Underground cavities are frequently taking place in urban areas due to soil loss caused by structural defects of underground buried pipes. In this study, a field experimental program was conducted to detect ground condition using the electrical resistivity survey and the pneumatic cone penetration test. In addition, we proposed a method to estimate the weighted mean resistivity value by quantifying the electrical resistivity measurements through image analysis in order to compare the results of pneumatic cone penetration test. Consequently, it was found that as the weighted average resistivity value decreased, the smaller the N-value (penetration depth per blow number) from the pneumatic cone penetration test results. Based on the limited number of field experimental measurements, the correlation between weighted average resistivity value and the N-value of pneumatic cone penetration test is deemed promising in assessment of ground conditions associated with developing underground cavitation.

Abstract
 1. 서 론
 2. 본 론
  2.1 현장실험 위치 선정
  2.2 현장실험 방법
  2.3 현장 실험 수행 및 결과
  2.4 전기비저항과 공압콘관입시험 측청치 상관관계
 3. 결 론
 REFERENCES

• 조동환(서울교통공사 사원) | Cho Dongwhan (Manager, Track Engineering Office)
• 김민수(한국교통대학교 철도융합기술연구소 연구원) | Kim Minsu (Researcher, Railway Technology Institute, Korea National University of Transportation)
• 오정호(한국교통대학교 철도인프라시스템공학과 부교수) | Oh Jeongho (Associate Professor, Dept. of Railroad Infrastructure System Engineering, Korea National University of Transportation) Corresponding author