NUMERICAL VALIDATION OF SIMPLIFIED ANALYTICAL METHOD FOR SEISMIC RESPONSE OF CIRCULAR TUNNELS

To provide a quick and easy calculation for the seismic design loads of tunnel lining, the simplified analytical solutions are widely employed in preliminary tunnel design. So it is very important to assess the accuracy and applicability of these analytical solutions. In this study, the time-domain finite element method is adopted to verify the accuracy of four simplified analytical solutions for different types of surrounding soil or rock and different tunnel depths. Through the numerical validation, it can be concluded that: the analytical solutions by Wang, Bobet and Park generate the same thrusts; with the increasing of flexibility ratio, the error deceases for shadow tunnels, and decreases first and then increases for deep tunnels; the Bobet’s and Park’s solutions generate the same bending moments, more accurate than Wang’s solution; the error of Bobet’s and Park’s solutions decreases with the increasing of flexibility ratio; the errors of Bobet’s and Park’s solutions are lower than 15% for tunnel’s internal forces when the tunnel depth is over 10 m, 5 m, 5 m, 1 m and 1 m, respectively for soft soil, medium soft soil, medium hard soil, hard soil or soft rock and hard rock.