| The wall rock of soft rock tunnel is very fractured and its bearing capacity is low, whichwill be showing the obvious plastic deformation and strong rheological behaviour in engineeringloads. The traditional and single supporting means will not guarantee its safety and stability. The2-2 upcoal seam roadway of GaoJialiang colliery is typical of soft rock tunnel, whose wall rockwill appear mud optimization, inflation and crumbling phenomenon when meeting water, whichcause roadway appeared some instability phenomena such as reduction in area, sloughing,abscission layer and collapse of the roofs and so on. This paper design a bolting-steelmesh-shotcreting combined support and a bolt-mesh-anchor+concrete-filled steel tube of Pillarform in local area combined support scheme combined with the engineering geologicalconditions and wall rock physic-mechanical characteristic to solve the soft rock problem of20110feedbelt tunnel and20110subsidirary transportation tunnel combined mining face in2-2upcoal seam respectively. The results showed that the combined supporting schemes couldeffectively control the large deformation of the two soft rock tunnels to ensure the safeproduction of the colliery. FLAC3Dis used to make three-dimensional numerical simulation onthe displacement field and stress field of the tunnel before and after supporting, and themonitoring results is compared with the simulation results, which proving the the effectivenessof the numerical calculation and analysising the mechanical system of the combined supportstructure controling the deformation of the soft tunnel. |
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