Research purposes: The vacuum combined surcharge preloading technology has been widely applied in construction of port and road.However,its reinforcement mechanism and settlement calculation methods are still in controversy or unclear to affect its development and application.Combining the engineering test data,this paper analyzes the characteristics of vacuum combined surcharge preloading technology,including the№nsferring law of vacuum degree,change and dissipation characteristics of pore water pressure,foundation settlement rule and control effect of post—construction settlement and SO on.and discusses the relative problems in design and construction with vacuum combined surcharge preloading,such as the calculation methods for the foundation settlement and the influence factors on the post—construction settlement.
Research conclusions:fter eliminating the effect of vacuum degree,the increases and dissipation characteristics of excess pore water pressure under vacuum combined surcharge preloading foundation is basically consistent with that of single surcharge preloading,and there is no essential difference in reinforcement mechanism of them.Additional stress and reinforcement depth of vacuum preloading foundation is obviously different with that of single surcharge preloading,SO it should be considered in settlement calculation.At last,the control of the post—construction settlement under vacuum combined surcharge preloading is closely related to foundation conditions and embankment height and 80 on,80 its application must be considered in design and construction according to technical standard.