The Characteristics Of Red Clay And The Mechanism Of Sliding Are Examples Of Red Clay In The Bahe River Basin

Red clay is distributed in the south and north of China.This paper studies the northern red clay,also known as ”Hipparion laterite”,generally refers to the Late Neogene semi-diagenetic soil-like deposits stacked widely in northern China,most of them distributed noncontinuously in the overlying loess and alluvial layer.Due to the characteristics of red clay and its control function in the slope structure,the landslide in red clay distribution area has the characteristics of large scale,nepotism distribution and serious damage.This is based on the "Bahe River Basin Geological Disaster Investigation" geological survey project and "loess water sensitivity mechanism and slip mechanism" key fund project,through field investigation,indoor experiment,unsaturated characteristic analysis,numerical simulation and other means,studies the characteristics of red clay and the mechanism of slipping in Bahe River Basin,the main results are as follows:(1)systematically summarizes the characteristics and distribution of red clay in Bahe River Basin.Through 1: 50000 field geological survey,the red clay in the watershed is mainly distributed in loess terrace and loess hilly areas,exposed to the white deer plateau edge,Hengling plateau large gully in the upper reaches and sporadic exposed in the Qinling Mountains,missed in the Qinling Mountains and the valley.(2)It reveals the control effect of red clay on the formation of landslide in Bahe River Basin.To statistic the kinds of red clay landslide in this basin,the results show that the distribution of landslides is controlled by the red clay type,the position of the sliding surface is closely related to the type of slope structure,The main types of landslides in the red clay type are loess + red clay + bedrock,sliding surface is located in red-rock contact surface,with large scale,cut sliding characteristics.(3)The engineering geological properties and unsaturated characteristics of red clay in Bahe River Basin were obtained.In the watershed,the red clay samples were subjected to soil test.The results showed that the red clay was mainly composed of powder and clay;water,tuberculosis,dry and wet cycle is an important factor affecting the strength of red clay.The non-saturated characteristics of red clay and loess in the basin were obtained by transient dehumidification and hygroscopic experiment,the results show that the red clay exhibits greater substrate suction and compressive stress,higher intake value and water holding capacity.Under the same conditions of water content change,the red clay property changes more.(4)Through the engineering characteristics analysis and numerical simulation of red clay,the mechanism of red clay slip mechanism in Bahe River Basin is revealed.The experimental parameters of red clay were used for numerical simulation to obtain the stability and stress strain of slope under different conditions.The simulation results show that when the slope structure type is loess + red clay + bedrock,after the red clay first reaches saturation,the strength decreases rapidly,the red clay displacement increases at the slope foot,and continues to develop into the red clay layer.Finally,under the action of overburden loess,the sliding body slides along the contact surface between the red clay and the bedrock.