Research on the Resistance Characteristics of Pipeline Transportation for Shield Muck Paste

Earth pressure balance shield is widely used in urban tunnel construction due to its high excavation efficiency and strong geological applicability. For the traditional earth pressure balance shield the shield muck discharge method involves belt conveyor, battery truck and gantry crane, which can result in mud and water splashing and cause a harsh working environment. The power consumption of the dilute phase pipeline transportation is huge, and the post-processing is cumbersome. The paste like pipeline transportation of shield muck can achieve the full process and enclosed transportation of shield muck, and it can simplify the post-processing program. In this paper the pipe transport resistance characteristics of shield muck paste was explored using multifunctional paste ring pipe pumping experimental device by improving shield muck and producing muck paste. Experimental study shows that the modified shield muck sample with a slump of 19 cm～25.2 cm could be pumped by pipeline, and the larger the slump the smaller the pipe transport resistance; when paste flow in the pipes of the same size at a certain flowrate, the pressure loss of the horizontal pipeline is the largest. After adding THS-266 foam agent, the pressure loss of the horizontal section of the steel pipe is reduced significantly, and the yield stress is reduced by 20.9%, and the plastic viscosity is decreased by 38.4% for the paste transportation. Adding sodium hexametaphosphate and methyl acrylate can significantly reduce the yield stress of the paste. The research results provide a reference for the development of shield muck paste pipe conveying technology