裂隙性膨胀土抗剪强度的试验研究  

Experimental Study on Shear Strength of Fissured Expansive Soil

作　　者：康文献 周进[2] 王玲玲[3] 张晓丽[2] 

机构地区：[1]河南卓越建设工程有限公司,河南郑州450016 [2]华北水利水电大学,河南郑州450045 [3]中国电建集团北京勘测设计研究院有限公司,北京100024

出　　处：《人民黄河》2016年第9期131-134,138,共5页Yellow River

基　　金：河南省科技创新人才计划项目(目(154100510006);河南省重点科技攻关项152102210111);新疆维吾尔自治区科技援疆项目(201491105);新疆维吾尔自治区高层次人才引进工程项目;华北水利水电大学研究生教育创新计划基金资助项目(YK2014-10)

摘　　要：裂隙赋予了膨胀土特殊的结构性,裂隙的存在破坏了土体的整体性,使土体强度试验及评价变得十分困难。以南水北调磁县段膨胀土为研究对象,通过直接快剪、反复直剪和"预切面"三轴试验,来研究裂隙对膨胀土体强度的影响规律以及裂隙面的强度特性。结果表明:无论是直接快剪、饱和快剪或是饱和固结快剪试验,得到的重塑样的抗剪强度均较原状样的有所减小,残余强度也相对减小;原状膨胀土的裂隙强度低于原状样的峰值强度,略高于残余强度;采用含有不同倾角的"预切面"三轴试验测得的土体抗剪强度随切面倾角增大出现先减后增的现象;裂隙面倾角近似等于(45°+φ/2)时,试样土体的强度主要由裂隙强度所控制。Fissures give expansive soil special structural, which destroys the integrity of the soil, so the expansive soil＇s strength test and evaluation become very difficult. In orxder to study fissures＇ impact on shear strength of expansive soil and the strength of crack surface, the paper conducted quick shear and “ Pre-section” triaxial tests on expansive soil in Cixian County of Hebei Province of South- to-North Water Diversion Project. Studies have shown that, whether quick shear, saturated quick shear, or saturated consolidated quick shear, the shear strength of remodeling comp decreases, comparing with undisturbed samples; residual strength also decreases relatively. Undisturbed expansive soil＇s fracture strength is lower than that of the peak strength of undisturbed samples, slightly higher than the residual strength; the soil shear strength measured by triaxial tests with different inclination section appears the phenomenon of first decreasing and then increasing with the inclination＇s increasing; when fracture surface＇s inclination is approximately equal to （ 45°＋ φ/ 2 ） , the soil strength is mainly controlled by fracture surface＇s strength.

关 键 词：裂隙 抗剪强度 预切面 倾角 膨胀土 

分 类 号：TU411[建筑科学—岩土工程] TV443[建筑科学—土工工程]