Ventilated Well Method for Efficient Dewatering of Soft Soils: Experimental Investigations
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 147, Issue 11
Abstract
Two of the conventional methods to improve soft soil deposits are evaporative dewatering and accelerated consolidation of the deposits using prefabricated vertical drains (PVDs). Evaporative dewatering is limited in application to densification of the surficial layers providing little to no improvement of the soft consistencies that lie at the bottom of the deposit. Development of smear zones around PVDs has been understood to affect their efficacy. To this end, this paper discusses a novel method of dewatering using controlled evaporation through ventilated wells [the ventilated well method (VWM)] that traverse the thickness of the deposit. Air, under controlled conditions, is circulated inside the perforated well, which progressively drives the moisture out of the soil skeleton. This is accompanied by development of an internal stress (suction) condition in the soil system leading to its densification. First, the paper introduces the method and discusses its underpinning physical principles and a laboratory-scale implementation of the VWM. Next, a systematic parametric study was carried out to understand the corresponding effects on the efficacy of the VWM due to varying dimensions of the well and the testing mold, rate of the air flow, and soil and pore fluid properties. Based on the laboratory-scale investigations, it is observed that the VWM performed better than surficial evaporative dewatering. The method is transferrable to the field and has a great potential in ground improvement exercises involving soft deposits such as those encountered in dredged sediments, mine tailings, and fluidized industrial waste.
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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 funded by the Australian Research Council (ARC) through a linkage grant on the project “Engineering the Strength and Consolidation of Reclaimed Soft Soil” awarded to Professor A. Scheuermann. The authors would like to acknowledge the scholarship supports through Australian Government Research Training Program Scholarship (formerly the International Postgraduate Research Scholarship), University of Queensland Centennial Scholarship (University of Queensland), and Top-Up scholarship (School of Civil Engineering, University of Queensland) awarded to Mr. P. N. Mishra. The support through the Port of Brisbane–University of Queensland research venture is gratefully acknowledged. The authors would like to thank Ms. X. Lei and Mr. S. Quintero at University of Queensland for technical assistance. We would like to express our gratitude to Professor John McCartney, the associate editor, and the anonymous reviewers for their time and suggestions to improve the manuscript.
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Journal of Geotechnical and Geoenvironmental Engineering
Volume 147 • Issue 11 • November 2021
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© 2021 American Society of Civil Engineers.
History
Received: May 15, 2020
Accepted: Jun 17, 2021
Published online: Aug 17, 2021
Published in print: Nov 1, 2021
Discussion open until: Jan 17, 2022
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Cited by
- Partha Narayan Mishra, Yuan Zhang, Alexander Scheuermann, Ventilated Well Method for Efficient Dewatering of Soft Soils: Dimensional Analysis and Validation through Numerical Modeling, Journal of Geotechnical and Geoenvironmental Engineering, 10.1061/JGGEFK.GTENG-10728, 149, 9, (2023).
- Peng Wang, Jianfeng Wu, Xueyan Ge, Fan Chen, Xiaotian Yang, Non-uniform Consolidation of Soil and Influence of Corresponding Clogging Effect During Vacuum Preloading, International Journal of Geosynthetics and Ground Engineering, 10.1007/s40891-022-00402-1, 8, 5, (2022).