Development of a Design Tool for Selecting Soft Ground Improvement Methods to Ensure Trafficability of Temporary Roads

Hyun-Jun Choi; Young Beom Kim; YoungSeok Kim

doi:10.12814/jkgss.2026.25.2.025

All Issue

2026 Vol.25, Issue 2 Preview Page Next Page

Research Article

Development of a Design Tool for Selecting Soft Ground Improvement Methods to Ensure Trafficability of Temporary Roads 가설도로 주행성 확보를 위한 연약지반 개량공법 산정 도구 개발

30 June 2026. pp. 25-37

PDF XML

Abstract

This study develops an Excel-based design tool for selecting soft ground improvement methods to ensure the trafficability of temporary roads on soft ground. To obtain practical input parameters in the field, rapid assessment methods were adopted, including the field vane shear test for undrained shear strength, the dynamic cone penetrometer (DCP) test for soft layer thickness and strength indices, and the time domain reflectometry (TDR) test for water content. A three-dimensional numerical model was built using FLAC3D to quantify the maximum surface settlement under a representative contact pressure condition. Parametric analyses were performed by varying the soft ground elastic modulus and the soft layer thickness for five improvement configurations: single-layer geobag, double-layer geobag, single-layer geocell, combined single-layer geobag with a beach mat, and shallow soil stabilization. The settlement limit of 100 mm was adopted as a trafficability criterion by referring to the allowable residual settlement commonly used in soft ground road design. The results indicate that the elastic modulus and soft layer thickness dominantly control the maximum settlement, and the improvement thickness is also a key factor in settlement reduction. Based on the parametric results, applicability ranges of each method were established and embedded into the proposed tool. The tool consists of four sheets: soil condition assessment, soft ground determination, improvement method evaluation, and selection of improvement method, providing a workflow from field inputs to method selection and required resources. The proposed framework can support rapid and consistent decision-making for temporary road planning and construction on soft ground.

Keywords

Temporary road

Trafficability

Soft ground

Improvement method

Excel-based design tool

본 논문에서는 연약지반 구간에서 가설도로 주행성을 확보하기 위한 엑셀 기반의 연약지반 개량공법 산정 도구를 개발하였다. 도구의 현장 적용성을 높이기 위해 현장 간이평가 항목으로 현장 베인전단시험, 동적콘관입시험, TDR(Time Domain Reflectometry) 시험을 적용하였다. 또한 공법별 적용 가능 범위를 정립하기 위해 FLAC3D 기반 3차원 수치해석 모델을 구축하고, 연약지반 변형계수 및 연약층 두께를 변화시키며 매개변수해석을 수행하였다. 수치해석은 지오백 1단, 지오백 2단, 지오셀 1단, 지오백 1단-비치매트 복합 적용, 천층고화 등 5개 공법 조합을 대상으로 수행하였으며, 허용침하량 100mm는 연약지반 도로 설계에서 사용되는 허용잔류침하량 기준을 참고하여, 가설도로의 단기 주행성 판정 기준으로 준용하였다. 그 결과 연약지반 변형계수와 연약층 두께가 최대침하량에 지배적인 영향을 미치고, 공법 두께 또한 침하 저감에 중요한 인자로 작용함을 확인하였다. 도출된 공법별 적용 가능 범위를 개량공법 산정 도구에 반영하여, 사용자가 간이평가 결과와 장비 조건, 연약지반 길이 및 공법 적용 폭을 입력하면 공법별 적용 가능 여부와 소요 자원을 산출할 수 있도록 구성하였다. 새롭게 개발한 개량공법 산정 도구는 가설도로 계획·시공 단계에서 신속하고 일관된 공법 선정에 활용될 수 있다.

References

Choi, J. (2008), “Fundamental study on establishing the subgrade compaction control criteria of DCPT with laboratory test and in-situ tests”, International Journal of Highway Engineering, Vol.10, No.4, pp.103-116.

Cuelho, E. V. and Perkins, S. W. (2017), “Geosynthetics subgrade stabilization – Field testing and design method calibration”, Transportation Geotechnics, Vol.10, pp.22-34.

10.1016/j.trgeo.2016.10.002

Gabr, M., Hopkins, K., Coonse, J. and Hearne, T. (2000), “DCP criteria for performance evaluation of pavement layers”, Journal of Performance of Constructed Facilities, Vol.14, No.4, pp.141-148.

10.1061/(ASCE)0887-3828(2000)14:4(141)

George, V., Rao, N. C. and Shivashankar, R. (2009), “PFWD, DCP and CBR correlations for evaluation of lateritic subgrades”, International Journal of Pavement Engineering, Vol.10, No.3, pp.189-199.

10.1080/10298430802342765

Giroud, J. P. and Han, J. (2004), “Design method for geogrid-reinforced unpaved roads. I. development of design method”, Journal of the Geotechnical and Geoenvironmental Engineering, ASCE, Vol.130, No.8, pp.775-786.

10.1061/(ASCE)1090-0241(2004)130:8(775)

Giroud, J. P. and Noiray, L. (1981), “Geotextile-reinforced unpaved road design”, Journal of the Geotechnical Engineering Division, ASCE, Vol.107, No.9, pp.1233-1254.

10.1061/AJGEB6.0001187

Ham, H. S. and Lee, S. D. (2018), “Experimental study on the reinforcement effect of geogrid in soft ground improvement”, Journal of Korean Geosynthetics Society, Vol.17, No.2, pp.1-7.

10.12814/JKGSS.2018.17.2.001

Jones, C. (2004), Dynamic cone penetrometer (DCP) tests and analysis, Technical Information Note, Project Report PR/INT/277/04, TRL Limited, Crowthorne, Berkshire, United Kingdom.

Ju, J. W., Park, J. B., Seo, K. W. and Jang, M. H. (2007), “Bearing capacity of soft ground reinforced by geosynthetics and sand mat”, Journal of Korean Geosynthetics Society, Vol.6, No.1, pp.1-7.

Kang, H., Kim, K., Park, S. and Kim, J. (2008), “A study on the relation between dynamic deflection modulus and in-situ CBR using a portable FWD”, Journal of the Korea Institute for Structural Maintenance and Inspection, Vol.12, No.2, pp.149-155.

Kim, B., Jeon, S. and Lee, M. (2006), “Comparison of field bearing capacity tests to evaluate the field application of dynamic cone penetration test”, International Journal of Highway Engineering, Vol.8, No.4, pp.75-85.

Kim, J., Kim, J., Kim, N., Baek, S. and Cho, J. (2022), “Evaluation of compaction quality control applied the dynamic cone penetrometer test based on IoT”, Journal of Korean Geosynthetics Society, Vol.21, No.4, pp.1-12.

10.12814/JKGSS.2022.21.4.001

Lee, S. H., Yoo, I. K. and Lee, D. Y. (2012), “Evaluation of bearing capacity for permeable pavement using geocell”, Journal of Korean Geosynthetics Society, Vol.11, No.3, pp.11-17.

10.12814/jkgss.2012.11.3.011

Morris, P. and Williams, D. (1994), “Effective stress vane shear strength correction factor correlations”, Canadian Geotechnical Journal, Vol.31, No.3, pp.335-342.

10.1139/t94-041

Robinson, D., Jones, S., Wraith, J., Or, D. and Friedman, S. (2003), “A review of advances in dielectric and electrical conductivity measurement in soils using time domain reflectometry”, Vadose Zone Journal, Vol.2, No.4, pp.444-475.

10.2136/vzj2003.4440

Schlue, B., Moerz, T. and Kreiter, S. (2010), “Influence of shear rate on undrained vane shear strength of organic harbor mud”, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol.136, No.10, pp.1437-1447.

10.1061/(ASCE)GT.1943-5606.0000356

Seo, S. G., Kim, Y. S. and Cho, D. S. (2020), “A study on the field application of ground stabilizer using circulating resource for improvement of soft ground in Saemangeum area”, Journal of Korean Geosynthetics Society, Vol.19, No.1, pp.103-110.

10.12814/JKGSS.2020.19.1.103

Shin, E. C., Kim, S. H. and Kim, Y. J. (2009), “Study of ground reinforced effect using the porous geocell”, Journal of Korean Geosynthetics Society, Vol.8, No.1, pp.33-40.

Topp, G., Davis, J. and Annan, A. (1980), “Electromagnetic determination of soil water content: Measurements in coaxial transmission lines”, Water Resources Research, Vol.16, No.3, pp.574-582.

10.1029/WR016i003p00574

Information

Publisher :Korean Geosythetics Society
Publisher(Ko) :한국지반신소재학회
Journal Title :Journal of the Korean Geosynthetics Society
Journal Title(Ko) :한국지반신소재학회 논문집
Volume : 25
No :2
Pages :25-37
Received Date : 2026-06-02
Revised Date : 2026-06-11
Accepted Date : 2026-06-23
DOI :https://doi.org/10.12814/jkgss.2026.25.2.025

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

All Issue