Consolidation effect of prefabricated radiant drain vacuum preloading technology: A physical model case study

Abstract

The large amount of dredged soil produced annually by rivers, lakes, seas, and oceans affects the ecological environment. Dredged material such as soft clay, which has high fluidity and high water content, is often utilized for building ground in engineering practice. Conventional vacuum preloading can effectively treat such soil but has a deprived consolidation effect. To improve the treatment effect, in this study, prefabricated radiant drain (PRD) vacuum preloading technology is proposed innovatively by adding prefabricated horizontal drains (PHDs) based on a prefabricated vertical drain (PVD). And a four-way connector is designed to connect PVD and PHDs, PHDs are attached to PVD to transmit vacuum pressure. A series of laboratory tests are run to compare and analyze the differences between conventional PVD and PRD vacuum preloading. The water discharge, average surface settlement, water content, and undrained shear strength values are analyzed. Then the parametric analysis of PHD spacings and length-width ratios (characterizing PHD length) are investigated. Overall, with the new PRD method, the consolidation effect of soft clay ground with a water content of 80% is improved by approximately 15%.

Keywords:

• Vacuum preloading
• soft clay ground
• prefabricated radiant drain
• consolidation effect
• prefabricated horizontal drain

Acknowledgments

The authors acknowledge the National Natural Science Ground of China (Grant No.: 52108336), the Laboratory Open Fund of Key Laboratory of Earthquake Engineering Simulation and Seismic Resilience of China Earthquake Administration (Grant No.: EESSR21), Tianjin University Independent Innovation Fund (Grant No.: 2022XYY-0003), China Postdoctoral Science Foundation (Grant No.: 2022M712367) for their support.

All statements, results, and conclusions are those of the researchers and do not necessarily reflect the views of these grounds. The authors also sincerely thank the anonymous reviewers for their insightful comments and suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.