Variation of excess pore pressure around jacked piles considering the three-dimensional strength of soil
LI Jingpei1，2，FANG Rui1，2，LI Lin1，2
(1. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education，Tongji University，Shanghai 200092，China；2. Department of Geotechnical Engineering，Tongji University，Shanghai 200092，China)
Abstract：The pile-sinking process in saturated clay is regarded similar as the cylindrical cavity expansion under undrained conditions. Considering the soil strength in three-dimensional stress state，the SMP criterion-based Cam-clay model was adopted to solve the cylindrical cavity expansion and to derive the general solution. On this basis，the fixed solution of spatial axisymmetric consolidation equation was built. A series solutions of the dissipation of excess pore water pressure were derived by using the methods of separation of variables. The development of excess pore water pressure around piles with time and space was discussed. It was revealed that the impact of the radial and vertical permeability coefficient，the stress history and the shear modulus on the initial excess pore water pressure and the rate of consolidation. The theoretical solution was proved reasonable and applicable in comparison with the measured data. The excess pore water pressure around piles decreases with the increase of logarithmic radical distance. Shear modulus and vertical permeability coefficient have little effect on the rate of consideration，but the radial permeability coefficient and over consolidation ratios has a significant effect on it，that reflects the dissipation mainly along the radial direction.
2016, Vol. 35 
