The analysis of the bearing characteristics and deformation mechanism of composite foundation reinforced with geogrid-encased stone columns is presented in order to obtain its settlement calculation method. The settlement of composite foundation is divided into three sections which are the reinforced section, unreinforced section, and underlying stratum. Based on Hooke’s law of space problem and the thoughts of the layer-wise summation method, the relative slip displacement between pile and soil of reinforced section without plastic zone is analyzed. The settlement of reinforced section is calculated by the layered iteration method based on the pile element model. The compatibility of vertical and radial deformations of unreinforced section is analyzed based on the pile-soil element model. The settlement of underlying stratum is still calculated by the layer-wise summation method. Finally, two engineering examples are analyzed and the results show that the settlement calculated by the presented method is close to the measured one. The method overcomes the defect that the calculated results by the other existing methods are more dangerous and it is more feasible and can be applied in engineering practice.
Settlement calculation of composite foundation is a hot field in geotechnical engineering research . In the paper with an engineering example, useing the equivalent natural settlement calculation methods and weighted modulus settlement calculation methods to calculate the settlement of composite foundations combined by CFG pile and concrete ramming enlarge pile, which compared with the practical measurement result . The results show that the errors of calculated value of the equivalent natural settlement calculation method were permitted and suitable for calculating composite foundation settlement.
The settlement calculation model for soft clay foundation is established based on Hooke’s law and the Duncan-Chang model. By introducing the concept of damage ratio, the method for determining the deformation modulus of soil before and after damage under load is presented, and a nonlinear settlement calculation method which considers the structural characteristics of soft clay is proposed. In the end, a practical engineering example is analyzed with the proposed method and some current methods for soft clay settlement calculation. The results indicated that the proposed method is feasible and applicable in practical engineering.
On the basis of rigid pile composite foundation mechanism, This paper makes assumptions and establishes settlement calculation models, then applies shear displacement method to solve interaction flexibility coefficient of the pile-soil system and raises a rigid pile settlement calculation method, considering the effect of cushion.By calculating a certain experiment, it was found that theoretical and measured values of the relative error is smaller ,which can provide a reference for settlement calculation of rigid pile composite foundation in engineering.
A Three-Section-Settlement Calculation Method for Composite Foundation Reinforced by Geogrid-Encased Stone Columns