Aseismic Analysis of Circular Deep Grouting for Tunnel Surrounding Rock in Strong Earthquake Zone

Many tunnels were severely damaged during high-intensity earthquakes in recent years, especially for those in mountainous areas. This paper analyzes the seismic responses of the circular deep grouting technique for mountain tunnels with surrounding rocks. Eight circular, deep grouting, pre-reinforcement schemes are simulated using 3D Finite Element Method. The deformation and stress characteristic and dynamic responses of the tunnel structure are analyzed. Results demonstrate that different grouting schemes should be applied for tunnel structure in the high-intensity areas. A new seismic performance evaluation approach is proposed in the paper based on the maximum relative displacements of adjacent locations on the tunnel lining. This evaluation method provides a better interpretation of the tensile and compressive states of tunnel structures that are subject to strong ground motion during an earthquake. The approach described in the paper provides guidance to seismic design and construction of tunnels in seismic, active, mountainous areas.