Field instrumentation and evaluation of ground treatment by combined air-booster and straight-line vacuum preloading without sand

Abstract

Ground treatment via the vacuum preloading technique has been extensively used in coastal belts worldwide in the field of civil engineering. However, due to the poor effect of traditional ground treatment, a new technology of combined air-booster and straight-line vacuum preloading without sand was proposed. Field tests were conducted in this study to illustrate the treatment effect. Based on the monitoring data of field tests, this paper carefully studied the pore water pressure, and an empirical formula for predicting the average consolidation degree and settlement was provided. In addition, both the soil sensitivity and the undrained shear strength before and after vacuum preloading treatment were discussed. Finally, to illustrate the phenomenon in which the combined air-booster and straight-line vacuum preloading without sand technique can decrease the pore water pressure or accelerate the soil consolidation, a two-dimensional elastoplastic model was established, and the validity of the model was verified.