黏土黏附力试验研究

发布时间：2018-01-31 23:47

  本文关键词： 黏土 组合吸盘 黏附力 拉拔速率 含水率　出处：《岩土力学》2017年05期 　论文类型：期刊论文

【摘要】：座落于黏土地基上的结构物在起浮或上拔过程中将受到地基对其的抗拉阻力。黏土对结构的黏附力是地基抗拉阻力的组成部分,其值的选取对地基抗拔承载力的确定有重要的影响。为了研究黏附力的发展规律和影响因素,改进了组合测盘,将内测盘底部和外界空气相通,从而消除孔隙水压力对黏附力的影响,并采用该测盘测量黏土在不同含水率、不同拉拔速率下的黏附力。试验结果表明,黏土对基础的拉拔应力随着基础拉拔位移的增加而线性增加,达到黏附力后将迅速消失。黏附力在含水率较小时为0,当土体的含水率超过塑限后黏附力开始增加,增加到峰值后下降,最后衰减到一个稳定值。相同拉拔速率下含水率变化时黏附力的峰值随拉拔速率的增加而增加,其对应的含水率随拉拔速率的增加而降低。相同含水率下,黏附力随拉拔速率的对数呈S型曲线变化。黏附力和土体不排水抗剪强度之间的比值随含水率的增加而增加。以上研究结果为深入理解黏附力变化规律并指导工程实践提供了依据。
[Abstract]:The structure located on the clay foundation will be subjected to the tensile resistance of the foundation during the process of floating or uplifting. The adhesion force of the clay to the structure is a part of the tensile resistance of the foundation. The selection of the value has an important impact on the determination of the uplift bearing capacity of the foundation. In order to study the law of the development of the adhesion force and the influencing factors, the combined test plate is improved, and the bottom of the inner test plate is connected with the outside air. Therefore, the influence of pore water pressure on adhesion force is eliminated, and the adhesion force of clay under different water content and different drawing rate is measured by using the plate. The drawing stress of clay to the foundation increases linearly with the increase of the drawing displacement of the foundation, and then disappears rapidly when the adhesion force is reached, and the adhesion force is 0 when the moisture content is small. When the soil moisture content exceeds the plastic limit, the adhesion force begins to increase, increases to the peak value and then decreases. The peak value of the adhesion force increases with the increase of the drawing rate, and the corresponding moisture content decreases with the increase of the drawing rate. The ratio between adhesion force and undrained shear strength of soil increases with the increase of moisture content. The above results are helpful to understand the change of adhesion force and guide the engineering. The practice of Cheng provides the basis.
【作者单位】： 天津大学建工学院岩土工程研究所;中水北方勘测设计研究有限责任公司;
【基金】：国家自然科学基金项目(No.41272323) 国家优秀青年科学基金项目(No.51322904)~~
【分类号】：TU41
【正文快照】： 大量的海洋工程结构物将承受上拔荷载,如何确定它们的地基抗拔承载力是工程设计、施工的关键。对于吸力锚、桶基、抗拔桩等工程,抗拔承载力是这些结构物稳定的重要保障;而对于自升式钻井平台、沉船打捞、拔桩等工程,抗拔承载力则是工程设计过程中需要克服的阻力。在抗拔承载力，

本文编号：1480321