泥水盾构泥膜形成过程中超静孔隙水压力随时间的变化

Change Laws of Excess Pore Water Pressure during Forming of Filter Cake in Slurry Shield

泥水盾构施工是利用压力泥浆支护开挖面稳定,泥浆在渗透过程中在地层中产生的超静孔隙水压力会影响泥浆对地层的支护能力,分析泥膜形成过程中超静孔隙水压力的变化规律,对提高开挖面的稳定有重要意义。在一个能够测量地层中超静孔隙水压力的泥浆渗透装置中,用三种高渗透性地层和五种泥浆展开渗透实验,研究开挖面处超静孔隙水压力的变化规律。结果表明开挖面处超静孔隙水压力变化存在三种模式,而且泥浆有效粒径和地层代表粒径的比值是影响开挖面处超静孔隙水压力变化的主要因素。

In the construction of slurry shield, the working face is supported by pressurized slurry, and the excess pore water pressure generated when the slurry infiltrates into the stratum could lower the supporting capability of the slurry and affect the stability of the working face. So analyzing the change laws of the excess pore water pressure is of important significance for improving the stability of the working face. In an infiltration apparatus to be able to measure the excess pore pressure in the stratum, the infiltration tests are done in three kinds of high permeability strata with five kinds of slurry to study the change laws of the excess pore water pressure during the forming of filter cake. The results indicate that there are three change models of the excess pore pressure in the working face, and the ratio of the effective grain size of the slurry to the representative diameter of the stratum is the main influence factor to the change of the excess pore pressure.