Recent Developments in the Vacuum Preloading Technique in China

Abstract

A series of studies have confirmed that vacuum preloading can effectively accelerate the consolidation process of soft soil. In recent years, further improvement in the efficiency of this method is still the continuing goal of scholars. This paper reviews the recent improvements in the vacuum preloading techniques as well as their practical applications in China. The advantages and disadvantages of each method are discussed. It is found that replacing or eliminating one or more components of the vacuum preloading system, such as sand-free, membrane-free, horizontal drain, multiple-step, and air booster vacuum preloading methods, achieved similar soil improvement effects to those of the traditional vacuum preloading method. Vacuum preloading combined with other soil improvement methods could improve the soil with the lower average water content and the higher average shear strength.

Substitution of sand ditch system method on vacuum preloading (study case: Land preparation project in Kalimantan)

“…The collectors are installed in place of the membrane and horizontal drains, and the PVDs are connected to the collectors. After the system's airtightness has been verified, a conventional fill can be carefully constructed above the connectors and collector tubes [16].…”

Large‐strain consolidation of vacuum preloading combined with partially penetrating prefabricated vertical drains

“…The construction procedure is first to mix the dredged marine clay with seawater and pump the mixed slurry into the reclamation site as shown in Figure 1A, B. The methods of surcharge and vacuum preloading combined with prefabricated vertical drains (PVDs) are commonly utilized to improve the engineering properties of the slurry‐type dredged clay 7–15 . However, the poor engineering properties of the dredged soil restrict the installation of PVDs and the application of preloading.…”