Reason Analysis And Prevention Measures Of Water Leakage For Shaft Lining At Frozen Shaft In West Area

With economic growth and the implementation of the western development strategy, history of the largest mine construction being carried out in the western region. Freezing Sinking method is widely used in mine construction, the problem about water bursting and leakingof concrete shaftling have not been solved completely. In the structure design of frozen shaftlinings, the parameters in the existing design specifications and design between east and west manuals are to the area of middle and eastern, therefore, the stratigraphic differences should be considered in the causes and prevention of water leakage for shaftlining.In this paper, double reinforced concrete wall structure the object of study, By researching the domestic related experimental results in the western region, we can know the bedrock freezing pressure property of the Jurassic and Cretaceous. According analysis of the overall stress characteristics and stress mechanism for the inner and the outer layers of the concrete wall in the western region.Pointting out that we can thinning outer shaft linings and strengthen waterproof measures of the inner shaft linings. As porous medium, concretes of shaftlining are affected by groundwater seepage and concrete damage softening. From analytical analysis of water leakage mechanism for concrete inner shaftlining at high water pressure,we can kown that Poc (the critical water pressure of shaftlining)decreases with the increase of φ(the porosity of concrete)and E√E(the ratio of concrete damage softening modulus and Young’s modulus), at the same time, the critical plastic damage zone radius of shaftlining is also decreases gradually. In addition, analyzed by ABAQUS simulation software for the force of the concrete shaftlining, when considering fluid-solid coupling theory, we can kown concrete stress, displacement increased significantly and the equivalent plastic strain and damage increase,which is unfavorable to the stability of the coal mine concrete shaftlining. So using the seepage stress coupling analysis method, the actual force situation about he coal mine concrete shaftlining is more truly reflected.In order to prevent water bursting and leaking of concrete shaftling, in this paper, propose to reduce the amount of cement by add slag and other admixtures, and use low heat hydration of cement at the same time. We can not only ensure the strength of concrete but also reduce cement hydration heat of freezing shaftling, so as to reducing temperature stress and temperature cracks of concrete. At the same time, it has advanced a method which mix polypropylene fibers, expansive agent and Superplasticizer into high-performance concrete of shaftling in order to enhance impervious and anti-cracking of high-performance concrete. This method can reduce concrete shrinkage deformation and increase the volume stability and solidity of shaftling concrete, improving of cracking and permeability characteristics, and playing a very good role in preventing water bursting and leaking of concrete shaftling in the bedrock segment of western section.