A method for determining second lining supporting opportunity in soft rock tunnel

摘要

The determination criteria and methods are summarized for the reasonable supporting opportunity which is obtained from the numerical calculation of GeoFEM. It is the limit state of surrounding rock when the second lining undertakes 10 percent of load in IV grade rock(buried depth 121m), and the surrounding rock with burial depth 43meters reaches its limit state when the second lining bears 5 percent of load in V grade rock. The reasonable supporting opportunity will be obtained from those two limit states with the criteria.