冲击荷载下饱和砂土孔压发展模式的影响因素分析OA

Understanding the pore pressure development pattern in saturated sand under dynamic load-ing is fundamental to the study of soil liquefaction behavior.In addition to cyclic loads such as seismic motion,impact loads including blasting,pile driving,and ground contact of building collapse are also common in practical engineering,and the pore pressure changes caused by such transient loads also de-serve attention.To investigate the effects of different factors on pore pressure development during sand liquefaction under impact loading,a series of impact liquefaction tests of saturated sand were de-signed and conducted.The results showed that factors such as permeability coefficient,relative densi-ty,and load amplitude were mutually coupled and significantly influenced the development characteris-tics of pore pressure.(1)The permeability coefficient was one of the most important parameters affect-ing dynamic pore pressure development,primarily governing the basic pattern of pore pressure devel-opment and the duration of pore pressure dissipation.(2)When the permeability coefficient of the soil layer was large(coarse sand),relative density had a significant influence on the peak pore pressure and became the main controlling factor,while the changes in load amplitude mainly affected the peak value of pore pressure at this time.(3)When the permeability coefficient of the soil layer was small(medium and fine sand),relative density had a greater influence on the stage characteristics of pore pressure de-velopment and became the dominant factor,whereas the changes in load amplitude primarily affected and controlled the duration of pore pressure dissipation.(4)When the permeability coefficient was small,the dissipation of excess pore water pressure generally exhibited the distribution characteristics of a two-stage exponential function,and each stage was related to factors such as permeability coeffi-cient and relative density.