方钢约束混凝土拱架力学性能及破坏机制

针对处于深部、高应力、构造破碎带等条件下的困难支护巷道，提出了方钢约束混凝土（SQCC）新型支护体系，并对其主要组成部分方钢约束混凝土拱架进行了深入研究。推导出任意节数直腿半圆形拱架的内力计算公式，结合工程实际计算出现场采用的4节拱架在均布荷载作用下的内力分布，得到内力最大的部位为拱腿上部和拱顶；通过SQCC构件强度分析对可能的关键部位进行校核，得到拱架均压作用下最先破坏的部位为拱腿上部以及拱架的极限承载力为1 315 kN。采用地下工程约束混凝土拱架1∶1大型试验系统对SQCC全尺寸拱架进行了力学加载试验，结合利用ABAQUS软件对SQCC拱架进行的数值试验，分析了极限承载力误差率δFe-Ft=-7.1%，δFe-Fn=-1.1%和关键破坏部位、内力以及应力应变等多个结果，从而对拱架力学性能和变形破坏机制进行了研究，同时也验证了理论计算和数值试验的正确性。

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 kN.The mechanics experiment of SQCC arch centering are carried out by using designed 1∶1 mechanics test system of confined concrete arch centering.Meanwhile combined 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.