长沙板岩地层地铁盾构施工渣土改良试验研究  

Soil conditioning test for EPB shield tunneling in slate stratum in the Changsha region

作　　者：胡焕校[1] 杨万松[1] 孙端阳[1] HU Huanxiao;YANG Wansong;SUN Duanyang(School of Geoscience and Info-Physics,Central South University,Changsha,Hunan 410006,China)

机构地区：[1]中南大学地球科学与信息物理学院,湖南长沙410006

出　　处：《水文地质工程地质》2018年第4期100-107,共8页Hydrogeology & Engineering Geology

基　　金：中南大学研究生自主探索项目(2017zzts563)

摘　　要：长沙地铁4号线土压平衡盾构掘进微风化板岩地层时,刀具磨损严重,出渣不畅。对此通过XRD、SEM及室内力学试验,研究微风化板岩矿物成分、结构与物理力学性质,再进行渣土改良坍落度试验,研究不同改良参数条件下渣土改良效果,经现场验证实用性后,提出准确、合理的渣土改良参数。结果表明,微风化板岩富含石英、长石,岩性致密,研磨性高。膨润土泥浆和泡沫溶液渣土改良实用性强、效果显著,且泥浆改良最佳坍落度为19~22 cm,泥浆浓度14%~15%,注入比14%~17%,每环注水量5~7 m^3;泡沫溶液改良最佳坍落度19~21 cm,泡沫配比4%~6%,注入比约10%,每环注水量8~10 m^3。Serious abrasion of cutters and unsmooth soil occurred when EPB shield tunneling in the slightly weathered slate stratum of Changsha Metro Line 4 was performed.The mineral compositions,structural and physical properties of slate were obtained by XRD,SEM and laboratory mechanical test.The improvement effect of soil under different parameters was examined by laboratory slump test,and accurate,reasonable conditioning parameters after validating practicability in construction site were discussed.The results show that the slate is rich in quartz,feldspar and its lithology is dense,and may causes high abrasiveness.Besides,the conditioning soil by bentonite mud and foaming agent is of strong practicality as well as remarkable effect.The laboratory slump test of soil condition indicates that the best slump of value conditioning soil by bentonite mud is between 19 and 22 cm,and mud concentration is 14%~15%,mud injection ratio is 14%~17%and water injection of each segment is 5~7 m^3;the best slump value of conditioning soil by foaming agent is between 19 and 21 cm,and foam concentration is 4%~6%,foaming agent injection ratio is about 10%and water injection of each segment is 8~10 m^3.

关 键 词：微风化板岩 渣土改良 室内试验 改良参数 土压平衡盾构 

分 类 号：TU411.6[建筑科学—岩土工程] TU411.7[建筑科学—土工工程]