Research And Application Of Compressible Shaft Lining Joint In Frozen Shaft At Reconstruction Project Of Xutuan Mine

Since the1980s, China’s Anhui Huainan and Huaibei, Xuzhou, Jiangsu, Henan Yongxia, Yanzhou, Shandong and Heilongjiang have occurred, such as a large number of mining accidents Shaft Wall rupture, the existing shaft rupture reason to have reached a consensus that the ruptured well through the wall of the bottom surface soil aquifer overlying weathered bedrock direct segment, lack impermeable layer, due to the hydrophobic bottom aquifer have an effect on the settlement on the vertical wellbore additional force (negative friction) is caused by Shaft the main shaft rupture.New primary wells and wells north Xutuan mine expansion project are hydrophobic settlement through such formations, so the structural design of the wall, you should consider the impact of vertical additional force to prevent the wall rupture.In this paper, theoretical analysis, experimental and numerical simulation model combining research methods for coal mine expansion project Xutuan freeze well borehole shrinkable joint research, content and results are as follows:(1) According to the design principles and methods of freeze wells retractable wall of the joint, for Xutuan new primary wells and mines north wells, each set of vertical borehole retractable connector1, located357m and353m deep tired horizons and get a freeze wells may reduce the structural parameters of the wall joints.(2) the use of the model test method, can reduce the vertical joints of the wall, the lateral load model and triaxial tests. The results showed that the vertical wall of the case load of the compression fitting up to47percent rate, under triaxial loading conditions the wall joint compression rate of up to48.8%, the lateral wall of the joint case load bearing capacity of up to29.16MPa, we can see that the wall shrinkable joint has good compression properties and water resistance.(3) the use of numerical simulation methods, the mechanical properties of the wall can be reduced joint analysis. By numerical simulation of vertical bearing capacity of the wall fitting and model test results were compared to verify the reliability of the numerical simulation.(4) According to the freezing of the inner wall of the wellbore construction process, proposed freezing mine site construction technology compressible shaft wall joints.Freeze well shrinkable joints Xutuan mine borehole wells and northerly new primary wells have been successfully applied, the corresponding design and construction techniques can providea reference for similar projects. Freeze well shrinkable joints can be widely used in coal borehole construction of new wells and expansion project under similar conditions of formation, will generate greater social and economic benefits.