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Seismic Stability Evaluation of Sand Ground with Organic Soil by Using Shaking Table Test

진동대 시험을 이용한 유기질토가 협재된 모래지반의 내진 안정성 평가

  • Received : 2023.03.22
  • Accepted : 2023.04.06
  • Published : 2023.05.01

Abstract

The Gangneung region has an environment suitable for the formation of organic soil, and there is an alluvial layer in which sedimentary sand layers are distributed on the upper and lower parts of the organic soil. In order to evaluate the seismic safety of the railway roadbed passing through the Gangneung area, a railway roadbed and ground model considering the similarity ratio was fabricated, a shaking table test was conducted, and the seismic stability was evaluated by comparing the effective stress analysis results. The applied seismic waves were artificial seismic waves, Gyeongju seismic waves, Borah seismic waves, Nahanni seismic waves, and Tabas seismic waves. It became. Due to the ground reinforcement effect by jet grouting applied to the lower ground of the new roadbed, the displacement of the new roadbed was found to be reduced from a minimum of 33.7% to a maximum of 56.7% compared to the existing roadbed. The shaking table test results were verified by effective stress analysis using the Finn model of the Flac program, and showed a similar trend to the shaking table test values.

강릉지역은 유기질토가 생성되기 적합한 환경을 지닌 지역으로 유기질토 상부와 하부에 퇴적 모래층이 분포되어 있는 충적층 지반이 존재한다. 본 연구는 모래층 사이에 유기질토 및 점토가 협재된 지반 상부에 조성된 강릉지역을 통과하는 철도노반의 내진 안전성을 평가하기 위하여 상사율을 고려한 철도노반 및 지반 모형을 제작하여 진동대 시험을 실시하고 유효응력 해석 결과값을 비교하여 내진 안정성을 평가하였다. 적용된 지진파는 인공지진파, 경주지진파, Borah 지진파, Nahanni 지진파, Tabas 지진파를 적용하였으며 상부 모래층의 최대 응답가속도는 0.239g(인공지진파), 과잉간극수압비는 0.509(Borah파)가 발생하는 것으로 분석되었다. 신설노반의 하부지반에 적용된 jet grouting에 의한 지반보강 효과로 인해 신설 노반의 발생변위는 기존노반에 비해 최소 33.7%에서 최대 56.7% 감소한 것으로 나타났다. 진동대 시험결과는 Flac 프로그램의 Finn 모델을 적용한 유효응력해석으로 검증하였으며, 진동대 시험값과 유사한 경향을 나타내었다.

Keywords

References

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