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考虑土与上部结构共同作用更加符合工程实际。本文运用ANSYS软件对一双塔楼连体结构建立了考虑土体参与共同作用和不考虑土体共同作用的三维模型。分析结果表明,考虑共同作用后,结构周期变长,地震反应更为强烈,偏于不安全,不容忽视。 相似文献
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通过数值模拟方法研究了车辆动力荷载作用对基坑开挖变形的影响,对比分析了考虑车辆动力荷载、不考虑车辆动力荷载、不考虑车辆荷载三种荷载工况下基坑围护结构及周围土体变形规律。分析认为:基坑开挖完成后考虑车辆动力荷载与不考虑车辆动力荷载作用下基坑围护结构最大侧移差值不超过5%,地表最大沉降差值不超过5%,考虑车辆荷载与不考虑车辆荷载作用下坑底最大隆起位移差值不超过10%。 相似文献
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以某医院的超长复杂隔震结构为工程背景,对超长复杂隔震结构进行了抗连续倒塌研究。运用非线性有限元软件建立考虑楼板作用的精细三维模型和未考虑楼板作用的简化三维模型,通过非线性动力拆除构件法对两种模型进行了分析,对比两种模型的抗倒塌能力。结果表明:该超长复杂隔震结构仅拆除1根柱时,结构未发生连续倒塌,且角柱对该隔震结构的连续倒塌影响较大|拆除2根柱时,未考虑楼板作用的简化三维模型发生了连续倒塌,而考虑楼板作用的精细三维模型未发生连续倒塌。因此,不考虑楼板作用的简化三维模型计算结果会偏于保守,进行结构抗连续倒塌时需考虑楼板的影响。 相似文献
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《特种结构》2017,(1)
本文通过对比某地下综合管廊区间结构在考虑地震作用和不考虑地震作用时的内力及配筋方案对比,并进行裂缝宽度验算,为地下综合管廊区间结构设计时是否需进行考虑地震作用下的补充验算提供参考。本文以某地下综合管廊区间结构为例,参考地下结构相关规范的规定,运用midas Gen软件基于反应位移法对其在横向地震作用下的地震反应进行分析,并对比在考虑地震作用和不考虑地震作用下的内力、配筋,以及验算结构是否满足裂缝宽度要求。根据分析可知,对于地下综合管廊区间结构,若仅考虑静力荷载及裂缝宽度控制进行结构设计会使结构不满足抗震设计的要求,在对同类的地下综合管廊设计时,需进行在考虑地震作用下的补充验算。 相似文献
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上部结构-筏基-地基共同作用子结构法FEM分析 总被引:1,自引:0,他引:1
应用子结构法理论,将上部结构刚度矩阵凝聚到筏板基础,同时将采用D-P模型的地基土体弹塑性刚度矩阵也凝聚到筏板基础上,建立了考虑上部结构、基础、地基共同作用的三维弹塑性有限元模型理论.利用此理论建立某工程框架结构裙楼-框架芯筒结构主楼-筏板基础-地基共同作用FEM模型,通过ANSYS程序对此模型进行数值模拟.结果表明,主楼结构的柱、梁应力在考虑共同作用比不考虑共同作用有增大趋势,群楼柱轴应力在考虑共同作用比不考虑共同作用小,而群楼梁弯应力却相反.并进一步分析得出考虑共同作用基础沉降差引起上部结构杆件应力重新分布,尤其是基础沉降差引起主楼的柱轴应力、梁弯应力的变化率大于群楼柱轴应力、梁弯应力的变化率的结论,该结论对以后工程设计有重要参考价值. 相似文献
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应用子结构法理论,将上部结构刚度矩阵凝聚到筏板基础,同时将采用D—P模型的地基土体弹塑性刚度矩阵也凝聚到筏板基础上,建立了考虑上部结构、基础、地基共同作用的三维弹塑性有限元模型理论。利用此理论建立某工程框架结构裙楼一框架芯筒结构主楼一筏板基础一地基共同作用FEM模型,通过ANSYS程序对此模型进行数值模拟。结果表明,主楼结构的柱、梁应力在考虑共同作用比不考虑共同作用有增大趋势,群楼柱轴应力在考虑共同作用比不考虑共同作用小,而群楼梁弯应力却相反。并进一步分析得出考虑共同作用基础沉降差引起上部结构杆件应力重新分布,尤其是基础沉降差引起主楼的柱轴应力、梁弯应力的变化率大于群楼柱轴应力、梁弯应力的变化率的结论,该结论对以后工程设计有重要参考价值。 相似文献
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高压水射流冲击岩石会导致其发生结构破坏,不同的射流速度下,岩石呈现出各异的破坏形式。基于理论研究,分析水射流冲击岩石的应力波效应。选取速度分别为157,316,447,547,632,707和774 m/s的高压水射流开展冲击砂岩试验,分析不同射流速度下,砂岩内裂纹的数量、尺寸与形态。采用有限元法数值模拟了水射流破碎砂岩的过程,分析岩石内应力波的传播规律与裂纹的产生过程。研究表明:(1) 当射流速度大于72 m/s时,砂岩表面出现破碎坑和环形裂纹,前者由水锤压力的剪切作用导致,后者由瑞利表面波的拉伸作用导致;(2)当射流速度为300~700 m/s时,砂岩内部产生大量的横向裂纹并出现体积破碎,裂纹的产生主要由应力波产生的径向拉伸应力导致;(3) 当速度大于700 m/s时,砂岩产生的横向裂纹减少,主要以劈裂剪切方式破坏。 相似文献
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Most soil–water coupled analyses of saturated soil are based on the u–p formulation, where a set of equations is reduced by assuming that the acceleration of the fluid phase relative to that of the solid phase is less than that of the solid phase. Therefore, this analysis cannot be used for a coupled analysis with dynamic water flow in highly permeable soil. This study aims to present a soil–water coupled finite deformation analysis method based on full formulation, or u–w–p formulation. This method differs from conventional methods in the following ways: (1) the governing equations explicitly include the equation of motion for the fluid phase, (2) a relative convective term is used to describe a change in the relative configuration between the two phases, and (3) the moving/inclined discharge boundary is directly implemented to the discretized governing equations. Herein, one/two dimensional seepage and plane-strain deformation analysis results are reported. In the seepage analysis, accelerating permeation of pore water is obtained and the undrained constraint condition is verified. In the deformation analysis, dynamic migration in a high permeable soil specimen, i.e., wave propagation and rotational flow of pore water, is observed. 相似文献
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The purpose of this study was to better understand the impacts of dam-break on houses. Physical model experiments were undertaken to reproduce the process of flood water flowing around and through a house. Measurements of water level were obtained using pressure gauges and ultrasonic wave gauges, with both of them being non-intrusive. The results showed that the water level upstream of the house increased rapidly and oscillated as the flood wave reached the house. Several scenarios were tested to investigate the impact of flood water on the house, including the orientation of the house and the distance between the dam-break site and the house. The impact of flood flow on the front door, caused by velocity-induced and pressure forces, was also investigated. 相似文献
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龙游石窟砂岩在不同含水状态下的弹性波速与力学性能 总被引:2,自引:0,他引:2
为研究水环境变化对龙游石窟风化破坏的影响,进行不同含水状态下砂岩的力学性能和弹性波测试,分析在不同含水条件下砂岩的应力–应变曲线、峰值强度和弹性模量的变化规律。分析结果表明:含水率对岩石的应力–应变曲线、峰值强度和弹性模量等力学性质有显著影响,随着含水率的增加,应变软化特性弱化,峰值强度和弹性模量呈指数减少。弹性波速的测试结果表明,单轴抗压强度与波速具有线性关系;含水率为1.5%时,弹性波速出现反常,降低到一个很低的值,主要原因是砂岩中含有较多膨胀性的黏土矿物;各向异性受含水率的影响并不明显;干燥、稳定的环境有利于洞室的保护。 相似文献
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The objective of this study was to estimate the elastic wave velocity of an unsaturated soil slope, and to verify its applicability. The elastic wave velocity in a silty sand was measured. The individual influence of the volumetric water content and the tilt angle on the normalized wave velocity through unsaturated soil were investigated through a series of varied slope model tests. The relationship function of the normalized wave velocity-volumetric water content-tilt angle was established. To verify the proposed estimation function, a series of fixed slope model tests was carried out. The relationship functions were used to estimate the behaviors of the wave velocity in rainfall-induced slope failure model tests. The applicability of the proposed relationship functions for the wave velocity behaviors was also presented. It was found that the estimation function is highly consistent with the measurements for the wave velocity behaviors through unsaturated soil slope in the presented test conditions. In addition, the effects of the rainfall duration/initial water content, density, slope angle and surface layer thickness on the decrease rate of the normalized wave velocity with the volumetric water content and the tilt angle within the test conditions in this study were seen to be small. 相似文献
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