Application of Laboratory Pressurized Vane Shear Test and Discrete Element Method for Determination of Foam-conditioned Soil Properties

Tae-Ho Kang; Hyobum Lee; Hangseok Choi; Soon-Wook Choi; Soo-Ho Chang; Chulho Lee

doi:10.12814/jkgss.2020.19.4.065

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Research Article

Application of Laboratory Pressurized Vane Shear Test and Discrete Element Method for Determination of Foam-conditioned Soil Properties 폼제에 의해 개선된 흙의 물성 도출을 위한 실내 가압 베인 전단시험 및 개별요소법의 적용

31 December 2020. pp. 65-74

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Abstract

In earth pressure balance (EPB) shield TBM tunnelling, the application of soil conditioning which improves properties of the excavated muck by additives injection, is generally used for enhancing the performance of TBM. Therefore it is important to apply the soil conditioning in the numerical model which simulates excavation performance of TBM equipment, but related studies on a method that simulates soil conditioning are insufficient to date. Accordingly, in this study, an laboratory pressurized vane test apparatus was devised to evaluate the characteristics of conditioned soil. Using the apparatus, the vane shear tests were performed on foam-conditioned soil with different shear rates, and the test was numerically simulated with discrete element method (DEM). Finally, the contact properties of particles in DEM were determined by comparing the results of test and analysis, and it indicates that the applicability of pressurized vane test and DEM model for reproducing soil conditioning in TBM excavation model with DEM.

Keywords

Discrete element method

EPB shield

Foam

Soil conditioning

TBM

Vane shear test

토압식(EPB, earth pressure balance) 쉴드 TBM 공법에서 첨가제 주입을 통해 굴착한 흙을 개량하는 쏘일 컨디셔닝(soil conditioning) 기법의 적용은 TBM의 굴진성능을 향상시키는데 필수적이다. 따라서 TBM 장비의 굴진 성능을 모사하는 수치해석 모델에서도 쏘일 컨디셔닝을 적용하는 것은 중요하나, 이를 해석적으로 모사하는 기법에 대한 연구는 현재까지 부족하다. 따라서 본 연구에서는 컨디셔닝 된 흙의 특성을 파악하기 위해 실내 가압 베인시험 장치를 고안하였다. 고안된 장치를 통해 폼에 의해 컨디셔닝 된 흙에 대하여 전단속도를 달리하며 시험을 수행하였으며, 시험은 개별요소법(DEM, discrete element method)을 통해 모델링 되었다. 시험결과와 해석결과의 비교를 통해 개별요소법에서의 입자 접촉조건을 결정하였으며, 이는 개별요소법을 사용한 TBM 굴진해석 모델에서 쏘일 컨디셔닝을 재현할 때 가압 베인시험과 개별요소법 모델의 적용 가능성을 보여준다.

References

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Information

Publisher :Korean Geosythetics Society
Publisher(Ko) :한국지반신소재학회
Journal Title :Journal of the Korean Geosynthetics Society
Journal Title(Ko) :한국지반신소재학회 논문집
Volume : 19
No :4
Pages :65-74
Received Date : 2020-11-19
Revised Date : 2020-12-07
Accepted Date : 2020-12-09
DOI :https://doi.org/10.12814/jkgss.2020.19.4.065

Journal of the Korean Geosynthetics Society ISSN:2508-2876(Print) 2287-9528(Online) 한국지반신소재학회 논문집

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