桩基贯入过程中土体大变形分析与流动机理研究

发布时间：2018-12-09 14:06

【摘要】：土体大变形问题是海洋岩土工程界研究的难点,由于其变形梯度较大、流动机理复杂等特点,常规的岩土工程分析方法在求解该问题时表现出明显的局限性。因此,该文研究了求解土体大变形问题的解析方法,即Strain Path Method(SPM)和Shallow Strain Path Method(SSPM),详细介绍了这两种方法的计算原理;并基于大、小应变理论,采用SSPM分析了理想土性条件下桩基础贯入过程中周围土体的流动机理和位移场变化规律;最后,将SPM和SSPM计算结果进行比较分析,阐明了两者之间的内在关系。基于大应变理论,采用SSPM计算得到的土体位移场与Sagaseta给出的结果具有较好的一致性,验证了计算结果的准确性。研究结果显示桩端上部土体会发生隆起现象,而桩端附近及底部土体具有下沉的位移,且在贯入深度位置处,土体下沉位移达到最大值。在径向位置r/R=3(距桩壁1倍直径)处,基于大、小应变理论计算结果具有较好的一致性。研究成果有助于了解土体的大变形特性,也可为数值计算结果的校验提供基本数据。
[Abstract]:The problem of large soil deformation is a difficult problem in marine geotechnical engineering. Because of its large deformation gradient and complex flow mechanism, the conventional geotechnical engineering analysis method has obvious limitations in solving this problem. Therefore, this paper studies the analytical method for solving the problem of large deformation of soil, that is, Strain Path Method (SPM) and Shallow Strain Path Method (SSPM), introduce the calculation principle of these two methods in detail. Based on the theory of large strain and small strain, SSPM is used to analyze the flow mechanism and displacement field of soil around the pile foundation in the process of penetration. Finally, the results of SPM and SSPM are compared and analyzed, and the relationship between them is clarified. Based on the theory of large strain, the displacement field calculated by SSPM is in good agreement with the result given by Sagaseta, which verifies the accuracy of the calculated results. The results show that the uplift occurs in the upper part of the pile, and the displacement of the soil near the pile end and at the bottom of the pile has the subsidence displacement, and the maximum displacement of the soil is reached at the depth of penetration. At radial position r/R=3 (1 times diameter from pile wall), the calculation results based on the theory of large strain and small strain are in good agreement. The research results are helpful to understand the large deformation characteristics of soil and provide basic data for the verification of numerical results.
【作者单位】：中海油研究总院;中国科学院力学研究所;
【基金】：中国海洋石油总公司科技项目(ZHKY-2013-ZY-05) 中国博士后科学基金项目
【分类号】：TU473.1

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