Research And Application On Excavation Construction Technology Of Vertical Shaft In Hard Loess Layer

The western region is covered with a thick layer of Quaternary loess, reached a depth of 200 m~300 m, its deep is the old middle Pleistocene loess, which soil contains calcium cement, particularly hard. Loess layer generally has collapsibility, weak expansibility, water is easy to cause the loess layer bonding structure destruction, produce the larger plastic deformation. Blasting drill in loess layer prone to collapse holes, deflection and slagging problems and other technical problems. At the wellbore wall rock blasting will produce large artificial disturbance, the blasting parameters is difficult to determine. Meanwhile, technical problems of ordinary construction are caused by the special structure of the loess spalling, high plastic deformation, and so on.The thesis background with Shaozhai mine return air shaft construction conditions, based on common law Shaft Construction Technology, theoretical analysis, numerical simulation and engineering practice methods have been employed to study hard and special thick layer of loess Shaft excavation construction technology.The paper based on the theory of stability of surrounding rock of shaft lining, analyzed the shaft surrounding rock stress distribution, predicted shaft surrounding rocks displacement and thickness of shaft lining. FLAC3 D numerical simulation method is used, analyzed the different height of excavation section and support thickness effects on shaft stability of surrounding rock, obtained the reasonably height of excavation section and support thickness.The thesis based on the principle and advantages of spiral drilling, puts forward the umbrella drill with special spiral drill pipe dry drilling technology, achieved fast and efficient in loess layer of purpose to fight deep eye, and the spiral drill parameter calculation method and its parameters.is presented; Based on loose blasting technology, theoretical calculation and optimization of the deep hole loose blasting parameters,to reduce blasting anthropogenic disturbance on the surrounding rock of the shaft is reduced.The research results have been applied successfully in the Shaozhai coal mine, the umbrella drill with special auger drilling technology and the deep-hole loose blasting technique are worked in the deep loess layer, and a short sectional excavation and lining combined single-line operation is applied to the conventional mine shaft sinking. The engineering practice shows that the method achieved a safe continuous shaft excavation and lining construction 294 m of special thick and hard loess layer, where construction speed 0 ~-100 m section is 82 m/month,and-100 ~-294 m section is 80 m/month. A better economic and technical result is achievedand and it provided a reliable theoretical basis for the thick loess layer of mine shaft rapid construction. The advancement and development of the loess layer of shaft construction technology is promoted.