Research on Key Technologies of Construction Of Tunnel in Aeolian Stratum: A Case Study of Shenmu No. 1 Tunnel
Abstract The naturally formed aeolian sand dunes in northern Shaanxi have unique engineering characteristics. Several difficulties restrict the construction of road tunnels under this stratum, such as the poor self-stabilization ability of the surrounding rock, difficultly in injecting grout, and insufficient construction experience. Therefore, in this study, a case study of the Shenmu No. 1 tunnel was conducted to investigate the engineering characteristics of aeolian sand tunnels, compare the grouting effects of commonly used grouting materials, and discuss the reinforcement effects of different construction schemes in aeolian sand tunnels. Based on a field grouting test, it was found that it is difficult to inject ordinary cement grout into an aeolian sand layer; superfine cement grout and modified sodium silicate grout can be injected, but the former has a poor reinforcement effect. Through numerical analysis, it is found that an approach based on a concept of “horizontal jet grouting pile + benching partial excavation method with a temporary invert” is suitable for the construction of tunnels in aeolian sand in China.