Support technology of jacking trapezoidal concrete-filled steel tube support
The headentry of 0102303 working face in Baijigou Coal Mine is under the goaf of upper slice,the roof was a metal mesh artificial roof,and the original support deformed seriously due to the disturbance of the upper slice goaf.To solve the problem,the jacking trapezoidal concrete-filled steel tube support was designed,and the jacking performance of various types of supports was tested through grouting jacking test.The test results showed that,the grouting effect of Φ194 mm×10 mm steel pipe was good,and the jacking force reached 3.93 kN,which met the requirements of the jacking of the support and the initial support of the artificial roof.In order to increase the bending strength of the steel pipe beam,the bending round steel was set in the hollow steel pipe,and the calculated support reaction force was 2.3 MPa,which is 5.4 times higher than the original support.At the same time,in order to solve the installation difficulties of various kinds of supports in the roadway,a lifting support installation machine was designed with a maximum lifting force of 6.8 kN.The basic area of the support load was stable 30 days after the grouting,and the maximum support load was 0.8 MPa within half a year after installation.The on-site monitoring shows that the roof-to-floor convergence and side-to-side convergence were both within 50 mm,demonstrating a favorable supporting effect.
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