一种新型EPB渣土改良相似模型试验系统及功能验证

New-Type of Similar Model Experiment System for EPB Soil Conditioning and Its Function Verification

基于对国内外EPB渣土改良的研究现状以及室内试验方法的总结与分析,指出不同试验方法的局限性;研发了一种新型渣土改良相似模型试验系统——EPB渣土改良试验系统。系统集合了泡沫发生、盾构掘进、螺旋输送机输出等功能,可实现地层重塑、盾构掘进过程模拟、切土及土仓渣土搅拌;可将泡沫改良剂按设计配比加入土仓并搅拌,判断改良土体对掘进参数的影响;可模拟敞开式、半土压平衡式、土压平衡式、过压掘进模式等4种状态EPB盾构掘进;可模拟螺旋输送机出土过程及土塞效应实现过程。通过"盾构掘进模拟"和"渣土改良试验"等功能试验,验证了该试验系统各功能的准确性和可靠性。系统为研究EPB渣土改良优化配比及效果评价提供了新手段,可为大直径土压平衡盾构施工、特殊地层下盾构控制技术等条件下渣土改良提供可靠的施工参数,指导施工。

Based on a summary and analysis of the research of soil conditioning at home and abroad,the limitations of various current indoor experiment methods were pointed,and a newly developed similar model experiment system for soil conditioning called the EPB Soil Conditioning Experimental System was introduced.This system gathers the functions of foam generating,shield tunneling,screw conveying,etc.to realize the following advancements and innovations： Enabling strata remodeling,simulating the process of shield tunneling,realizing soil cutting and soil residue mixing; Adding a foam modifier according to the design ratio of the soil warehouse,mixing it,and determining the effects of soil conditioning on boring parameters;Simulating four states of EPB shield tunneling： the open style shield,semi-earth pressure balance shield,earth pressure balance shield,and overvoltage drilling models; Simulating the processes of screw conveyor soil output and soil plugging effect realization.At last,functional tests such as shield boring simulation and soil conditioning tests were carried out in order to verify the accuracy and reliability of the system.The development of this experimental system provides a new method for researching the impact assessment of the ratio of soil improvement and optimization.It simulates the excavation process of the large diameter EPB shield,particularly under complex geological conditions,obtains the optimal construction parameters of the EPB shield,and guides construction.