Numerical Simulation And Optimization Analysis Of Design Parameters For Deep-base Pit Rotary Spray Anchor Pile Support

Spin-spray anchor pile support structure is a relatively new anchoring technology developed in recent years,relative to the ordinary anchoring technology,high-pressure rotary spray anchor pile carrying capacity is high,unit length anchoring force is large,the quality of construction process is easier to ensure,can solve the soft land area due to large compression,small permeability,The problem of foundation pit support caused by characteristics such as low shear strength and drift variability.However,because most of the rotary spray anchor sprinkling is still the design method of the ordinary anchor rod,and in the design process,in order to maintain the safety of the structure,all favor conservative design,resulting in the waste of materials,so there are many parameter optimization selection problems in the actual design process.The main work of this paper is as follows:(1)Through consulting a large number of documents and norms,the construction process of the rotary spray anchor,the technical control points during construction and the design and calculation method of the rotary spray anchor rod are summarized and analyzed in detail.(2)The load transfer law of the rotary spray anchor under the conditions of the peer-to-peer and variable-section is analyzed theoretically,and the factors affecting the anchor ingress of the spin-spray anchor are analyzed by parsing method according to the theoretical formula obtained.(3)Combined with concrete examples of pit engineering,ABAQUS software is used to model and simulate the excavation and supporting process of the pit.The monitoring results are compared with the simulation results to demonstrate the rationality of ABAQUS software modeling.On this basis,starting with numerical simulation,the effect of different anchor parameters on support effect is studied.(4)Based on the results obtained by numerical simulation,the orthogonal test model of multi-indicators is established,the value simulation of orthogonal test is carried out,the key influence parameters affecting the support effect of the spin-spray anchor rod are found,and the optimal combination of parameters is obtained.The optimization results reduce the engineering cost and provide a reference for the optimized design of similar engineering rotary-spray anchors.(5)According to the above research results,the idea of improving and optimizing the design and optimization of the support structure of the spin-spray anchor pile is put forward.