共查询到15条相似文献，搜索用时 656 毫秒
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本文在以前研究的基础上,对场地土液化引起的地下管道上浮的影响因素进行了较为全面的研究,包括液化土的弹簧刚度、管道的初始变形、液化区长度、管道的初始轴力、管道材料、管道半径等的影响.得到了一些有益的结论. 相似文献
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液化场地土中埋设管线的上浮反应分析 总被引：10，自引：4，他引：6
本文利用虚功原理,建立了液化场地土中埋设管线的上浮反应分析模型,考虑到土的非线性约束作用和管道的初始轴力的影响,采用非线性增量有限元法,分析了液化场地土中埋设管线的上浮反应,并给出了部分计算结果。 相似文献
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不均匀场地土液化引起的地下管道上浮反应研究 总被引：3，自引：3，他引：0
本文采用非线性增量有限元迭代法,对不均匀场地土液化引起的地下管道的上浮反应进行了研究,考虑了液化土3种不均匀的情况,给出了一些计算结果。 相似文献
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利用ANSYS有限元分析软件,建立了由场地土液化引起的地下管道上浮反应的分析模型。用土弹簧模型模拟地下管道的受力特点,考虑了管土之间相互作用的非线性特征,通过算例分析了管道在发生上浮反应时的应力应变曲线,探讨了液化区埋地管道在发生上浮位移时的受力特征,得出了一些有意义的结果。主要有:管线的应力应变以轴向为主,并且管顶和管底的受力最大,管侧相对于管顶和管底轴向应力应变很小可以忽略;最大应变位于液化区和非液化区交界处;管线中点处等效应力达到极值等等。 相似文献
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砂土液化是埋地管道遭受地震破坏的主要原因之一。液化土对管道产生上浮力,使管道发生上浮反应,它是随地震发生时间而变化的动态过程。将地震载荷作用下的液化区埋土管道模拟成两端弹性支承的直梁模型,考虑管-土间的相互作用和管内流体与管道之间的流固耦合作用,采用模态叠加法对液化区埋地管道进行地震响应的动态分析,探讨了管道和液化土参数对管道动态上浮反应的影响。通过数值仿真得到了管内流体的流速、流体压力、流体密度、管截面轴向力,管道黏弹系数、液化土容重和相对弹簧系数、地震加速度幅值等因素对管道上浮位移的影响情况。 相似文献
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本文采用圆柱壳单元模拟地下管道,用有限元模拟手段建立了管道-土相互作用分析模型,采用非线性接触问题分析方法分析了管道因断层运动而产生的反应,通过大量数值计算,对影响管道地震反应的各种因素进行了研究,如断层位错量、管道跨越角、断层运动方式、管道埋设深度、管道初始轴向力、断层裂缝宽度、管道径厚比等,得到了一些规律性的结论。 相似文献
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地下管道的震害预测方法简述 总被引：1，自引：0，他引：1
强烈的地面运动或场地失效等因素是造成地震中地下管道破坏的主要因素。本文对地震波作用下和砂土液化条件下管道的震害预测方法进行了概述,并基于综合概率法对埋地管道进行了分析预测。 相似文献
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In this paper, a nonlinear stochastic seismic analysis program for buried pipeline systems is developed on the basis of a probability density evolution method (PDEM). A finite element model of buried pipeline systems subjected to seismic wave propagation is established. The pipelines in this model are simulated by 2D beam elements. The soil surrounding the pipelines is simulated by nonlinear distributed springs and linear distributed springs along the axial and horizontal directions, respectively. The joints between the segmented pipes are simulated by nonlinear concentrated springs. Thereafter, by considering the basic random variables of ground motion and soil, the PDEM is employed to capture the stochastic seismic responses of pipeline systems. Meanwhile, a physically based method is employed to simulate the random ground motion field for the area where the pipeline systems are located. Finally, a numerical example is investigated to validate the proposed program. 相似文献
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液化场地地下管线地震反应研究述评 总被引：1，自引：1，他引：0
本文简要介绍了地下管线的震害特征和主要影响因素。对国内外在液化场地地下管线方面的研究现状从试验研究和理论分析2个方面进行了论述并探讨了液化场地地下管线反应需进一步研究的一些问题。 相似文献
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Pipelines buried in saturated sand deposits, during earthquake loading could damage from resulting uplift due to excess pore water pressure generation. Several studies have been made to better understand the uplift mechanism and evaluate the effectiveness of mitigating techniques through experiment, but little numerical works have been done to assess the influence of soil properties and field conditions in pipeline floatation. Especially for previously buried pipelines, in order to set the priority for seismic retrofit, evaluating the risk of floatation in each region could be a concern. In this paper, effects of several parameters including dilatancy angle and density ratio of natural soil, diameter and burial depth of pipe, underground water table and thickness of the saturated soil layer on uplift of pipe have been investigated. Results show the prominent role of burial depth in pipe response and that there exits an optimum level for drop of water table to reduce floatation. 相似文献
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Shantanu Joshi Amit Prashant Arghya Deb Sudhir K. Jain 《Soil Dynamics and Earthquake Engineering》2011
Presently available simplified analytical methods and semi-empirical methods for the analysis of buried pipelines subjected to fault motion are suitable only for the strike-slip and the normal-slip type fault motions, and cannot be used for the reverse fault crossing case. A simple finite element model, which uses beam elements for the pipeline and discrete nonlinear springs for the soil, has been proposed to analyse buried pipeline subjected to reverse fault motion. The material nonlinearities associated with pipe-material and soil, and geometric nonlinearity associated with large deformations were incorporated in the analysis. Complex reverse fault motion was simulated using suitable constraints between pipe-nodes and ground ends of the soil spring. Results of the parametric study suggest that the pipeline's capacity to accommodate reverse fault offset can be increased significantly by choosing a near-parallel orientation in plan with respect to the fault line. Further improvement in the response of the pipeline is possible by adopting loose backfill, smooth and hard surface coating, and shallow burial depth in the fault crossing region. For normal or near normal orientations, pipeline is expected to fail due to beam buckling at very small fault offsets. 相似文献
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埋地管线的腐蚀情况十分复杂,具有随机性的特点,从而导致其在地震激励下的反应必然具有随机性。本文在管线腐蚀离散状态模型和弹性地基梁原理的基础上,利用随机摄动理论推导给出了腐蚀管线在地震激励下位移和应力的解析表达式,并进行了均值和标准差的计算。实例分析中将该方法计算结果与Monte Carlo模拟方法计算结果进行了对比。结果表明,利用随机摄动方法可以快速、精确地求得腐蚀管线的随机地震反应。 相似文献