Research On Dynamic Response Of Expansive Soil Landslide Mini-pile Reinforcement System

Earthquake action is an important influencing factor of landslide disasters in expansive soil areas,the aseismic treatment of landslide disasters has become a hot issue in engineering and theoretical research.As a new type of supporting structure,micro piles are widely used in the treatment of small and medium landslides,its research on static conditions has been gradually improved,but little is known about the mechanical and deformation characteristics of micro pile support systems under earthquakes in expansive soil regions.The thesis is based on the landslide management project in the expansive soil area of southern Shaanxi,based on the theoretical basis of higher soil mechanics and soil dynamics,based on laboratory soil tests and dynamic triaxial tests.Study on dynamic response of micropile reinforcement system using FLAC3 D numerical calculation method.The main research contents are as follows: expansion characteristics and dynamic parameters of expansive soils in southern Shaanxi are studied through indoor expansion rate test and dynamic triaxial test;using FLAC3 D software to perform thermal expansion simulation of soil humidification and expansion,combined with the loading conditions of the Wenchuan earthquake wave load,comparison and analysis of the total displacement?pile top displacement?pile axial force?pile shear force and pile bending moment of the two landslide models of independent micro pile and transverse coupling beam micro pile.Advice on seismic fortification for micro pile management of landslide in expansive soil area.The research results show that the total displacement?pile top displacement?axial force?bending moment and shear force of the lateral coupling beam micro pile landslide are smaller than those of the independent micro pile landslide.The lateral coupling beam micro pile landslide reinforcement system has better seismic performance and bearing capacity.Under the expansion force and earthquake,the bending moment of the micro pile body shows an “S”-type distribution,and the micro pile body shear stress distribution is a “Z”-type,which generates peak shear stress near the sliding surface and the bottom of the pile top.The axial force of the pile body The front and rear piles are characterized by one tension and one compression.The paper studies the dynamic response law of the micro pile reinforcement system for landslides in expansive soil areas,provides ideas for the seismic design of micro pile,and provides seismic fortification suggestions for landslide management in related areas.