GPR 반사 특성과 탄성파 속도를 이용한 매설부 지반 특성 연구 : 지하 매설 통신 케이블 탐지를 위한 GPR 및 탄성파 탐사를 활용한 위치 검증 = Location Verification of Underground Communication Cables Using GPR and Seismic Surveys

다국어 초록 (Multilingual Abstract)

Urban underground spaces contain densely installed utilities such as power cables, communication lines, and water and sewage pipelines. As these facilities age under repeated traffic loading and environmental fluctuations, the surrounding ground gradually deteriorates, forming cavities, loosening zones, and saturated layers. These subsurface changes rarely appear as surface deformation in the early stages, making timely detection difficult. Because conventional inspection methods such as excavation and CCTV provide only localized information and disrupt traffic, there is increasing demand for non-destructive techniques capable of continuously assessing subsurface conditions along extended pavement sections.
Ground Penetrating Radar (GPR) has been widely used to detect changes in dielectric properties associated with variations in water content, porosity, and material transitions. GPR reflection characteristics—such as amplitude variation, attenuation, and hyperbolic signatures—are particularly effective for identifying cavities and abrupt structural discontinuities. However, in clay-rich or highly saturated soils, increased electrical conductivity leads to rapid signal attenuation, reducing penetration depth and complicating interpretation. Seismic methods complement these limitations by evaluating mechanical stiffness through wave velocity. Reductions in P- or S-wave velocities are strongly associated with loosened ground, weakened bedding layers, and disturbed zones surrounding deteriorated pipelines. While seismic techniques often provide clearer detection of gradual stiffness loss, they offer lower spatial resolution compared to GPR. Given the complexity of urban subsurface conditions, no single geophysical method can fully characterize the overlapping mechanical and hydraulic changes occurring beneath pavements. Therefore, integrating GPR and seismic investigations enhances diagnostic reliability by combining sensitivity to dielectric contrasts with sensitivity to elastic property variations. The complementary nature of these techniques enables more robust identification of subsurface anomalies and reduces interpretation uncertainty. This study aims to develop an integrated assessment framework for pavement substructure diagnostics by jointly analyzing GPR reflection responses and seismic velocity structures. GPR is used to characterize dielectric anomalies, while seismic data delineate stiffness variations and weakened layers. The correlation between electromagnetic and elastic responses is subsequently examined to derive a multi-physics interpretation scheme. The proposed integrated approach provides a more comprehensive understanding of subsurface deterioration processes and supports proactive management of urban buried infrastructure to prevent settlement and sinkhole hazards.

목차 (Table of Contents)

• 목 차 ⅰ
• 그림목차 ⅱ
• Ⅰ. 서 론 01
• 1. 연구 필요성 01
• 2. 연구의 목적 03
• Ⅱ. 지반 물리탐사 기반 포장하부 특성 이론 05
• 1. 지반 물리탐사 개요 05
• 1) 지반 물성의 기본 개념 06
• 2) 포장하부 지반의 일반적 변화 유형 07
• 2. Ground Penetrating Radar(GPR)의 기초 이론 08
• 1) 전자기파 전파 특성 08
• 2) GPR 시스템 구성 09
• 3) 반사 매커니즘 및 이상신호 특성 11
• 3. 탄성파 탐사의 기초 이론 14
• 1) 탄성파 종류 및 물리적 특성 14
• 2) 주시곡선 해석 15
• 3) 속도층 기반 지반 평가 방법 17
• 4. GPR 및 탄성파 자료의 처리 및 해석 방법 19
• 1) GPR 데이터 해석 방법 19
• 2) 탄성파 데이터 해석 방법 21
• 3) 이상부 판별 지표 23
• Ⅲ. 연구 방법 26
• 1. 연구 대상지 26
• 1) 지형 및 지질 개요 27
• 2) GPR 탐사 위치 및 측선 설정 28
• 3) 탄성파 탐사 위치 및 측선 설정 32
• 2. GPR 및 탄성파 기반 현장 탐사 절차 37
• 1) GPR 탐사 수행 방법 37
• 2) 탄성파 탐사 수행 방법 38
• Ⅳ. 연구 결과 40
• 1. GPR 탐사 결과 40
• 2. 탄성파 탐사 결과 66
• Ⅴ. 토 론 81
• Ⅵ. 향후 연구의 필요성 85
• Ⅵ. 결 론 88
• 참 고 문 헌 90
• 영 문 초 록 94