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Calibration of Borehole Roughness Measurement System for Large Diameter Drilled Shafts in Water

수중에서 적용가능한 대구경 현장타설말뚝의 굴착공 벽면거칠기 측정장치의 보정에 관한 연구

  • Published : 2009.08.31

Abstract

Based on recent studies on rock socketed drilled shafts, it was found that the side resistance of rock socketed drilled shafts is affected by unconfined compressive strength of rock, socket roughness, rock types and joints, and initial normal stress. Especially, the socket roughness is affected by rock types and joints, drilling methods, and diameters. Since existing roughness measurement systems could be conducted only in the air, a new roughness measurement system, which can measure rock socket roughness in the air and also in the water, is needed. However, the development of new roughness measurement system fur civil engineers has been faced with difficulties of electrical applications. In this study, the laboratory verification system far BKS-LRPS (Backyoung-KyungSung Laser Roughness Profiling System) was developed, which can be applied both in the water and air. Based on the laboratory verification, it was found that the improved BKS-LRPS could define effective measurement distances for the conditions reflecting the apparatus and in-situ situations.

암반에 근입된 현장타설말뚝의 주면마찰력에 대한 최근의 연구결과에 따르면 주면마찰력은 암석의 일축압축강도 외에 굴착면의 거칠기, 암반의 재료특성, 초기 수직음력, 말뚝의 직경, 암반의 절리 및 풍화도 등에 크게 영향을 받는 것으로 보고되어 있다. 지금까지 개발된 굴착면 거칠기 시스템들은 공기 중에서만 측정가능하므로 현장의 굴착공내에서 직접 측정하는 것은 불가능하였다. 따라서, 본 연구에서는 수중에서 사용가능한 굴착공 벽면거칠기 측정 시스템(BKS-LRPS)을 개발하였으며, 특수 제작된 보정장치를 통하여 여러 가지 경우에 대한 검증을 수행하였다. 연구결과에 의하면, 개발된 BKS-LRPS는 장치제작조건 및 현장조건을 반영하도록 계획된 검증조건들에 대하여 유효측정영역을 제시할 수 있었다.

Keywords

References

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