Mechanical properties and failure mechanism of square type confined concrete arch centering

In order to solve the problem in deep high-stress rock roadway and roadway with structural fracture zone,a new support system—square-type steel confined concrete( SQCC) was developed. And the important component of it,square-type steel confined concrete arch centering was further studied. The inner force expressions of straight wall semicircle arch was deduced with the force method,and combined with the engineering practice to calculate the inner force distribution of four section arch,which is the field application,under uniformly loads. From the inner force distribution of arch centering,that arch legs and vault is the key position of the arch centering failure is confirmed. Through the strength analysis of the SQCC component to check the key parts of the possible,get that first failure part is arch leg and the ultimate bearing capacity of SQCC arch centering is 1 315 k N. The mechanics experiment of SQCC arch centering are carried out by using designed 1 ∶ 1 mechanics test system of confined concrete arch centering. Meanwhilecombined with the results of numerical experiments on SQCC arch centering by using ABAQUS software. Through the analysis on the error rate of ultimate bearing capacity,δFe- Ft=- 7. 1%,δFe- Fn=- 1. 1%,the key position,the inner force,deformation and stress,research the mechanical properties and faileure mechanism of SQCC arch centering,and verify the conclusion based on the theoretical arithmetic and laboratory experiment is right.