Deformation Characteristics of Undisturbed Q3 Loess Under the Coupling of Moisture-Compression-Vibration

WANG Qiang; SHAO Shengjun; ZHANG Zhe; DENG Guohua

doi:10.13512/j.hndz.2025.02.16

Abstract：To study the deformation characteristics of loess under the moisture-pressure-vibration coupling,dynamic simple shear tests were conducted on undisturbed Q3 loess under initial water contents of 5%,10%,15%,and 20%,consolidation pressures of 50,100,150,and 200 kPa,and dynamic shear strain amplitudes of 0.15%,0.5%,1.0%,2.2%,3.3%,and 4.5%.The test results show that both the seismic subsidence and its single-cycle increment increase with the shear strain.Under low water content conditions,the seismic subsidence deformation increases significantly as consolidation pressure increases.Under high water content conditions,the compression-vibration effect shows different patterns of influence on seismic subsidence deformation.Under low consolidation pressure conditions,seismic subsidence deformatopn increases significantly with the increase of water content,while under high consolidation pressure conditions,the moisture-vibration effect also shows different patterns of influence on seismic subsidence deformation.It is concluded that shear strain amplitude,consolidation pressure,and water content have obvious effects on the seismic subsidence of loess,with the increase of any influencing factor leading to larger seismic subsidence.The influence of consolidation pressure and water content on seismic subsidence deformation needs to consider the coupling effect between them.When either variable reaches a critical value,the influence of the other variable will become relatively weak.