Study on variable stiffness foundation treatment technology and settlement control

A new method of foundation treatment, called post treatment of variable stiffness composite foundation, is studied in the paper, by using the non-sand concrete micropile technology to treat the deep mixing cement-soil pile composite foundation. This method is suitable to treat the abutment transition section and control the post settlement of high-fill embankment. In order to investigate the efficiency of the new method, twelve in-situ tests has been taken at Daguang freeway consisted of high-fill embankment. The test results demonstrate the advantages of this method such as reducing the settlement of road shoulder, preventing the crack along the lengthways and so on. Then a numerical modeling was employed to calculate the settlement by using an equivalent composite modulus. The numerical results are good consistent with the field monitoring. Finally, the control method of post settlement was proposed which was proved by specific project. The new method presented in the paper is of not only theoretical significance, but also engineering practical value.