南京纬三路过江通道泥水盾构泥浆配制试验研究

泥水盾构以其良好的适应性在过江过河隧道中得到了广泛应用。合理的泥浆配比及泥浆参数直接关系到盾构掘进的效率、安全及施工成本。以南京纬三路过江通道为背景,选取隧道穿过的4种砂性地层进行泥浆成膜试验,得到各地层的泥浆成膜参数;然后利用淤泥质粉质黏土地层中产生的废弃泥浆作为基础材料,向其中添加膨润土浆或CYHS-3型增黏剂溶液,得到满足4种地层施工需要的泥浆配方。结果表明:1)密度小于1.05 g/cm3的泥浆,不适于在砂性地层中成膜;2)膨润土浆和增黏剂溶液可以调节泥浆黏度;3)当泥浆黏度大于20 s时,膨润土浆对泥浆黏度有明显的调节作用;4)泥浆密度越大,增黏剂溶液对泥浆黏度的提高越明显,当泥浆密度小于1.10 g/cm3时,增黏剂溶液对泥浆的黏度几乎没有影响。

Experimental Study on Preparation of Slurry for Slurry Shields: Case Study on Weisanlu Yangtze River Tunnel in Nanjing

Slurry shields have been widely used for the construction of river crossing tunnels. Because of the complexity of the strata, adjusting the parameters of the slurry timely and reasonably is of great importance for smooth tunneling. In this paper, taking Weisanlu Yangtze River Tunnel as the study background, the authors select four types of sand strata to make the slurry membrane test, so as to determine the density and viscosity of the slurry. Then, the authors use the waste slurry produced when the shield bores through the silty clay strata as the base material, add bentonite slurry or Type CYHS 3 tackifier solution into the base material, and get the mixing proportions of slurries that can meet the requirements of the four types of strata. Conclusions drawn are as follows: 1) Slurry with its density being less than 1.05 g/cm3 is not suitable to form filter membrane in sandy strata; 2) Bentonite slurry and tackifier solution can adjust the viscosity of the slurry; 3) When the viscosity of the slurry is larger than 20 s, the bentonite slurry has obvious effect in adjusting the viscosity of the slurry; 4) The larger the slurry density, the better effect the tackifier solution has on the viscosity of the slurry; when the slurry density is less than 1.10 g/cm3, the tackifier solution has almost no effect on the viscosity of the slurry.