Study On The Large Deformation Prediction And Controlling Technology Of Fault Fracture Zone In Daxiangling Tunnel

By taking of the Ministry of Transportation western transportation construction technology project " Study on Daxiangling Tunnel Rock Blasting and Large Deformation Control Technology", the site monitoring measurement, theoretical analysis and three-dimensional numerical simulation were carried out to investigate the high ground stress fault fracture zone deformation mechanism in the key controlling project of Yaxi highway—Daxiangling deep and extra-long tunnel.In this paper, the method of fault fracture zone deformation prediction has been proposed, and the forecasting process has been programmed. In addition, the security of Daxiangling Tunnel support through the fault fracture zone was analyzed and the supporting structure was further optimized.The main research results was following:(1) Combination of weak surrounding rock deformation to study the status and fault broken with the surrounding rock deformation characteristics, summed up the mechanism of surrounding rock mass deformation and large deformation criterion, and then select the large deformation criterion of this article.(2) In this paper, Training the BP neural network by GA genetic algorithm, and give full play to the ability of local search optimization of the global search optimization of the GA algorithm and BP neural network algorithm, the integrated superiorities of both the preparation of Daxiangling tunnel’s high ground stress fault fracture zone rock mass deformation prediction program GA-BP neural network genetic algorithm and contrast to demonstrate its practicality of the project measured.(3) Due to the fault fracture zone of high field stress is extremely complex geological conditions, the surrounding rock is extremely broken, in order to effectively simulate faults with the surrounding rock engineering mechanical properties, using the three dimensional discrete element software3DEC numerical simulation, analysising the mass deformation characteristics of Daxiangling tunnel and stress characteristics, For further analysis of surrounding rock major deformation mechanism the paper recommended of the concept of shear slip zone.(4) Large relative to the tunnel support design problems in the Bolt length, vertical spacing optimization, the cross sectional shape of the tunnel as well as support facilities for the timing to provides a valid reference point for the future high ground stress fault fracture zone rock mass support designing.