筒型基础在粉质黏土中的静压沉放试验研究

发布时间：2018-07-31 08:21

【摘要】：筒型基础是一种常见的海洋基础型式,其成功地沉放就位是正常使用的前提。故针对筒型基础,在均匀粉质黏土中开展了不同长径比的模型静压沉放试验,得到了筒型基础在静压沉放过程中的筒端和筒壁内外压力的变化情况。试验结果表明:筒内压力呈双折线形式,筒外压力线性增加,筒壁的侧向挤压是产生筒内压力的主要原因,筒内的挤土效应明显高于筒外;筒外的挤土程度为上部小,下部大,并与土塞增长率IFR成线性关系;筒端阻力与土的强度直接相关。根据规范,基于不排水剪强度和静力触探(CPT)可较准确的计算筒侧阻力和端阻力,由于挤土效应的差异,计算筒内阻力时的?、kf要取较大值。在基础沉放过程中主要阻力由端阻转变为侧阻,静压阻力和土塞的发展对0.1~0.2 cm/s之间的下沉速度不敏感,长径比L/D在1~2间的筒型基础的挤土效应和阻力特性是相近的。
[Abstract]:Cylindrical foundation is a common type of ocean foundation, and its successful placement is the premise of normal use. In view of the cylindrical foundation, the static pressure sinking test of different aspect ratio model was carried out in homogeneous silty clay, and the pressure change of cylinder end and cylinder wall during static pressure settlement was obtained. The test results show that the pressure inside the tube is in the form of double broken lines, the pressure outside the tube increases linearly, the lateral extrusion of the wall of the cylinder is the main cause of the pressure in the tube, the squeezing effect in the tube is obviously higher than that outside the tube, and the degree of soil compaction outside the tube is small in the upper part and large in the lower part of the tube. It has a linear relationship with the growth rate of soil plug (IFR), and the resistance at the end of the tube is directly related to the strength of the soil. According to the code, based on the undrained shear strength and static penetration (CPT), the cylinder side resistance and the end resistance can be calculated more accurately. In the process of foundation sinking, the main resistance changes from end resistance to side resistance. The static pressure resistance and the development of soil plug are not sensitive to the subsidence velocity between 0.1 cm/s and 0.2 cm/s, and the compaction effect and resistance characteristics of cylindrical foundation with L- / D ratio between 1 and 2 are similar.
【作者单位】：天津大学水利工程仿真与安全国家重点试验室;天津大学建筑工程学院;
【基金】：国家创新研究群体科学基金(No.51321065) 高等学校学科创新引智计划资助(No.B14012) 国家国际科技合作专项资助(No.2012DFA70490) 天津市海洋经济创新发展区域示范专项(No.cxsf2014-15)~~
【分类号】：TU447;TU476

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