Grouting Treatment and Parameters Optimization in Watery Karst Areas of High Speed Railway Tunnel Based on Comprehensive Geological Forecast: A Case Study

Abstract

Based on the failure of the initial grouting scheme in tunnel engineering, an integrated geological forecasting system incorporating an industrial endoscope was used to detect watery karst areas in this tunnel. Numerical simulations were used to analyze the change patterns of arch top settlement, arch bottom bulge, and water surge in the tunnel under different grouting thicknesses. Compared to the displacement of the support structure, curtain grouting thickness is mainly reflected in reducing the amount of water surge. When the grouting thickness exceeds 5 m, the water-stopping effect of the tunnel is almost unchanged. Finally, a grout thickness of 5 m and a grout length of 25 m were selected as the grouting range for this project. During grouting, the combination of the three grouting techniques can effectively solve the problems of high water surges and difficult hole formation. The principle of “combination of exploration and injection” was followed to obtain real-time geological information and optimize the subsequent grouting plan. After the grouting, the grouting evaluation results and the field construction conditions showed that the grouting effect was good.