Study on Optimization of Core Piliar in Large-span Tunnel Excavated with Double-side Heading Method

摘要

Based on the underground Hongtudi station of Chongqing Rail Transit Line VI, stress and plastic strain of surrounding rock, internal forces of supporting structure and vault settlement are calculated in different widths of core pillar. Comprehensive analyses indicate that there is an optimal value of core pillar width in the construction of tunnel with the double-side heading method. Width of core pillar, 0.3 times as large as the tunnel span, is suggested in other projects with the same construction method, which is of great significance in practices.