In the seismic evaluation of underground utility tunnels, selecting an analytical method is critical to estimating reasonable seismic responses. In simplified pseudo-static analysis methods widely applied to typical seismic design and evaluation of underground tunnels in practice, it is essential to check whether the methods provide valid results for cut-and-cover tunnels buried in shallow to medium depth. The differences between the two simplified pseudo-static methods are discussed in this study, and the analysis results are compared to those obtained from FLAC models. In addition to the analysis methods, seismic site classification, overburden soil depth, and sectional configuration are considered variables to examine their effects on the seismic response of underground utility tunnels. Based on the analysis results, the characteristics derived from the concepts and details of each simplified model are discussed. Also, general observations are made for the application of simplified analysis methods.
PURPOSES : Since the 1990s, underground utility projects have been conducted to solve the problem of aerial communication cables. The purpose of this study is to derive optimal measures for preventing collisions with existing underground utilities and for future maintenance in the implementation of the utilities undergrounding projects. This study considered the identifier sensor and tested the optimal sensor performance for more accurate and systematic management. METHODS : In this study, three representative technologies were selected from identifier sensors generally used in air and the possibility for their use in soil and asphalt was confirmed by simulating the environment via a test construction. Three identifier sensors were selected: BLE (Bluetooth low energy) beacon, ultra-high frequency radio frequency identification (UHF RFID), and a geomagnetic recognizer. The long-term recognition performance of each identifier sensor was tested using the underground depth as a variable and the results were analyzed for comparison.
RESULTS : The results of the test under limited conditions and environment demonstrated that the BLE Beacon had advantages in equipment composition, recognition range, and speed but exhibited problems with batteries in winter. The geomagnetic recognizer did not show the exact location and its influence on the surrounding environment was a disadvantage.
CONCLUSIONS : Although the performance of UHF RFID has been demonstrated to be relatively suitable under these test conditions, it seems that the impact of the more diverse installation depth or medium should be reviewed for actual commercialization.
지진시 사회 인프라시설물의 피해는 시설물 자체의 피해보다 사회 전반에 걸친 2차 피해를 야기한다. 그 중, 지하 공동구 구조물은 통신, 가스, 전기 등 사회의 라이프라인에 해당하여 지진에 대한 취약성을 정확히 평가하여야 할 필요가 있다. 따 라서, 본 연구에서는 지하 공동구의 지진 발생 지반가속도에 따른 파괴가능성을 평가하였다. 평가를 위한 입력지반운동은 해 외 실측 지진데이터와 한반도에서 발생가능한 인공지진파를 차용하였으며, 지진해석 방법은 응답변위법과 시간이력해석법 을 사용하였다. 파괴여부를 판별하는 한계상태는 휨모멘트와 전단 파괴를 바탕으로 하였다. 취약도 함수 도출을 위한 방법은 최우도법이 사용되었으며, 그 분포함수는 대수정규분포로 가정하였다. 이는 지진시 지하 공동구 시설물의 피해 평가는 물론 지하 공동구 시설물의 내진설계를 위한 기초자료로 활용될 수 있다.