结构性土强度准则探讨  

INVESTAGATION ON STRENGTH CRITERION FOR THE STRUCTURED SOILS

作　　者：刘恩龙[1] 沈珠江[1] 

机构地区：[1]清华大学水利水电工程系,北京100084

出　　处：《工程力学》2007年第2期50-55,共6页Engineering Mechanics

基　　金：国家自然科学基金资助项目(50479007)

摘　　要：基于岩土二元介质模型思想,建议了一个适用于结构性土的强度准则。结构性土的土工特性与重塑土的有很大的区别,强度变化规律方面也不例外。已有的强度准则是建立在重塑土或扰动土的基础上的,它们不能很好的反映结构性土的强度变化规律。在大量的结构性土强度试验资料的基础上,分析了结构性土的强度变化规律和机理,基于考虑结构性岩土材料破损机理的二元介质模型概念,通过引入随应力状态变化的剪切抗力分担率参数,建立了结构性土的强度准则,并对准则中参数的变化对强度规律的影响进行了分析。最后,通过两种结构性土Lacustrine clay和Louis clay的固结不排水强度试验进行了验证,验证表明所建议的准则具有较好的适用性。Based on the concept of geo-binary medium model, a strength criterion for structured soils is proposed in the paper. The geotechnical characteristics of structured soils and remoulded soils are distinct in many aspects, without the exception of strength evolution rules. The strength criterions established already are formulated on the basis of the properties of reconstituted or remoulded soils, which can not reflect the influence of soil structures （bonding and fabric） on the properties of structured soils. After the strength evolution rules and mechanisms of structured soils analyzed through the many strength tests on the structured soils, the strength criterion for structured soils can be established by means of the concept of geo-binary medium model considering the breakage mechanism of geomaterials. The parameter of shear resistance share ratio is introduced and the determination of the parameter is also presented. By making comparisons between the data predicted by the criterion and the experimental data from two structured soils, Lacustrine clay and Louis clay, it is demonstrated that the new strength criterion provides satisfactory qualitative and quantitative modeling of the shear strength features of structured soils.

关 键 词：岩土工程 强度准则 二元介质模型 结构性土 剪切抗力分担率 

分 类 号：O346[理学—固体力学] TU43[理学—力学]