共查询到18条相似文献，搜索用时 93 毫秒
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《东北石油大学学报》2020,(4)
为研究矩形钢管混凝土翼缘的H型蜂窝组合柱(STHCC)的偏压力学性能,以偏心距、长细比、翼缘钢管厚度及核心混凝土立方体抗压强度为主要控制参数,设计17根STHCC中长柱试件。基于考虑套箍效应的混凝土本构模型和简化的钢材模型,利用有限元软件ABAQUS建立8根STHCC和2根方钢管混凝土柱的有限元模型并开展轴压和偏压分析,获得试件的荷载-位移曲线,与已有试验数据对比,二者吻合较好,验证有限元建模的合理性。同时,对17根STHCC中长柱试件进行扩展参数分析,考察不同参数对中长柱偏压极限承载力的影响规律,获得跨中截面沿高度应变分布曲线和荷载-挠度曲线。结果表明:偏压作用下,STHCC中长柱截面应变变化基本符合平截面假定;随偏心距和长细比的增大,STHCC中长柱偏压的极限承载力逐渐降低,而随核心混凝土强度和翼缘钢管厚度的增大,STHCC中长柱偏压的极限承载力逐渐增大,提高核心混凝土强度和钢管厚度可有效提高组合柱的偏压极限承载能力。统计回归该类组合中长柱偏压极限承载力计算表达式,为进一步开展该类组合柱抗震性能研究奠定基础。 相似文献
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以GFRP管直径、管厚度、纤维缠绕层数和角度,以及长细比、活性粉末混凝土(RPC)抗压强度、型钢截面面积、型钢屈服强度为主要参数,设计25根足尺GRS组合短柱试件;基于钢材的双线性本构模型和考虑RPC约束效应的非线性本构模型,采用ABAQUS有限元软件,对25根足尺GRS组合短柱进行数值模拟分析,分别提取荷载—位移曲线和轴压承载力,分析不同参数对试件轴压承载力和极限位移的影响规律;采用1stOpt软件统计回归足尺GRS组合短柱轴压承载力计算公式.结果表明:随试件的GFRP管直径和管厚度、纤维缠绕层数和角度、型钢屈服强度和截面面积、活性粉末混凝土抗压强度增加,试件轴压承载力显著提高;随试件的GFRP管厚度、纤维缠绕层数和角度、长细比和工字型钢截面面积增加,试件极限位移明显增大;随试件的GFRP管直径增加,试件极限位移逐渐减小.试件表现很好的持荷能力,呈连续鼓曲的破坏形态. 相似文献
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为了研究软岩地基桥桩的荷载传递性状、破坏机理,并获取在该地质条件下更为可靠的桩基计算参数,对秦巴山区软岩地基3根钻孔灌注试桩进行竖向静载试验.结果表明:秦巴山区软岩地基桥桩试桩荷载沉降曲线呈陡降型,实测竖向极限承载力为20500kN,桩的破坏方式为桩身材料强度破坏;淤泥质亚黏土地层中的碎石起到一定的骨架作用,增强了此地层桩极限侧阻力,发挥极限侧阻力所需的桩土(岩)相对位移为4~8mm;强风化砾岩表现为加工软化型,发挥极限侧阻力所需的桩土(岩)相对位移为3~8mm;中风化砂砾岩表现为明显的加工硬化型,所需的桩岩相对位移大,且桩极限侧阻力的特征点不明显;淤泥质亚黏土地层桩侧阻力占总荷载的60%~70%,随着桩顶荷载的逐步加大,该地层桩侧阻力所占比例不断下降,而嵌岩段桩侧阻力所占比例逐渐上升,达到55%~65%,嵌岩段桩侧阻力沿桩深的分布曲线表现出非线性的特征;试桩为端承摩擦桩,桩端阻力约占桩顶荷载的20%左右,且未充分发挥,在上部结构允许的沉降范围内,适当增加桩端的沉降有利于端阻力的发挥;桩侧阻力先于端阻力发挥,建议单桩承载力设计时分别采用不同的端阻力和侧阻力安全系数. 相似文献
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欧名星 《国土资源导刊(湖南)》2003,22(2):139-142
根据当地工程地质条件,结合工程结构特点和当地施工技术水平,高层建筑软弱地基采用刚性桩和褥垫层处理,形成复合地基,是一种安全、经济的方法,施工难度小,能充分发挥桩和桩间土的承载力.本文分析了刚性桩桩顶设置粒状材料褥垫层后的桩土变形协调原理,桩和桩间土共同承载荷载的受力机制,复合地基的承载力设计和变形计算方法.提出了复合地基的桩和褥垫层施工质量要求. 相似文献
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桩基检测有两个主要目的：一是确定单桩的承载力；二是对桩体的质量（桩体尺寸及桩的完整性等）进行检测，以便对有缺陷的桩及时采取补救措施。 相似文献
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门玉明 《地球科学与环境学报》1996,(2)
本文应用塑性力学中的极限分析法原理，建立了滑动面为折线时的土坡稳定性极限分析公式。通过工程实例证明，该公式具有使用简便、可靠性强等优点。它对于评价斜坡的稳定性，合理地进行滑坡治理等，都具有实际意义。 相似文献
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近几年来，齐齐哈尔市楼房基础普遍应用钻孔压浆桩，该工艺很适合齐市地层情况，承载力高，施工效率高，是北方地区施工期短的优选桩型。由于应用广泛，很多施工队伍前来招标，所以施工质量就难免出现问题，根据多年的施工经验，浅谈一下钻孔压浆桩施工质量的保证措施。 相似文献
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大同--运城高速公路某软基复合地基检测结果分析 总被引：2，自引：2，他引：0
毛新虎 《地球科学与环境学报》2004,26(1):33-37
以山西大运高速公路某段软基处理为例,从挤密碎石桩的加固机理和破坏方式入手,通过对软基复合地基的原位测试结果分析,得出碎石桩不但提高了地基的承载力,增加了桩间土的强度,减少了地基沉降,而且消除或减轻了地基的液化,使复合地基承载力达到了设计要求,特别是为以后在高速公路修筑中的软基处理提供了参考资料. 相似文献
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In this paper, the finite element analysis software ABAQUS is used to analyze the ultimate bearing capacity of three-dimensional rectangular footing of marine structures. The deformation law and the failure mode of homogeneous seabed soil beneath the rectangular footing are analyzed in detail. According to the equivalent plastic strain of soil under rectangular footing, an allowable velocity field of homogeneous seabed soil is reasonably constructed. Based on the plastic limit analysis theory of soil mass and by using the Mohr-Coulomb yield criterion, an upper bound solution of the ultimate bearing capacity of three-dimensional rectangular footing on general homogeneous seabed soil is derived, and a correction factor of ultimate bearing capacity of three-dimensional rectangular footing is given. To verify the rationality and applicability of this theoretical solution, some numerical solutions are achieved using the general-purpose FEM analysis package ABAQUS, and comparisons are made among the derived upper bound solution, the solution of Vesic, and the solution of Salgado et al. The results indicate that the upper bound solution of the three-dimensional shallowly embedded rectangular footing proposed in this paper is accurate in calculating the bearing capacity of homogeneous seabed soil. For undrained saturated clay foundation and sandy foundation with smaller internal friction angle, this upper bound solution can evaluate the ultimate bearing capacity of rectangular footing; with the gradual increase of the internal friction angle of the soil, the ultimate bearing capacity of the proposed upper bound solution is slightly higher than that of the rectangular footing. 相似文献
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In the current theory of bridge foundation design,all of the loads above the cap are loaded by the pile,and the bearing capacity of the soil among piles is not taken into account.In order to analyze the bearing capacity of the soil among piles in bridge pile foundation,a model of pile foundation is established based on a bridge foundation which is under construction,and by the finite element analysis software ANSYS.According to the results of finite element analysis(FEA)and current bridge foundation design theory,a feasible composite pile foundation which can be applied in the design of bridge foundation,is recommended.Additionally,a number of modifications are made to the original design.It was confirmed that these modifications derived from numerical simulations can improve the performance of the foundation. 相似文献
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对于承受轴向荷载的水平受荷桩，以往研究大多基于线弹性或弹塑性水平荷载传递模型。为提升轴横受荷桩的计算设计水平，采用轴向荷载传递法计算桩身轴力，考虑桩身轴力引起的P-Δ效应，基于双曲线型水平荷载传递模型考虑桩-土体系变形的非线性特征，对成层土中轴横受荷桩的水平响应进行分析求解，得到了轴横荷载作用下桩身变形和内力的非线性有限差分解，并采用MATLAB语言编制了计算程序。使用模型试验算例与基于现场试验的有限元算例对非线性解的准确性进行对比验证，结果表明:计算结果与算例数据吻合良好，可靠性较高；采用不同荷载传递模型的计算结果在不同荷载水平下有所差异，在较大荷载水平下桩-土变形的非线性特点不容忽视。 相似文献
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The pressure grouting pile of driven tube can improve the load bearing capacity of the single pile from the mechanism of pressure grouting pile of driven tube. On the basis of analyzing the mechanism, the authors designed the machines and tools of pressure grouting, determined the operating manufacture and technology parameter on the pressure grouting secondly. The result shows that the pressure grouting pile of driven tube not only changes the pile type but also reduce the length of the pile and its engineering cost, it enhances the load bearing capacity of single pile an the same time. 相似文献
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Dianqi PAN Zupei ZHANG Diancai PAN Yong CHEN Maosen TAN 《东北亚地学研究》2006,9(2):194-196
The pressure grouting pile of driven tube can improve the load bearing capacity of the single pile from the mechanism of pressure grouting pile of driven tube.On the basis of analyzing the mechanism,the authors designed the machines and tools of pressure grouting,determined the operating manufacture and technology parameter on the pressure grouting secondly.The result shows that the pressure grouting pile of driven tube not only changes the pile type but also reduce the length of the pile and its engineering cost,it enhances the load bearing capacity of single pile an the same time. 相似文献
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This paper aims to present a theoretical method to study the bearing performance of vertically loaded large-diameter pipe pile groups. The interactions between group piles result in different bearing performance of both a single pile and pile groups. Considering the pile group effect and the skin friction from both outer and inner soils, an analytical solution is developed to calculate the settlement and axial force in large-diameter pipe pile groups. The analytical solution was verified by centrifuge and field testing results. An extensive parametric analysis was performed to study the bearing performance of the pipe pile groups. The results reveal that the axial forces in group piles are not the same. The larger the distance from central pile, the larger the axial force. The axial force in the central pile is the smallest, while that in corner piles is the largest. The axial force on the top of the corner piles decreases while that in the central pile increases with increasing of pile spacing and decreasing of pile length. The axial force in side piles varies little with the variations of pile spacing, pile length, and shear modulus of the soil and is approximately equal to the average load shared by one pile. For a pile group, the larger the pile length is, the larger the influence radius is. As a result, the pile group effect is more apparent for a larger pile length. The settlement of pile groups decreases with increasing of the pile number in the group and the shear modulus of the underlying soil. 相似文献
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文章通过钻孔灌注桩施工方法对土的承载力影响的分析，提出了解决影响承载力的方法和措施，对提高施工质量进行了有益的探讨。 相似文献