The Stability Analysis Of Tunnel Construction In Water-rich Altered Rock

Based on Dongke Ling tunnel which belonged to Hezhou section of GuiyangGuangzhou high-speed rail, this paper mainly studied the engineering propertieswhich had water-rich weathering altered granite formation layer and stability oftunnel. Due to the presence of the water, saturated weathered granite formation madethe surrounding rock collapse easily and self-stabilizing ability was very weak.By using fluid-solid coupling theory calculation method and FLAC-3Dnumerical simulation, this paper considered CD and core indigenous method andcompared the surface subsidence caused by tunnel construction, holes nearbydisplacements and internal forces of supporting structure. Because the displacementindicators were larger and the deformation rate was also large, the core indigenousconstruction could not use. The CD-construction method could use but wasinefficient.After using watering wells, precipitation between using the CD methodand the core indigenous was small. CD method could meet the requirement of theconstruction stability and construct easily. So this method was recommended.The core indigenous should be reinforced without precipitation.This paperstudied the reasonable grouting circle and drew a reasonable thickness reinforcementring. This ring thickness was2.5m. At the same time, this paper studied thereasonable grouting angle based on the2.5m ring thickness. This paper drew thereasonable grouting angle was vaults240degree. This time of the displacement andstress indicators were to meet the requirements. Extent of grouting circle angle,displacement and stress had no effect obviously.