试样尺寸对击实黏土抗拉特性的影响研究  

Study on the Effect of Sample Size on the Tensile Properties of Compacted Clay

作　　者：凌会坤 王俊杰 黄诗渊 吕川 李林洁 LING Hui-kun;WANG Jun-jie;HUANG Shi-yuan;LÜChuan;LI Lin-jie(College of River and Ocean Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Department of International Application Technology,Yinbin University,Yibin 644000,Sichuan Province,China;College of Materials Science and Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Tuoan Construction Group Co.,Ltd,Yinbin 644000,Sichuan Province,China)

机构地区：[1]重庆交通大学河海学院,重庆400074 [2]宜宾学院国际应用技术学部,四川宜宾644000 [3]重庆交通大学材料科学与工程学院,重庆400074 [4]拓安建设集团有限责任公司,四川宜宾644000

出　　处：《中国农村水利水电》2024年第8期144-149,159,共7页China Rural Water and Hydropower

基　　金：重庆市自然科学基金创新发展联合基金(市教委)A类项目(CSTB2022NSCQ-LZX0049);重庆市研究生联合培养基地建设项目(JDLHPYJD2018001);国家自然科学基金项目(52109113);重庆市自然科学基金面上项目(cstc2021jcyj-msxmX1114)。

摘　　要：为探究尺寸效应对黏土抗拉特性的影响机制,开展土梁三点弯拉试验,结合数字图像相关(DIC)技术,从宏观和细观角度分析了几何相似和非几何相似(试样高度h、厚度b变化)条件下击实黏土梁的拉裂破坏过程。结果表明:几何相似和非几何相似试样的尺寸增大,均会提升试样的峰值荷载。土体抗拉强度σ_(t)受尺寸效应影响显著,几何相似土梁σ_(t)随试样尺寸增大呈线性递减趋势;仅增大土梁h时,σ_(t)先增长后下降,仅改变土梁b时,σ_(t)随b增大呈先降后增的走势,其中b的变化对σ_(t)的影响更小;引入细观评价指标—局部应变度ε_(a),得出几何相似试样的ε_(a)随尺寸增大而增大,非几何相似试样的ε_(a)随试样h或b的增大呈现先增后降的规律。This study has carried out the three-point bending test with the digital image correlation technology(DIC)to explore the mechanism of size effect on the tensile properties of clay,and the tensile crack failure process of compacted clay beam under the condition of geometric similarity and non-geometric similarity(the change of sample height h,thickness b)is analyzed from macro and micro perspective.The results showed that:The increasing of the size of geometrically similar and non-geometrically similar specimens prompted the increasing of the peak load of the specimens.The tensile strength σ_(t) of soil is significantly affected by the size effect andσ_(t) of geometrically similar soil beam linear decreases with the increase of sample size.When only increasing the soil beam h,σ_(t) increases at first and then decreases.When the soil beam b is changed,σ_(t) decreases first and then increases with the increase of b,in which the change of b has less influence onσ_(t).By introducing the meso-evaluation index:Local strain degreeε_(a),it is concluded that theε_(a) of geometrically similar specimens increased with the increase of size,while theε_(a) of non-geometrically similar samples increased at first and then decreased with the increasing of h or b.

关 键 词：击实黏土 抗拉强度 尺寸效应 三点弯拉 DIC 

分 类 号：TU452[建筑科学—岩土工程]