Triaxial Shear Property of Geocell-reinforced Loess
YAN Chang-gen;GU Liang-jun;YANG Xiao-hua;LU Hao;YUAN Hang;School of Highway,Chang'an University;Ningbo Zhengxin Detection Technology Co.,Ltd.;
To investigate shear properties of geocell-reinforced loess,triaxial shear tests were conducted on compacted loess and geocell-reinforced loess with different patterns of reinforcement,by dint of the micro-geocell. The stress-strain curves and shear strength indexes of reinforced loess and compacted loess were obtained. Meanwhile,the stress-strain properties of reinforced loess and compacted loess were investigated. The effect of different reinforcement types was analyzed, and the mechanism of reinforcement with geocell under different layers was discussed. The results show that the stress-strain curves of compacted loess and reinforced loess with geogrid present slight strain-hardening behavior,while the stress-strain curves of geocell-reinforced loess present obvious strong strain-hardening behavior.The reinforcement effect of geocell with 4 layers is optimal,and the reinforcement effect of geocell with 2 layers can act well under the low confining pressure or the large strain. The stress-strain curves ofcompacted loess and reinforced loess with geogrid are hyperbolas. The fitting effect of such curves by dint of Duncan-Chang model is good. Furthermore,it is better to use power function type to fit the stressstrain curves of reinforced loess with geocell. The friction angle and cohesion of soil increase by the reinforcement with geocell,and the friction angle as well as cohesion of reinforced loess with geocell of 2 layers increases by 38% and 50%,compared with that of compacted loess respectively. Moreover,the friction angle and cohesion of reinforced loess with geocell of 4 layers increase by 63% and 120%respectively,which are higher than that of reinforced loess with geogrid. The reinforcement effect of geocell is better than that of geogrid,and the increase of the layer of geocell can further improve the shear property of loess on account of the existence of "enhanced zone"and "indirect effect zone". The more the layers are,the larger the thickness of "enhanced zone"and "indirect effect zone"will be. The shear strength of reinforced loess will be improved as well. The results will provide the theoretical basis for the selection of design parameters in the practical engineering.
【Fund】： 国家自然科学基金项目(41272285);; 甘肃省科技重大专项项目(1302GKDA009);; 甘肃省交通运输厅科技项目(2017-002)
【CateGory Index】： U412.22
【CateGory Index】： U412.22