Post-cyclic strength degradation behavior of soft clay under anisotropic consolidation and numerical simulation
WANG Yuan-zhan1, LEI Ji-chao1, LI Qing-mei1, HU Shen-rong2
1. National Key Laboratory of Water Conservancy Engineering Simulation and Security, Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Tianjin University, Tianjin 300072, China; 2. CCCC First Harbor Engineering Design Institute Co., Ltd., Tianjin 300222, China
Abstract：Under the action of cyclic loading of waves, the strength degradation of the soft clay beneath the offshore structures will take place, which will weaken the stability of the upper structure. A series of triaxial tests on silty clay of Yantai Port are carried out to investigate the strength degradation of the soft clay under different anisotropic consolidation stress ratios and different cyclic stress ratios. The behavior of post-cyclic undrained effective stress paths is also studied. Through the analysis of post-cyclic undrained effective stress paths, it is discovered that once the cyclic stress ratio is over 0.4, the trend of strength degradation of soils will accelerate, the critical effective stress ratio M will decrease and there will be some damage of the structure of the clay. The mechanism of strength degradation of clay is discussed. Furthermore, based on the equivalent super consolidation theory, a formula is proposed for the calculation of post-cyclic strength degradation of soils considering the increase of the initial effective stress induced by anisotropic consolidation. The formula is verified by the test results. Finally, through the secondary development of ABAQUS, it is applied to the numerical model of a breakwater in Yantai Port using the quasi-static method.
王元战, 雷继超, 李青美, 胡珅榕. 偏压固结下软黏土循环强度弱化分析及数值模拟[J]. 岩土工程学报, 2017, 39(9): 1557-1564.
WANG Yuan-zhan, LEI Ji-chao, LI Qing-mei, HU Shen-rong. Post-cyclic strength degradation behavior of soft clay under anisotropic consolidation and numerical simulation. Chinese J. Geot. Eng., 2017, 39(9): 1557-1564.
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