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.

The super-long and large-diameter steel pipe piles are often adopted for the construction of offshore oil platforms in deep sea. One constructability issue related to driving heavy pipe piles is the pile running. The term pile running refers to the quick penetration of a pile into the seabed as a result of its high self-weight and low resistance from the seabed. The unexpected pile running can cause the steel wire of the hammer to break or even the loss of the hammer. A case study of pile running at an oil platform is introduced in this paper. A simplified theoretical method is proposed to explain the mechanisms of the pile running in this case. A factor of friction degradation is proposed to calculate the dynamic skin friction from the static ultimate skin friction of surrounding soil. The comparisons between the predictions to the case history show that the proposed simplified method can be used to predict the pile running condition.