The Research On The Application Of The WSS Grouting Pre-reinforcement Technology In Loess Subway Tunnel

The construction of grouting pre-reinforcement has got a very good application in the subway of Beijing,Guangzhou and Shenzhen,its effect is obvious. But it is the first time for its large-scale application in the loess stratum of Xi'an,its effect remains controversial.And the projects of grouting pre-reinforcement are concealed works,the testing and evaluation of the effect of construction are much more complicated than the Surface engineering,so it is very important to evaluate the effect of grouting reasonably.This paper based on the implementation of grouting pre-reinforcement with the WSS method between the Chaoyang subway and Kangfulu subway of the left line of the Xi'an metro line 1, introducing the WSS method briefly, designing the parameters of grouting rationally combined with practical engineering and past engineering experience, in order to evaluate the effect of grouting more better, on the one hand,setting up the computational model with finite element software ANSYS,the numerical simulation based on the stress of primary support and the development of the plastic zone of heading face under two working cases non-grouted and grouted in the process of section excavation; on the other hand, designing detection scheme, by field observation,on-site sampling, assaying performance index of soil by indoor experiment,and comparing with the performance index of non-grouted soil,to evaluate the effect of grouting. Come to a conclusion:the construction of grouting pre-reinforcement make a good effect.