일정수직강성조건의 직접전단시험을 통한 말뚝-암반 경계면의 전단거동 분석 = Shear Behavior Charateristics of Drilled Shaft - Rockmass Interface Using Direct Shear Test Under Constant Normal Stiffness Condition

국문 초록 (Abstract)

본 연구에서는 암반에 근입된 현장타설말뚝의 전단거동 분석을 위하여, 기존 문헌 및 실내외시험을 수행하여 암반 거칠기를 정량화하였으며 말뚝-암의 경계면의 전단거동을 모사할 수 있는 일정수직강성도(CNS) 전단시험을 수행하여 암의 거칠기, 일축압축강도, 초기수직응력 등에 따른 암석과 콘크리트 부착면의 전단거동을 파악하였다. 이를 토대로 암석시편의 거칠기 및 일축압축강도 뿐만 아니라 거칠기의 탄성압축에 의한 영향을 반영 가능한 전단 강도식을 산정하였으며, CNS 직접전단시험 결과와의 비교분석 결과 본 제안식이 전단거동의 여러 영향요소들을 적절히 반영하고 있음을 알 수 있었다. 또한 본 제안식과 기존의 국내 기준식을 통하여 산정된 말뚝-암 시편의 전단강도의 비교분석 결과, 본 제안식을 통해 산정된 최대전단강도는 암석시편의 거칠기와 초기수직응력이 커질수록 기존 기준으로부터 산출된 최대전단강도에 비해 상당히 크게 나타냄을 알 수 있었다.

다국어 초록 (Multilingual Abstract)

This paper described the theoretical shear strength function proposed to predict the shear behavior of pile-rock joint under constant normal stiffness condition. The quantified values of rock socket roughness were determined through previous studies and this study. Constant normal stiffness direct shear tests were carried out to quantify the shear behavior characteristics based on major influencing factors of shear behavior such as asperity angle, unconfined compressive strength, initial confining stress. Based on CNS test results, this paper proposed the shear strength function simulating the major influencing factors of shear behavior of pile-rock joint, including asperity angle, unconfined compressive strength and elastic compression displacement as well. The proposed function was verified by the CNS test result performed to artificial rocks molded to describe regular asperities, granite and gneiss. Through comparisons with the CNS test results, it is shown that the shear strength function by this study is in good estimation with the general trend observed by the tests. Through comparisons of the maximum shear strength between the domestic criterion of shaft resistance and shear strength function of this study, it was shown that the maximum shear strength by the function of this study considerably increased than the strength by the doemstic criterion along with the higher asperity angle and initial confining stress.

목차 (Table of Contents)

• Abstract
• 요지
• 1. 서론
• 2. 암반 굴착면 거칠기 정량화
• 3. CNS(Constant Normal Stiffness) 직접전단시험
• 4. 전단거동의 영향요소가 반영된 전단함수식의 산정
• 5. CNS 전단시험결과의 비교분석
• 6. 전단함수식 특성분석
• 7. 결론
• 참고문헌

참고문헌 (Reference)

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• 2 한국도로공사, "암반에 근입된 현장타설말뚝 설계기준 수립" 한국도로공사 2002
• 3 설훈일, "굴착면 거칠기를 고려한 암반 근입 현장타설말뚝의 주면하중전이함수 제안" 한국지반공학회 22 (22): 2006
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• 5 한국지반공학회, "구조물 기초설계기준해설" 한국지반공학회 2003
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