Study On Reinforcement Mechanism And Calculation Method Of Double Rows Of Micro-pile Group Used In High Soft Rock Slopes

Micro-pile group is a new type of light anti-sliding retaining wall structure which is consist of a number of small diameter,big slenderness of bored piles and at the top of the pile connected by the top plate,and it is especially suitable for the slope engineering application under the condition of limited emergency measures for rush repair and limited construction conditions.This paper,based on the sichuan SuiZi highway high cutting soft rock slope engineering,makes a research for two-stage micro-pile group mechanism and calculation of pile group analysis method which is suitable for the design of slope or landslide has large landslide thrust force,and get the following results:(1)Based on the mechanism of single stage micro-pile group which reinforces the landslide,it preliminary reveals the two-stage micro mechanism of action of pile group of landslide reinforcement,and gets the calculation by considering the pressure of the back micro-pile group on the front slope to calculate the landslide thrust between two stage micro-pile group?(2)The pile deflection differential equation,which is based on the theory of beam on elastic foundation,before considering resistance in front of the pile,the method of power series miniature and finite difference are given.In the method of power series,the micro-pile is calculated by segmentation and considering the coupling between the displacement,angle,bending moment and shear force of the truncation.For finite difference method,the whole pile is calculated by the whole.The calculation procedure of Matlab is used to realize the calculation of the displacement,angle,bending moment and shear force of the micro-pile.(3)Based on the analysis of the prototype of SuiZi highway K12 worksite of high cutting soft rock slope,by Flac3D numerical simulation,calculation and analysis for the micro-pile displacement,rotation,bending moment and shear force and to determine the distribution and size of landslide thrust force.In the back micro-pile group,the thrust force of the landslide is close to the rectangular distribution,and the slope of the front micro-pile group landslide is close to the triangle distribution,and the bottom condition is close to the free end.(4)Based on an engineering example,the theory of power series method,finite difference method to calculate the results and analyzes the results of numerical simulation,theoretical analysis and numerical simulation method of pile bending moment,shear force and displacement calculation results conform to whole,shows both has certain rationality.This paper is based on the two-stage micro-pile group action mechanism of pile group of landslide reinforcement with micro analysis method to calculate the pile of research results,and can provide guidance and reference for practical engineering,with both important theoretical and practical significance.