Research On Blocking Diffusion Law And Control Parameters Of Microcracks Rock Mass

In the process of building city subway and the mountains tunnel,we often encountered a sudden surge of water disaster,usually grouting is the method of the sudden flood water disaster governance.Because of the complexity of underground engineering rock mass and the concealment of the grouting engineering factors such as constraints,the grouting theory is difficult to provide effective engineering of actual grouting engineering technical guidance. Micro-fractured rock mass water disasters is an important type of water disasters. The scale of the microcracks is lesser, width is between 0.1-1 mm,and conventional grouting materials and grouting parameter does not apply; Space of the bedrock micro-fracture is anisotropy,and channel complex lead to the damage,and targeted treatment was carried out on the water disasters;Due to micro-fracture structure concentrated,the grouting treatment improved the grouting pressure at the same time to ensure that the surrounding rock and the stability of the support under the condition of high pressure grouting;So it is necessary to establish a complete set of micro-fracture grouting theory and rock grouting control method to ensure the smooth implementation of grouting engineering.This article from the micro-fracture rock grout injection can be research,considering the effect of fluid-structure interaction micro-fracture grouting diffusion regularity of rock mass;the micro-fracture rock grouting control technology of three aspects research, has made a series of research results:(1)From the micro-fracture rock geological cause,the geometrical characteristics and distribution of microcracks and some of the fractured rock mass structure characteristic,and on the basis of the analysis of the micro-fracture rock types and characteristics of water disasters;Through analyzing the characteristic of the fracture structure and the influence of the grouting at the same time, with the help of a porous medium can note quality criterion.Getting the micro-fracture rock grouting cement slurry can note quality criterion, which consider different crack width and water cement ratio under the condition of ordinary cement and superfine cement slurry can note.(2)Considering in the process of the micro-fracture rock grouting slurry flow field and stress field of rock mass coupling, based on multiple physical field analysis software COMSOL Multiphysics,we establish micro-fracture rock grouting diffusion process finite element model,and research the micro-fracture rock grouting slurry pressure in the process of long time and space distribution rule and the crack opening and the regularity of deformation of surrounding rock stress,and grouting parameters and the quantitative relationship between grout diffusion range. Finally,we can gain micro-fracture grouting seal rock microcracks formed practical control parameters.(3)Relying on the Qingdao metro line 2 Dong～ Huan interval granite microcracks seepage grouting treatment project, apply of cement slurry and three of the ultrafine cement fineness micro-fracture rock grouting field test study, the grout injection can be theory and numerical simulation results verifies the correctness.(4)In view of the micro-fracture rock grouting engineering, puts forward the selection of grouting materials and water cement ratio control standards, grouting pressure and grouting flow dynamic control technology.And successful management of Qingdao metro line 2 Dong-Huan interval of 730m micro-fracture seepage disasters, meet the requirement of tunnel whole package.