Diffusion of Grouting Cement in Water-Rich Ultracataclasite Stratum

When the tunnel and underground engineering construction encounters water-rich soft broken surrounding rock, it is very easy to occur serious disasters such as mud inrush, water inrush collapse, threatening safety of construction. Taking ultracataclasite stratum exposed by 4th branch Xianglushan Tunnel in Central Yunnan Water Diversion Project an example, this has strong compactness, weak permeability, softening other unfavorable geological characteristics. During excavation process, several major have occurred. In paper, basic physical mechanical properties rock are tested based on field examples, grouting diffusion law under condition studied PFC2D numerical calculation software. The research results show that according parameters density, content, permeability coefficient, particle size distribution, specific gravity, porosity, cohesion internal friction angle obtained from laboratory test analysis shows shear strength low, further leading outburst collapse disasters. Under comprehensive consideration number split grout veins, distribution range risk damage existing support, optimal pressure determined.