红黏土干湿循环裂隙发育规律及强度关系研究  

Study on crack development law and strength relationship of red clay under dry-wet cycle

作　　者：张重重 赵代尧 陈筠 杨永宇 陈泰徐 ZHANG Zhongzhong;ZHAO Daiyao;CHEN Jun;YANG Yongyu;CHEN Taixu(School of Resources and Environmental Engineering,Guizhou University,Guiyang 550025;Power China Guiyang Survey,Design and Research Institute,Guiyang 550081;School of Continuing Education,Guizhou Institute of Technology,Guiyang 550003;Guizhou Provincial Oil and Gas Exploration and Development Engineering Research Institute,Guiyang 550081)

机构地区：[1]贵州大学资源与环境工程学院,贵阳550025 [2]中国电建集团贵阳勘测设计研究院有限公司,贵阳550081 [3]贵州理工学院继续教育学院,贵阳550003 [4]贵州省油气勘查开发工程研究院,贵阳550081

出　　处：《土工基础》2024年第4期729-734,共6页Soil Engineering and Foundation

基　　金：贵州省科学技术基金委员会项目(黔科合基础[2019]1142号)。

摘　　要：研究了贵州原状与重塑红黏土在干湿循环作用下土体的裂隙发育规律与强度关系,通过干湿循环试验及直接剪切试验获取其力学指标,利用颗粒(孔隙)及裂隙图像识别与分析系统(PCAS)处理图像,对裂隙指标进行分析。结果发现:①原状土的裂隙发育程度较重塑土高;②随着循环次数的增加,原状土的表面裂隙率、裂隙条数、裂隙总长度存在着正相关,而重塑土裂隙发育随循环次数变化不大;③循环次数对破坏土样的整体性有影响,且存在循环次数拐点值(3~4次),说明干湿循环只在一定次数下,对土样裂隙发育产生影响,土样中的裂隙不会因循环次数的增加而增加。此外重塑红黏土力学性质较原状红黏土低,原状红黏土黏聚力随裂隙发育有所降低,重塑红黏土的黏聚力变化受裂隙发育影响较小;内摩擦角均出现了小幅度的增加。The relationship between the development of cracks and the strength of the original and the remolded red clay in Guizhou under the action of dry-wet cycles are studied in this paper.The mechanical indicators are obtained through dry-wet cycle tests and direct shear tests.The particles(pores)and fracture images are used to identify.The analysis system(PCAS)processes the image and analyzes the fracture index.The results show that:(1)the degree of fissure development of the undisturbed soil is higher than that of the remolded soil;(2)as the number of cycles increases,there is a positive correlation between the surface crack rate,the number of cracks,and the total length of fissures in undisturbed soil samples.The development of soil cracks does not change much with the number of cycles;(3)The number of cycles has an impact on the integrity of the damaged soil samples,and there is an inflection point value for the number of cycles(3-4 times),indicating that the dry-wet cycles only affect the soil under a certain number of times.The development of the sample fissures will have an impact,and the fissures in the soil sample will not increase due to the increase in the number of cycles.In addition,the mechanical properties of the reshaped red clay samples are lower than that of the original red clay.The cohesion of the original red clay decreases with the development of cracks,and the change of the cohesive force of the remolded red clay is less affected by the development of cracks.The angle of the internal friction all increased slightly.

关 键 词：红黏土 干湿循环 裂隙图像特征 抗剪强度 

分 类 号：TU411[建筑科学—岩土工程]