Monitoring And Verification Study Of Vacuum Combined With Surcharge Preloading In Soft Soil Foundation

Saturated clay is the modern sedimentary soft soil in the coastal reclaimed land area, the new accumulation of reclaimed soil and backfill soil cover on the sea bed soft soil, belong to owe such soft soil consolidation soil. As the soft soil foundation, if not treated and the building directly built on top of it, shear deformation and consolidation settlement will happen on the soft soil foundation, then will make the settlement of building large or larger differential settlement of with the surrounding buildings.Treatment of soft soil foundation is commonly used in the current construction measures are:stack preloading, composite foundation, vacuum preloading and vacuum combined pile load preloading, dynamic consolidation and various construction schemes. In this paper, according to the practical application, do the following work.Separately on the basis of the existing theory and experiments of vacuum preloading, stack preloading joint preloading and their respective characteristics and principle is analyzed., combination with the engineering application of law, and further explains the deformation law of soft base joint preloading process, and put forward reasonable guidance.Aiming at Zhoushan coastal reclamation of soft soil foundation reinforcement engineering, construction and monitoring method, put forward the corresponding to the construction of the data information feedback, ensure the effect of the reinforcement. Based on the vacuum combined pile load pre press site measured data, and to screening and processing of data, analysis of the vacuum combined pile load preloading construction of data of various monitoring items. In order to get a more accurate monitoring data, and at the same time puts forward the reasonable monitoring scheme and method.Through the analysis of pore water pressure data, found within the scope of the depth of the vertical 1/2 plastic drainage plate and vacuum degree caused the reduction of pore water pressure is greater than the depth of the hydrostatic pressure of the absolute value of, the maximum depth of the negative pore pressure of plastic drainage plate 1/2.The soil horizontal displacement data, the study found within the scope of the depth of the vertical 1/2 plastic drainage plate, the horizontal displacement of soil can reach more than 50% of the maximum horizontal displacement; the holeAlso found under the 1/2 in certain depth range, there will be a horizontal displacement reverse.After reinforcement, on analysis was found within the scope of the depth of the vertical 1/2 plastic drainage plate, the soil shear strength are increased by more than 2 times, namely, significantly increase the depth of soft soil shear strength can be up to 1/2 of the drainage plate.In terms of theoretical research and the construction technology, the vacuum preloading method has a great progress, but there are still some problems to be further solved. Vacuum preloading consolidation scope, underground water level in the process of vacuum preloading and vacuum preloading foundation stable situation in the process of the problem.