Instrumentation Management of the Deep Soft Ground with Dredged Clay Reclaimed in the Upper

Na-Young Jung; Seung-Chan Kang; Tae-Hyung Kim

doi:10.7843/kgs.2022.38.12.67

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2022 Vol.38, Issue 12 Preview Page Next Page

Instrumentation Management of the Deep Soft Ground with Dredged Clay Reclaimed in the Upper 준설점토가 상부에 매립된 대심도 연약지반 계측관리

31 December 2022. pp. 67-78

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Abstract

In this study, the measurement results of the coastal deep soft ground buried in the upper part of the dredged clay were analyzed and compared with the current specification standards. Based on the results, a suitable proposal was suggested for the selection, installation, data arrangement, and analysis of each instrument used in the deep soft ground improvement construction. The pore water pressure meter has a range of 1.5 times or more of the expected measurement range, considering the field conditions of the soft ground. The groundwater level meter installed in the horizontal drainage layer checks the change in the groundwater level during the embanking as well as the performance of the catchment well and the horizontal drainage layer. Therefore, it is important to manage so that the groundwater level exists inside the horizontal drainage layer during embanking. It is enough to install the inclinometer in the gravel layer below the soft ground or weathered rock with an N value of 40 or more for the deep soft ground. It seems desirable to install a screw type for differential settlement meter. However, the screw type should not settle due to its own weight. Considering that it is a dredged landfill where subsidence occurs significantly, it is sufficient to manage the tolerance of leveling at about 10 mm (L is the one-way distance (km)).

Keywords

Data arrangement and analysis

Deep soft ground

Dredged clay reclaimed

Instrumentation management

Measuring instruments

본 연구에서는 준설점토가 상부에 매립된 해안가 대심도 연약지반의 계측결과를 분석하고 현재의 시방기준과 비교하여 그 결과를 바탕으로 대심도 연약지반 개량공사에 사용되는 각 계측별 계측기 선정, 설치, 데이터 정리 및 분석에 대하여 적합한 안을 제안하였다. 간극수압계의 경우, 연약지반 현장 여건을 고려하여 예상 가능한 측정범위의 1.5배 이상 정도의 계측 범위가 가능한 게이지를 적용하는 것이 바람직하다. 수평배수층에 설치되는 지하수위계는 성토 중 지하수위의 변화, 집수정 및 수평배수층의 성능을 확인하는 것으로 성토 중에는 지하수위가 수평배수층 내부에 존재하도록 관리하는 것이 중요하다. 대심도 연약지반에서 지중경사계의 설치심도는 N치가 40 이상인 풍화암 또는 연약지반 하부의 자갈층에 설치하면 충분하다. 층별침하계는 스크류타입을 설치하는 것이 바람직해 보인다. 그러나 스크류타입 게이지가 자중에 의한 침하가 발생하지 않아야 한다. 폐합 또는 결합측량 시 수준측량의 허용오차는 침하가 크게 발생하는 준설매립지임을 고려하면 10Lmm(L은 편도거리(km)) 정도로 관리하면 충분하다.

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Information

Publisher :The Korean Geotechnical Society
Publisher(Ko) :한국지반공학회
Journal Title :Journal of the Korean Geotechnical Society
Journal Title(Ko) :한국지반공학회 논문집
Volume : 38
No :12
Pages :67-78
Received Date : 2022-11-09
Revised Date : 2022-11-17
Accepted Date : 2022-11-17
DOI :https://doi.org/10.7843/kgs.2022.38.12.67

Journal of the Korean Geotechnical Society ISSN:1229-2427(Print) 2288-646X(Online) 한국지반공학회 논문집

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