华南典型路基红黏土动力学特性动三轴试验分析  

Analysis of dynamic characteristics of subgrade red clays in Southern China using dynamic triaxial tests

作　　者：胡永强[1] 汤连生 林沛元 HU Yongqiang;TANG Liansheng;LIN Peiyuan(School of Civil Engineering,Guangzhou University,Guangzhou 510006,China;School of Earth Science and Engineering, Sun Yat-Sen University,Guangzhou 510275,China;Department of Civil Engineering,Ryerson University,Toronto M5B 2K3,Canada)

机构地区：[1]广州大学土木工程学院,广东广州510006 [2]中山大学地球科学与工程学院,广东广州510275 [3]Ryerson University土木工程系,加拿大多伦多M5B2K3

出　　处：《自然灾害学报》2018年第6期34-41,共8页Journal of Natural Disasters

基　　金：国家自然科学基金项目(40872205);广东省自然科学基金项目(07003738).

摘　　要：红黏土是华南地区典型的路基土类之一,其长期循环荷载作用下的动力学特性目前研究不多。利用室内动三轴试验,对4类重塑红黏土样的动应力应变关系、动应力累积效应、以及循环门槛应力比展开研究。研究结果表明:密实度对红黏土路基强度的影响远大于路基红黏土含水量的影响;正常运营条件下,长期车辆荷载导致的路基竖向变形与加载次数之间呈现稳定型关系,因此不会导致红黏土路基过度变形而诱发路基失稳等病害;华南地区红黏土反复荷载下其循环门槛应力比一般处于40%～50%之间,建议取值为45%。Red clay is one of the most typical subgrade soils in Southern China.Studies on the dynamic characteristics of red clays are far from complete at the current stage.This study presents triaxial testing outcomes from 4red clay samples focusing on dynamic stress-strain relationship,accumulation of dynamic stress,and threshold cyclic stress ratio under cyclic loading conditions.The results show that the influence of compactions on the shear strength of subgrade red clays is much stronger than that relating to variation of soil water content.Under normal operation conditions,the subgrade soil vertical settlement will be ultimately stabilized with increasing number of cyclic loading;as a result,the deformation will not be excessively large and induce instability of the subgrade and other rele- vant road hazards.The cyclic dynamic stress threshold of red clays in Southern China under repeated vehicle loading is about 40% to 50% of the maximum shear stress under static conditions;this study suggests 45%to be used in practice.

关 键 词：路基红黏土 动三轴试验 应力-应变 动应力累积效应 循环门槛应力比 

分 类 号：X43[环境科学与工程—灾害防治] X93