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2025 Vol.41, Issue 6 Preview Page
Effect of Impact System Parameters on Microphone-Based Detection of Subsurface Cavities behind Wall Structures

벽체 하부 공동 검측을 위한 음파 탐사시 타격 시스템의 영향

Jeong Eon Park1
,
Jong-Sub Lee2
,
Hoang Ngoc Quy3
,
Seonghun Kang4*
박 정언1
,
이 종섭2
,
호앙 녹퀴3
,
강 성훈4*
1Member, Graduate Student, School of Civil, Environmental and Architectural Engineering, Korea Univ.
2Member, Prof., School of Civil, Environmental and Architectural Engineering, Korea Univ.
3Post-Doctoral Researcher, Department of Civil and Environmental Engineering, Univ. of Waterloo, Canada
4Member, Research Prof., Future and Fusion Lab of Architectural, Civil and Environmental Engineering, Korea Univ.
1정회원, 고려대학교 건축사회환경공학과 석사과정
2정회원, 고려대학교 건축사회환경공학부 교수
3비회원, 캐나다 워털루 대학교 박사후 연구원
4정회원, 고려대학교 초융합건설포렌식연구센터 연구교수
*Corresponding Author
31 December 2025. pp. 167-177
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Abstract

Depth of a cavity behind a wall structure is a primary factor in assessing risk, so evaluating detectability versus depth is essential. This laboratory study examined how impact system parameters influence cavity detection using microphone measurements. Parameters include the distance between the cavity center and impact point, hammer tip material, and wall thickness. A model chamber with a simulated wall and adjustable cavity depth was used. Acoustic signal and impact loads were measured while varying top-plate thickness and hammer tip material. Flexibility was derived from the measured signals and compared across test conditions. Results show that measured flexibility increased as the impact point approached the cavity center, and that a rubber hammer tip produced deeper-penetration responses than a plastic tip. These findings indicate that microphone-based methods can effectively detect deep cavities behind wall structures.

Keywords
Cavity detection
Flexibility
Hammer tip
Microphone
Wall structure

벽체 구조물 배면의 공동 깊이는 공동의 위험도와 직결되므로, 공동 깊이에 따른 공동 검측 가능성에 대한 연구가 필수적이다. 본 연구에서는 공동 중심과 타격 지점 간의 거리, 해머 팁 재질, 벽체 두께와 같은 타격 시스템 변수들이 공동 검측 가능성에 미치는 영향을 평가하고자 실내 실험을 수행하였다. 모형 공동과 벽체를 포함한 토조를 조성하였으며, 상부 판으로부터의 거리를 조절하며 토조 내에 모형 공동을 매설함으로써 서로 다른 깊이의 공동을 모사하였다. 상부 판의 두께 및 해머 팁 재질을 변화시켜 음파 신호를 측정하였다. 본 연구에서는 구조물에 단위 하중이 가해졌을 때 발생하는 처짐과 동일한 개념인 유연성 값을 측정된 음파 및 하중 신호를 활용하여 산정하였으며, 이를 바탕으로 타격 시스템 변수에 따른 유연성 변화를 비교 분석하였다. 실험 결과 타격 지점이 공동 중심에 근접할수록 유연성이 크게 나타났으며, 고무 팁이 플라스틱 팁에 비해 더 깊은 가탐 깊이를 보였다. 본 연구는 마이크로폰이 벽체 배면의 깊은 공동을 검측하기 위해 유용하게 이용될 수 있음을 보여준다.

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Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 41
  • No :6
  • Pages :167-177
  • Received Date : 2025-11-14
  • Revised Date : 2025-12-08
  • Accepted Date : 2025-12-09
  • DOI :https://doi.org/10.7843/kgs.2025.41.6.167
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