Evaluation of Design Characteristics in the Reinforced Railroad Subgrade Through the Sensitivity Analysis

Dae-Sang Kim; Sung-Ho Hwang; Ung-Jin Kim; Young-kon Park; Seong-Yong Park

doi:10.12814/jkgss.2013.12.3.015

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2013 Vol.12, Issue 3 Preview Page Next Page

Evaluation of Design Characteristics in the Reinforced Railroad Subgrade Through the Sensitivity Analysis 민감도 분석을 통한 철도보강노반 설계 특성 평가

30 September 2013. pp. 15-22

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Abstract

By changing from ballasted track to concrete slab track, new type railroad subgrade is strongly required to satisfy strict regulations for displacement limitations of concrete slab track. In this study, sensitivity analysis was performed to assess the design characteristics of new type reinforced railroad subgrade, which could minimize residual settlement after track construction and maintain its function as a permanent railway roadbed under large cyclic load. With developed design program, the safety analysis (circular slip failure, overturning, and sliding) and the evaluation of internal forces developed in structural members (wall and reinforcement) were performed according to vertical installation spacing and stiffness of short and long geotextile reinforcement. Based on this study, we could evaluate the applicabilities of 0.4 H short geogrid length with 0.4 m vertical installation spacing of geotextile as reinforcement and what the ground conditions are for the reinforced railroad subgrade. And also, we could grasp design characteristics of the reinforced railroad subgrade, such as the importance of connecting structure between wall and reinforcement, boundary conditions allowing displacement at wall ends to minimize maximum bending moment of wall.

Keywords

Reinforced Railroad Subgrade

Sensitivity analysis

Wall stiffness

Concrete Track

Residual settlement

도상구조의 자갈(연성)에서 콘크리트(강성)로의 변화는 이를 지지하는 철도 노반구조에서도 보다 엄격한 변형 규제에 적합한 신형식 철도보강노반 구조를 요구하고 있다. 본 논문에서는 공용 후 잔류침하를 최소화할 수 있으면서도 대용량 반복하중이 작용하는 철도노반 영구구조물로서의 기능을 유지할 수 있는 강성벽 일체형 철도보강노반의 설계 특성을 평가하기 위한 민감도 분석을 실시하였다. 개발한 설계프로그램을 이용하여 단보강재와 장보강재의 간격, 보강재 강성 등 설계 입력변수 변화에 따른 원호활동, 전도 및 활동파괴에 대한 안전율 및 발생 부재력을 평가하였다. 이를 통하여 철도보강노반에서는 높이의 40%(0.4H)의 짧은 보강재를 연직간격 0.4m로 적용할 수 있으며 보강노반 적용을 위한 원지반 조건 등을 평가할 수 있었다. 또한, 철도보강노반을 구성하는 벽체와 보강재 연결구조의 중요성, 벽체 경계조건에서의 변위 허용구조 적용을 통한 하중 재하 시 발생 최대휨모멘트를 저감시키는 설계상의 특징을 파악할 수 있었다.

References

1.Associations of RRR (2001), RRR-B design and construction manual, pp. 23.

2.Horii, K., Kishida, H., Tateyama, M. and Tatsuoka, F. (1994) “Computerized design method for geosynthetic-reinforced soil retaining walls for railway embankments”, Proceeding of Seiken symposium, 11, pp.205-218.

3.Korea Railway Network Authority (2011), Railway design standard for roadbed, pp.6-11.

4.Kim, D.S., Park, S.Y. and Kim, K.H. (2012), “Effects of Vertical Spacing and Length of Reinforcement on the Behaviors of Reinforced Subgrade with Rigid Wall”, Journal of the Korean Geosynthetics Society, Vol.11, No.4, pp.27-35.

5.Tatsuoka, F., Tateyama, M. and Murata, O. (1989), “Earth retaining wall with a short geotextile and a rigid facing”, Proc. 12^th Int. Conf. on SMFE, Rio de Janeiro, 12(2), pp. 1311-1314.

6.Tatsuoka, F., Tateyama M., Uchimura T. and Koseki J. (1997) Geosynthetic-reinforced soil retaining walls as important permanent structures (1996-1997 Mercer Lecture), Geosynthetics International, Vol.4, No.2 pp.81-136.

Information

Publisher :Korean Geosythetics Society
Publisher(Ko) :한국지반신소재학회
Journal Title :Journal of the Korean Geosynthetics Society
Journal Title(Ko) :한국지반신소재학회 논문집
Volume : 12
No :3
Pages :15-22
Received Date : 2013-06-24
Revised Date : 2013-09-09
Accepted Date : 2013-09-10
DOI :https://doi.org/10.12814/jkgss.2013.12.3.015

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

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