Application Of Vacuum Concerting Stack Preloading For Highway Soft Ground Treatment

In the past over ten years, many problems, especially soft ground's non-uniform settling and large subsidence after finished and jump-off on bridge's end, arise from highway's building along national construction progresses. Whether the method for ground treatment selects appropriate or not may have a great influence on engineering's quality, period, maintenance and economic benefit. Stack preloading method is usually adopted for ground treatment by that time, and several years'studies and experiments and construction practice show that it is a tried and true method for soft ground treatment. But soft clay's low shearing strength limits loading speed, meanwhile, in order to reduce subsidence after finished to satisfy specification requirements, over preloading method or prolonging preloading time is usually adopted, which adds cost on one hand and affects progress on the other. If time limit is short, the above method is not good. Vacuum preloading can solve this problem, and it plays an increasingly important part role along the maturing and expansion of vacuum preloading concerting stack preloading technology. This article introduces vacuum stack preloading's developing process, reinforcement mechanism and use on soft ground treatment. Through comparative analysis among the vacuum stack preloading and other methods and instances, it shows that the vacuum preloading concerting stack preloading technology is increasingly maturing, the method is simply, and it can not only strengthen ground, but also shorten total period efficiently. It may be expanded further as a mean for highway soft ground treatment. Therewith, it indicates that the consolidation principle between vacuum drainage preloading and vacuum stack preloading is similar, but some aspects such as drainage mechanism exist large differences, and attention shall be paid to during designing and construction.