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This paper describes the development of a boundary element analysis for the behaviour of single piles and pile groups subjected to general three‐dimensional loading and to vertical and lateral ground movements. Each pile is discretized into a series of cylindrical elements, each of which is divided into several sub‐elements. Compatibility of vertical, lateral and rotational movements is imposed in order to obtain the necessary equations for the pile response. Via hierarchical structures, 12 non‐zero sub‐matrices in a global matrix are derived for the basic influence factors. Solutions are presented for a series of cases involving single piles and pile groups. In each case, the solutions are compared with those from more simplified existing pile analyses such as those developed by Randolph and by Poulos. It is shown that for direct loading effects (e.g. the settlement of piles due to vertical loading), the simplified analyses work well. However, for ‘off‐line’ response (such as the lateral movement due to vertical loading) the differences are greater, and it is believed that the present analysis gives more reliable estimates. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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各向异性研究是当令地震学研究领域中重要课题之一;三分量地震资料中各向异性的检测是各向异性理论研究成果解决地球科学实际问题的重要桥梁。本文简要描述了各向异性介质中横波分裂现象,分别介绍了现有的四种主要检测技术,即偏振图法、协方差拒阵法、质,点振动分辨率法及传输矩阵法,并对这四种技术作了一定的评述。 相似文献
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This paper's primary purpose is to compare the 2D and 3D analysis methodologies in investigating the performance of a concrete faced rock‐fill dams under dynamic loading conditions. The state of stress on the face plate was obtained in both cases using a total strain based crack model to predict the spreading of cracks on the plate and the corresponding crack widths. Results of the 2D and 3D analyses agree well. Although significantly more demanding, 3D analyses have the advantage of predicting the following: (i) the opening of the vertical construction joints; (ii) the cracking at the valley sides; and (iii) the crushing of the plate during the seismic action. During the earthquake loading, the cracking predicted at the base of the face plate after the impounding spread significantly towards the crest of the dam; however, the crack widths are obtained relatively small. Crushing of the face plates at the construction joints is the primary cause of the large scale cracking predicted on the face plate for high intensity earthquakes. Earthquake induced permanent deformation of the fill increases the compressive stresses on the face plate, thereby reducing the minute cracking on the plate. However, this effect also leads to significant increases in the residual openings at the construction joints and at the plinth level. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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以吉林省境内红星构造带(已发现油田)和杨柳青构造带(未发现油田)为试验区,首先利用地震地层学方法,研究间接参数特征,确定有利相带和有效圈闭,并在有效圈闭上选择了39个2×2cm时窗。在时窗内提取与地震波动力学有关的信息,即频率、振幅、频谱能量等,然后对这种信息进行统计计算,获得振幅方差等九个参数并对其进行综合分析,从已知油气藏出发,对未知圈闭油气状况进行了三级预测,指出了最有利的勘探靶区。 相似文献
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2001年昆仑山口西8.1级地震地表破裂带 总被引:30,自引:8,他引:30
2001年11月14日昆仑山口西8.1级地震是近50年来在我国大陆发生的震级最大、地表破裂最长的地震事件.地震地表破裂带全长426km,宽数米至数百米,总体走向90°~110°,具有明显的破裂分段特征,自西向东由5条次级破裂段组成.各破裂段又由若干更次级左阶或右阶斜列的破裂组成,具有自相似的分形结构特征.地震破裂带以左旋走滑为主,倾滑量很小.宏观震中区位于库赛湖东北93.0°~93.5°E一带的昆仑山南麓断层谷地内.最大地表同震左旋水平位移6.4m,最大垂直位移为4m.地表水平位移沿地震破裂带走向出现6个峰值,各峰值之间存在相对独立的衰减序列,这表明此地震具有多点破裂特征. 相似文献
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Different models were developed for evaluating the probabilistic three-dimensional (3-D) stability analysis of earth slopes and embankments under earthquake loading using both the safety factor and the displacement criteria of slope failure.The probabilistic models evaluate the probability of failure under seismic loading considering the different sources of uncertainties involved in the problem. The models also take into consideration the spatial variabilities and correlations of soil properties. The developed models are incorporated in a computer program PTDDSSA.These analysis/design procedures are incorporated within a code named SARETL developed in this study for stability analysis and remediation of earthquake triggered landslides. In addition to the dynamic inertia forces, the system takes into consideration local site effects.The code is capable of assessing the landslide hazard affecting major transportation routes in the event of earthquakes and preparing earthquake induced landslide hazard maps (i.e., maps showing expected displacements and probability of slope/embankments failure) for different earthquake magnitudes and environmental conditions. It can also beused for proposing a mitigation strategy against landslides. 相似文献
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