Application of High Pressure Spiral Jet Grouting Piles in Shield Tunnel Portal Soil Reinforcement Engineering

摘要

When the shield machine launching or arriving is under construction in the shield tunnel construction,firstly the built retaining structure (piles in a row,diaphragm wall,etc.) of the shield tunnel portal needs to be excavated manually by tradition method,and then the shield machine launch or arrival construction is carried out.Consequently,after the built retaining structure of shield tunnel portal is excavated,it has become a key issue to ensure the soil stability of the work shaft portal for a period of time before the rotary cutter head of shield machine penetrating into or drilling through the stratum.Based on the project case,the principle of high pressure spiral jet grouting,the grouting parameters and the construction technology about dual pipe high-pressure spiral jet grouting piles for reinforcing the soil of the end well portal are discussed in this paper.Furthermore,some suggestions are put forward on the questions that exist in the jet grouting piles for the shield launching or arrival construction.