Construction Safety Risk Analysis And Research Of Prevention And Control Measures Of Erlangshan Tunnel In Yakang High-Speed Railway

As a bottleneck project of Yakang Highway, Erlang Mountain tunnel is located in Erlang Mountain mountainous area on the border between Tianquan County of Ya’an City and Luding County of Ganzi Prefecture,Sichuan Province,which passes through two faults,with the length of 13459m and the maximum depth of 1468.93m.Given the huge hidden security trouble under construction of Erlang Mountain tunnel caused by several disadvantages including huge buried depth、some large cross-section and complicated interchanges、crossing faults and large deformations of soft rock,it is certainly necessary to carry out construction safety risk analysis and prevention measures against Erlang Mountain tunnel.The thesis main research content is as follows:(1)Construction risk factors that may occur during construction are screened by combining with Erlang Mountain Tunnel’s own situation and using the method of Risk Factor Checklist,and correspondingly counteractions are also proposed against major risks.(2)With the means of geological prediction, a more accurate forecast is carried out against geological conditions within a certain range in front of the tunnel face,which provides much time to take replied measures and reduces or avoids the occurrence of geological disasters effectively.(3)Using finite difference software, dynamic simulation under the overall tunnel construction is carried out against the parts of large deformations of soft rock under Erlang Mountain tunnel,and large deformation risks occurred on different construction stages are also analyzed from the aspects of the surrounding rock deformation and force of structure.(4)3D simulation analysis about the safety of the multifunctional large-section transport-transferring with supporting structure is conducted,and several prevention and control measures are proposed against structural instability problem that may occur.