Discussion On The Effectiveness Of Various Components In The Initial Support Structure Of The Tunnel In Shallow Buried Weak Surrounding Rock

During the initial stage of tunnel supporting the bolting and shotcreting support is in the tunnel excavation process to control the deformation of tunnel surrounding rock and adjustment of tunnel surrounding rock should stress, an important means to ensure tunnel construction safety, but also to undertake the surrounding rock pressure load the important supporting structure. But compared with shotcrete support extensive application in the engineering practice, for the relationship of the interplay between the various components in the tunnel primary support structure, and these support components in parameter selection effect on supporting effect and the member itself still vague understanding, in this put face to a great extent, still need more in-depth study and discussion.In this paper, according to the anchor spray support support existing theory and in the field of geotechnical engineering related theoretical knowledge combined with code for design of highway tunnel in China are given the main parameters of surrounding rock and tunnel composite lining design related parameter range as the basis, the primary support structure numerical simulation analysis. The main contents of the paper are as follows:1)Of primary support structure anchor and shotcrete support support theory analysis, of bolt anchoring force, anchoring bolt on the surrounding rock of the mechanism and sprayed concrete support mechanism of surrounding rock were analyzed, from the perspective of qualitative interpretation of primary support structure anchor pole, jet concrete of tunnel surrounding rock supporting effect.2)Using finite element analysis software Madis/GTS through numerical simulation and analysis from the surrounding rock and supporting structure interaction relation analysis of supporting structure of surrounding rock reinforcement mechanism.3)Using finite element calculation software Madis/GTS of tunnel primary support structure for simulation analysis, the primary support structure in sub branch of the supporting structure of different support parameters selection, analysis of primary support structure support support parameters change of surrounding rock and support supporting effect influence.