An Experimental Study on the Estimation of Optimum Length of Soil Flow Protector with Wall Stiffness

Yoo, Jae-Won, Seo, Min-Su, Son, Su-Won, Im, Jong-Chul

doi:10.12652/Ksce.2019.39.6.0789

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2019 Vol.39, Issue 6 Preview Page Next Page

Geotechnical Engineering

An Experimental Study on the Estimation of Optimum Length of Soil Flow Protector with Wall Stiffness 벽체 강성에 따른 토사유입차단판의 최적 길이 산정에 관한 실험적 연구

December 2019. pp. 789-799

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Abstract

교대, 통로박스 등 말뚝기초로 지지된 구조물에서는 침하가 거의 발생하지 않지만, 구조물 저면 하부에는 공동이 발생하게 된다. 이에 따른 문제점으로는 측면지반에서 공동으로 유출된 토사에 의해 구조물 측면 지반의 침하를 가속화하여 더 큰 침하가 발생하게 된다. 따라서 말뚝 기초로 지지된 구조물 하부의 공동 발생으로 인한 문제점을 예방하고자 구조물의 측면에 쉽게 설치가 가능한 토사유입차단판(soil Flow Protector; 이하 ‘FLP’)이 개발되었다. 본 연구에서는 FLP의 침하감소 효과를 입증하고 최적 길이를 산정하고자 실내모형실험을 수행하였고, 그 결과 FLP의 설치함으로서 측면지반의 침하량이 감소하고 공동으로의 토사 유출을 방지하였고, FLP의 강성이 작으면 상부의 토압은 정지 또는 주동영역이 되어 안정성에 유리하지 않지만, 충분히 크면 상부의 토압은 수동영역이 되어 안정성에 유리하다. 또한 FLP의 강성이 작은 경우에는 일정 길이 비 이상에서는 오히려 감소하였으나, 큰 경우에는 설치길이가 증가할수록 침하량 감소에 효과적이다. 이에 따른 박스구조물 높이(H = 250 mm)에 대한 최적 길이 비는 연성 1.38, 강성 0.73으로 산정되었다.

키워드

공동

토사유입차단판

침하 감소 효과

최적 길이 비

The settlement hardly occurs in structures supported by pile foundation such as abutment, culvert but a cavity is formed in the lower part of a structure. As a result, soil discharged from the lateral ground to the cavity accelerates the settlement of the lateral ground of the structure, resulting in a larger settlement. Therefore, in order to prevent problems caused by cavity under the structure supported by pile foundation, soil Flow Protector (briefly called ‘FLP’), which can be easily installed on the side of structure, was developed. In this study, an laboratory model test was carried out to prove the reduction effect of settlement and to estimate the optimal installation length of the FLP. As a result, the installation of the FLP reduced the settlement of the lateral ground and prevented the leakage of lateral ground soil into the cavity. If the stiffness of the FLP is small, the state or active earth pressure is generated in the upper part, which is not favorable for stability. But if the stiffness of the FLP is high enough, the passive earth pressure area is generated in the upper part, which will be advantageous for the stability. Also, the increased installation length of FLP is effective to reduce the settlement. And the ratio of the optimal length of the FLP to the box structure height (H = 250 mm) are flexible FLP 1.38, stiff FLP 0.73.

Keywords

Cavity

Soil flow protector

Reduction effect of settlement

Ratio of the optimal length

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Information

Publisher :Korean Society of Civil Engineers
Publisher(Ko) :대한토목학회
Journal Title :KSCE JOURNAL OF CIVIL AND ENVIRONMENTAL ENGINEERING RESEARCH
Journal Title(Ko) :대한토목학회 논문집
Volume : 39
No :6
Pages :789-799
Received Date :2019. 06. 04
Revised Date :2019. 07. 08
Accepted Date : 2019. 10. 02
DOI :https://doi.org/10.12652/Ksce.2019.39.6.0789

KSCE JOURNAL OF CIVIL AND ENVIRONMENTAL ENGINEERING RESEARCH ISSN:1015-6348(Print) 2287-934X(Online) 대한토목학회 논문집

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