Study On Key Technology Of Tunnel Passing Through Fault Fracture Zone Construction

Tunnel passing through fault fracture zone is a very difficult problem of tunnelconstruction, many engineering geomechanics problems caused by fault, The fault fracturezone geological changes variety, causes instability of engineering rock mass, geologicaldisasters frequently occurres. This dissertation relies on the Gui-guang passenger railway lineJinbaoding tunnel long fault fracture zone construction project, by means of theoreticalanalysis, numerical simulation, site monitoring and measurement, forepoling, excavation andsupport of Jinbaoding tunnel passing through fault fracture zone has been systematicallystudied, The following knowledge and results were obtained:(1) Analysis of Jinbaoding tunnel surrounding rock geological situation and existingproblems, summed up the experience and achievements of the various types of tunnel support,technical support is provided for Jinbaoding tunnel fault fracture zone construction, foradverse geological section, it’s necessary to strengthen the advanced geological prediction,ahead of borehole geophysical, to provide a scientific basis for the successfully constructionof the tunnel.(2) Analysis of the problems encountered and original construction plan characteristicsof Jinbaoding tunnel fault fracture, optimized Tunnel excavation and support design of tunnelfault fracture zone, formulated double row of small pipe grouting advance support andthree-step seven-step excavation program, and to develop a monitoring and measurementprogram for Jinbaoding tunnel fault fracture zone geological conditions.(3) By means of finite element numerical simulation, surrounding rock stability ofdouble row small pipe grouting and the three-step seven-step excavation program wasanalysed, surrounding rock stress and influence, interaction between support and surroundingrock was explored, the key parts of surrounding rock stability control and reinforcementmeasures was determined. By numerical simulations to verify the effect of the constructionprogram, obtained the stress and displacement field after the excavation, it can providetechnical support for the tunnel support and excavation program.(4) Field test, monitoring and measurement surrounding rock deformation and supportforce, realized the surrounding rock stress and deformation conditions, to evaluate thestability of the tunnel, through the on-site monitoring and measurements, timely monitoring ofsurrounding rock deformation, inspection the construction programs reasonable and thestability of the supporting structure.