围压与含水率对冻结砂土破坏应变能密度影响特性研究

发布时间：2019-06-14 13:32

【摘要】：基于一系列不同围压、不同含水率条件下的冻结砂土的三轴压缩试验,在一个宽泛的含水率范围内,研究了围压与含水率对冻结砂土破坏应变能密度的影响特性。试验结果表明:含水率为30.6%的冻土试样容易发生塑性破坏,其他含水率的冻土试样容易发生脆性破坏。围压对破坏应变能密度的影响可以分为低围压阶段、中围压阶段、高围压阶段,并且含水率对临界围压有重要影响。含水率对破坏应变能密度的影响也可以分为两种类型:当围压较低时(50 k Pa),随着含水率的增大,破坏应变能密度有一个初始增加的阶段,在含水率约为30.6%时破坏应变能密度达到最大值600 k Pa,之后随着含水率的继续增大,破坏应变能密度转而减小,达到60 k Pa后含水率的进一步增大不再影响破坏应变能密度,即此时冻土的破坏应变能密度接近于冰的破坏应变能密度;当围压较高时(大于等于500 k Pa),与低围压阶段相比,破坏应变能密度没有初始增加的阶段。
[Abstract]:Based on a series of triaxial compression tests of frozen sand under different confining pressure and different moisture content, the effects of confining pressure and moisture content on the failure strain energy density of frozen sand are studied in a broad range of moisture content. The experimental results show that the frozen soil samples with moisture content of 30.6% are prone to plastic failure, and the other frozen soil samples with moisture content are prone to brittle failure. The effect of confining pressure on the failure strain energy density can be divided into low confining pressure stage, middle confining pressure stage and high confining pressure stage, and the moisture content has an important influence on the critical confining pressure. The effect of moisture content on failure strain energy density can also be divided into two types: when the confining pressure is low (50 k Pa), with the increase of moisture content, the failure strain energy density has an initial increase stage, when the moisture content is about 30.6%, the failure strain energy density reaches the maximum value of 600k Pa, and then decreases with the increase of moisture content. When the moisture content reaches 60 k Pa, the further increase of moisture content no longer affects the failure strain energy density, that is to say, the failure strain energy density of frozen soil is close to Yu Bing's failure strain energy density. When the confining pressure is high (greater than or equal to 500 k Pa), the failure strain energy density does not increase at the initial stage compared with the low confining pressure stage.
【作者单位】：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;
【基金】：国家重点基础研究发展计划(973)项目(No.2012CB026106) 国家自然科学基金(No.41571064,No.41630636) 冻土工程国家重点实验室自主课题(No.SKLFSE-ZT-07);冻土工程国家重点实验室开放基金(No.SKLFSE201605)~~
【分类号】：TU445

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