Stability Analysis Of Neighborhood Tunnel Through Fault Zone And Its Optimization For Construction Scheme

Fault is refers to the formation in the long-term geological activity, with tectonic stress is given priority to, a lot of strain energy accumulation to a certain degree, the discontinuous rock or geological interface of a structure, and a significant occur along the rock on both sides of the fault plane displacement of the fracture rock on either side of the loss of continuity and integrity. Fault and fault belt with similar engineering characteristics, main performance in the surrounding rock integrity declined, carrying capacity, easy to cause landslides in the process of tunnel construction. The current for small clear distance tunnel through the study of fault fracture zone is relatively small, for a small clear distance tunnel construction experience in the fault fracture zone is not rich. Study the effect of fault of small clear distance tunnel stability has important engineering significance. In this paper, based on Dapingwei tunnel in Wenzhou engineering, on the basis of existing research results, on the subject carried on the thorough research of the system.First of all, this paper expounds the formation mechanism of the fault, using numerical simulation method from the angle of displacement variation of tunnel and tunnel oblique fault fracture zone problem was analyzed, and the analysis results show that the fault section of can make a significant increase in the displacement of surrounding rock, and makes the displacement change is asymmetrical distribution and excavation section on both sides of the fault area about the size of the asymmetric distribution of decisive results.Secondly this paper analysis the dapingwei tunnel in fault buried small clear distance for construction scheme optimization, simulation with different excavation methods(whole section method, steps method, single wall pilot tunnel method) for level of surrounding rock ?of the fault, fault of surrounding rock excavation, the simulation results show that before entering the fault level of surrounding rock is the most suitable? excavation method in step method, the surrounding rock in the fault can only be used in the single side method of pilot tunnel excavation can ensure the stability of the tunnel. This paper also discusses simulation about hole excavation sequence to contain the fault buried section on the stability of small clear distance, analysis results show that both left first excavation hole and little influence on the stability of tunnel excavation right hole.Finally this paper to dapingwei tunnel F6 fault monitoring measurement analysis of measured data and simulation results are compared with the measured data of multiple sections can verify the results of numerical simulation analysis, there are some of the measured data with the numerical simulation results is not the same, the article on the causes of this phenomenon are analyzed and expounded, too.Based administered front, adopted the advanced numerical calculation method and analysis method, to carry out the fault of deep research on the effects of small clear distance tunnel stability, did research work has the high value of engineering application, the design and construction of similar engineering have higher reference value.This thesis is on the forefront of academic research. Using advanced numerical methods and analytical means, the study for the dynamic response characteristics of the tunnel affected by fault zone and the optimal grouting scheme was carried out. The work done has a high engineering application value, and provides an effective means to systematically analyze the influence of tunnel with the fault zone during the period of blasting excavation.