• Geomechanics and Engineering
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• 제22권5호
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• pp.449-460
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• 2020

The double-lane arrangement model is frequently used in underground coal mines because it is beneficial to improve the mining efficiency of the working face. When the double-lane arrangement is used, the service time of the reserved roadway increases by twice, which causes several difficulties for the maintenance of the roadway. Given the severe non-uniform deformation of the reserved roadway in the Buertai Coal Mine, the stress distribution law in the mining area, the failure characteristics of roadway and the control effect of support resistance (SR) were systematically studied through on-site monitoring, FLAC 3D numerical simulation, mechanical model analysis. The research shows that the deformation and failure of the reserved roadway mainly manifested as asymmetrical roof sag and floor heave in the region behind the working face, and the roof dripping phenomenon occurred in the severe roof sag area. After the coal is mined out, the stress adjustment around goaf will happen to some extent. For example, the magnitude, direction, and confining pressure ratio of the principal stress at different positions will change. Under the influence of high-stress rotation, the plastic zone of the weak surrounding rock is expanded asymmetrically, which finally leads to the asymmetric failure of roadway. The existing roadway support has a limited effect on the control of the stress field and plastic zone, i.e., the anchor cable reinforcement cannot fully control the roadway deformation under given conditions. Based on obtained results, using roadway grouting and advanced hydraulic support during the secondary mining of the panel 22205 is proposed to ensure roadway safety. This study provides a reference for the stability control of roadway with similar geological conditions.

• Geomechanics and Engineering
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• 제27권6호
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• pp.537-550
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• 2021

There are various technical problems need to be solved in the construction process of pre-setting an isolation wall into a double lane in the outburst prone mine. This study presents a methodology that pre-setting an isolation wall into a double lane without a coal pillar. This requires the excavation of two small section roadways to dig a wide section roadway, followed by construction of the separation wall. During this process the connecting lane is reserved. In order to ensure the stability of the separation wall, the required bearing capacity of the isolation wall is 4.66 MN/m and the deformation of the isolation wall is approximately 25 cm. To reduce the difficulty of implementing support the roadway is driven by 5 m/d. After the construction of the separation wall, the left side coal wall is brushed 1.5 m to make the width of the gas roadway reach 2.5 m and the roadway support utilizes anchor rod, ladder beam, anchor cable beam and net configuration. During construction, the concrete pump and removable self-propelled hydraulic wall mold are used to pump and pour the concrete of the isolation wall. In the process of mining, the stress distribution of coal body and isolation wall is detected and measured on site. The results demonstrate that the deformation of the surrounding rock of roadway and separation of roof in the roadway is small. The stress of the bolt and anchor cable is within equipment tolerance validating their selection. The roadway is well supported and the intended goal is achieved. The methodology can be used for reference for similar mine gas control.

• 한국산학기술학회논문지
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• 제11권10호
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• pp.4005-4011
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• 2010

본 연구는 도로 다이어트 (차로폭 축소) 기법을 적용해 자전거전용도로를 확보한 부산시 남구 자전거도로 시범사업을 중심으로 자전거도로 설치가 자동차흐름에 미치는 영향을 분석하였다. 분석결과 비첨두시간 동안 자동차의 평균지체시간 및 평균정지횟수는 자전거전용도로 설치 후 다소 증가하였으나 통계적으로 유의한 차이를 나타내지 않은 반면, 첨두시간 동안 자동차의 평균지체시간 및 평균정지횟수는 자전거전용도로 설치 후 유의한 증가를 나타냈다(alpha=0.1). 첨두시간 분석결과는 교통량이 많을 경우 도로 다이어트가 차로혼잡의 가능성을 높일 수 있다는 기존 국외 연구 결과와 일치하며, 비첨두시간 분석결과는 여유용량으로 인해 자동차의 흐름이 도로 다이어트에 의해 큰 영향을 받지 않는 사실을 반영한 결과로 판단된다.