侧压系数及回填材料对双护盾TBM卡机控制的影响分析

Impact of Lateral Pressure Coefficient and Backfilling Material on Double Shield TBM Jamming Control

为研究深部挤压地层侧压系数λ、回填材料弹性模量E、软填充长度Lr对双护盾TBM卡机控制的影响,采用3DEC建立了TBM与围岩相互作用模型。数值计算中采用了改进的Burgers(CVISC)黏弹塑性蠕变本构,模拟了TBM动态分步开挖,结果表明:(1)λ越大,对TBM卡机控制越不利:当λ≤1时,其影响程度较小;当1<λ≤1.2时,其影响程度逐渐增大;当λ≥1.2时,TBM的总阻力急剧上升,对卡机控制极为不利;(2)回填材料E越大,TBM的总接触压力和总阻力越小,对TBM卡机控制越有利;(3)Lr越大TBM总阻力越大,TBM的卡机概率也越大;TBM掘进中,为了降低卡机概率应尽量缩短软填充阶段的长度。

In order to study the impact of lateral pressure coefficient(λ),elastic modulus of backfilling material( E) and length of soft backfilling( Lr) on TBM jamming control in deep squeezing ground,models were established by 3DEC to explore the interaction between DS-TBM and surrounding rock mass. The Modified Burgers( CVISC) model was adopted to simulate different excavation stages of TBM in the numerical calculation and the main conclusions were drawn as follows:( 1) the greater the λ was,the more disadvantageous to TBM jamming control: when λ≤1,its influence on jamming control was small;when 1<λ≤1. 2,its influence was increasing gradually;when λ≥1. 2,the total resistance of TBM increased sharply and it’s very adverse for TBM jamming control;( 2) The greater the E was,the less the total contact force and total resistance of TBM were and the more favorable to TBM jamming control;( 3) the longer the Lrwas,the greater the total resistance and probability of TBM jamming were;In TBM driving,the length of Lr should be shortened as far as possible in order to reduce the probability of TBM jamming.