Experimental study on the behavior of retaining wall according to underground excavation distance

Abstract

The changes in earth pressure and ground settlement due to the underground excavation nearby the existing retaining wall according to the separation distance between underground excavation and retaining wall, were studied experimentally. A soil tank having 160 cm in length and 120 cm in height, was manufactured to simulate the underground excavation like tunnel by using 5 separated bottom walls. The variation of earth pressure was measured according to the excavation stages by using 10 separated right walls simulating the retaining wall. The results showed that the earth pressure was changed by the lowering of first bottom wall(B1), however the earth pressure was not changed significantly by the lowering of third bottom wall(B3) since B3 had sufficient separation distance from retaining wall. Lowering of first bottom wall(B1) induced the decrease of earth pressure in lower part of retaining wall, on the contrary, lowering of first bottom wall(B1) induced the increase of earth pressure in middle part of retaining wall proving the arching effect.

Geophysical Survey Applications in Underground Research Laboratories and Deep Disposal Sites of Spent Nuclear Fuel

“…직접처분 방식은 사용후핵연료를 재처리하지 않고 처분 하는 것으로, 국제원자력기구(International Atomic Energy Agency, IAEA)에서는 지하 수백 m 심층의 안정적인 지층 구조에 방사성 폐기물 처분장(심층처분장)을 건설하여 처 분하는 방법이 가장 적절하다고 권고하고 있다 (Gonzalez, 1997). 이러한 심층처분장은 인간과 생태계에 방사선으로 인한 피해가 없도록 방사성 폐기물을 지하 심층에 처분하 여 영구적으로 격리하는 시설로, 원자력 발전에 사용되었 던 사용후핵연료 등 고준위 방사성 폐기물이 주요 처분 대 상이다 (Park and Park, 2016). 사용후핵연료는 원자력 발전으로는 더 이상 사용할 수 없지만 계속해서 방사성 핵종을 방출하는데, 심층처분장 에 처분하였을 때 시설의 예상치 못한 결함이나 시설 통로 등을 통해서 방사성 핵종이 누출될 위험이 있다.…”