The Influence of One-Dimensional Damage on the Strength and Deformation of Low Moisture Content of Expansive Soil

HU Dong-xu;MAO Xin;ZHANG Ya-qian;WANG Xiao-qi;WANG Shi-ji;School of Engineering and Technology,Southwest University;

one-dimensional damage;;expansive soil;;low water content;;damage behavior;;failure mode

In order to research the stress-strain properties,volumetric strain characteristics and one-dimensional damage morphologies of reconstituted expansive soils with cylindrical-hole damage at low moisture content(w =7%),15 different cylindrical-pore damaged expansive soil samples were divided into three groups,under the net confining pressure of 50 kPa,100kPa and 150 kPa,respectively.Then,triaxial tests were conducted.The results showed that differing from the past conventional studies(i.e.w was about 20%),soil strength was not obviously weakened nor reinforced,and samples with the same pore area did not show similar strength as well as deformation characteristics,revealing that soil peak strength influenced by the damage is closely related to its water content.Generally,soil samples showed a property of shearing shrinkage first,and then dilation.Furthermore,the shearing shrinkage stage was shortened significantly along with the increase in net confining pressure.Observed from the morphology of cracks,the length of fissure was shortened,and the inclination of the cracks became smaller as the confining pressure increased,which indicated that net confining pressure has a significant restraining effect on the development of cracks.