Research On Moistening And Numerical Simulation Of Compacted Loess

With the rapid development of western economy, Compacted loess is widely used in the construction of foundation embankment and other projects, so the practical significance of compacted loess. By trench seepage, rainfall infiltration and other reasons make local water content of loess foundation increase, The local soil layer of the foundation reach different moistening water content along width and depth direction, which brings uneven moistening collapse deformation, and make engineering safety.Now, most research on the characteristics of loess deformation, focused predominantly on undisturbed loess, but paid less attention to compacted loess. In this study, with QingHai remolded loess as study object, through direct shear tests and compression test of compacted loess, with the dry density of 1.4、1.5、1.6、1.7、1.8 g/cm3 and water content of 10%、13%、15%、18%、20%, moistening property and deformation property of compacted loess considering influence of water content and dry density, According to the experimental results, compressive modulus of compacted loess increased with the increasing of dry density, the increment of compression of compacted loess first increased then decreased with the increasing of dry density when water content is small, it decreased with the increasing of dry density when water content is large; compressive modulus of compacted loess decreased with the increasing of water content, the amplitude decreased with the increasing of water content; The compressive modulus-water content curves of compacted loess can be expressed with the exponential function Es=aew, moisture force and friction of compacted loess decreased with the increasing of water content, moisture force-water content can be expressed with the exponential function c= aew,while friction-water content is φ= aw+b; moisture force and friction of compacted loess increased with the increasing of dry density, moisture force-dry density can be expressed with the exponential function c= aeρd.Based on deformation parameters and strength parameters, this paper through FLAC3D to research compacted loess foundation moistening deformation because of trench seepage. it shows the settlement decreased fast in the moistening area, it decreased slow out of the moistening area, When the dry density is less than 1.6g/cm3, increase the dry density can significantly reduce foundation settlement and nonuniform settlement, When the dry density is greater than 1.6g/cm3 greater increase the dry density is ineffective.