土样厚度对橡胶加筋膨胀土裂缝演化规律的影响研究  

INFLUENCE OF SOIL SAMPLE THICKNESS ON CRACK EVOLUTION LAW OF RUBBER-REINFORCED EXPANSIVE SOIL

作　　者：吕建航 杨忠年[1] 时伟[1] 路钊驰 张琦[1] 凌贤长 Lü Jianhang;YANG Zhongnian;SHI Wei;LU Zhaochi;ZHANG Qi;LING Xianzhang(Qingdao University of Technology,Qingdao 266000,China;Harbin Institute of Technology,Harbin 150000,China)

机构地区：[1]青岛理工大学,中国青岛266000 [2]哈尔滨工业大学,中国哈尔滨150000

出　　处：《工程地质学报》2022年第4期1140-1147,共8页Journal of Engineering Geology

基　　金：冻土工程国家重点实验室开放基金项目(资助号:SKLFSE201601);山东省泰山学者专项基金(资助号:2015-212);国家重大科研仪器开放基金项目(资助号:41627801)。

摘　　要：膨胀土具有多裂缝性的不良工程特性,对边坡等膨胀土地区工程具有潜在威胁。再生橡胶加筋膨胀土(ESR)对膨胀土动力、静力以及胀缩性有良好的改良效果。膨胀土的裂缝演化形态会受到土样厚度的影响,本文使用橡胶加筋膨胀土,对照素膨胀土探究橡胶粉末对膨胀土裂缝演化的影响与ESR裂缝的厚度效应。试验共设计未添加橡胶素膨胀土与ESR各4组不同厚度试样展开研究,结果如下:(1)膨胀土自然干燥过程含水率可分为3阶段变化,ESR的含水率变化更为迅速;(2)膨胀土的开裂过程存在明显厚度效应,ESR的厚度效应相较更不明显,裂缝演化更具有均匀性;(3)膨胀土开裂过程中的裂缝总长度与总面积受厚度效应影响严重,橡胶加筋可以约束膨胀土裂缝长度与面积并减少不同厚度样品间差值;(4)膨胀土裂缝发育的分形维数最终在1.4~1.5之间,不同厚度橡胶加筋膨胀土的分形维数变化更为接近。Expansive soil is multi-cracked and has unfavorable engineering characteristics,which poses a potential threat to projects in expansive soil areas such as slopes.Regenerated rubber reinforced expansive soil(ESR)has good improvement effect on dynamic,static and expansion characteristics of expansive soil.The crack evolution pattern of expansive soil can be affected by the thickness of soil sample.In this paper,rubber-reinforced expansive soil is used to explore the effect of rubber powder on crack evolution of expansive soil and thickness effect of ESR crack.Four groups of samples with different thicknesses without adding rubber expansive soil and ESR are designed for the test.The results are as follows:(1)Water content of expansive soil during natural drying can be divided into three stages.The change of water content of ESR is more rapid.(2)There is obvious thickness effect in the cracking process of expansive soil.But the thickness effect of ESR is less obvious and the crack evolution is more uniform.(3)The total length and total area of cracks during cracking of expansive soils are seriously affected by thickness effect.Rubber reinforcement can restrain the length and area of cracks in expansive soils and reduce the difference between samples of different thicknesses.(4)The fractal dimension of crack development of expansive soil eventually ranges from 1.4 to 1.5.The change of fractal dimension of rubber-reinforced expansive soil with different thicknesses is closer.

关 键 词：膨胀土 橡胶加筋 裂缝演化 厚度效应 分形维数 

分 类 号：P642.3[天文地球—工程地质学]