A study of the rich-water ground rock deformation features as shield tunneling along with inclined shaft

During shield tunneling in water-rich soft rock strata, the stress state of surrounding rock will change. Accurate grasp of its changing law is conducive to the adoption of appropriate disposal methods to avoid engineering accidents such as inclined shaft collapse, water gushing and clamping hoops. Previous studies generally considered only one or two conditions of shield, inclined shaft and soft rock, and did not compare the two conditions with or without seepage, and less involved in the influence of slope under different burial depth conditions. In this paper, the mechanical characteristics of surrounding rock during shield tunneling in water-rich soft strata are studied by using finite element model. Through monitoring several observation sections, it is found that the whole soft rock presents a trend of “cross-duck-egg” elliptical deformation, and the top is more susceptible to construction disturbance than both sides and bottom. The trend is strengthened. Five kinds of burial depth and five kinds of slope conditions are set to simulate the displacement of top and lateral monitoring points under different conditions during shield tunneling. The results show that the vertical displacement of arch roof around shield tunnels is generally larger than the horizontal displacement on both sides. When the slope of inclined shaft is less than 4 degrees, the vertical displacement and lateral displacement of the monitoring points on top of shield tunnels are simulated. The difference in horizontal displacement between monitoring points is small, but it increases with the increasing depth of inclined shaft. When the slope is more than 4 degrees, the difference between vertical displacement and lateral horizontal displacement caused by shield tunneling increases with the increaseing buried depth.