Application Of Vacuum Preloading In The Basic Treatment Of Yongding New River Floodgate Soft Clay And Its Effect Analysis

With the development of national economy and urban construction, the demand for construction land became more and more urgent, but its limited amount led to the contradiction between the two. Tianjin is a coastal city with extensive soft cohesive soil layers. In order to alleviate construction land shortage, the problems of project construction on soft foundation had to be solved during the development and construction of Tianjin, especially in Binhai New Area. Soft cohesive soil layer has the characteristics of high moisture capacity, large void ratio, low intensity, high compressibility and low permeability. To ensure the architecture's safety and normal service, it is necessary to strengthen the natural base of soft cohesive soil layers.Mathematic analysis and on-spot measurement were combined to analyze the measuring data and conduct classified prediction. In accordance with the characteristics of soft clay in Tanggu District of Tianjin, the thesis collected the engineering geology materials and testified the mechanism of vacuum preloading foundation treatment on soft foundation through the analysis of applicable effect of vacuum preloading foundation treatment in the first stage construction of Yongding New River treatment project.Taking the soft clayed foundation treatment of the floodgate of first stage construction of Yongding New River treatment project as the engineering background, the thesis analyzed the treatment techniques of vacuum preloading and the practical effect of vacuum preloading zone. Engineering curve graphics of under-membrance vacuum degree, pore water pressure, groundwater level, land subsidence, etc. were drew out to accumulate experiences for relevant work in the future.The construction process of strengthening soft soil base in first stage construction of Yongding New River treatment project verified the feasibility and reliability of treating the soft clayed river channel base by the use of low-order vacuum preloading method, and relevant parameters were obtained. The practical experience proved that the effect of low-order vacuum preloading method on strengthening soft soil was obvious, and it was suitable for soft soil strengthening during first stage construction of Yongding New River treatment project.Specific monitoring data were obtained through all dimensional investigation during vacuum preloading process. Through contrast and analysis on trial indexes and intensities before and after soil strengthening, the trial testified whether the vacuum preloading strengthening effect was attained.Combining with the practical engineering case of first stage construction of Yongding New River treatment project, construction process of vacuum preloading method on soft soil base strengthening was analyzed; suggestions of improvement were put forward, so as to make the project construction more convenient, rapid and economic.