一类特殊的泥水盾构掘进绿色泥浆实验研究

Experimental Study on Environment Friendly Slurry for Slurry Shield Tunnelling

摘要:

采用普通水、增效土(天然黏土)、淀粉和微量固体碱,利用淀粉的凝胶化特性,发明了一类特殊的泥水盾构穿越砂质地层的绿色泥浆.利用真三轴仪和研究级智能数字全自动立体显微镜,研究了复杂应力状态下绿色泥浆土的力学特性,并对泥膜的细观结构进行了观察,发现该绿色泥浆具有形成泥膜时间短、结构致密、抗渗透能力强和有效泥浆支护压力范围广的特性.对不同复杂应力水平下泥浆土的应力—应变关系实验研究表明：在排水和不排水的条件下,泥浆渗入对砂质地层土体的强度和变形均有较大影响,且不同的泥浆均存在有效泥浆支护压力上、下限值.

Abstract:

Based on water,clay,starch and minor solid alkali,an environment friendly slurry for slurry shields driving in sandy soils was invented by using the gelatinization property of starch.The true triaxial test coupled SteREO Discovery (V12) were performed to explore the mechanical property of an environment friendly slurry under the complicated stress state.And the mesostructure of a tight membrane and filter cake even in sandy soils were also observed.Experimental results indicate that the environment friendly slurry is characterized by short formation time,compact structure,strong infiltration capacity and wide area with respect to effective support pressure of the slurry.Furthermore,under the drained or undrained condition,the permeability of slurries has great effect on the strength and deformation of sandy soil,and the effective support pressure of slurries has an upper and lower limit value.