Evaluating Subgrade Compaction for Different Soils Using Nondestructive Lightweight Deflectometer
Publication: Journal of Materials in Civil Engineering
Volume 36, Issue 5
Abstract
Insufficient compaction of the subgrade can result in nonuniform deformation, leading to severe subgrade distress. To address this issue and find a new method for rapid detection and evaluation of subgrade compaction, we used the lightweight deflectometer (LWD) to analyze the dynamic deformation modulus () of subgrades filled with four types of soils—silt (ML), well-graded gravel (GW), lean clay (CL), and poorly graded sand (SP)—in different regions of Gansu province, China. Concurrently, we measured the degree of compaction () using the sand replacement method (SRM) to establish its correlation with dynamic deformation modulus (). A strong correlation between the degree of compaction and dynamic deformation modulus was established for soils ML, GW, CL, and SP, and suitable formulas were selected based on curve variations. The developed formulas enabled back-calculation of the dynamic deformation modulus requirements corresponding to different degrees of compaction ranging from 90 to 100, facilitating direct queries and quick field checks. Results demonstrated that the LWD, as a reliable rapid detection method, effectively controlled subgrade compaction quality in field construction. Moreover, it extended the testing area and increased measurement frequency, thus providing a practical means for quickly evaluating the qualification rate and uniformity of subgrade compaction.
Practical Applications
When we build roads, most subgrade underneath the roads needs to be filled with soil. If we don’t pack the soil properly in the filling process, the subgrade can crack and become uneven over time. It’s hard to fix this problem once the road is open, so it’s important to make sure the soil is packed tightly enough before the road is finished. There are two ways to check if the soil is packed properly: one is a traditional method called the sand replacement method, and the other is a machine called the lightweight deflectometer. These methods help identify insufficient compaction of the subgrade and prevent uneven deformation problems during the filling process. What’s more, the lightweight deflectometer is a fast, convenient, and reliable tool that can assist or serve as an alternative to the traditional sand replacement method for controlling subgrade construction quality. This study is important because it helps us understand how to evaluate compaction of the filled subgrade in a different way.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
This work was supported by the Gansu Provincial Department of Transportation Program (Grant numbers 2022-14 and 2022-54) and the Department of Science and Technology of Gansu Province Program (Grant numbers 22ZD11GA296 and 21YF1GA381). The support by Key Laboratory of Technology Research Institute for Highway Maintenance of Gansu Province is greatly acknowledged.
References
AASHTO. 2017. Standard method of test for determining the resilient modulus of soil subgrade, subbase, and base materials. AASHTO T 307-06. Washington, DC: AASHTO.
Adigopula, V. K., C. Bogireddy, and S. D. Guzzarlapudi. 2022. “Comparison of overlay design in between lightweight deflectometer and Benkelman beam deflection test results.” In Advances in geoengineering along the belt and road, 175–182. Singapore: Springer. https://doi.org/10.1007/978-981-16-9963-4_14.
Al-Fattehallah, R., A. M. Shaban, and S. Al-Busaltan. 2020. “Use of lightweight deflectometer for evaluating in situ strength characteristics of pavement foundations in Kerbala.” In Modern applications of geotechnical engineering and construction: Geotechnical engineering and construction, 185–196. Singapore: Springer. https://doi.org/10.1007/978-981-15-9399-4_16.
Alshibli, K. A., M. Abu-Farsakh, and E. Seyman. 2005. “Laboratory evaluation of the geogauge and light falling weight deflectometer as construction control tools.” J. Mater. Civ. Eng. 17 (5): 560–569. https://doi.org/10.1061/(ASCE)0899-1561(2005)17:5(560).
Arshad, A. K., E. Shaffie, and F. Ismail. 2018. “Comparative evaluation of soil subgrade strength using laboratory and in-situ tests.” Int. J. Civ. Eng. Tech. 9 (7): 1184–1191.
ASTM. 2016. Standard test methods for density of soil and rock in place by the sand replacement method in a test pit. ASTM D4914/D4914M-16. West Conshohocken, PA: ASTM.
ASTM. 2017. Standard classification of soils for engineering purposes (unified soil classification system). ASTM D2487. West Conshohocken, PA: ASTM.
ASTM. 2020. Standard test method for measuring deflections with a light weight deflectometer (LWD). ASTM E2583-07. West Conshohocken, PA: ASTM.
Bilodeau, J. P., M. Kandji, and M. L. Nguyen. 2022. “Response analysis of subgrade soils using signal phase shift obtained from laboratory lightweight deflectometer (LWD) tests.” Can. J. Civ. Eng. 49 (7): 1184–1191. https://doi.org/10.1139/cjce-2021-0095.
Fleming, P. R., M. W. Frost, and J. P. Lambert. 2007. “Review of lightweight deflectometer for routine in situ assessment of pavement material stiffness.” Trans. Res. Rec. 2004 (1): 80–87. https://doi.org/10.3141/2004-09.
Huang, L. S., and Y. V. Kang. 2010. “Nondestructive evaluation of thickness and bearing capacity of roadway pavement structure.” Int. J. Pavement Res. Technol. 3 (6): 326–335. https://doi.org/10.6135/ijprt.org.tw/2010.3(6).326.
Jibon, M., and D. Mishra. 2021. “Light weight deflectometer testing in proctor molds to establish resilient modulus properties of fine-grained soils.” J. Mater. Civ. Eng. 33 (2): 06020025. https://doi.org/10.1061/(ASCE)MT.1943-5533.0003582.
Klvac, R., P. Vrána, and R. Jiroušek. 2010. “Possibilities of using the portable falling weight deflectometer to measure the bearing capacity and compaction of forest soils.” J. Forest Sci. 56 (3): 130–136. https://doi.org/10.17221/71/2009-JFS.
Kuttah, D. 2019. “Strong correlation between the laboratory dynamic CBR and the compaction characteristics of sandy soil.” Int. J. Geo-Eng. 10 (1): 7. https://doi.org/10.1186/s40703-019-0102-x.
Kuttah, D. 2021. “Determining the resilient modulus of sandy subgrade using cyclic light weight deflectometer test.” Trans. Geo. 27 (3): 100482. https://doi.org/10.1016/j.trgeo.2020.100482.
Livneh, M., and Y. Goldberg. 2001. “Quality assessment during road formation and foundation construction: Use of falling-weight deflectometer and light drop weight.” Trans. Res. Rec. 1755 (1): 69–77. https://doi.org/10.3141/1755-08.
Makwana, P., and R. Kumar. 2019. “Correlative study of LWD, DCP and CBR for sub-grade.” Int. J. Eng. Trends Tech. 67 (9): 89–98. https://doi.org/10.14445/22315381/IJETT-V67I9P215.
Nabizadeh, H., E. Hajj, R. Siddharthan, S. Elfass, and M. Nimeri. 2017. “Application of falling weight deflectometer for the estimation of in-situ shear strength parameters of subgrade layer.” In Bearing capacity of roads, railways and airfields, 743–749. London: Taylor & Francis.
Nabizadeh, H., R. V. Siddharthan, E. Y. Hajj, M. Nimeri, and S. Elfass. 2019. “Validation of the subgrade shear strength parameters estimation methodology using light weight deflectometer: Numerical simulation and measured testing data.” Trans. Geotech. 21 (Dec): 100259. https://doi.org/10.1016/j.trgeo.2019.100259.
Nazzal, M. D., and L. N. Mohamma. 2010. “Estimation of resilient modulus of subgrade soils using falling weight deflectometer.” Trans. Res. Rec. 2186 (1): 1–10. https://doi.org/10.3141/2186-01.
Sudarsono, I., L. Aisyah, and R. N. P. Prakoso. 2020. “Correlation of modulus elasticity between light weight deflectometer (LWD) and dynamic cone penetrometer (DCP) for subgrade of pavement.” J. Phys. Conf. Ser. 1517 (1): 012030. https://doi.org/10.1088/1742-6596/1517/1/012030.
Xu, K. 2006. “Evaluating base course uniformity using falling weight deflectometer.” [In Chinese.] J. Shandong Univ. Arch. Eng. 21 (2): 112–116.
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© 2024 American Society of Civil Engineers.
History
Received: Mar 29, 2023
Accepted: Oct 13, 2023
Published online: Feb 24, 2024
Published in print: May 1, 2024
Discussion open until: Jul 24, 2024
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