Research On Pressure Strengthening Support Technology Of Soft Rock Roadway In Qingshuiying Coal Mine

As the mining depth increases,the surrounding rock stress of the roadway gradually increases,and the amount of water inflow continues to increase.The roadway often produces plastic deformation and exhibits soft rock characteristics.The support of soft rock roadways has always been a complicated mechanical problem of rock mass.This article takes the soft rock roadway in Qingshuiying Coal Mine of Ningdong Coalfield Ningxia Hui Autonomous Region as the research object.This paper adopts research methods such as mechanical theory analysis,physical experiment of concrete-filled steel tube short columns,numerical calculation of support design,and monitoring of field control effects.This article clarifies the principle of roadway pressure ring support measures,studies the soft rock roadway pressure strengthening support technology of Qingshuiying Coal Mine,describes new support measures for low-strength soft rock roadways,effectively controls the stability of roadway surrounding rocks,and realizes the roadway to meet full-cycle service.It has important research significance for the promotion of surrounding rock control of roadways.This paper clarifies the soft rock support mechanism based on the roadway pressure ring.The geometry and mechanical boundary of the roadway pressure ring and the criterion of the stability of the soft rock roadway under the action of the roadway pressure ring are determined.The components such as the anchor rod(cable),anchor shotcrete and concrete-filled steel tube support in the roadway pressure ring are qualitatively analyzed The function of the surrounding rock reveals the mechanical response characteristics of the surrounding rock after excavation of the roadway.This paper studies the bearing performance of concrete-filled steel tube supports in roadway support.The pressure-bearing characteristics of five materials such as concrete,confined concrete,steel tube,concrete-filled steel tube,and U-shaped steel are compared,and the advantages of concrete-filled steel tube as a soft rock roadway support for roadway pressure ring are clarified.The effects of the nominal diameter and wall thickness of concrete-filled steel tubes on the load-bearing properties of short columns were experimentally studied.In this paper,the steel pipe concrete support model of soft rock roadway in Qingshuiying Coal Mine is established,and the control law of steel pipe concrete support in soft rock roadway is revealed.Comparing the stability of the surrounding rock of the tunnel after the excavation of the tunnel is unsupported at the beginning of excavation and the composite support of the concrete-filled steel tube support,the action force of the concrete-filled steel tube support and anchor(cable)support is analyzed.And the support schemes of 7 different sections of the main substation tunnel are designed.This paper monitors the control effect of concrete-filled steel tube supports in soft rock roadways.Measured the amount of roof sag of the soft rock roadway,the amount of approaching the two sides,the amount of bottom deflection and the amount of deformation of the concrete-filled steel tube support.,Analyzed the social benefits of concrete-filled steel tube supports,and put forward reasonable suggestions to reduce costs.There are 47 figures,11 tables and 70 references in this paper.