floor response spectra considering the soil-structure interaction (SSI) effect were obtained by direct method. Finally, comparison analyses of different floors, different inputs and different damping ratios were carried out.ResultsThe computation results show that the above-ground floor response spectra are much larger than that of the underground part, and the spectral values vary greatly due to the structure, load and other factors. The response spectra of each floor on the ground are larger in the vertical direction than in the horizontal direction.ConclusionsIn the seismic design of nuclear facilities, it is suggested to increase the vertical stiffness of the ground floor. The results of this study lay preliminary basis for seismic safety assessment of TMSR-LF1.

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To study on the mechanical behaviors of steel H-pile of integral abutment jointless bridges (IAJBs) at the ambient temperature or on earthquake, reciprocating low-cycle pseudo-static tests on soil-steel H-pile interaction were carried out under balanced and unbalanced earth pressure, respectively. The soil resistance, the strain and the bending moment of the steel H-piles were comparatively analyzed. The results indicate that the unbalanced soil pressure has a significant influence on the mechanical behavior of the pile foundation under positive loadings, but a less influence under negative loadings. The soil resistance, the stain and the bending moment of the piles for abutment-steel H-pile (AHP) specimen and the steel H-pile with the unbalanced earth pressure of backfiil behind a-butment(UHP) under positive loadings are lager than those under negative loadings. However, the soil resistance, the stain and the bending moment of the piles for steel H-pile considering the balanced earth pressuure-P) are basically the same under positive and negative loadings. The soil resistance, the stain and the bending moment of the piles for AHP specimen are largest, followed by those of the UHP specimen, and those of the HP specimen are minimum. Therefore, AHP specimen enter the elastic-plastic state fastest. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A detailed three-dimensional finite element model including soil-structure interaction was developed for a 1.5 MW onshore wind turbine. A comparative study was performed to investigate the soil-structure interaction (SSI) effects on the seismic responses of the wind turbine under operating conditions. Wind speed time histories were converted to wind load time histories under the operating condition by using the FAST program. Simulation analysis was conducted using the EERA program to derive earthquake excitations at the base of the soil model. Then modal analyses and seismic response analyses were performed. The results show that soil-structure interaction has significant influences on the dynamic characteristics of the wind turbine tower, which results in amplification of the structural responses.

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Vibration Engineering is the property of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Vibration Engineering is the property of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A Chebyshev nested lumped-parameter model (LPM) was proposed to incorporate the frequency-dependent impedances into the time history analysis of soil-foundation-wind turbine systems. The complex Chebyshev polynomials were introduced to approximate the foundation impedances with the least squares curve-fitting technique. The computational program for seismic analysis of the system was developed based on the direct integration of the governing e-quation in the time domain. The validity and efficiency of the computational program were verified through the comparison examples. The time history analysis of a wind turbine supported by a pile group foundation under seismic excitation shows the universality and stability of the computational program. The advantage of the Chebyshev nested LPM is that it can express the frequency-dependent impedance accurately in the time domain and avoid the high-order numerical oscillation. The nested form of the model enables wider application to different kinds of foundations . In addition, as the present model adopts no mass unit, it avoids the problem of modifying the seismic loading at the node of the foundation and makes the analysis of practical engineering more convenient. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Vibration Engineering is the property of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To study the seismic response and the ultimate strength of super-large span reticulated domes accurately, an analysis about the seismic response of super-large span reticulated dome (800 m span) using the time-history analytic method was made considering complexity effects such as ground motion with spatial coherency and wave-passage effect, soil-structure interaction and material damage accumulation. Results show that the complexity effects can influence the seismic performance of super-large span reticulated domes. By comparing the failure modes of structures under uniform excitation and multi-support excitation, it is found that the multi-support excitations increase the internal forces of outer members, while decreasing those of inner members. Therefore, the outer members fail earlier, and the failure mode was changed which severely weakens the ultimate strength of the structure. The soil-structure interaction effect and material damage accumulation effect both increase the magnitude of seismic responses of a structure to different extent. The soil-structure interaction effect amplifies the influence of seismic action on structure, and material damage accumulation effect influences the structure obviously when the seismic amplitude is high. [ABSTRACT FROM AUTHOR]

In order to investigate the seismic behavior and isolation effectiveness of a high-rise isolated structure on soft soil foundation, the shaking table tests of a high-rise isolated model on rigid and soft soil foundation were conducted. A laminar shear soil container was fabricated to minimize the boundary effects. With the similitude of the soil pressure, five-story steel frame models of aspect ratio 4, either with or without rubber bearings, supported by a pile group, and seated on a silty clay deposit, were subjected to different strong ground motions. From the results, it is found that soil-structure interaction (SSI) effects on high-rise isolated structure models are not as important as those in unisolated counterpart. Due to SSI, the natural frequency of the isolated model system is obviously reduced, and damping ratio largely increased. The efficiency of the presented isolation system on soft soil is confirmed. However, the ratio of peak acceleration of the isolated model to the unisolated one on soft soil is increased, with the isolation effectiveness reduced relatively. SSI can increase or decrease the seismic response of high-rise isolated model, depending on not only the type but also the intensity of the earthquake motion. It is also observed that the acceleration response spectrum of the foundation input motion agrees well with that of the free-field motion for the isolated structure. While, for the unisolated one, it is close to those of the ground motions at greater depths of soil. [ABSTRACT FROM AUTHOR]

Under the situation of considering the anchor prestress effects on stability of loess slope, according to the damage of the sliding surface, stability model of slope supported by frame with pre-stressed anchors under earthquake was established. By the method of lumped-mass explicit finite element, the soil was separated into soil-static-dynamic micro-unit and soil-prestressed micro-unit discretely, and the corresponding discrete element dynamic equilibrium equation was established, the displacement response and the stress field in sliding surface of the supporting slope were deduceed. Based on the displacement response and the soil stress field, a calculation method of stability safety factor for slope supported by frame with pre-stressed anchors under earthquake was proposed. A project example was analyzed by using the method proposed in this paper, the result was compared with the one of the quasi-static method. Comparison results show that the method proposed in this paper for the homogeneous loess slope is feasible, the earthquake reaction of the supporting loess slope and the dynamic performance of the soil can be showed primely compared with pseudo-static method. [ABSTRACT FROM AUTHOR]

The influence of soil-structure interaction (SSI) on Park-Ang damage index (PADI) of energy dissipating structures was investigated under seismic excitation. A systematic lumped-parameter model was used to represent dynamic impedance function of foundation-soil. The structure was assumed to be shear-type system which was based on the Takeda hysteretic model. Two parameters were used as the key parameters: peak ground motion acceleration of earthquakes and soil shear wave velocity. It is found in this study that, for the structures without energy dissipation devices, decreasing soil shear wave velocity has very little effect on PADI when peak ground motion acceleration is 0.1g. However, for the structures with energy dissipation devices, decreasing soil shear wave velocity increases PADI when peak ground motion acceleration is 0.1g. In addition, for the structures with energy dissipation devices and without energy dissipation devices, decreasing soil shear wave velocity increases PADI when peak ground motion acceleration is 0.3g. [ABSTRACT FROM AUTHOR]

A three-dimensional FEM analytical model for train-bridge-pier-pile-soil coupled vibration system considering soil-structure interactions is built using a high-speed train car simulated by 32m long simply supported beam as example. The car was modeled as a multiple degrees of freedom system with two layer suspensions. Soil foundation data were measured on-site at the Beijing-Shanghai high-speed railway, and as part of the soil modeling, visco-elastic artificial boundary elements were employed to simulate the soil in semi-infinite domain. Contacts between train-car wheels and the underlying rails were simulated using 3D dynamic contact elements which were based on a Coulomb's contact algorithm. The influences of the underlying structures, such as piers and piles, on vehicle-bridge coupled vibrations were analyzed, and the effects of the coupled vibrations on the vibrations of the surrounding soil were studied too. The results show that the coupled vehicle-bridge vibrations are significantly influenced by nearby piers and piles. Furthermore, vertical vibration levels are found to attenuate with increasing distance to foundation, whereas attenuation of horizontal vibrations is not so obvious. The high frequency components in field vibration attenuate more rapidly than low frequency ones, therefore remote field vibrations contain dominant low frequency components. Field vibration levels do not linearly correlate with vehicle speed, but they are largely affected by their superstructure vibrations. [ABSTRACT FROM AUTHOR]

Low-frequency excitation experiment of a 1:4 scaled steel frame model was performed in an indoor soil bin. Using an exciter which can output different seismic waves to excite the steel frame, vibration picking devices were used to measure the acceleration and displacement responses of floors. By spectral analysis the fundamental frequency and natural period of the model were obtained, and the shock absorption coefficient was calculated. Using SAP2000 to simulate the model on rigid foundation, the same seismic waves were input on the model to calculate the fundamental frequency, natural period, peak acceleration and displacement of the top floor of the model. Compared with the results of experiment, several conclusions are drawn. After considering soil-structure interaction, natural period of the model is elongated. With the same stiffness, the greater the mass of the floor is, the more obvious the elongation effect is. The peak displacement of top floor increases, while the peak acceleration decreases. Curves of displacement amplification and acceleration reduction coefficients versus structural stiffness were drawn. It is found that the displacement amplification and acceleration reduction coefficients vary in accordance with √k/m, which can be defined by two fitted curves obtained by regression analysis. The curves can be referred in practical seismic design. [ABSTRACT FROM AUTHOR]

In general, the soil stratum consists of two-phase saturated poroelastic zones and single-phase viscoelastic zones duo to ground water. In most cases of dynamic impedance analysis, the soil has been assumed to be a viscoelastic or saturated medium. Little attention has been paid to the analysis of foundation on stratum consisting viscoelastic and saturated soil. Based on the fact that single-phase soil is a special case of two-phase saturated soil, the dynamic analysis of single-phase soil can be unified into the analysis of saturated soil by setting the bulk modulus of pore fluid, porosity and the coupling mass density to be zero. Thus, the dynamic impedance of foundations on viscoelastic and saturated stratum can be analyzed by a method for saturated medium case. The technique is applied to the computation of the dynamic impedance of rectangular foundations on viscoelastic and saturated stratum. The effect of dry soil thickness and the embedded depth of foundation on the dynamic impedance are examined. [ABSTRACT FROM AUTHOR]