Experimental Investigation of Influence of Air-Boost Pressure and Duration on Air-Boost Vacuum Preloading Consolidation
Publication: International Journal of Geomechanics
Volume 21, Issue 6
Abstract
The air-boost vacuum preloading method has become popular in soft soil foundation reinforcement, especially in land reclamation projects. However, there are still some consolidation mechanism issues that need to be investigated, especially with respect to the determination of the air-boost pressure and duration. In this study, a set of macro- and microlaboratory tests including scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) were carried out to investigate the improvement effects of different working pressures and durations. The test results indicated that air-boost vacuum preloading can enhance the consolidation efficiency, and the water discharge and surface settlement distinctly increased after gas injection. As a result, the tests with higher pressures and longer durations have higher strength and increment of the degree of consolidation (DOC). In some ranges, the higher pressure leads to the longer consolidation period, and the longer duration improves the effectiveness of each pressurization cycle. Based on the result analysis, the air-boost vacuum preloading process after pressurization could be divided into three stages, and the second stage was the most sensitive to changes in the air-boost pressure and duration. Furthermore, the increasing setting of air-boost pressure and duration was more suitable for the consolidation process in air-boost vacuum preloading.
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Acknowledgments
The authors acknowledge the National Key R&D Plan (Grant No. 2017YFC0805402), the Open Project Fund of the State Key Laboratory of Disaster Reduction in Civil Engineering (Grant No. SLDRCE17-01), and Youth Program of the National Natural Science Foundation of China (Grant No. 51908406) for their financial support.
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Published In
International Journal of Geomechanics
Volume 21 • Issue 6 • June 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Jan 23, 2020
Accepted: Jan 25, 2021
Published online: Apr 5, 2021
Published in print: Jun 1, 2021
Discussion open until: Sep 5, 2021
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