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고강도 암반에서 수직구 기계굴착을 위한 연마재 워터젯 활용에 관한 연구

A study on the utilization of abrasive waterjet for mechanical excavation of hard rock in vertical shaft construction

  • 조선아 (한전전력연구원 송변전연구소 구조건설연구실 ) ;
  • 정주환 (한전전력연구원 송변전연구소 구조건설연구실) ;
  • 류희환 (한전전력연구원 송변전연구소 구조건설연구실 ) ;
  • 박준식 (부산대학교 사회환경시스템공학과 ) ;
  • 오태민 (부산대학교 사회환경시스템공학과 )
  • Seon-Ah Jo (Structure & Construction Technology Group, Transmission & Substation Laboratory, KEPCO Research Institute) ;
  • Ju-Hwan Jung (Structure & Construction Technology Group, Transmission & Substation Laboratory, KEPCO Research Institute) ;
  • Hee-Hwan Ryu (Structure & Construction Technology Group, Transmission & Substation Laboratory, KEPCO Research Institute) ;
  • Jun-Sik Park (Department of Civil and Environmental Engineering, Pusan National University (PNU)) ;
  • Tae-Min Oh (Department of Civil and Environmental Engineering, Pusan National University (PNU))
  • 투고 : 2023.07.24
  • 심사 : 2023.08.18
  • 발행 : 2023.09.30

초록

TBM을 이용한 전력구 공사에서 수직구는 TBM 장비 및 전력선의 진출입을 위해 필수적인 구조물이다. 수직구는 지반을 수직으로 관통하여 굴착하기 때문에 암반을 굴착하는 경우가 많다. 암반 지반은 대부분 발파나 할암 공법을 적용하여 굴착하므로 이때 발생하는 소음 및 진동, 도로 점유로 인해 민원이 발생하고 있다. 따라서 기존 공법의 대안으로 기계식 굴착장비를 이용한 수직구 굴착을 고려하였다. 다만, 현 기술 수준에서 수직구 굴착장비는 암반의 압축강도 약 120 MPa 이상에서는 굴착성능이 현저히 저하되어 고강도 암반 지반 적용에 한계가 있다. 본 연구에서는 암반에서 기계식 굴착 성능 개선을 위해 연마재 워터젯 기술을 굴착 보조공법으로 활용하는 방안에 대해 검토하였다. 연마재 워터젯 절삭성능에 대한 검증을 위해 암석 절삭실험을 수행하고, 실험결과로부터 이격거리, 이송속도, 수압 조절을 통해 지반조건 변화에 대응하여 굴착성능을 확보하는 것이 적절할 것으로 판단하였다. 또한, 일축압축강도와 RQD, 굴진율의 관계를 이용하여 연마재 워터젯을 이용한 인위적인 절리생성을 통해 굴착성능을 향상시키는 방안을 제시하였다. 본 연구결과는 향후 수직구 기계식 굴착장비 도입을 위한 기초자료로 활용될 수 있을 것으로 기대된다.

In cable tunnel construction using TBM, the vertical shaft is an essential structure for entrance and exit of TBM equipment and power lines. Since a shaft penetrates the ground vertically, it often encounters rock mass. Blasting or rock splitting methods, which are mainly used to the rock excavation, cause public complaints due to the noise, vibration and road occupation. Therefore, mechanical excavation using vertical shaft excavation machine are considered as an alternative to the conventional methods. However, at the current level of technology, the vertical excavation machine has limitation in its performance when applied for high strength rock with a compressive strength of more than 120 MPa. In this study, the potential utilization of waterjet technology as an excavation assistance method was investigated to improve mechanical excavation performance in the hard rock formations. Rock cutting experiments were conducted to verify the cutting performance of the abrasive waterjet. Based on the experimental result, it was found that ensuring excavation performance with respect to changing in ground conditions can be achieved by adjusting waterjet parameters such as standoff distance, traverse speed and water pressure. In addition, based on the relationship between excavation performance, uniaxial compressive strength and RQD, it was suggested that excavation performance could be improved by artificially creating joints using the abrasive waterjet. It is expected that these research results can be utilized as fundamental data for the introduction of vertical shaft excavation machines in the future.

키워드

과제정보

본 연구는 한국전력공사 자체연구개발 과제(R23SA01) '전력구 터널용 뒷채움재 적용기준 및 친환경 뒷채움재 개발'의 지원으로 수행되었습니다. 연구지원에 감사드립니다.

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