振动荷载作用下软土加速蠕变的微观机制研究  

Research on microscopic mechanism of accelerated creep of soft clay under vibration loads

作　　者：雷华阳[1,2] 卢海滨[1] 王学超 李宾[1] 任倩[1] LEI Hua-yang LU Hai-bin WANG Xue-chao LI Bin REN Qian(School of Civil Engineering, Tianjin University, Tianjin 300072, China Key Laboratory of Coast Civil Structure Safety of Ministry of Education, Tianjin University, Tianjin 300072, China Baoli （Tianjin） Real Estate Development Co., Ltd., Tianjin 300022, China)

机构地区：[1]天津大学土木工程系,天津300072 [2]天津大学滨海土木工程结构与安全教育部重点实验室,天津300072 [3]保利(天津)房地产开发有限公司,天津300022

出　　处：《岩土力学》2017年第2期309-316,324,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51378344);天津市应用基础与前沿技术研究计划项目(No.14JCYBJC21700);天津市科技兴海项目(No.KJXH2013-15)~~

摘　　要：研究软土加速蠕变过程中的微观结构变化可深入了解加速蠕变特性的内在机制。在对天津滨海地区软土进行多种条件下的三轴蠕变试验的基础上,利用微观定量化技术,对比静、动荷载蠕变条件下土样的微观结构,从微观角度对加速蠕变机制进行了解释。研究表明,土样产生加速蠕变后,结构单元体的丰度和复杂度降低;结构单元体形状趋向扁圆形,边缘趋于圆滑;土体颗粒在自然状态下无明显定向性,加速蠕变后其定向性显著增强。振动荷载使得蠕变程度增大,也使得土体蠕变的速率加快。研究结果揭示了土体的加速蠕变实际上是在动荷载作用下土体的内部结构不断自我调整再造的过程。Through researching variation of soft clay microstructure in accelerated creep condition, we can deeply understand internal mechanism of accelerated creep characteristics. According to the micro quantitative technology and triaxial creep test of a variety of conditions of soft clay in Tianjin area, comparison between microstructures of soil samples under static and dynamic loads is made for explaining creep mechanism from microcosm. Research shows that the abundance and complexity of the structure element reduce when the accelerated creep appears, and the shape of the structural unit body becomes oblate and tends to smooth edges. Soil particle has no obvious directional property under natural condition. The particle orientation enhances obviously after the accelerated creep. Vibration loads make the creep degree increase and the soil creep rate be accelerated. It reveals that the accelerated creep of soil mass is actually a self adjusting and reengineering process of the soil internal structure under dynamic loads.

关 键 词：软土 加速蠕变 孔隙 颗粒 微观结构 

分 类 号：TU447[建筑科学—岩土工程]