南宁外环膨胀土抗剪强度非线性特征及影响因素分析  

Analysis of Nonlinear Characteristics of Shear Strength of Nanning Expansive Soil and Its Influencing Factors

作　　者：肖杰[1] 杨和平[1] 王兴正 唐咸远[1] 

机构地区：[1]长沙理工大学交通运输工程学院,湖南长沙410004

出　　处：《中国公路学报》2014年第10期1-8,共8页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(50978035;51108049);交通运输部西部交通建设科技项目(2009 353 311 060);道路灾变防治及交通安全教育部工程研究中心开放基金项目(kfi090303);广西交通科技项目(2011-20)

摘　　要：以南宁外环膨胀土为对象,开展含低应力条件的不同干密度、不同初始含水率、无荷和有荷干湿循环作用重塑样、有荷干湿循环作用原状样的饱和慢剪以及重塑样饱和三轴固结排水试验,研究干密度、初始含水率、无荷和有荷干湿循环作用等因素对其低应力条件下抗剪强度的影响。结果表明:各抗剪强度包线均呈非线性特征,可用广义幂函数很好地拟合;低应力、干密度及初始含水率对饱和慢剪强度的影响显著;试件初始含水率相同时,干密度越大,强度越大;干密度相同时,初始含水率越大,强度也越大;随干湿循环次数的增加,无荷条件下土样的抗剪强度衰减强于有荷条件。To study the influences of dry density,initial water content and dry-wet cycles with or without loading on shear strength under low stress,with Nanning expansive soil as obj ect, saturated slow shear tests were conducted on remoulded samples of various dry densities and initial water contents, and under dry-wet cycles with or without loading, and undisturbed samples under dry-wet cycles with loading.Saturated consolidated triaxial compression tests were conducted on remoulded samples.The results indicate that all shear strength failure envelopes are nonlinear,which can be fitted well by generalized power function.The saturated slow shear strength is greatly influenced by low stress,dry density and initial water content.The shear strength increases with the increase of dry density for the samples with the same initial water＆amp;nbsp;content.The shear strength increases with the increase of initial water content for the samples with the same dry density.The shear strength decreases greater for dry-wet cycles without loading than with loading,with the increase of dry-wet cycles.

关 键 词：道路工程 膨胀土 试验研究 抗剪强度 广义幂函数 非线性 

分 类 号：U416.167[交通运输工程—道路与铁道工程]