共查询到19条相似文献，搜索用时 125 毫秒
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将已有的沉桩挤土变分理论解答应用于室内模拟压桩验证计算与分析。结果表明,理论计算与模型试验测试数据、数值计算结果吻合得较好,而桩土作用的变分解答和模拟压桩实测结果之间的主要误差是由扩张模型假设条件引起的。研究成果可以提高应用理论计算方法定量分析解决实际问题的能力,并提高压桩模拟试验设计水平。 相似文献
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《浙江大学学报(A卷英文版)》2020,(3)
目的:群桩基础在近海建/构筑物及桥梁中广泛应用,而风、浪、船舶撞击等在群桩基础中产生的水平和扭转荷载往往影响群桩基础的安全。本文旨在提出一套能够计算水平和扭转荷载联合作用下的群桩非线性响应简化分析方法。创新点:1.采用广义p乘子法考虑群桩中各桩水平变形导致的桩-土-桩相互作用;2.建立基于瞬时转动中心的基桩桩头位移关系和承台平衡方程。方法:1.通过理论分析给出基桩桩头位移之间的关系,建立承台平衡方程;2.采用荷载传递模型(p-y和τ-θ曲线)模拟桩周土体非线性响应;3.采用广义p乘子法考虑群桩中各桩水平变形导致的桩-土-桩相互作用,并采用耦合因子计算基桩中推-扭耦合响应;4.通过迭代方法求解各基桩p乘子和群桩响应。结论:1.多组算例均表明本文提出的群桩非线性分析模拟能够较准确地模拟群桩响应,尤其在承台位移较大的情况下;2.广义p乘子能够有效地模拟群桩效应的主要部分;3.模型中的简化公式能够应用于实际工程问题分析。 相似文献
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考虑水流等作用建立桩-承台固端连接的高承台桩基础力学模型,分析并列出模型的边界条件和连续性条件,对力学模型进行求解得到问题的解析解答。结合工程算例,对文中的解答进行工程应用验证,对高承台桩在水平荷载作用下的水平位移和基于上述解答桩体内力分布计算结果进行分析。 相似文献
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张新建 《五邑大学学报(社会科学版)》1988,(2)
本文采用模型桩进行了桩在几种水平荷载作用下桩的静力特性的试验研究,得到了桩身弯矩、桩头位移及土抗力系数等参数的一些变化规律。并进行了《m》法、《c》法及《k》法的计算比较,得出在砂土中《m》法稍优于其它两种方法。 相似文献
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苏慧 《连云港职业技术学院学报》2008,21(2)
利用弯曲理论设计钢管桩现场水平力测试方案,将测试方案应用于青岛海湾大桥桩的现场测试中,实测结果与计算吻合较好,得出在不同水平荷载作用下,桩身各截面弯矩、水平位移等关系曲线和数据。测试结果表明：最大弯矩发生在2～3倍桩径附近的桩身处,弯矩沿桩身向下呈非线性递减,所得结论对工程设计具有较好的参考价值。 相似文献
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采用三维数值方法,建立长短桩、变径桩双桩模型,通过大量的数值计算,分析桩顶荷载水平、桩距径比、不同桩长、桩端土模量比及不同桩径对相互作用系数的影响。分析表明,在线弹性变形阶段,桩-桩相互作用系数近似为恒定值,与桩顶荷载水平无关,进入塑性变形之后,则逐渐减小直至极限状态时趋于0;长短桩桩长比及桩端土模量比对短桩-长桩相互作用系数影响大,而对长桩-短桩相互作用系数影响小;变径桩相互作用系数仅与受荷桩桩径有关;并提出了针对长短桩、变径桩的简化计算公式,为实际工程提供参考。 相似文献
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胜利浅海小型采油平台和栈桥平台多采用独立桩支撑,由于受到风、海流、波浪及海冰的联合作用,平台的水平位移成为设计时必须重点考虑的因素.对独立桩的晃动研究是在P-y曲线法的基础上,应用有限元分析软件ANSYS,把桩周土体简化为作用在桩单元上的水平向非线性弹簧单元,模拟独立桩在水平荷载作用下的受力和变形,通过模型桩试验验证此方法的合理性和准确性,为研究海洋独立桩结构提供了一种计算方法. 相似文献
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本文采用弹塑性有限元方法对水平承载桩的受力状态进行了详细的分析,提出嵌岩深度、桩侧边长度对水平承载桩受力状态的影响,研究表明随着桩侧边长度的增大,水平抗力的扩散作用就越发明显;同时在一定的嵌岩深度范围内,随着嵌岩深度的增加,桩所能承受的水平荷载也随之增加。 相似文献
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根据挤扩支盘桩的受力机理,应用荷载传递理论和分层总和法计算沉降的概念,提出了一种多支盘不等支臂钻孔灌注桩基础沉降计算方法．并编制了相应的计算软件,计算值与实测结果吻合较好． 相似文献
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利用自主研制的大型土工试验装置,在考虑桩长和桩尖角度影响的情况下,开展了静压桩的沉桩以及静载荷试验,以研究试验过程中桩端阻力的变化规律。试验结果表明:沉桩过程中,桩端阻力随沉桩深度的增加而非线性增大,也随桩长和桩尖角度的增加而增大,沉桩深度为25D时,桩端阻力基本达到极值,同一沉桩深度处桩端阻力在沉桩阻力中的占比随桩长(20D~30D范围内)的增加而减小,随桩尖角度的增加而增大;静载荷试验过程中,桩端阻力随沉降量的增加而非线性增大,也随桩长和桩尖角度的增加而增大,同一沉降量处桩端阻力在桩顶荷载中的占比随桩长的增加而减小,随桩尖角度的增加而增大。 相似文献
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文章利用C 语言编制了ANSYS到FLAC的接口程序,模拟了砂土粘聚力、内摩擦角、标贯数、桩长细比、动荷载等因素对液化砂土中桩的弦振效应的影响,得出了相关的规律曲线及各因素影响的敏感曲线.研究结果表明,桩基弦振效应随砂土粘聚力、内摩擦角、标贯数、动荷载频率、桩弹性模量的增加而减小,随桩长细比、动荷栽振幅增加而增大. 相似文献
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Taper angle is one of the effective methods to reduce the dragload and downdrag of piles under the surcharge load. The model tests on the tapered pile and uniform cross-section pile embedded in sand were carried out under the surcharge load. The values of dragload and downdrag of piles versus the surcharge loads were measured. Based on the concentric cylinder shearing theory, a simplified theoretical model for calculating the dragload and downdrag of tapered piles with small taper angles under the surcharge load was proposed considering the angle effect. The correctness of the developed theoretical model was validated through comparing with the model test results obtained in this study and previous literature. Then the parametric studies of the taper angle, surcharge, strength and modulus of soil were discussed. It is shown that the tapered pile with the taper angle of 3° can reduce approximately 65% of the maximum dragload value and 30% of the downdrag value compared with a uniform cross-section pile. The value of downdrag can be decreased by approximately 50% compared with a uniform crosssection pile in the same average pile diameter. 相似文献
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The vertical vibration of a large diameter pile embedded in inhomogeneous soil with hysteretic type damping is investigated based on the 3D axisymmetric model. Firstly, the pile is assumed to be a Rayleigh-Love rod with the consideration of its transverse inertia effect. Following this assumption, the pile-soil system is divided into several segments according to the stratification of the surrounding soil, and the dynamic interactions of the adjacent soil layers are simulated using the distributed Voigt model. Meanwhile, the surrounding soil is discretized into finite annular vertical zones to consider its radial inhomogeneity, and the force equilibrium and displacement coordination are satisfied at the interfaces of the adjacent soil zones and the interface of the pile-soil. Then, the analytical solution in the frequency domain and the semi-analytical solution in the time domain are obtained by solving the vibration governing equations of pile-soil system. Based on the solutions, a parametric analysis is conducted to investigate the influence of the transverse inertia effect on the dynamic response of the large diameter pile and its relationship with the pile parameters and the radial inhomogeneity of the surrounding soil. Finally, a comparison with the measured result and two other calculated results is presented to verify the effectiveness of the present solution. 相似文献
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Dragload and Downdrag Performances of Inclined Pile Group Embedded in Consolidating Soil 总被引：1，自引：1，他引：0
The performance of inclined pile group embedded in consolidating soil under surcharge load was investigated by experiment in comparison with vertical pile group and single pile under the same conditions; dragload, downdrag, and layered soil settlement were measured. A three-dimensional numerical model was built via FLAC3D software, and verified by the experimental results. Influence factors, such as consolidation time, pile spacing, and pile tilt angle were analyzed. The results show that dragload of inclined pile group increases with the increase of consolidation time and pile spacing or the decrease of pile tilt angle. Downdrag of inclined pile group increases with the increase of consolidation time, pile spacing and pile tilt angle. 相似文献
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Reading is seen as a communication process, a meaningful interaction between the reader and his reading text. A number of factors are known to affect this interaction. One prominent factor is the type of text being read. That is, reader strategies may vary in relation to text characteristics. This study used miscue analysis to find out patterns of reader strategies on two types of texts: a syntactically complex and high vocabulary loaded text and a syntactically simple and low vocabulary loaded text. To this end, cloze tests of passages derived from two versions of a newspaper editorial completed by twenty undergraduate education students from the University of Jos were analysed. The results indicated that the readers of the difficult text had less access to semantic and syntactic cues than the readers of the simplified text. Readers for whom the difficult text was on frustration level made less use of context than did readers for whom the same text was on instructional level. There was very little difference in quality of miscues by readers of the simplified text reading on independent level as compared with those reading the same text on instructional level. Readers who performed on instructional level on the difficult passage used similar reading strategies to those who performed on instructional level on the simplified passage. The implications of the findings for reading instruction were discussed. 相似文献
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曾锦秀 《福建工程学院学报》2021,(6):548-544
基于上限法、平面刚架理论与弹性地基梁理论,对双排桩加固边坡中结构变形进行解析,通过数值模拟验证所提方法的合理性,研究了影响双排桩桩身位移的6 个因素。结果表明:当连系梁厚度/ 桩径小于0.7、嵌固段与受荷段长度之比小于0.8、桩径小于1.0 左右时,对桩身位移影响较大,且呈现出明显的非线性特征?桩身弹性模量对双排桩桩身位移同样具有较大影响,但表现出近似线性的特征。对于双排桩加固边坡,可适当增大连系梁厚度、嵌固段长度、桩径、桩身弹性模量或联合注浆改善桩周岩土体的力学性能。研究结果可为边坡中双排桩的设计提供参考。 相似文献
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严复的"信、达、雅"三难说对翻译标准进行了高度的概括。"信、达、雅"蕴涵着丰富的辩证法思想,"信"是最基本的,指译者要如实地表达原文的意思,"达"是指译文要顺畅,"雅"是指译文要有文采。"三难说"主次有序,既提出了"达"对"信"的制约,又提出了"雅"对"信"和"达"的影响,三者构成了一个统一的有机体。 相似文献