The Applied Research Of Arch Rock Bands Support In Thin Roof Roadway

Anchor rock bands support technology is a new type of practical support technology,which combines the flexible formwork pump-concreted support technology and boltsupporting technology, and firstly used in underground support. It provides a new means fordevelopment of underground space and exploitation of underground resources. The technicalprocess of Anchor rock bands support technology was that firstly produced flexible templates,and fixed to the roadway surrounding rocks by short bolts, and then pumped self-compactingconcrete into the soft modes by the pump, finally Anchor rock bands support moldingcompleted. Anchor net arranged in Anchor rock bands support molding and then formed thestrip arch type supporting structure, in which the anchors were retractable. Arching section isrigid support segment, which can resistance surrounding rock pressure; anchor segment isflexible retaining section to buffer rock stress. This technology combined rigid and softsupporting, first soft and then rigid, and the pressure of surrounding rock of roadwayautomatically adjusted, which maintained dynamic stability. This method, without cable,avoided the cable penetrated roof to the upper goaf. While its construction area was large, thestructure form keep good entirety, then anchor ARCH support was not only a simple process,low cost, and high mechanization degree, but rapid construction and new support technology.The calculation model of Anchor rock bands support structure was established on fourtheories, which were the combined arch theory, pu’s theory, design code for highway tunnel,thick tube theory. According to the structural mechanics knowledge，this paper deduced abending moment calculate formula for rock-arch combination beam. Results calculated fromthe formula proved that rock-arch combination beam could effectively reduce the bendingmoment of soft mold arch. Based on those theories, these papers not only present methods tocalculate the geometric dimensions of flexible template, reinforcement net and anchor, but arrangement mode. In addition, it proposed method to calculate thickness of concrete support.Surrounding rock mass pressure calculation according to design code for highway tunnel,roadway side pressure of calculation used general type theory and thickness of concretesupport calculation combined tunnel design safety factor and thick tube theory in thecalculation process.This paper simulation validation the Anchor rock bands support simulation based on thepractical engineering of Bide coal. Through the analysis of the structure, it proved that thestructure strength and stability meet the design requirements, and then presented the concreteconstruction method and construction process.Comparative analysis of numerical simulation, the theoretical calculation andengineering practical, it proved that Anchor rock bands support technology were reasonablesupport structure. In addition, it was not only simple but practicality strong, so that it isvaluable reference for the following engineering supporting design.