| In recent years,the country has developed rapidly,many highway projects will occupy the slope land construction.Red clay is widely distributed in Southwest China and there is frequent rainfall.The unique properties of red clay promote the development of landslides and make landslide disasters occur frequently.Liuzhou City,located in the north of the central part of Guangxi,there are a lot of engineering projects occupying the toe of slope.In this paper,the red clay landslide of Transverse Thirteen Road,which is caused by the excavation of slope toe,is taken as the research object in this paper,the formation process and stability of the landslide are discussed,and compared with the actual monitoring data.The details are as follows:(1)Through on-the-spot investigation and reading relevant data,the geological and hydrological environment of landslide area and its surrounding area are analyzed,and the soil layer parameters obtained from geotechnical test are sorted out.The material composition and structural characteristics of the main soil layer of the lands lide are identified.Combined with the characteristics of the project area,this paper analyzes the internal and external factors affecting the landslide mass,and expounds the influence of each factor on the landslide mass.It is found that the initial local surcharge plays an important role in the formation of tension cracks,The rainfall increases the ability of fracture development,and the cyclic rainfall causes the continuous development of cracks,and finally causes the creep and even instability of the landslide.Research on the formation of red clay landslide in Transverse Thirteen Road by stages.(2)Considering the characteristics of Transverse Thirteen Road red clay landslide,the unbalanced thrust transfer coefficient method is selected to calculate,considering natural and saturated and saturated+expansibility conditions.It is found that section 1-1,2-2 and 3-3 are under stable state,and section 4-4 is in stable state in the natural condition.The four landslide sections under saturated and saturated+expansibility condition are in unstable state.It is found that landslide is more likely to destabilize when considering expansion force.(3)Based on the calculation results of stability coefficient,the sensitivity analysis and comparison of soil parameters of landslide show that the internal friction angle is the most sensitive geotechnical parameter.According to the results of sensitivity calculation,the probability of landslide instability is 76.8%(Fs<1.0).(4)The safety factor of landslide is calculated by finite element method,make landslide stability evaluation,the evaluation result is consistent with the transfer coefficient method.The displacement value calculated by finite element method is analyzed,it is found that the maximum displacement of saturated state is smaller than that of natural state.It shows that the deformation required for landslide failure in saturated state is less than that in natural state.(5)The actual monitoring value,standard limit value and finite element calculate-ion value of anti slide pile displacement are compared.It is found that the actual monitoring value is less than the standard limit value,at the same time,it is less than the calculated value of finite element method.It shows that the design of anti slide pile meets the requirements of treatment,and there is a certain security reserve. |
