砂卵石地层泥水盾构泥浆渗透试验分析

Mud Seepage Tests for Slurry Shields Driving in Sandy Cobble Ground

采用自制试验仪器,通过渗透试验研究泥浆对地层的适应性。试验表明,泥浆相对密度越大,泥膜质量越好,在相对密度达到1.08时,增大泥浆的黏度并不能有效减少泥浆的渗流量。泥膜的抗渗性与泥膜形成时的压差以及渗透时间密切相关,渗透成膜的压差越大,泥膜破坏需要的渗透压力也越大,而渗透时间长短决定泥膜凝胶强度的大小以及致密性。

Seepage tests were carried out by using home-made devices to study the adaptability of slurry to the ground of interest. Results showed that the larger the slurry specific gravity, the better the mud membrane quality, and that when the slurry specific gravity reached 1.08, the mud seepage discharge could not be efficiently reduced by increasing the mud viscosity. The impermeability of the mud membrane was closely related with the differential pressures at the time of mud membrane forming and the seepage time, and the larger the differential of pressures, the larger the required seepage pressures to destroy the mud membrane. Seepage time governed the gel strength and the compactability of the mud membrane.