Study On The Effect Of Moisture Content On Shear Strength Of Unsaturated Remolded Loess And Plexiglass Contact Surface

With the development of physical simulation tests,more and more use of plexiglass in experiment,especially in the physical model test of soil landslide.In this paper,a series of studies on the effect of water content on the shear strength characteristics of unsaturated remolded loess and plexiglass contact surfaces were carried out.The research carried out some improvements on the test instrument,and through the improved instrument,the direct shear test of the unsaturated remodeling loess and plexiglass contact surface is carry out.Through the experimental data,the shear strength characteristics of the interface between unsaturated remolded loess and plexiglass were compared and analyzed.Finally,the difference of the maximum shear strength between unsaturated remolded loess and the interface shear strength between unsaturated remolded loess and plexiglass under different water content,the variation law and the main influencing factors are obtained.In this paper,the direct shear test is used to shear the contact surface between unsaturated remolded loess and plexiglass to obtain the shear strength of the contact surfaces of the two materials.According to the control test method:firstly,the unsaturated remolded loess samples with different water content were sheared to obtain the control data of the control group;then the shear test of the contact surface between the unsaturated remolded loess samples and the plexiglass was carried out.The test group data were obtained;finally,the data obtained from the test were comprehensively compared,and the difference of shear strength between the two shear tests,the shear strength between the contact surface of the unsaturated remolded loess and the plexiglass,the cohesive force of the contact surface and The variation law of the friction angle was studied by the microscopic analysis of the contact surface between the soil and the plexiglass.The reasons for the change of the cohesive force and the friction per unit area of the contact surface were studied.The main conclusions of this paper are:(1)According to the data obtained from the test,the maximum shear strength of the unsaturated reconstituted loess direct shear specimen is much larger than the maximum shear strength of the unsaturated remolded loess specimen and the plexiglass contact surface under the same water content;(2)Under different water content,the direct shear test of the unsaturated remolded loess sample and the plexiglass contact surface,the parameters of the contact surface shear strength and contact surface cohesion,unit area friction and friction angle are obtained,with the increase of water content.The change law of increasing first and then decreasing is observed.The shear strength of the contact surface,the cohesive force of the contact surface,the friction per unit area and the friction angle all peak at the plastic limit moisture content of 14.8%;(3)The cohesive force of the contact surface and the friction per unit area are the main components of the shear strength of the plexiglass contact surface.The moisture content changes the contact surface adhesion by changing the contact mode and contact area of the test soil and the plexiglass surface.Convergence,the frictional force per unit area of the contact surface,and thus the shear strength between the contact surfaces.