土压平衡盾构刀盘泥饼堵塞改善研究  

Study on improvement of Cutter Head-Mud Blocking to EPB Shield Tunneling Machine

作　　者：王文[1] 潘雪瑛 赵延平 颜梦秋 陆地 陈孔磊 WANG Wen;PAN Xueying;ZHAO Yanping;YAN Mengqiu;LU Di;CHEN Konglei(Guangxi Key Laboratory for Geomechanics and Geotechnical Engineering,Guilin University of Technology,Guilin 541004;CNBM Geological Engineering Investigation Academy Co.Ltd.,Guilin 541002;Guilin University of Aerospace Technology,Guilin 541004)

机构地区：[1]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004 [2]中国建材集团建材桂林地质工程勘察院有限公司,广西桂林541002 [3]桂林航天工业学院,广西桂林541004

出　　处：《土工基础》2022年第3期304-307,共4页Soil Engineering and Foundation

基　　金：广西自然科学基金项目(2019JJA160124)。

摘　　要：盾构刀盘泥饼堵塞会减慢施工速度,严重时还会导致塌方等工程事故。为了研究水化学-力学耦合作用下对盾构刀盘渣土流塑性以及强度的影响,使用0 mol·L^(-1)、0.5 mol·L^(-1)、1.0 mol·L^(-1) CaCl_(2)溶液对盾构刀盘渣土进行饱和,并对饱和后的土样进行界限含水量试验以及改良的直剪试验。试验结果表明,盐溶液的增加能够有效地降低土样的液塑限以及塑限指数;剪切强度有所增加,黏聚力降低,内摩擦角增大。主要是因为结合水膜在高浓度下变薄,土样持水能力变弱导致液塑限的降低;盐溶液浓度的增加抑制了土样双电层厚度,使得土颗粒团聚,颗粒之间的排斥力减弱,土颗粒的咬合力增强,于是黏聚力减弱、内摩擦角增大。在沿海地区以及盐渍土地区进行渣土改良时,应该避免盐分的加入,降低土中的盐分能够有效降低盾构刀盘渣土的强度,研究对盾构刀盘渣土改良有着一定的指导作用。The mud cake blocking at the cutter head will slow down the construction progress of the shielded excavation and event result in serious accidents such as excavation failure and other geohazards.In order to study the effect of hydro-chemical-mechanical coupling on the flow plasticity and the strength of shielded cutter slurry,CaCl2 solutions with different concentrations,such as,0 mol/L,0.5 mol/L,1.0 mol/L,were used to saturate the shield cutter mud cake samples.The mud cake samples after the saturation were tested for Atterberg Limits and modified direct shear tests.The test results show that the increase of the solution concentration can effectively reduce both the plastic and the liquid limits of soil samples;reduce the soil cohesion.However,the increase the solution concentration,the internal friction angle and the overall shear strength are increased.These changes might be the results of the thin water film incorporated at a high concentration;the soil sample’s water retention capacity becomes weak resulting in a decreased plastic limit.With the increase of the solution concentration inhibit soil electric double layer thickness,so that the soil particle agglomeration,the repulsion between the particles decreases,biting force among soil particles increases,thus weakening the cohesion,the internal friction angle increases.

关 键 词：盾构刀盘渣土 盐溶液 界限含水量试验 直剪试验 

分 类 号：U456[建筑科学—桥梁与隧道工程]