摘要
为了探讨干湿循环对黄土强度的影响,采用三轴试验方法,考虑了干密度、含水量、干湿循环幅度的影响,获得伊犁黄土干湿循环强度劣化规律,并利用复合函数拟合劣化度,建立伊犁黄土干湿循环强度损伤模型。结果表明:黄土在干湿循环作用下会产生明显的劣化效应,干湿循环幅度和干密度的影响显著;受原状黄土和压实黄土的劣化影响的主要是黏聚力,首次干湿循环对压实黄土黏聚力影响最大,3次干湿循环时原状黄土黏聚力劣化最多,内摩擦角受干湿循环作用影响不大;干湿循环效应使原状黄土的力学特性向重塑黄土发展,5次干湿循环后原状黄土的强度与压实黄土趋于一致;增湿过程土体孔隙发育和减湿过程土样内外出现裂隙是黄土出现强度劣化的主要原因。
To explore the influences of the dry-wet cycles on the strength of loess,triaxial test method considering the effects of dry density,water content,and dry-wet cycle amplitude is adopted to obtain the strength degradation law of Ili loess under the wetting-drying cycle.Dry-wet cycle strength damage model of Ili loess is established by fitting the degradation degree using a composite function.The results show that:The Ioess possess an obvious deterioration effect under the effect of wetting-drying cycles,and the influence of dry-wet cycle amplitude and dry density is significant.The cohesion is greatly influenced by the degradation of undisturbed loess and compacted loess.The first dry-wet cycle has the greatest effect on the cohesion of compacted loess,the third drywet cycle has the greatest deterioration on the cohesion of undisturbed loess,and the internal friction angle was not affected by the dry-wet cycle.The mechanical properties of undisturbed loess developed to remolded loess,and the strength of undisturbed loess was consistent with that of compacted loess after 5 dry-wet cycles.The development of soil pores during the process of humidification and cracks inside and outside the soil sample during the process of dehumidification are the main reasons for the strength deterioration of loess.
作者
胡江洋
郭志豪
潘涛
陈婧
Hu Jiangyang;Guo Zhihao;Pan Tao;Chen Jing(CCCC First Highway Consultants Co.,Ltd.,Xi’an 710075,P.R.China;School of Highway,Chang’an University,Xi’an 710064,P.R.China;Yunnan Tongqu Engineering Testing Co.,Ltd.,Kunming 650041,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2023年第S01期181-191,共11页
Chinese Journal of Underground Space and Engineering
关键词
土力学
干湿循环
伊犁黄土
强度劣化
拟合分析
soil mechanics
wetting-drying cycle
Ili loess
strength deterioration
fitting analysis
