地基承载力计算的一种新方法     

张钦喜  李继红 《岩土工程技术》2010,24(4):166-170

通过假定地基整体失稳时的滑动面为一通过基础边缘的圆弧,运用极限平衡方法,建立了新的条形基础下地基极限承载力的计算公式,并与现有的几种地基承载力计算方法进行了比较分析,提出的方法比经典的理论公式结果合理,并与现行常用方法结果甚为接近,表明提出的新方法是合理和具有工程实用价值的。  相似文献   

均质地基上浅埋矩形基础极限承载力上限分析     

栾茂田  张其一  杨庆  王志云 《海洋工程》2008,26(2):69-77

基于土体塑性极限分析理论,推导一般黏性土地基上矩形基础承载力的上限解。为了证实上限解的合理性与适用性,采用大型通用有限元分析软件ABAQUS进行数值分析,并分别与Vesic理论解和Salgado et al理论解进行了对比。结果表明,推导的三维矩形基础上限解能较好地计算黏性土地基的极限承载力。  相似文献   

按单桩极限承载力设计复合桩基方法的可靠度分析   总被引：6，自引：1，他引：6  

宰金珉  陆舟  黄广龙 《岩土力学》2004,25(9):1483-1486

从按单桩极限承载力设计复合桩基的总安全度方法出发，运用可靠度理论，结合工程实例，建立了用该法确定的承载力极限状态方程，进行了可靠度分析与验证。对抗力及各基本变量的敏感性、设计参数不同组合时的安全系数与可靠度指标的关系进行了全面的分析，研究了天然地基承载力满足率ψ的合理取值范围，证实了天然地基满足率ψ≥0.5的必要性。  相似文献   

上海湖沼平原浅层硬土对单桩承载力的影响     

郭连江  陈锦剑  王建华 《岩土力学》2004,25(Z2):174-177

从现有计算单桩承载力的方法出发,结合工程实践分析上海湖沼平原地区浅层硬土对预制短桩承载力的影响.上海泻湖沼泽平原地区的地基土层次分布与上海市区滨海平原有较大差别,存在较厚的浅部硬塑态粉质粘土和中密性砂质粉土层(称为浅层硬土),该层土具有压缩性低、承载力高的特点.通过现场静载荷试验比较了按现行规范计算单桩承载力和实测结果的差异,分析了浅层硬土中预制短桩的极限侧摩阻力,讨论了侧摩阻力和静力触探比贯入阻力的关系,所得研究结果可为今后相关场地的类似工程建设提供参考.  相似文献   

Flexural deformation capacity of rectangular RC columns determined by the CAE method     

Iztok Peru&#x;  Karmen Poljan&#x;ek  Peter Fajfar 《地震工程与结构动力学》2006,35(12):1453-1470

A non‐parametric empirical approach, called the conditional average estimator (CAE) method, has been implemented for the estimation of the flexural deformation capacity of reinforced concrete rectangular columns expressed in terms of the ultimate (‘near collapse’) drift. Two databases (PEER and Fardis), which represent subsets of the original databases, were used. Four input parameters were employed in the basic model: axial load index, index related to confinement, shear span index, and concrete compressive strength. The results of analyses suggest that, in general, ultimate drift decreases with increasing axial load index, and increases with better confinement. An increase in the shear span‐to‐depth ratio has a beneficial effect until a turning point is reached. After that the opposite trend can be observed, i.e. a decrease in the ultimate drift with further increasing of the shear span‐to‐depth ratio. No clear trend is observed in the case of concrete compressive strength. The predictions, obtained by using the Fardis database are in general somewhat larger than the predictions from the PEER database, due to the difference in the definition of ultimate drift. The scatter of results is large. The local coefficient of variation, which is a measure for dispersion, amounts to about 0.2–0.5. The ultimate drifts obtained by using the two databases, were compared with the values predicted by the Eurocode 8 empirical formula. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

非均质地基承载力及破坏模式的FLAC数值分析   总被引：3，自引：0，他引：3  

赵少飞  栾茂田  范庆来  吕爱钟  袁凡凡 《岩土力学》2006,27(11):1909-1914

利用基于Lagrangian显式差分的FLAC算法，通过数值计算，对黏结力随深度线性增长的非均质地基上条形基础和圆形基础的极限承载力及地基破坏模式进行了对比计算与系统分析。研究表明：（1）随着地基黏结力沿深度非均匀变化系数的增大，地基的破坏范围逐渐集中在地基表层和基础两侧：（2）即使地基的非均质程度较小，当将非均质地基近似地按均质地基考虑时，由此所估算的承载力可能过于保守；（3）地基承载力系数随黏结力沿深度非均匀变化系数的增大而非线性地增大。与数值解相比，skempton与Peck等近似公式均可能高估了非均质地基承载力。  相似文献   

固底管桩单桩承载力的研究     

李连营  白牧  赵志峰 《岩土工程技术》2006,20(4):163-165,169

通过现场对预应力管桩底部采用高压旋喷法进行加固这一新的施工工艺试验,探讨预应力管桩桩端为水泥土情况下的受力机理及提高管桩端阻力和单桩极限承载力的效果,并探讨其在天津地区的适用性。  相似文献   

Charts for probabilistic design of strip footings in cohesionless soils     

I.A. Basheer  Y.M. Najjar 《Geotechnical and Geological Engineering》1998,16(1):1-16

Design charts that enable quick determination of the probability distribution parameters related to the ultimate bearing capacity of shallow foundations resting on (c = 0) soils are developed. These charts are intended to assist foundation designers and analysts in studying the reliability of structures as related to the capacity of the foundation system. The approach presented herein provides a more reliable alternative to foundation design and analysis than the current conventional design procedure which employs the assumption of an appropriate factor-of-safety. © Rapid Science Ltd. 1998  相似文献   

Laboratory model tests for cyclic load-induced settlement of a strip foundation on a clayey soil     

B. M. Das  E. C. Shin 《Geotechnical and Geological Engineering》1996,14(3):213-225

Laboratory model test results are presented for the cyclic load-induced settlement of a strip foundation supported by a saturated clayey soil. In performing the tests, the foundation was initially subjected to an allowable static load, after which a cyclic load with a frequency of one cycle per second was superimposed on it. The magnitudes of the static load and the amplitude of the cyclic load were varied. Based on the model test results, relationships for the foundation settlement and intensities of the static and cyclic loads are presented.  相似文献   

嵌岩桩静载试验结果的研究与讨论   总被引：13，自引：2，他引：13  

吕福庆  姬晓辉 《岩土力学》1996,17(1):84-96

根据１９个工程７１根嵌岩桩静载试验的实测资料，论述了嵌岩桩静载试验结果的特点，对Ｐ－Ｓ曲线进行了分区；提出了嵌岩桩质量分类体系表；研究了嵌岩桩的变形与破坏特点，并对破坏类型作了划分；同时，还讨论了嵌岩深度和嵌固力的测定。  相似文献