On Construction Technology In Tunnel Of Soft And Weak Surrounding Rock

Based on the construction practices in Yangmahe Tunnel, Guanlupo Tunnel and Chibanggou Tunnel of Shenyan Raiway Contract W9, this paper elucidates the construction methods in long tunnels with soft and weak surrounding rock, proposing that the construction shall be organized strictly on the principle of New Austrian Tunneling Method, short footage, quick support and fast lining; weak blasting can be adopted in construction of hard surrounding rock; but for weak surrounding rock, blasting shall not be permitted; monitoring and measurement for deformation of surrounding rock shall be carried out regularly so as to ensure secondary lining in time and effective dynamic construction management on the basis of monitoring result. The author explains construction technology in brief and brings forward technical economy evaluation. As for the mountain fissures occurring in the exit zone of Chibanggou Tunnel, the author summarizes the concrete construction method and procedure, that is to monitor deformation, analyze reasons and treatment measurement accordingly.The author puts a high value upon the effect of geological prediction in the course of construction, makes a study of the method and means of the geological prediction together with geological hazard prediction, takes consideration to the combination application of geological means into construction.As for the management of construction site, the author summarize feasible operating methods as follows:a) Stress shall be put on investigation and study so as to optimize construction organization.b) Investigation and study shall be carried out properly to gasp first hand information of unfavorable geology and groundwater.c) Construction methods and measures shall be adjusted according to the condition of geology.d) Pay attention to construction site management of the Tunnels.