Monitioring Of Mechanics Properties Of Geogrid-Reinforced And Pile-Supported Embankment In Chaoshan Station

It is a new method for the geogrid-reinforced and pile-supported embankment to be used in treatment of soft ground. Based on the in-situ monitoring of the geogrid-reinforced and pile-supported embankment on wide deep soft soil in Chaoshao railway station, The pile and soil stress, the pore water pressure, the layered settlement, the flexibility in geogrid-reinforced and the lateral displacement were analysed in this dissertation. The main conclusions have been reached as followings:(1) With the load increased, the piles stress, the soil stress, the pile-soil stress ratio have to be increased. The pile-soil stress ratio reached 17 in the latter part. It shows that the pile bears most of load.(2) The change of pore water pressure is closely related with the filling. It generates excessive pore water pressure during the filling, it dissipates the excessive pore water pressure during the interval of filling. However, the variation of total pore water pressure was small, it will shows that the consolidation effect of pile was good.(3) The axial force and lateral friction is non-linear distribution along the pile. The axial force transmission is slower and lateral friction is smaller in the muck and mucky soil etc, the axial force transmission is faster and lateral friction is larger in the coarse sands and so on. As the load increases, the axial force and lateral friction was increased.(4) In the filling period, the layered settlement of soil between the pile is increasing, the settlement of shallow layered is becoming larger. When the filling is complete, the settlement is tending towards stable and even some layered settlement will be rebounded. But the total settlement is small, it shows that geogrid-reinforced and pile-supported embankment can effectively control the settlement of foundation.(5) As the load increases, the tension amount of geogrid-reinforced was increased, the tension amount of geogrid-reinforced on the pile is smaller than on the soil between piles. The total tension amount was small, and the maximum stretch ratio was less than 2%.(6) As the load increases, the lateral displacement was increased. However, the total lateral displacement is small, it shows that the pile effectively limiting the lateral displacement of foundation.