Shaft Frozen Wall And Sidewall Interaction Analysis Of Cretaceous

The major coal-producing regions of the western raised a new climax of well constructions with the further implementation of the country's western development strategy. But most of the formation which western mines through is the Cretaceous, and the Quaternary alluvium is no more than 30m. So far, for lacking of knowledge and construction experience in these special strata, the outer wall was crushed and flooding accident emerged have appeared in the construction of several mines. which give great impct to wellbore safety and mine construction. At present, many new theoretical and technical issues need to be resolved for the application of freezing sinking in Cretaceous strata.This paper took the Inner Mongolia Bojiang-Haizi mine as the research background and two walls problems of freezing sinking in Cretaceous strata as the main line, the exploratory study was conducted for the temperature field, stress field of the interaction of two walls through theoretical analysis, field measurement and numerical simulation. This paper mastered the temperature changes of the frozen wall and the shaft wall in various stages of the freezing, frozen outer shaft wall force characteristic and its distribution along with depth, and proposed the linear equations of the Cretaceous frozen pressure varied with the depth:P=0.00138H+1.0065 MPa (P—the frozen pressure, H—the depth of the strata,m).The study of the issues explored the load design problems of the outer shaft wall of the Cretaceous in western China, and successfully applied to the optimal design of frozen wall in the Bojiang-Haizi mine. Through the field measurement, the load value on the edge of outer shaft wall caused by the blasting and the security blasting distance and other parameters were obtained.Figure 57 table 24 reference 57...