Study On Instability Failure And Prevention Strategy Of Soil Slope In Mountainous Roads In Fuzhou Area

Fuzhou is located in the eastern part of Fujian Province.It is rainy and hot in summer,and it is the season of geological disasters on the slope.This has caused great losses to the economy of Fuzhou.Therefore,the stability analysis and prevention of mountain roads in Fuzhou has become one of the important topics for scholars and experts.After reviewing a large number of domestic and foreign information about the instability and damage of mountain road slopes,the GK0+500~GK0+700 sections of the Damuxi slope of Minhou County,Fuzhou City were analyzed with examples.Through the finite element numerical simulation method,the stability and prevention strategy of the Damu River slope were studied.The specific research contents and results are as follows:(1)Collecting a large amount of data about the Damu River slope,including topography,geological structure,stratum lithology,climatic conditions,hydrological conditions and site seismic effects evaluation,combined with field investigations and previous experience,to obtain formation lithology,Factors such as geological features,hydrology and rainfall will have a huge impact on the stability of mountain road slopes in Fuzhou.(2)Taking the section GK0+550 of GK0+500 ~ GK0+700 section of Damuxi Highway in Minhou County,Fuzhou City as an example,the stability analysis of the slope is carried out by the limit equilibrium method(Morgenstern-Price method)and the strength reduction method respectively.The calculations show that the two safety factors are roughly equal,which are less than the specification requirements,indicating that there is a safety hazard in the case of the Damuxi slope without the prevention and control,and further treatment is needed.(3)In the simulation analysis of the strength reduction method based on ABAQUS,if the analysis is only performed from the conventional cohesion and internal friction angles,the results are not comprehensive enough.The paper also considers the gravity,elastic modulus and Poisson's ratio of the soil in the Damuxi slope.The stability of the Damu River slope is analyzed by different values,and the slope safety factor corresponding to each parameter value is obtained.Forexample,when the soil internal friction angle increases from 21° to 23°,the safety factor is 1.025.Increased to 1.029,when the soil elastic modulus is increased from2 MPa to 5MPa,the safety factor is changed from 1.015 to 1.019.(4)After analyzing that the Damu River slope was in an unstable state,it immediately began to take control measures.Firstly,the common methods of slope prevention can be divided into drainage measures(surface water drainage and groundwater drainage),slope protection measures(sand plastering,hanging net shotcreting,geogrid grating planting and greening technology,etc.)and treatment measures(Slope reduction load shedding,retaining wall,anti-slide pile,anchor rod).The Damuxi slope adopts the comprehensive prevention and control of the slope foot back pressure + anti-slide pile project + anchoring project + support engineering + drainage engineering.After the analysis and calculation of the Damu Creek slope,the safety factor has reached the safety standard.At the same time,the monitoring of the Damu River slope after the treatment can not obtain the horizontal displacement variation of different monitoring depths,and it is found that the horizontal displacement is very small and within the controllable range.It is indicated that the comprehensive prevention and control measures implemented on the Damu River slope are feasible.This paper studies the instability and damage of the Damu River slope and has certain reference significance for the prevention and control of other similar slopes in Fuzhou.