增压式真空预压在铁路站场地基处理的优化设计研究

增压式真空预压能弥补常规真空预压时间长、长期效果差等缺点,基于该方法的加固机理,利用PLAXIS平面有限元进行设计参数优化研究,优化参数包括排水板板长、板间距、板型、增压强度等。研究结果表明,在预压前期,渗透系数对沉降量的影响较显著,而预压后期则排水板的尺寸产生的效果更为显著;对于工期和工后沉降都比较严格的工程,尽可能使排水板长度大于压缩层厚度,选取大尺寸、高渗透性排水板、间距取1.0m,并尽可能增加增压装置的功率。

Study on Optimized Design of Vacuum Preloading with Air Pressure Boosted for Treatment of Railway Station & Yard Foundations

Vacuum preloading with air pressure boosted can make up for shortcomings of the conventional vacuum preloading method in respect of time-consuming and poor effect in the long term.On the basis of its reinforcement mechanism,design parameter optimization was studied by use of the PLAXIS plane finite element,and the optimized parameters included the length of the drain board,board spacing,board types and pressurized intensity.The results show as follows: In the early stage of preloading,the permeability coefficient affects settlement greatly,and in the late stage the size of the drain board has more significant impact;for projects with limited construction time and strict post-construction settlement requirements,The drain board of larger size and with higher permeability coefficient should be chosen,the length of the drain board should be made longer than the compression layer thickness if possible,the board spacing should be taken as 1.0m,and the power of the pressure boosting device should be maximized.