Selection And Optimization Of Highway Foundation Treatment Methods In The Fujian Putian Soft Soil Area

A lot of important traffic lines have to be built on lands with poor soil conditions that were affected by lake wetlands,river,etc.The foundation must be treated to increase the stability of roadway platforms.The choice of an effective foundation treatment method with a reasonble economic cost is a key problem for the design of a traffic project.Soft soils may result in the uneven settlement of the subgrade,resulting in uneven,surface water,ground pavement cracking phenomenon such as serious damage and even the whole road.Therefore,enhance the soft soil foundation,and optimize the treatment plan,has the very high practical significance,provides a certain basis for engineering construction.In soft soil area of FuJian PuTian,plans to build a first class road of 3.33 km.Combined with engineering background,this paper mainly to the following:(1)For the specific project of area of all kinds of basic situation,this study did the geological survey firstly.Research the general situation of the economy in the project,and summarized the soil and hydrological conditions.The soil layer in this area is not suitable for natural foundation.(2)Combined with the data of geological survey and most kinds of conventional treatment,this study choose the PTC pile composite foundation,sand pile composite foundation and CFG pile composite foundation as the optimized measures,and hace made their implementation plan.(3)In view of the three kinds of measures,appropriate monitoring survey is worked out.On the basis of monitoring data,combining with the bearing capacity calculation,the engineering cost and construction time were estimated in limited ranges.This study finally concluded that the most suitable method is the CFG pile composite foundation.(4)This study uses the ABAQUS to simulation soft soil displacement and pore pressure and the change of effective stress.At the same time,compared with the measured data of test and verify the reliability of the model.Then use the model to do the parameter analysis.Finally,combining with the project cost analysis,specific optimization scheme is given.And it is suggested that the replacement rate of the CFG foundation should be controlled between 0.05 and 0.06 in terms of the project.The pile length should be controlled just through the soft soil layer about 1m.The pile diameter shall be controlled between 0.4m and 0.6m.