Experimental Study On Highway Soft Subgrade Reinforced By Vacuum And Surcharge Preloading Method

Soft ground territory is distributing abroad in our country, so a lot of highways are constructed on the soft ground, this kind of soil has the character of rich water-content, high compressibility, lower bearing capacity. It brings many problems to the highway construction. So it is always treated with surcharge preloading method, composite foundation method and so on, but these methods can not satisfy the needs of construction stabilization, time, settlement after construction. But vacuum and surcharge preloading method has mortal superiority.This paper introduces the application of vacuum and surcharge preloading method in the practice of a highway project. First, it analyses the mechanism of consolidation in vacuum preloading and surcharge preloading method, then introduces the characteristics of vacuum and surcharge preloading method; Moreover, according to the test results it has a systematic analysis and study on the deformed regularity of this reinforcing highway. It also makes an inquiry into the variable regularity of vacuum degree and pore water pressure, the deformed regularity of vertical settlement and water level displacement of the embankment during the three different stages of the construction. Second, according to the test results the conventional and finite element method were adopted to analyze the final settlement during the construction period. Then it brings forward settlement correcting coefficient that adapts to this territory. Finally, the paper analyses the concretion degree and intensity increase, validates that whether it will appear the attenuation of shear strength like surcharge preloading method.Through summarizing the design and test results, the conclusion will be helpful for engineering design and construction.