Research On Support Technology Of Deep Soft Rock Roadway

Coal is still an indispensable resource to support China’s economic development.In order to ensure the safety and efficiency of coal mining,the stability of roadway surrounding rock must be ensured.Methods such as field investigation,theoretical analysis and field test were adopted In this paper.The deformation characteristics of surrounding rock in the east wing belt conveyor roadway of-891 m in a coal mine are analyzed.The reasons of surrounding rock deformation were discussed.On this basis,the technique of controlling surrounding rock deformation in deep soft rock roadway was put forward.The main research results are as follows:(1)The surrounding rock loosening circle of east wing belt conveyor roadway is basically symmetric about the longitudinal symmetry plane of the roadway.Due to the change of stress state after roadway excavation,the surrounding rock will release a large amount of deformation energy in a short term.As a result,the elastic deformation of roadway surrounding rock is large in the early stage.In view of the deformation characteristics of the east wing belt conveyor roadway,the comprehensive support scheme of full section shed,anchor,cable,net and injection was proposed.The anchor rod and i-beam are used to lock the legs of the u-shaped bracket.The arch is reinforced with anchor cables and i-beams.(2)The mechanical model of U-shaped shed was established.The expressions of the key reinforcement parts of the u-shaped shed legs and the vault were derived.The key reinforcement parts of the u-shaped shed legs and the arch roof of the east wing belt conveyor were calculated.Respectively,they are two tent legs from the bottom of0.69 m,the center of the arch section and arch on both sides of the middle section84.6 ° cross-section.(3)Industrial tests were carried out on site.The results show that about 40 days after the excavation of the roadway,the displacement of the two sides gradually slows down.The displacement increment of two sides has the characteristic of two stages.Grouting can obviously restrain the displacement of two sides of roadway,roof subsidence and floor heave.The displacement of two sides cannot be controlled by the construction anchor cable at the key part of roadway roof.However,it has a significant effect on controlling roof subsidence and restraining floor heave.It can also control the displacement of surrounding rock deep in the roof.Figure[20] table[3] reference [80]...