不同应力水平下结构性黏土动力特性试验与研究.pdfVIP

第十一届土力学及岩土工程学术会议 中国·兰州 2011 年 8 月 16—19 日 不同应力水平下结构性黏土动力特性试验研究* 1,2 1 1 雷华阳 刘景锦 霍海峰 （1.天津大学 土木工程系，天津 300072；2.滨海土木工程结构与安全教育部重点实验室（天津大学）， 天津 300072） 摘要：为探讨天津滨海地区典型结构性软黏土的动力变形特性，进行了压缩试验和不同固结应力下的 循环三轴试验，结果表明：结构性软黏土的静力变形特性以先期固结应力和结构屈服应力为分界点， 可分为 3个阶段。不同固结应力下的动应变-振次关系曲线上存在着一个临界动应力比，且该值并非一 个定值，而是随着围压的增大而降低。同时，孔隙水压力的变化以结构屈服应力为转折点呈现出不同 的变化规律。当振动频率为 2Hz时，固结应力的改变对轴向动应变的影响不明显。 关键词：应力水平；结构性；黏土；动力变形特性；试验研究 中图分类号：TU 443 文献标识码：A 文章编号： Experimental study on dynamic properties of structural soft clay with different stress level 1,2 1 1 Lei Hua-yang , LIU Jing-jin , HUO Haifeng (1.Department of Civil Engineering, Tianjin University, Tianjin 300072, China; 2.Key Laboratory of Coast Civil Structure Safety (Tianjin University), Ministry of Education, Tianjin 300072, China) Abstract: A series of compression test and cyclic triaxial shear tests under different consolidation stress were performed on typical structural soft soil of Tianjin, which reveals the law of cyclic deformation under dynamic loading. The results show that the static deformation of structural soft clay is divided into three parts by preconsolidation stress and structural yield stress. Curves of cyclic strain vs. cycle number under different consolidation stress have a critical dynamic stress ratio which is not a fixed value, it reduces as the pressure increases. At the same time, the changes of pore water pressure show a different variation law with the structural yield stress as a turning point. When vibrating frequency