Research On Retarding Cement Replacement Technology Of Waterproof In Vertical Shaft Ultra-deep Freezing Hole

In recent years, with the construction of western rock mining which is well watered,ultra-ground freezing method for shaft sinking is gradually widely used. In order to prevent freezing holes become vertical guide water channel, threat Underground tunnel cavern even the safety of the mine, Freezing hole to seal hole is the key problem in urgent need of research to solve. In view of the problem, for the freezing hole retarding cement grout hole sealing construction faced by retarding cement retarding time, water sealing performance of slurry concretion body and a series of key technical problems. Combined with theoretical analysis, this research through a large number of indoor test, conducted a relatively comprehensive researchFirst of all, through consulting relevant literature, Summarizes and analyzes the deep freeze hole retarding mechanism of cement waterproof technology. Block freezing holes and the annular space, blocking the upper to the lower water flow, by the slurry consolidation. The key technology of extracting waterproof technology, initial setting time of Slurry is to reach 30 h, slurry has a good stability, stone body mechanics performance to meet the requirements of deep ground pressureSecondly, through lots of laboratory tests, researches on the coagulation time and stability of retarded cement slurry are conducted. The study shows that, by applying the JS-1 type concrete retarder developed by Xi’an University of Science and Technology, the initial setting time of the cement slurry can reach over 40 hours, meeting the requirement of ultra-ground freezing method for shaft sinking, that is through mixing bentonite into the cement slurry, the stability of retarded cement slurry will be greatly improved.Lastly, via the method of laboratory sample simulation experiment, study is carried out to measure how the uniaxial compressive strength of the cement grout stones with different water cement ratios will change in the freezing and thawing. At the same time, how the shear strength between the cement grout stones and the cementation plane of the neighboring medium will change in the freezing and thawing is also measured. By mixing expanding agent into the retarded cement grouts, conclusion is made that shear strength between cement grout stones and its neighboring medium can be effectively improved through mixing the expansion agent.