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http://dx.doi.org/10.7782/JKSR.2015.18.1.53

Correction Factors for Modulus Calculation Equation used in Light Weight Deflectometer Considering Track Foundation  

Choi, Chan Yong (Korea Railroad Research Institute)
Lee, Jin Wook (Korea Railroad Research Institute)
Lim, Yuijn (Department of Civil, Environmental and Railroad Engineering, Paichai University)
Cho, Hojin (Department of Civil, Environmental and Railroad Engineering, Paichai University)
Publication Information
Journal of the Korean Society for Railway / v.18, no.1, 2015 , pp. 53-62 More about this Journal
Abstract
LWDT was developed for use as an alternative technique to measure the stiffness of trackbed soils. In this study, numerical and theoretical analyses of LWDT's acting mechanism were performed. The effectiveness of the adapted elastic formula used for calculation of the dynamic modulus, Evd, was investigated theoretically and also numerically by running ABAQUS analysis. The minimum thickness of the upper layer is proposed based on the analysis. Correction factors for the formula of elastic modulus are also proposed in this study. In the future, following field test results and laboratory mechanical tests such as the resonant column test, a guideline for the use of LWDT as a standard test protocol in track construction sites, as a measuring tool for the degree of compaction and/or stiffness and dynamic modulus, will be proposed based on this analysis.
Keywords
LWDT; Dynamic modulus; Trackbed; Finite element analysis; Compaction control;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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1 Korea Rail Network Authority (2013) Design Specification for Railroad: Road bed.
2 S.P. Timoshenko, J.N. Goodier (1970) Theory of elasticity, McGraw-hill, New York, pp. 46-54.
3 H. Brandl, D. Adam, F. Kopf (2003) Der dynamische Lastplattenversuch mit dem Leichten Fallgewichtsgerat, Rep. No. 533, Vienna Technical Univ. Vienna, Austria (in German), pp. 1-4.
4 P.R. Fleming, M.W. Frost, J.P. Lambert (2007) A review of the lightweight deflectometer LWD for routine in situ assessment of pavement material stiffness, Transportation Research Record. 2004, Transportation Research Board, Washington D.C., pp. 80-87.
5 M. Nazzal, M.Y. Abu-Farsakh, K. Alshibli, L. Mohammad (2004) Evaluating the potential use of a portable LFWD for characterization of pavement layers and subgrades, ASCE GSP 126, M. K. Yegian and E. Kavazanjian, eds., ASCE, New York, pp. 915-924.
6 J. A. Siekmeier, Young, D. Young, D. Beberg (2000) Comparison of the dynamic cone penetrometer with other tests during subgrade and granular base characterization in Minnesota, Nondestructive testing of pavements and backcalculation of moduli: ASTM STP 1375, S. D. Tayabji and E. O. Lukanen, eds., 3, ASTM, Philadelphia.
7 C. Adam, D. Adam (2003) Modelling of dynamic load plate test with the light falling weight device, Asian Journal of Civil Engineering, 4, pp. 73-89.
8 M. Mooney, P. Miller (2009) Analysis of light weight deflectometer test based in in-situ stress and strain response, J Geotech Geoenviron Eng ASCE, 135(2), pp. 199-208.   DOI
9 I. Paulmichl (2004) Numerical simulation of static and dynamic compaction controls on layered half-spaces with the edge element method, Master thesis, Institute of Soil Mechanics and Foundation, Vienna University of Technology.
10 C. Adam, D. Adam, F. Kopf (2009) Computational validation of static and dynamic plate load testing, Acta Geotechnica, 4(1), pp. 35-55.   DOI
11 N. Ryden, M.A. Mooney (2009) Analysis of surface wave from the light weight deflectometer, Soil Dynamics and Earthquake Engineering, 29(7), pp. 1134-1142.   DOI
12 Y. Lim, D.S. Kim, H. Cho, M. Sagong (2013) Investigation of stiffness characteristics of subgrade soils under Tracks based on stress and strain levels, Journal of the Korean Society for Railway, 16(5), pp. 386-393.   DOI