Failure Mechanism and Optimization of Arch-Bolt Composite Support for Underground Mining Tunnel

Table 7

Main results of Schemes 11–15 at the 50^th day.

Scheme no.	Deformations			Plastic volume (m^3)	Maximum forces			Working status of support members
	Roof (mm)	Side wall (mm)	Floor (mm)		Arch axial force (kN)	Arch bending moment (kN)	Bolt axial force (kN)	Arch	Bolt
11	168.2	172	247.5	84.8	640.2	66.5	260	Normal	Normal
12	188.5	207.4	252.6	90.8	440.8	66.1	171.8	Failed	Normal
13	125.2	132.0	238.6	75.1	2105	39.5	260	Normal	Normal
14	270.0	399.1	337.9	111.6	345.5	91.4	260	Failed	8 bolts are broken
15	182.4	179.0	253.2	91.4	1184	48.3	260	Failed	Normal