封闭系统中饱和冻结粘土冻胀率的解析解  

Analytic Solution to Frost Heaving Ratio of Saturated Clay under Closed System

作　　者：覃英宏[1] 韦国荣[1] 张建明[1] 郑波[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,兰州730000

出　　处：《科学技术与工程》2007年第19期5042-5045,共4页Science Technology and Engineering

基　　金：中国科学院寒区旱区环境与工程研究所知识创新工程项目(2004104);中国科学院知识创新工程重要方向项目(KZCX3-SW351);中国科学院知识创新工程重大项目(KZCX1-SW-04)资助

摘　　要：冻土冻胀变形是由于土样中的水变成冰,使得土样的孔隙受到法向冻胀力的作用,导致孔隙扩展,土体的冻胀率由孔隙的扩展长度和水变成冰的膨胀率决定。封闭系统中饱和冻结粘土冻胀过程中,孔隙受到冻胀力的作用使得孔隙长轴扩展、短轴膨胀,长轴尖端屈服,致使孔隙的面积增大。通过分析孔隙受到冻胀力的作用而扩展,借助小屈服假设求得冻胀量的解析解。对青藏高原北麓河白青粘土的实验表明,所求得的解析解与实验结果较好地吻合。The heaving metamorphose of frozen soil comes from the growth of soil cracks which suffer from heaving stress when water in the soil is frozen. Meanwhile ,growth length of crack and freezing rate determine the heaving rate of frozen soil. Since porosity subject to heaving stress when saturated clay is freezing, grows brachy-axis is expanded,and yield point appears in micro-axis tip of porosity. As a result,＇area of porosity dramatically aggrandizes. Resorting fracture mechanics to analyze the mechanism of crack growth and employing minimize yield assumption to deduce the critical length of crack growth ,the analytical solution of heaving rate of frozen soil is obtained. Finally,the experiment＇s result of white soil which was taken from Beiluhe Qinghai-Tibet plateau well inosculates with the analytical solution.

关 键 词：裂纹扩展率 冻胀率 屈服应力 临界孔隙长度 

分 类 号：P642.14[天文地球—工程地质学]