Abstract:

Since the safety of mid partition is an important issue in underground multi-cavern structure, a method is proposed to calculate the safety degree of mid partition quantitatively based on fictitious stress coefficient theory. In the method, a special fictitious stress coefficient K is sought to meet the condition that the equivalent plastic strain runs through the partition exactly under the K times initial geostress, which is the down limit of safety degree. At the same time, the up limit of safety degree is found by analyzing the inflexion point of curve between opposite deformation of typical points at partition and fictitious stress coefficient. So, the safe interval is gained for the stability assessing of mid partition in multi-cavern. Verification of a physical model test and application of multi-cavern indicate that the interval calculation method is reasonable to assess the safety of caverns and tunnels and is useful to optimize the supporting proposal of mid partition.

Key words: underground engineering, multi-cavern, mid partition, safety degree, fictitious stress coefficient