Study On Stress-strain And Strength Characteristics Of Typical Silty Clay In Zhengzhou

Silt especially the silty clay,is widely exists in the alluvial plain of the Yellow River.The formation of soil in each area has its unique history.This paper selects silty clay from a subway station in Zhengzhou as the research object,using the GDS triaxial apparatus and the plane strain apparatus developed by the laboratory to research the stress-strain characteristics and strength characteristics of Zhengzhou typical silty clay,so as to provide a useful reference for engineering practice in this area.?1?For the remoulded silty clay specimens,the form of the stress-strain curves obtained by triaxial shear tests is different from that obtained by plane strain tests,and the shear strength indexes obtained by plane strain tests are higher than that obtained by triaxial shear tests.?2?The general triaxial shear tests were carried out on the silty clay specimens to explore the influence of different consolidation and drainage conditions on the shear strength of the specimens,as well as the relation between the stress-strain behaviors of the specimens and their failure patterns.?3?The K₀ consolidated shear tests were carried out on the specimens by using the GDS triaxial apparatus to explore the change rule of K₀ during the consolidation process,and compared the shear strength of specimens under K₀ consolidation and isobaric consolidation.The results show that the shear strength of specimens under K₀consolidation are higher than under isobaric consolidation.The shear strength indexes of soil obtained by K₀ consolidated shear test is closer to the engineering practice.?4?The K₀ over-consolidated and isobaric over-consolidated shear tests?the confining pressure is 100kPa during shearing?were carried out to explore the effects of different consolidation modes and confining pressures on the shear strength of the specimens.The results show that the over-consolidated shear has a more significant effect on the undrained shear strength instead of the drained shear strength of the soil,regardless of K₀ consolidation or isostatic consolidation.?5?The stress path tests with reducing p,constant p and increasing p were carried out on the specimens by using the triaxial apparatus to explore the effects of different stress paths on the stress-strain behaviors,strength and deformation characteristics of the specimens,as well as the differences in the effective shear strength indexes.The results show that the effective strength indexes of the specimen are less affected by the shear stress paths.?6?The stress controlled consolidated-drained shear tests were carried out on the specimens by using the plane strain apparatus developed by the laboratory to explore the stress-strain behaviors and the strength characteristics of the specimens,and analyzing the reason of the differences between the plane strain shear and the triaxial shear.