利用城区高铁隧道尾水配制泥水盾构掘进用泥浆技术

Preparation Technology of Slurry for Shield Tunneling by Using Tail Water of Urban High Speed Railway Tunnel

北京—沈阳客运专线望京隧道采用絮凝-带式压滤快速脱水的泥浆处理工艺会产生大量尾水,若弃置则会造成大量浪费。利用尾水配置黏土泥浆,并添加不同比例的增黏剂溶液和膨润土浆,得到多种密度泥浆的配合比。采用密度1.13 g/cm3,漏斗黏土20 s的泥浆在该工程典型粉细砂地层中开展泥浆渗透成膜试验。结果表明:增黏剂溶液和膨润土浆均能提高黏土泥浆的漏斗黏度;对于密度1.15 g/cm3的黏土泥浆,增黏剂溶液最佳掺量为5%;泥浆密度较低时,须加入膨润土浆进一步提高泥浆的漏斗黏度及密度;采用尾水配置的泥浆在粉细砂地层表面能形成泥膜,从而阻止泥浆中的水向地层中渗透;采用尾水每配制1000 m3泥浆至少可节约用水954 t,经济效益和环保效益明显。

In Wangjing Tunnel of Beijing-Shenyang Passenger Dedicated Line,a large amount of tail water will be produced if the slurry is treated by flocculation belt pressure filtration rapid dewatering process,which will cause a lot of waste if discarded.The tail water was used to prepare clay slurry,and different proportions of tackifier solution and bentonite slurry were added to obtain the mixture ratio of slurry with various densities.The slurry with a density of 1.13 g/cm3 and funnel viscosity for 20 s was used to carry out the slurry permeability membrane formation test in the typical silty fine sand formation of the project.The results show that,both the tackifier solution and the bentonite slurry can improve the funnel viscosity of the clay slurry.For the clay slurry with the density of 1.15 g/cm3,the optimal dosage of tackifier solution is 5%.When the slurry density is low,bentonite slurry should be added to further improve the funnel viscosity and density of the slurry.The slurry prepared by tail water can form a mud film on the surface of silty fine sand formation,thus preventing the water in the slurry from penetrating into the formation.At least 954 t of water can be saved for every 1000 m3 slurry prepared by tail water,which has obvious economic and environmental benefits.