长春风化泥岩黏性地层渣土改良与应用研究

Study on the soil conditioning and application in weathered mudstone strata in Changchun

依托长春地铁2号线西延线盾构隧道工程,为解决盾构下穿黏土和风化泥岩地层时出现的排渣困难、结泥饼难题,开展渣土改良技术研究。介绍了泡沫剂、抗粘剂、膨润土、聚合物四种渣土改良剂及其应用范围,针对风化泥岩高黏地层,主要使用泡沫剂、泡沫剂+抗粘剂进行改良,并进行了改良剂的配比优化试验,得到改良剂的最优浓度及掺入比。针对改良后的渣土,开展了室内坍落度试验,得到了满足开挖土体流动性要求的最理想泡沫剂溶液浓度及相应掺入比。对现场盾构机掘进参数进行监测,根据监测数据显示采用“高效泡沫剂+抗粘剂”比普通的改良方式效果更好,解决了黏土地层中的开挖难题,保证了盾构施工的正常掘进。

Relying on the shield tunnel project of the west extension line of Changchun Metro Line 2,in order to solve the problems of slag drainage and mud cake formation when the shield passes through clay and weathered mudstone formations,research on slag improvement technology was carried out.This article introduces four types of soil conditioners,including foaming agents,anti-sticking agents,bentonite,and polymers,and their application scope.For weathered mudstone high-viscosity formations,foaming agents,foaming agents and anti-sticking agents are mainly used for improvement,and the modifiers are modified.The optimal test of the proportion of the mixture yields the optimal concentration and blending ratio of foaming agent,foaming agent and anti-adhesive,and the slump test of the improved slag,the optimal foam that meets the requirements of excavated soil fluidity is obtained.Agent solution concentration and corresponding incorporation ratio.Finally,according to the improved solution of foaming agent and anti-adhesive agent,the driving parameters of the shield machine were monitored(advancing thrust,cutter head torque).The data show that the clay formation shield tunneling uses the“efficient foaming agent and anti-sticking agent”.The improvement method of slag soil is better,it solves the problems related to the excavation of clay strata,and achieves the technical effect that cannot be achieved by ordinary foaming agents.Ensures normal excavation of shield construction.