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1.
The influence of the change of structure plane size on seismic response was studied for a soil-structure interaction system. Based on the finite element method, a soil-structure interaction calculation model was established to analyze the seismic response by changing the structure plane size and choosing different earthquake waves for different soil fields. The results show that when the natural periods of vibration for different structure plane sizes are close, under the same earthquake wave, the total displacement on the top layer of the structure and the foundation rotation displacement decrease with the increase of structure plane size, and the proportion of superstructure elastic selfdeformation displacement to the total displacement increases with the increase of structure plane size. While for different types of sites and seismic waves, under the horizontal and vertical seismic waves, the seismic responses of different plane sizes have a similar change rule. 相似文献
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INTRODUCTION Adequate information on dynamic soil proper-ties, especially dynamic shear modulus and dampingratio, is essential for accurate computations of groundresponse and soil-structure interaction problems.Many experimental investigations carried out onsandy soils through resonant column test or improvedcyclic triaxial test in early studies (Hardin and Richart1963; Hardin and Black, 1968; Drnevich and Richart,1970; Seed and Idriss, 1971; Kokusho, 1980) showedthat the small … 相似文献
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The dynamic stress path of a rock and soil mass under seismic action has a crucial influence on its catastrophic behavior. In soil dynamics, earthquakes are commonly simplified as vertically incident shear waves and the seismic stresses in soil are estimated based on rigid foundation models. However, the great effect of P-waves should not be overlooked in strong earthquakes, which have happened frequently in recent years. The characteristics of the dynamic stress path under longitudinal waves with significant oblique incidence are still unclear. Analytical formulas for the seismic stresses at any depth of a semi-infinite elastic space under obliquely incident P-waves are derived, which degenerate into the traditional rigid foundation method in soil dynamics when both the incident angle and Poisson’s ratio are taken as zero. Here, we reveal the fundamental characteristics of a dynamic stress path under obliquely incident P-waves. The stress path is proved mathematically to be an oblique ellipse in the plane of normal stress difference and horizontal shear stress. We identify factors affecting the stress path, including the incident angle, Poisson’s ratio, and depth corresponding to unit wavelength. The possible variation in the range of an oblique elliptic stress path is systematically analyzed, which lays a theoretical foundation for further study of the dynamic response of sites under obliquely incident seismic waves. 相似文献
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程怡 《福建工程学院学报》2018,(4):320-325
以某跨径为110 m的独塔异形斜拉桥为工程背景,通过非线性有限元分析对斜拉桥在强震作用下的地震响应特性及减震措施进行了研究,得出如下结论:相比Lander-amboy波,卓越周期与桥梁固有周期较为接近的Cerro Prieto波能够引起结构较大的地震响应。行波效应能够显著增大工程背景斜拉桥的地震响应,且随着视波速的增大,桥梁的加速度响应明显增大。阻尼系数25 000 kN·s/m为工程背景斜拉桥的最优粘滞阻尼器设计参数,且在塔梁连接处安装该参数粘滞阻尼器后,斜拉桥减震效果显著,尤其能明显减小结构的位移响应。 相似文献
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黄颖 《福建工程学院学报》2012,(4):313-317
以广州国际会展中心单向空间张弦梁结构这一典型张弦梁结构为计算分析算例,应用大型有限元软件ANSYS对张弦梁结构的地震响应进行了空间非线性时程反应分析。通过考虑地震波以不同速度传播引起的行波效应,研究了大跨度张弦梁结构在此类情况下的地震响应,分析了大跨空间张弦梁结构在横向、竖向和纵向3向地震联合作用下考虑非一致输入条件的地震响应变化规律的关系。研究结果表明,行波效应的影响与波有关,不同地震波作用下结构的响应有很大的差异,视波速越小对结构的地震响应越明显。 相似文献
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TSP地震波波速与隧道围岩类别关系探讨 总被引：1，自引：0，他引：1
介绍了TSP超前地质预报技术的基本原理和过程，提出了在TSP所测的波速预测隧道围岩类别时存在着预测结果偏大的问题，探讨了TSP地震波波速与隧道围岩类别关系。 相似文献
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研究目的：创新要点：为多塔斜拉桥在一致激励和非一致激励下地震响应的研究提供地震模拟振动台全桥试验方法,并有助于加强多塔斜拉桥抗震性能和抗震设计的认识。1．建立了地震模拟振动台多台阵试验方法,并首次将其应用于多塔斜拉桥全桥比例缩尺模型的地震响应分析之中;2．通过地震模拟振动台试验,揭示了多塔斜拉桥在多点一致激励和多点非一致激励的地震响应特性并提出了多塔斜拉桥在强震下的破坏模式。研究方法：1．基于动力相似理论,设计与制作了多塔斜拉桥的全桥比例缩尺模型（图2）;2．利用地震模拟振动台多台阵试验,根据在不同地震波作用下和考虑行波效应后多塔斜拉桥模型的主梁和主塔响应,分析了多塔斜拉桥在多点一致激励和多点非一致激励的地震响应特性（图5～图8）;3．根据在地震波不同强度作用下多塔斜拉桥模型的主梁和主塔响虚,分析了多塔斜拉桥在强震下的破坏模式和地震响应（图9）。重要结论：1．江心波作用下该多塔斜拉桥的地震响应大于其他三种地震波;2．多塔斜拉桥在抗震设计时需要考虑行波效应的影响;3．在El-Centro波的加速度峰值高达4．0m／s^2时,多塔斜拉桥模型出现了支座破坏。 相似文献
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The soil-structure interaction (SSI) decoupling is applied to simplify buried structure against internal blast load as spring effect. Shear failure, bending failure and combined failure modes are considered based on five transverse velocity profiles for the rigid-plastic structural element. The critical equations for shear and bending failure are derived respectively. Pressureimpulse diagrams are accordingly developed to assess damage of the buried structures against internal blast load. Comparison is done to show influences of soil-structure interaction and shear-to-bending strength ratio of a structural element. A case study is conducted to show the application of damage assessment to a reinforced concrete beam element of buried structure. 相似文献
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Correlation of liquefaction resistance with shear wave velocity based on laboratory study using bender element 总被引：1，自引：0，他引：1
INTRODUCTION Evaluation of soil liquefaction resistance is an important aspect of geotechnical engineering practice, and several types of evaluating procedures have evolved over the last three decades. The well known “simplified procedure” originated by Seed and Idriss (1971) can be used to evaluate liquefaction resistance based on standard penetration test (SPT) blow counts. Over the years, the simplified procedure has been modified and updated with additional data, and has become th… 相似文献
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Ultrasonic wave testing was applied to investigate the quality and weathering status of rock specimens obtained in two borings
situated in the Xishan Buddha rock slope in Taiyuan, China. This paper pays special attention to the distribution of bulk
density, dynamic parameters and static parameters of rock specimens as well as the relationship between static and dynamic
parameters. The results illustrate that the distribution of both parameters is identical along the depth of two drilled holes
in the rock slope. When the hole depth increases, the density of rock mass, saturated compression strength and static elastic
modulus, dynamic elastic modulus and wave velocity also show increase tendency. The weathering degree in the rock mass ranging
from the surface of cliff to the depth of 2.5 m is the highest while the rock mass is unsalted and more rigid when the depth
is larger than 3.0 m. The relationship between dynamic elastic modulus, sonic wave velocity and horizontal depth indicates
that dynamic elastic modulus is more sensitive than sonic wave velocity. Conversely, by comparing quantity relationship between
static elastic modulus and sonic wave velocity, it is found that the composition of rock has a great influence on the relationship
between static and dynamic parameters, that is, inequality of rock composition will lead to dispersion and abnormality of
the distribution of static and dynamic parameters. 相似文献
12.
Shaking table test of pile-water-pier superstructure 总被引：1，自引：1，他引：0
The model test of seismic simulation shaking table is an important method to study the seismic design of bridge structure. In order to evaluate the seismic response and dynamic characteristics of pile-water-pier system for developing more reliable design procedures, shaking table model tests of a submerged bridge pier system, including pile groups-cap-pier and inertia mass, were conducted. Since different similitude laws corresponding to different test objectives affected the validity of test results, the similitude law with the aim to consider the effect of hydrodynamic pressure was proposed and confirmed through an actual example. Based on the test results, the effect of water around model on seismic response under seismic excitation input was analyzed and the failure level was judged by observing the variation of basic frequency. The test results indicate that the transfer function of analytical model with water is different from that without water, the natural frequency without water is always higher than that with water, and the first modal shapes are various. It is also concluded that the similitude law is suitable for practical application and the dynamic characteristics and seismic response of the structure system can be changed because of the existence of the surrounding water, which should be paid much attention in the further investigation. 相似文献
13.
铅芯橡胶支座屈服比对大开间密肋复合墙结构隔震效果的影响 总被引：1，自引：0，他引：1
将大开间密肋复合墙结构与基础隔震技术相结合,可以有效地减小大开间密肋复合墙结构的地震响应。运用有限元分析软件SAP2000,对隔震大开间密肋复合墙结构模型进行动力分析,研究在地震作用下铅芯橡胶支座屈服比的变化对隔震大开间密肋复合墙结构隔震效果的影响。研究表明,对输入的各种地震波及其幅值,铅芯橡胶支座不仅可以取得明显的减震效果,而且可以找到一个最佳屈服比使大开间密肋复合墙结构的最大层间剪力最小,同时获得最大的控制效果。 相似文献
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提出了基于人工神经网络（ＡｒｔｉｆｉｃｉａｌＮｅｕｒａｌＮｅｔｗｏｒｋｓ）对动力结构进行系统辨识的方法，即应用人工神经网络预测结构地震响应．采用ＢＰ算法的前馈网络（简称ＢＰ网络）对剪切模型结构进行系统辨识．首先用实际地震波及相应的模拟地震响应训练本文提出的ＢＰ网络，然后用“已学会”的ＢＰ网络预测其它地震波激励下的结构地震响应．还讨论了网络拓扑结构、输入单元数等对网络学习和预测的影响．通过本文可以发现，合适的人工神经网络结构能准确地辨识结构动力特性和预测结构动力响应 相似文献
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李克杰 《马钢职工大学学报》2013,(1):38-42
以结构基本自振周期的变化率作为自变量,构造识别精度较高的对数函数,将其作为结构损伤的表征量,借助有限元分析设计软件ETABS对14层钢筋混凝土纯剪力墙结构进行数值模拟,揭示了地震波属性（峰值速度与加速度之比）、结构高宽比及等效损伤位置、损伤程度对整体结构抗震性能的影响规律,提出了适用于RC剪力墙结构剩余抗震能力的评价模型。 相似文献
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Jian-hua SHAO Qiang GU Yong-kang SHEN 《浙江大学学报(A卷英文版)》2008,9(3):322-329
This paper presents some methods that the standard acceleration design response spectra derived from the present China code for seismic design of buildings are transformed into the seismic demand spectra, and that the base shear force-roof displacement curve of structure is converted to the capacity spectrum of an equivalent single-degree-of-freedom （SDOF） system. The capacity spectrum method （CSM） is programmed by means of MATLABT.0 computer language. A dual lateral force resisting system of 10-story steel frame-steel plate shear walls （SPSW） is designed according to the corresponding China design codes. The base shear force-roof displacement curve of structure subjected to the monotonic increasing lateral inverse triangular load is obtained by applying the equivalent strip model to stimulate SPSW and by using the finite element analysis software SAP2000 to make Pushover analysis. The seismic performance of this dual system subjected to three different conditions, i.e. the 8-intensity frequently occurred earthquake, fortification earthquake and seldom occurred earthquake, is evaluated by CSM program. The excessive safety of steel frame-SPSW system designed according to the present China design codes is pointed out and a new design method is suggested. 相似文献
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对强地震多发区黄河黑山峡下游段岩体破坏特征进行了分析,研究表明,地震作用下裂隙的生成与地震波的传播具有同时性、继承性和纵横渡在岩体破坏中的拉张和剪切共同作用的双重性等特点.对岩体地震破坏机理及岩体地震破坏模型进行了初步探讨.同时对地震破坏后岩体地球物理特性的变化进行了研究,发现研究区大范围地球物理参数明显变异,说明强震对坚硬的岩体同样具有严重的破坏性. 相似文献
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通过理论研究和数值计算，详细分析了大跨径钢管混凝土双肋拱桥的侧倾稳定性和地震响应。首先，根据双肋拱桥结构在竖向均布荷栽作用下的侧倾稳定临界力的近似解析解，讨论了横撑设置、横撑刚度等因素对稳定性的影响。其次，基于多点激振理论和拟静力位移概念，介绍了拱桥结构的动力特点和地震动作用下的响应，并讨论了行波效应的影响。分析表明，地震行波作用对大跨度拱桥影响很大，横撑设置对稳定性敏感。 相似文献
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The dynamic response of an infinite beam placed on a Pasternak foundation when the system was subjected to a moving load was investigated. We used the double Fourier transform and its inversion to solve the formulations of the problem. A closed form analytic solution of the beam was obtained by the theorem of residues. We selected a numerical example to illustrate the dynamic response of the beam on Pasternak and Winkler foundations, respectively. We discuss the effect of the moving load velocity on the dynamic displacement response of the beam. The maximum deflection of the beam increases slightly with increased load velocity but increases significantly with reduced shear modulus of subgrade at a given velocity. The maximum deflection of a beam resting on a Pasternak foundation is much smaller than that of a beam on a Winkler foundation. 相似文献