摘要
真空堆载联合预压法是综合运用真空预压和堆载预压两种技术对软土路基进行加固的一种方法。由达西定律可知,多孔介质中孔隙液的渗流速度与水力坡度成正比,通过提高水头压力或者减小排液路径,均能够实现加快土体固结的目的。结合具体案例,对该方法实施路段的沉降位移等进行监测,并于实验室内开展力学实验,综合评价真空堆载联合预压发的加固效果。研究发现,真空预压法是通过降低多孔介质孔隙水压力,与加固区内外形成水头差,产生加快孔隙液渗流的水力坡降;而堆载预压法则通过堆载使得孔压消散达到提高强度的目的。两者综合运用形成的正负超净孔隙水压力会大大提高软基加固效果。
The vacuum preloading-combined surcharging method is an effective way to consolidate soft soils by using both vacuum preloading and the surcharging preloading methods.Based on the Darcy’s law,the seepage rate of the pore fluids in the porous media is proportional to the hydraulic gradient,so that the soil consolidation can be accelerated by increasing the head pressure or decreasing the drainage path.This paper presents a case history of the ground improvement of a railroad subgrade over soil soils.By monitoring the surface settlement and performing the laboratory testing on the mechanical properties of the subsurface soils,the effect of the ground improvement by using the vacuum preloading combined with surcharging method can be evaluated.It is concluded that the vacuum preloading method can reduce the pore water pressure of porous media and form a hydraulic gradient to accelerate the flow of pore fluid.The surcharging can improve the shear strength of soft soils by dissipating pore pressure under the surcharging load.Under combination actions of two methods,the positive and negative excessive net pore water pressure will significantly improve the effect of soft improvement.
作者
龚逸
王良民
GONG Yi;WANG Liangmin(Wuhan New District Construction&Development Investment Co.,Ltd.,Wuhan 430050;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071)
出处
《土工基础》
2023年第5期703-706,711,共5页
Soil Engineering and Foundation
关键词
真空堆载联合预压法
软土层
路基加固
现场监测
路面沉降
Vacuum Preloading Combined Surcharging Method
Soft Slay
Subgrade Improvement
Field Monitoring
Surface Settlement
