Soil drainage clogging mechanism under vacuum preloading: A review

As a kind of weak foundation treatment method, vacuum preloading (VP) combined with prefabricated vertical drain (PVD) has been used in practical engineering successfully. The method is not only economical but also efficient. However, drainage clogging problem easily occurs in the later stage of VP and seriously impacts the efficiency of soil consolidation. Therefore, it is necessary to research how to relieve the drainage clogging effect under vacuum preloading. This review mainly performs the clogging mechanisms (including filter clogging, particle migration, and non-uniform consolidation), clogging evaluation measures, and the common relieving clogging methods. Moreover, to further contrast the clogging effect, this review also provides corresponding drainage efficiency and energy cost analysis of these anti-clogging vacuum methods. Finally, some new directions are provided to solve the drainage clogging problem, making the study on clogging prevention measures more clear.