盾构隧道壁后注浆柱形孔压滤扩散模型
Cylindrical cavity pressure-filter diffusion model forbackfill grouting of shield tunnel

假定同步注浆时盾尾脱离管片后，在盾构机尾部形成均匀柱形盾尾间隙，考虑浆液滤出水渗流和土体弹性变形的耦合作用，建立盾构隧道壁后注浆柱形孔压滤扩散模型。推导滤出水渗流半径、土体孔隙水压力、有效应力和浆液脱水系数的计算式。通过工程实例分析滤出水渗流半径、土体孔隙水压力、有效应力和浆液脱水系数的影响因素和变化规律。分析结果表明：滤出水渗流半径随着注浆时间的推移逐渐增大，随着土体有效应力比的增大而减小；土体孔隙水压力、径向有效应力和径向总应力均随着远离管片而逐渐减小；浆液脱水系数随着注浆时间的持续而增大，随着有效应力比的增大而减小。
Assuming uniform cylindrical shield tail interspace is formed on the tail after the segments out from shield tail when synchronous grouting. Considering the coupling action of seepage radius of filtered water and elastic deformation, and the cylindrical cavity pressure-filter diffusion model for backfill grouting of shield tunnel was established. A formula for calculating the seepage radius of filtered water, soil pore water pressure, effective stress and grout dewaterability coefficient were derived. Then, the influence factors and variation rules of the seepage radii of filtered water, soil pore water pressure,effective stress and grout dewaterability coefficient were analyzed on the basis of a detail engineering example. Analysis result shows that the seepage radii of filtered water increase with the increase of grouting time, and decrease along with the increase of soil effective stress. Soil pore water pressure, radial effective stress and radial total stress all become smaller when it is father away from segment. Grout dewaterability coefficient increase with the increse of grouting time, but it increases with the increase of effective stress ratio