Research On The Anisotropic Of Hangzhou Silt Soil By Laboratory Tests

Hangzhou silt soil is a typical kind of silt soil; it is formed by the Qiantang Riveralluvial. Particle size and composition of silt soil is between sand and clay, itsmechanical properties has a certain degree of particularity, therefore, to study theanisotropy of silt soil is necessary. Anisotropy is one of the important properties ofsoil, sand and clay anisotropy predecessors have carried out many studies. However,due to the particularity of silt, the anisotropy law of sand and clay are not necessarilyconsistent with the silt soil. In this paper, laboratory test method, the anisotropy of siltown study to be undertaken and the key findings are as follows:1, Used two different ways, static compaction and compaction to remodel silt, toknow how remodeling methods effect anisotropy of silt. Cut samples from differentdirections, preceded standard consolidation test, direct shear test, permeability test todiscuss the anisotropic of remolded silt soil on three aspects. The results show that:two kinds of remodeling silt soil are anisotropic, but there are some differencesbetween the anisotropic regularity.2, Used scanning electron microscopy micro-silt composition and morphology,from the microscopic point of view to analysis the formation and development of siltanisotropy.3, Used the method of static compaction to remodeling silt soil. Cut samplesfrom0°,45°,90°three directions, preceded the consolidated untrained triaxial sheartest. Comparison of sampling three directions of stress-strain relationship, shearstrength and index, and analyze how the anisotropy effect the Duncan-Chang modelparameters a and b.4, Carried out a series of such pressure consolidation and k0consolidatedundrained shear tests to study how k0consolidated effect the strength and deformation of the silt soil. The results showed that: k₀consolidation can improve the strength ofsilt, but ahead of the silt soil to yield. K₀consolidation and other pressureconsolidated undrained shear strength index of the total stress is different, but theeffective strength index difference is smaller.