Tidal Effect on Grouting in Karst Fracture with Flowing Water: Experimental Investigation and Its Application

To address the problem on grouting control of water inflow disaster in coastal area, a caisson-type grouting experimental system of a single fracture in flowing water under tidal action was developed independently. Through the tide simulation system, the tidal action of different intensity and frequency was effectively described. Tide simulation system, fracture system, grouting system, water supply system and information monitoring system were combined to realize the visualization of the whole grouting process under tidal action. Furthermore, the grouting experiments of a plate fracture under different tidal action were developed and the blocking mechanism under tidal action was revealed. The conclusions were as follow: 1) Under constant water head, the slurry had three typical diffusion patterns, which were circular distribution, double U-shaped distribution and elliptical distribution respectively. 2) Under tidal action, the pressure showed a periodic fluctuation growth, and the growth rate slowed down with the increase of fracture aperture. 3) Strong tidal action would promote the diffusion of and increased the outflow amount of slurry, which was not conducive to grouting. Based on the water inflow treatment project of limestone mine in Guangxi, Through the field grouting tests, the 2# water inflow point was blocked. The research results have a certain reference value for the technology optimization of grouting engineering in coastal areas.