Measurement of Retaining Tensile Load with the Relative Displacement Detector of Ground Anchors

Hyeon-Sik Jeong; Kwang-Suk Han; Yeong-Saeng Lee

doi:10.7843/kgs.2017.33.10.59

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2017 Vol.33, Issue 10 Preview Page

Measurement of Retaining Tensile Load with the Relative Displacement Detector of Ground Anchors 상대변위측정기를 이용한 지반앵커의 보유인장력 측정

31 October 2017. pp. 59-68

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Abstract

The tension load of the ground anchor inserted in the ground gradually changes over time. In this regard the change of the initial tension load is primarily decreased by the fixation condition of the fixing head and the mechanical characteristics of the tensile material. The subsequent additional tension load is a time-dependent loss mostly due to the fixing conditions of the bonded length and the surrounding ground properties of the field. In this paper, therefore, a measurement system using a relative displacement detector that can relatively easily measure the change of tension load is discussed. As a result of the review, it was confirmed that the results using the relative displacement detector are similar to those of the real scale model test, and it was also confirmed that similar results were obtained with the result of the pull-out test conducted on the ground anchors fixed to weathered rocks condition. In addition, a pull-out test was conducted on the test anchors whose initial tension load loss was relatively large and through this test pull-out behavior of the tension type ground anchors was verified.

Keywords

Ground anchors

Relative displacement detector

Retained bonding capacity

Pull-out test

Lift-off test

지반내 근입된 앵커의 인장력은 시간이 경과하면서 점차 변화하게 되는데 이때 초기 인장력의 변화는 보통 정착헤 드의 정착조건과 인장자재의 기계적 특성에 의해 1차적으로 감소하게 되며, 이후 추가적인 인장력의 변화는 대부분 정착장의 정착조건과 주변 지반특성에 기인한 시간의존적인 정착거동에 좌우된다. 따라서 본 논문에서는 이러한 인장 력 변화를 비교적 쉽게 측정 및 분석할 수 있는 상대변위측정기를 이용한 측정시스템에 대해서 연구하였다. 검토결과 실규모 모형시험을 통해서 본 측정시스템의 적용성을 확인 하였으며, 또한 풍화암에 정착된 지반앵커를 대상으로 실시한 현장 시험결과와도 유사함을 확인함에 따라 본 측정시스템의 적용성을 확인하였다. 그리고 초기인장력이 비교 적 크게 감소된 시험앵커를 대상으로 추가적인 인발시험을 실시하였으며 이를 통해 인장형 앵커의 인발거동을 확인하였다.

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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 : 33
No :10
Pages :59-68
Received Date : 2017-09-06
Accepted Date : 2017-10-10
DOI :https://doi.org/10.7843/kgs.2017.33.10.59

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

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