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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 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 Heilongjiang University of Science & Technology is the property of Journal of Heilongjiang University of Science & 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.)

Ｓｅｉｓｍｉｃ ｓａｆｅｔｙ ｉｓｓｕｅｓ ｍｕｓｔ ｂｅ ｃｏｎｓｉｄｅｒｅｄ ｉｎ ｔｈｅ ｄｅｓｉｇｎ ｏｆ ｕｒｂａｎ ｕｎｄｅｒｇｒｏｕｎｄ ｕｔｉｌｉｔｙ ｔｕｎｎｅｌ. Ｆｉｒｓｔｌｙꎬ ｔｈｅ ｒｅａｃｔｉｏｎ ｄｉｓｐｌａｃｅｍｅｎｔ ｍｅｔｈｏｄ ｗａｓ ｕｓｅｄ ｔｏ ｃａｌｃｕｌａｔｅ ｔｈｅ ｉｎｔｅｒｎａｌ ｆｏｒｃｅ ｏｆ ｔｈｅ ｕｔｉｌｉｔｙ ｔｕｎｎｅｌ ｓｔｒｕｃｔｕｒｅ ｄｕｒｉｎｇ ｔｈｅ ｓｅｉｓｍｉｃꎬ ａｎｄ ｔｈｅ ｗｅａｋ ｐａｒｔ ｏｆ ｔｈｅ ｕｔｉｌｉｔｙ ｔｕｎｎｅｌ ｗａｓ ｏｂｔａｉｎｅｄ. Ｔｈｅｎ ｔｈｅ ｄｙｎａｍｉｃ ｔｉｍｅ ｈｉｓｔｏｒｙ ｍｅｔｈｏｄ ｗａｓ ｕｓｅｄ ｔｏ ａｎａｌｙｚｅ ｔｈｅ ｓｅｉｓｍｉｃ ｒｅｓｐｏｎｓｅ ｏｆ ｔｈｅ ｕｔｉｌｉｔｙ ｔｕｎｎｅｌꎬ ａｎｄ ｔｈｅ ｎｕｍｅｒｉｃａｌ ｍｏｄｅｌ ｏｆ ｔｈｅ ｓｏｉｌꎬ ｓｔｒｕｃｔｕｒｅ ｗａｓ ｅｓｔａｂｌｉｓｈｅｄꎬ ａｎｄ ｔｈｅ ｈｏｒｉｚｏｎｔａｌ ｓｅｉｓｍｉｃ ａｃｔｉｏｎ ｗａｓ ｉｎｐｕｔ ａｔ ｔｈｅ ｂｏｔｔｏｍ ｏｆ ｔｈｅ ｍｏｄｅｌ. Ｔｈｅ ｓｏｉｌ￣ｓｔｒｕｃｔｕｒｅ ｉｎｔｅｒｆａｃｅ ｃｏｎｔａｃｔ ｕｎｉｔ ｗａｓ ｕｓｅｄꎬ ａｎｄ ｔｈｅ ｉｎｔｅｒａｃｔｉｏｎ ｂｅｔｗｅｅｎ ｓｏｉｌ ａｎｄ ｓｔｒｕｃｔｕｒｅ ｗａｓ ｃｏｎｓｉｄｅｒｅｄꎬ ａｎｄ ｔｈｅ ｓｅｐａｒａｔｉｏｎ ａｎｄ ｓｌｉｐ ｂｅｔｗｅｅｎ ｔｈｅ ｓｔｒｕｃｔｕｒｅ ａｎｄ ｔｈｅ ｓｏｉｌꎬｔｈｅ ｄｉｓｐｌａｃｅｍｅｎｔ ｄｅｆｏｒｍａｔｉｏｎ ａｎｄ ｓｔｒｅｓｓ ｄｉｓｔｒｉｂｕｔｉｏｎ ｏｆ ｔｈｅ ｕｔｉｌｉｔｙ ｔｕｎｎｅｌ ｕｎｄｅｒ ｈｏｒｉｚｏｎｔａｌ ｓｅｉｓｍｉｃ ｗｅｒｅ ｏｂｔａｉｎｅｄ. Ｔｈｅ ｒｅｓｕｌｔｓ ｓｈｏｗ ｔｈａｔ ｔｈｅ ｓｔａｎｄａｒｄ ｓｅｃｔｉｏｎ ｓｔｒｕｃｔｕｒｅ ｏｆ ｔｈｅ ｕｎｄｅｒｇｒｏｕｎｄ ｕｔｉｌｉｔｙ ｔｕｎｎｅｌ ｈａｓ ｏｂｖｉｏｕｓ ｌａｔｅｒａｌ ｄｉｓｐｌａｃｅｍｅｎｔ ｕｎｄｅｒ ｔｈｅ ａｃｔｉｏｎ ｏｆ ｈｏｒｉｚｏｎｔａｌ ｓｅｉｓｍｉｃ ａｃｔｉｏｎꎬ ｗｈｉｃｈ ｉｓ ｐｒｏｎｅ ｔｏ ｂｅｎｄｉｎｇ ａｎｄ ｓｈｅａｒ ｆａｉｌｕｒｅꎬ ｂｕｔ ｎｏ ｏｂｖｉｏｕｓ ｄｉｓｐｌａｃｅｍｅｎｔ ｉｎ ｔｈｅ ｈｏｒｉｚｏｎｔａｌ ｄｉｒｅｃｔｉｏｎ. Ｔｈｅ ｗｅａｋ ｌｉｎｋ ｉｎ ｔｈｅ ｓｅｉｓｍｉｃ ｄａｍａｇｅ ｏｆ ｔｈｅ ｕｔｉｌｉｔｙ ｔｕｎｎｅｌ ｓｔｒｕｃｔｕｒｅ ｉｓ ｏｎ ｔｈｅ ｒｏｏｆꎬ ｔｈｅ ｂｏｔｔｌｅ ｐｌａｔｅ ａｎｄ ｔｈｅ ｓｉｄｅ ｗａｌｌꎬ ａｓ ｗｅｌｌ ａｓ ｔｈｅ ｗａｌｌ ｅｎｄ ｏｆ ｔｈｅ ｐａｒｔｉｔｉｏｎ ｗａｌｌꎬ ａｎｄ ｒｅｉｎｆｏｒｃｅｍｅｎｔ ｍｅａｓｕｒｅｓ ａｒｅ ｒｅｑｕｉｒｅｄ ｉｎ ｔｈｅ ｓｅｉｓｍｉｃ ｄｅｓｉｇｎ. [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 Heilongjiang University of Science & Technology is the property of Journal of Heilongjiang University of Science & 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 Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing 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 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.)

In order to reveal the mutual response of silo-stock-foundation system under dynamic action, a small vibration table silo test was carried out. The rules of acceleration, displacement and earth pressure of the silo composite structure under seismic load were studied, and the seismic response of silo-stock-foundation interaction system was analyzed by numerical simulation. Results showthat: The peak acceleration of the silo top has a tendency to increase first and then decrease with the increase of the storage material. The relative movement of the storage material and the silo has a shock absorption effect on the silo system. The displacement patterns on the busbar of the same working condition are similar, and the displacement peak increases with the increase of the storage amount, and the difference between the upper and lower sides is larger. Under the action of seismic waves, the earth pressure fluctuates up and down, but the overall trend shows a gradual increase until it stabilizes at a certain value. The research can provide some theoretical basis and reference values for the safe operation of silo structure under earthquake actions. [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.)

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.)

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 Heilongjiang University of Science & Technology is the property of Journal of Heilongjiang University of Science & 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 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.)

Taking the seismic response of the annulus gravity drainage tank in the third generation nuclear power plant as the research object, an added mass dynamic analysis method suitable for the annular container with high accuracy and convenient realization is proposed. According to Housner’s I henry, the added mass distribution model applied to the annular water tank was improved. The modeling and calculation of the added mass method based on the improved distributed model was implemented in ANSYS. The applicability and accuracy in modal and dynamic time history analysis of the current approach and the commonly used 60% and 100% distributed added mass methods were compared with the fluid structure interaction finite element method (FSI-FEM) where the interaction between the fluid and structure was directly simulated. The results show that for various cases, such as different ground motions, model sizes and liquid storage rates, the improved added mass method has higher accuracy in the natural frequency, deformation and the internal forces results. Therefore, the improved added mass method can be used for the actual engineering analysis of the annular tank structure. The accuracy of 60% distributed added mass method is slightly lower and susceptible to the model size. However, this added mass distribution is simple and easy to implement, which make it meet the engineering application requirements to a certain extent. For the 100% distributed added mass method, however, the dynamic response is overestimated considerably and the calculation error is greatly affected by the model size. This study can provide insight in the application of the added mass method for annulus containers in industry. [ABSTRACT FROM AUTHOR]

A practical calculation method for apparent wave velocity was proposed for traveling wave effect analysis of super-long structures, and the influences of apparent wave velocity were analyzed in this paper. A multi-support excitation model taking account of both horizontal and rotational stiffness of the pile foundation was established. Taking a multistory super-long terminal structure with a large span roof as an illustrative example, the displacements, horizontal seismic forces, and internal forces of members under earthquake travelling along the longitudinal direction were analyzed comprehensively. The results show that，the apparent wave velocity is mainly affected by the shear wave velocity of bedrock, hypocenter depth and epicenter distance，where a faster bedrock shear wave velocity，a smaller epicenter distance，or a deeper focal depth could all lead to a larger the apparent wave velocity. The story shear forces caused by multi-support excitation is less than that caused by uniform excitation. With a decrease in apparent velocity, the differences between multi-support excitation and uniform excitation are more obvious. When under multi-support excitation along the longitudinal direction, the change of apparent wave velocity and foundation stiffness has a significant influence on the inter-story drift angle of the lower floor； when under multi-support excitation along the transverse direction, the apparent velocity has a great influence on the inter-story drift angle of the upper floor, but the effect of the foundation stiffness is small. When the symmetrical structure is excited in the direction parallel to earthquake propagation, torsional effect is insignificant ； but when excited in the direction perpendicular to earthquake propagation, an obvious torsional effect would occur. When under multi-support excitation along the longitudinal direction，the internal force of some frame columns on the bottom floor increases ； when under multi-support excitation along the transverse direction, the internal force of a small number of frame columns becomes critical. With an increase in apparent wave velocity, the internal force of the frame columns decreases gradually. After considering the foundation stiffness, the internal force of the frame columns can be reduced significantly. The internal forces of several members in the long-span roof are controlled by multi-support excitation G as the apparent velocity decreases, the internal forces of the long-span roof members gradually decrease, and the effect of the foundation stiffness is negligible. [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.)

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience 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 Heilongjiang University of Science & Technology is the property of Journal of Heilongjiang University of Science & 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 Heilongjiang University of Science & Technology is the property of Journal of Heilongjiang University of Science & 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.)

Because of its direct influence on the amount of unfrozen water and ice lens in a frozen soil, temperature has a significant effect on the mechanical behavior of the freeze-thaw soil. Accordingly, seismic responses of engineering structures such as canals in northern cold regions exhibit noticeable differences with seasonal alternation. To analyze the distinctive seismic characteristics of a canal in northern cold regions, a coupled water-heat-dynamics model was built based on theories of heat transfer, soil moisture dynamics, frozen soil mechanics, and soil dynamics. A well-monitored canal in northern cold regions was used to simulate seismic responses in two typical seasons in the 10th service year. The numerical results showed that the constructed canal disturbed the original thermal state and the geo-temperatures of the canal changed with seasonal alternation. In the freezing-thawing process, the unfrozen water migrated and ice lens formed in the canal soil under the forcing of temperature gradient. As a result, the unfrozen water and ice distributions of the canal exhibited obvious seasonal differences. For instance, there were little unfrozen water and much ice lens in the canal and shallow layer of soil at air temperature bellowing freezing, whereas the volumetric content of the unfrozen water was high and the ice content was equal to 0 when the temperature had its maximum during the year (on July 15). So the differential seismic responses of the canal were generated by different water-heat states in the two seasons. Among these two seasons in the 10th service year, although the general time histories of the acceleration and velocity were similar in the canal, their maximum amplitudes were relatively larger on July 15. For instance, in two different time (on January 15, on July 15), the accelerations of the canal bottom respectively got their maximum acceleration values which were 1.160 m/s2, 1.360 m/s2 in 12.165s and 2.404 s, whereas the accelerations of the canal top got their respectively in 8.995 s and 9.007 s maximum values which were 1.476 m/s2, 1.785 m/s2, so the earthquake accelerations of the canal were stronger on July 15 than January 15 under the earthquake. The horizontal velocity responses of the bottom and the top of the canal were smaller on January 15, their maximum velocity was 0.145 m/s and 0.149 m/s, respectively, while the maximum speed was 0.146 m/s and 0.150 m/s, respectively on July 15. The displacement was a direct expression of the seismic loading and also sensitive to temperature variation, the displacement responses of the canal to dynamic loading are also relatively larger on July 15 and the maximum horizontal displacement was 5.6 cm in the example. When the earthquake was over, there were still permanent differential deformations in the canal, and the residual displacement distributions of the canal were asymmetrical. In fact, the seismic response of the canal in seasonally frozen soil area was a very complicated water-heat-dynamic coupled problem, so there were few theoretical documents on the subject up to now. As a preliminary study, the numerical model proposed in this paper has some limitations. Therefore, further studies should be carried out on the subject. As a preliminary exploration, it is expected to provide theoretical basis and reference for design, construction, and maintenance of the canal in seasonally frozen regions. [ABSTRACT FROM AUTHOR]

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.)

The response analysis of tall buildings under earthquake action is a difficult task in civil engineering design. With the symplectic precise integration method, which has advantages of high precision of the precise integration method and excellent long-time numerical stability of the symplectic method, the seismic response analysis of a tall building was performed and the elastic/elasto-plastic time-history results of the structure were obtained. Comparison of the numerical results between the symplectic precise integration method and the EPDA software shows the feasibility and the effectiveness of the symplectic precise integration method for seismic response analysis of tall buildings. [ABSTRACT FROM AUTHOR]

The traditional AVA analysis of coal seam is based on the seismic isotropic theory,while the coal seam usually shows the characteristics of small thickness,cross layer distribution,low velocity and low density,which makes the coal bearing strata appears anisotropic.Therefore,the seismic responses of coal bearing strata are difficult to be described by the seismic isotropic theory.In order to obtain the multi-wave seismic responses more accurately,the coal bearing strata are equivalent to transversely isotropic media with vertical symmetry axis based on the seismic anisotropy and long-wavelength theory.The models are established according to the ratio of the total thickness of coal seam to the coal bearing strata and to the wavelength.By using the reflection coefficient equations of Ruger,the multi-wave seismic responses of different models with varying incident angle are analyzed in terms of AVA curves and AVO gathers.The results show that:both the interlayer structure and the ratio of the thickness of coal seam to the wavelength will affect the multi-wave seismic responses of coal bearing strata.Neglecting the anisotropy of coal bearing strata will cause a large error in the study of actual seismic responses,and using PP wave and PS wave simultaneously can better describe the anisotropy of coal bearing strata. [ABSTRACT FROM AUTHOR]

Abstract：To study the influence of member initial imperfections on seismic response of single-layer Kewitt latticed domes, a multiple beam elements method was used to model the member initial imperfections with OpenSEES. Appropriate parameters for the multiple beam elements method in modeling the hysteresis of circular pipes in spatial grid structures were presented, and equations describing the relationship between equivalent eccentric ratio and normalized slenderness ratio were derived by fitting the stability coefficients in GB 50017-2003. In consideration of stochastic distribution of initial member bending directions, single-layer Kewitt latticed dome models with different parameters were created, and the maximum displacements obtained from incremental dynamic analyses were compared. The results show that the influence of member initial imperfections on the seismic response can be neglected when the domes are in the elastic stage, whereas the influence cannot be neglected when the domes are in the inelastic stage. The dispersion level of the maximum displacements of the domes with different member bending directions basically increases with an increase of seismic intensity. The difference of response between the domes incorporating both structural and member geometric imperfections and those only consider member imperfections can be significant, and uncertainties exist in the prediction of the maximum displacement of the domes with the two cases of imperfection. The key influential factor is related to the dispersion level of the distribution of yielded members under earthquakes. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency 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 super high-rise frame-core tube structural elastic time-history analysis under the frequent earthquake of seismic fortification intensity zone 7 was researched. Two groups of ground motion records with obvious long-period components were selected as the seismic input. Main seismic response values were compared with the results under the corresponding normal ground motion input cases. Comparison of the results shows that seismic responses such as base shear, inter-story drift ratio and acceleration amplification factor under long-period ground motions are apparently higher than the seismic responses under normal ground motions, which indicates that the usage of conventional dampers may not be suitable for reducing structural responses under long-period ground motion. A new displacement amplification damping system and its theoretical formulas were proposed to improve energy dissipation capacity based on the viscous damper's mechanical characteristic. The responses of original structure and damping structure with and without displacement amplification damping system under long-period ground motion were compared. It is concluded that the proposed displacement amplification damping system can perform more effectively in reducing high-rise structural seismic responses subject to long-period ground motions. [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.)

In order to study the cable tension optimization problem of complex and long span cable stayed bridges and to study the influence of cable tension on seismic response of cable stayed bridges, a new strongly sub feasible SQP (Sequential Quadratic Programming) algorithm is proposed to establish a nonlinear mathematical programming model for automatic searching optimal cable forces, and the seismic dynamic analysis is carried out under different conditions. The results show that the new method is suitable for the optimization of cable tensions. The optimal cable tensions are in good agreement with the designed cable forces, and the bending moment distribution of the main girder is uniform. The main tower is mainly subjected to axial pressure, the bottom moment of the tower is small, and the deformations of the structure are much smaller than the standard limit values. The optimal cable tensions can effectively change the uneven distribution of the bending moments of the main beam, and reduce the longitudinal deformations of the main girder and the transverse deformations of the main tower so that the whole structure will be more secure under earthquake action. [ABSTRACT FROM AUTHOR]

Aiming at dynamic response and seismic performance of bridge type grab ship unloader under earthquake, the method for seismic analysis of structure based on ANSYS was put forward with the research on intensity, strain characteristics, wheel pressure stability and damage mode of ship unloader structure under earthquake. According to the traditional theoretical anti-seismic analysis of quayside container crane and architecture, a finite element model of the bridge-type grab ship unloader based on ANSYS was established for stability of major damage pattern and wheel pressure with equivalent static analysis in different conditions and seismic excitations. Aiming at dynamic behavior and seismic response of the ship unloader under longitudinal or transverse seismic action, according to the court sorts division and the vibration characteristic of structure, the anti-quaking design reacting spectrum of crane and the typical seismic record was used for time history analysis of ship unloader. The experimental data between the equivalent static analysis, response spectrum analysis and time history analysis was compared. The research result indicates that the ship unloader can satisfy the requirement of seismic fortification intensity and ensure the correctness of the design of steel structure. It has certain reference significance to the seismic research field and project application of bridgetype grab ship unloader. [ABSTRACT FROM AUTHOR]

A high-rise base isolated building in Xichang (seismic intensity of 9) is taken as prototype. The upper-structure employs frame-core tube form with a total height of 58.3m using lead rubber bearings as isolators. Shaking table test on a model structure with a similitude ratio of 1/15 was conducted to investigate the performance of the isolated structure under earthquake. Results illustrate that the isolation floor reduces acceleration response of upper-structure remarkably, and the amplification coefficient of the isolation layer is smaller than 0.5 which meets the requirement of decreasing one degree of seismic intensity for structural design. Horizontal displacement concentrates on isolation layer, thus story displacement is comparatively smaller and inter-story drift meets the limitation requirement in Chinese code. Besides, the full hysteretic loops of isolation layer indicate good ductility and energy dissipation property. However, under strong earthquake, tensile stress occurs in the bearings, which reveals the risk of overturning. After installation of tension-resistant device for bearings in the corner,the following experiment results reveal that this device would not pose significant effect on the horizontal mechanic properties of the structure and the regular vertical and horizontal motion of the bearing under compression state. And the tension resistant effect of the device when the bearing is under tensile state is proved by comparison results. [ABSTRACT FROM AUTHOR]

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.)

To make the seismic isolation design more reasonable, the lead rubber bearing（LRB） isolation parameters were selected by single index analysis to discuss the effect of stiffness ratio on seismic isolation. Two analysis models of the bridges with LRB and without LRB were established for Nanchang Chaoyang Bridge, and the Steel02 material was adopted to simulate the hysteric characteristic of LRB. Combining the numerical examples of El-Centro，Qian′an and Taft seismic waves, the comparison of time-history analyses in the two computation models was carried out by Opensees software. The results indicate that LRB has remarkable efficiency on seismic isolation and can effectively reduce seismic response of cable-stayed bridge. The stiffness ratio has slight effect on cable-stayed bridge seismic isolation. [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.)

Centrifuge shaking table tests about the bridge pile groups with embedded cap and elevated cap were earned out to investigate the effect of bridge group foundation with massive cap and exposed piles on the dynamic pile-soil interaction. Clayey silt was chosen as the test soil, the superstructure was simplified as mass point and connecting column and the foundation types included both the single pile and pile group. To simulate the soil movement under earthquake shear wave excitations, the laminar shear box was adopted for the free shear motion of layer soil and corresponding reflection at its boundary was further eliminated by using the rubber film on the inner wall of shear box. In the 50g centrifugal acceleration environment, the Chi-Chi seismic wave was selected as the input motion, and the seismic responses of structure-pile group were analyzed at different input peak acceleration of waves. The results show that, compared with the embedded cap pile groups, the exposure of the bridge pile groups with elevated cap increases the inertia effect of superstructure and cap, and the distribution of peak bending moments along the pile shaft are also changed, i. e., the peak bending moment is significantly decreased at the connection of pile and cap, while the values of maximum peak bending moments along the pile shaft only have a small change. [ABSTRACT FROM AUTHOR]

The substructure hybrid simulation testing method considering overturning moment by means of the axial deformation predicting technique and the force-displacement mixed control method was proposed. Using the ANSYS finite element software, the numerical simulation results considering different loading distributions, different experimental substructure stiffness, different beam-column linear stiffness ratios and different numbers of structural stories showed that the feasibility of the proposed method was validated preliminarily. After that, taking the six-story steel frame model as an example, the proposed hybrid simulation testing method was realized. The results of the steel model substructure hybrid simulation test show that the substructure hybrid simulation testing method without considering the overturning moment, which changes the structural internal force distribution and failure mode under earthquake, can not fairly reflect the mechanical properties under seismic action. [ABSTRACT FROM AUTHOR]

To simplify the algorithm of multi-mode Pushover analysis based on energy balance, two modified methods were proposed to take into account the higher mode effects and calculation efficiency. One was the combination method in which solution of Pushover analysis and higher-order elastic solutions were combined in modal analysis. The other was the envelope method in which the envelope of Pushover response and all the elastic responses from modal analysis was considered. Responses of 9-story and 20-story plan-asymmetric frame structures under typical earthquake loads were calculated by using these two methods separately. Comparisons were completed among the results of nonlinear time history analysis, Pushover analysis based on energy balance with basic mode only and the modified methods proposed here. It is shown that the higher mode effects on seismic response are estimated well by using the proposed methods. Both combination method and envelope method can get a reasonable prediction of responses at mass centers of torsionally-stiff and torsionally-flexible models, and the envelope method predicts the response of the stiff boundary better while the combination method predicts the response of the flexible boundary better. It is also found that the underlying response of combination method is generally higher than response of envelope method. Both of the two methods can get a better prediction of responses of 9-story structure than that of 20-story structure. [ABSTRACT FROM AUTHOR]

In this paper, a nine-story reinforced concrete frame structure was adopted as example, and modeled by using a program named SAP2000. A series of ground motions were selected, and further scaled to the levels corresponding to frequent and rare earthquakes so that the seismic response of the frame structure could be simulated reasonably. After that, buckling restrained braces and viscous dampers were added respectively to the frame. The parameter of dampers were trial calculated until displacement reduction ratios were controlled at around 40% for frequent earthquake. In this way, the seismic responses, including inter-story drift ratio, floor acceleration, base shear, axial compression force of frame columns, distribution of plastic hinges and damper performance were compared. It is concluded that under frequent earthquakes, buckling restrained braces amplify floor acceleration, whereas viscous dampers can effectively reduce floor acceleration. Both buckling restrained braces and viscous dampers can effectively reduce floor acceleration under rare earthquakes, while buckling restrained braces are more effective in reducing displacement, but less powerful in controlling column axial force. [ABSTRACT FROM AUTHOR]

Testing and theoretical studies of seismic response of the highly flexible structure under coupled horizontal and tilt (CHT) ground motion were conducted. The dynamic equations for the highly flexible structure were derived, in which the additional P-Δ effect caused by the tilt was considered as an equivalent horizontal lateral force and added into the equations as the excitation. Based on the different sensitivity caused by the tilt ground motion between the horizontal and vertical pendulum in the single-pendulum seismograph, the wavelet analysis was adopted to obtain the tilt component from the uncorrected horizontal component of ground motion. The shaking table tests of the scaled model for the highly flexible structure taking a television tower as the prototype under horizontal, tilt and CHT ground motion were carried out, and the test results were compared with the theoretical analysis. The results show that: the shaking table tests are consistent with the theoretical analysis adopting the developed dynamic equations and the correctness of the theoretical analysis is verified; the additional P-Δ effect caused by the foundation tilt not only increases the seismic effect of highly flexible structure, but also leads to a remarkable asymmetrical displacement effect, resulting in a great increase of the horizontal displacement of the structure. Therefore, it should be paid attention to through the practical seismic design and computation process. [ABSTRACT FROM AUTHOR]

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Seismic response behaviors of colluvial landslide were discussed by inputting Taft wave with different intensities based on dynamic centrifuge model test. Results under Taft wave and Qingxi wave were comparatively analyzed. Results show that both the horizontal and vertical peak ground acceleration (PGA) amplification coefficients at slope surface increase with the increasing of height. The landslide shows an obvious altitude amplification effect. The distributions of horizontal PGA amplification coefficients in the landslide body are different from those of the landslide surface. The landslide surface has an obvious reflect effect on input seismic wave， and it shows the surface effect. The bedrock also has amplification effect along with the height of the landslide， and it has reductive effect compared with the input seismic waves. At the same height， the PGA amplification coefficients at landslide surface， landslide body and bedrock have different distributions with the increasing of earthquake amplitudes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangdong University of Technology is the property of Journal of Guangdong 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.)