A Vibration-Based Method for the Measurement of Subgrade Soil Scaling Factor

Abstract

The subgrade soil scaling factor (SSSF) shows the basic properties of soil such as stiffness, gravimetry, density, and particle distribution, which are essential for disaster prediction and geotechnical engineering activities. In this paper, methods used for soil properties analysis are firstly summarized, and then a fiber Bragg grating (FBG) sensing technology is introduced. In order to acquire the properties and mechanical characteristics of soil accurately, a vibration-based method is presented and an experiment for judging the properties of soil is conducted. As for the experiment, an FBG sensor is adhered to the upside of the vibration rod to measure its fundamental frequency. The rod vibrates freely at different-depth level of soil, and the changed data of wavelength from the FBG sensor are carefully collected. The Winkler spring model is used to analyze the relationship between the fundamental frequency and stiffness of soil. The results of this experiment suggest that data collected from FBG sensor can reflect vibration situation clearly and quantitatively. Thus the SSSF value can be calculated from the frequency-stiffness equation. The experimental results are almost identical with the theoretical derivation results. This confirms that the method presented in the paper can determine the SSSF effectively.

Keywords

Vibration sensor / cantilever beam / Winkler reaction spring model / subgrade soil scaling factor

References

[1] Winkler E.. Die lehre von der elasticitaet und festigkeit, 1867, Prag, Czech Republic: H. Dominicus, 1-206.

[2] Blevins R. D.. Formulas for natural frequency and mode shape, 1979, New York, USA: Van Nostrand Reinhold, 1-461.

[3] Timoshenko S., Young D. H., Weaver W.. Vibration problems in engineering, 1974, New York, USA: Wiley, 1-521.

[4] Lai Y. C., Ting B. Y., Lee W. S., Becker W. R.. Dynamic response of beams on elastic foundation. Journal of Structural Engineering, 1992, 118(3): 853-858.

[5] Wang J.. Vibration of stepped beams on elastic foundations. Journal of Sound & Vibration, 1991, 149(2): 315-322.

[6] Kukla S.. Free vibration of stepped beams on elastic foundations. Journal of Sound & Vibration, 1991, 149, 259-265.

[7] Thambiratnam D., Zhuge Y.. Free vibration analysis of beams on elastic foundation. Computers & Structure, 1996, 60(6): 971-980.

[8] Thambiratnam D., Zhuge Y.. Dynamic analysis of beams on an elastic foundation subjected to moving loads. Journal of Sound & Vibration, 1996, 198(2): 149-169.

[9] Zhong R., Huang M. S.. Winkler model for dynamic response of composite caisson-piles foundations: lateral response. Soil Dynamics & Earthquake Engineering, 2014, 66(13): 241-251.

[10] Gao D. Y., Machalová J., Netuka H.. Mixed finite element solutions to contact problems of nonlinear Gao beam on elastic foundation. Nonlinear Analysis: Real World Applications, 2015, 22, 537-550.

[11] Hajialilue-Bonab M., Levacher D., Chazelas J. L., Kaynia A. M.. Experimental study on the dynamic behavior of laterally loaded single pile. Soil Dynamics & Earthquake Engineering, 2014, 66, 157-166.

[12] Zarafshan A., Iranmanesh A., Ansari F.. Vibration-based method and sensor for monitoring of bridge scour. Journal of Bridge Engineering, 2012, 17(6): 829-838.

[13] Pei H. F., Yin J. H., Zhu H. H., Hong C. Y., Fan Y. H.. In-situ monitoring of displacements and stability evaluation of slope based on fiber Bragg grating sensing technology. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(8): 1570-1576.

[14] Zhu H. H., Yin J. H., Jin W., Kuo T. M. K.. Health monitoring of foundations using fiber Bragg grating sensing technology. China Civil Engineering Journal, 2010, 43(6): 109-115.

[15] Zhu H. H., Shi B., Yan J. F., Chen C., Li Y., Wang J., . Physical model testing of slope stability based on distributed fiber-optic strain sensing technology. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(4): 821-828.

[16] Rodrigues C., Cavadas F., Félix C., Figueiras J.. FBG based strain monitoring in the rehabilitation of a centenary metallic bridge. Engineering Structures, 2012, 44(6): 281-290.

[17] Zhou Z., Huang M. H., Huang L. Q., Ou J. P., Chen G. D.. An optical fiber Bragg grating sensing system for scour monitoring. Advances in Structural Engineering, 2011, 14(1): 67-78.

[18] Li D. S., Ren L., Li H. N., Song G. B.. Structural health monitoring of a tall building during construction with fiber Bragg grating sensors. International Journal of Distributed Sensor Networks, 2012, 2012, 272190-1–272190–10.

[19] Wei C. L., Lai C. C., Liu S. Y., Chung W. H., Ho T. K., Tam H. Y., . A fiber Bragg grating sensor system for train axle counting. IEEE Sensors Journal, 2010, 10(12): 1902-1912.

[20] Wei C. L., Xin Q., Chung W. H., Liu S. Y., Tam H. Y., Ho S. L.. Real time train wheel condition monitoring by fiber Bragg grating sensors. International Journal of Distributed Sensor Networks, 2012, 2012(1550–1329): 47-54.

[21] Pei H. F., Yin J. H., Zhu H. H., Hong C. Y., Jin W., Xu D. S.. Monitoring of lateral displacements of a slope using a series of special fiber Bragg grating-based in-place inclinometers. Measurement Science and Technology, 2012, 23(2): 025007-1–025007–8.

[22] Pei H. F., Yin J. H., Jin W.. Development of novel optical fiber sensors for measuring tilts and displacements of geotechnical structures. Measurement Science and Technology, 2013, 24(9): 095202.

[23] Kister G., Winter D., Gebremichael Y. M., Leighton J., Badcock R. A., Tester P. D., . Methodology and integrity monitoring of foundation concrete piles using Bragg grating optical fibre sensors. Engineering Structures, 2007, 29(9): 2048-2055.

[24] Ye X. W., Su Y. H., Han J. P.. Structural health monitoring of civil infrastructure using optical fiber sensing technology: a comprehensive review. The Scientific World Journal, 2014 652329-1–652329–11.

[25] Ansari F.. Fiber optic sensors for structural health monitoring of civil infrastructure systems. Structural Health Monitoring of Civil Infrastructure Systems, 2009 260-282.

[26] Clough R., Penzien J.. Dynamics of structure, 1995, Berkeley, CA, USA: Computers and Structures, 1-729.