Reliability Analysis on Multiple Failure Modes of Underground Chambers Based on the Narrow Boundary Method

This paper proposes to study the stability of underground chambers while taking into account nonlinear characteristics geotechnical materials and pore water. According upper bound theorem limit analysis reliability theory, failure mode model are established considering water effect. The solution expression surrounding rock pressure in chamber is deduced. variation law analyzed under different parameters. At same time, based on narrow boundary method correlation multiple modes, influence random parameters probability index studied. results show that water-level line height, coefficient Hoek-Brown criterion parameter have significant effects reliability. In addition, concept safety level introduced, minimum-support force range with 1 obtained research can provide a theoretical basis reference for structural evaluation chambers.