基于透明土技术的泥水盾构开挖面泥膜渗透特性研究

Research on the Permeability Characteristics of Mud Film on the Excavation Surface of Mud-Water Shield Based on Transparent Soil Technology

为了更直观的观测盾构泥浆成膜试验中注浆扩散和泥膜形成过程,开发了一套泥水盾构开挖面可视化注浆试验系统,采用透明土和透明浆液结合光学技术开展多种变量下泥水盾构泥浆渗透过程的可视化试验,记录各横纵断面渗透图像,并对图像进行二值化处理,探究了地层粒径与浆液粘度对泥浆扩散形态的影响,并评估了所形成泥膜的渗透特性,研究结果表明:浆液在地层中的渗透距离是评估泥膜形成质量的重要标准,而地层的孔径和泥浆粘度是影响浆液渗透距离的重要因素。在高渗透性土层条件下,减小盾构机刀盘开口率和注浆压力有助于形成泥皮型泥膜。试验结果对盾构的泥浆工程具有重要的指导意义。

In order to more intuitively observe the process of grouting diffusion and mud film formation in the shield mud film formation test,this paper developed a set of visual grouting test system for the excavation surface of the mud-water shield.The visualization test of the mud infiltration process of the mud-water shield under variable conditions,recording the infiltration images of each transverse and longitudinal section,and binarizing the images,exploring the influence of formation particle size and slurry viscosity on the mud diffusion pattern,and evaluating the formed mud The research results show that the permeability of the slurry in the formation is an important criterion for evaluating the quality of mud film formation,and the pore size of the formation and the viscosity of the mud are important factors affecting the penetration distance of the slurry.Under the condition of high permeability soil layer,reducing the opening ratio of the shield machine cutter head and reducing the grouting pressure can help to form a mud-skin type mud film.The test results have important guiding significance for the mud engineering of shield tunneling.