论文部分内容阅读
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。
The problem of large deformation of soil is a difficult point in marine geotechnical engineering research. Due to its large deformation gradient and complex flow mechanism, conventional geotechnical engineering analysis methods have obvious limitations in solving this problem. Therefore, analytical methods for solving large deformation problems of soils are studied in this paper, namely Strain Path Method (SPM) and Shallow Strain Path Method (SSPM). The calculation principles of these two methods are described in detail; based on large and small strain theory. The SSPM was used to analyze the flow mechanism and displacement law of the surrounding soil during the penetration process of the pile foundation under ideal soil conditions. Finally, the calculation results of SPM and SSPM were compared and analyzed to clarify the internal relationship between the two. Based on the large strain theory, the soil displacement field calculated by SSPM and Sagaseta have a good agreement, verifying the accuracy of the calculation results. The results show that the uplift occurs in the soil at the upper end of the pile, while the soil near the bottom of the pile has subsidence displacement. At the penetration depth, the soil sinking displacement reaches its maximum. In the radial position r/R = 3 (1 times the diameter of the pile wall), based on large and small strain theoretical calculations have good consistency. The research results are helpful to understand the large deformation characteristics of soil, and can also provide basic data for the verification of numerical results.