Proceedings-DFI-India 2016: 6th Conference on Deep Foundation Technologies for Infrastructure Development in India, (DFI)
Determination of Coefficient of Modulus of Sub-Grade Reaction for Free Head Short Pile
Sumit Kumar Biswas, and Sibapriya Mukherjee, Civil Engineering, Jadavpur University, Kolkata, India, Moyukh De, PHED, Govt. of West Bengal, India
The piles often are also subjected to lateral (horizontal) forces and moments. In fact, there are some structures where the primary function of piles is to transfer lateral loads to the ground. Proper analysis of laterally loaded piles is very important to the geotechnical and civil engineering profession. In the present investigation an experimental study has been carried out with free head short model cast iron hollow piles of outer diameter of 24 mm and L/d ratios of 8, 10, and 15. The experimental results have been supplemented by numerical techniques using PLAXIS-3D Foundation version 2.1 software. The results have been found to agree reasonably well with the experimental results. Further finite difference approach has been adoptedto reduce the computational time and to calculate the coefficient of modulus of sub-grade reaction (h) from the load- deflection data obtained from PLAXIS output at different pile depths. The parametric study has been extended for the non-dimensional form defined as flexibility ratio (F.R.), ( where h, L, Ep and Ip are the coefficient of modulus of sub-grade reaction, the embedded length of model pile, elastic modulus of pile material and the moment of inertia of model pile about the central axis respectively).The variation of coefficient of horizontal modulus of sub-grade reaction (h) has been studied with respect to the following parameters for homogeneous soil system: relative density andL/d ratio. It has been found that the logarithm of flexibility ratio increases with increase inrelative density and increase inL/d Ratio. The values of h obtained by the proposed method have been, found to be close to the numerical results.As output of this research, graphs have been generated in respect of different parametric variations to gain an insight into behavior of piles under lateral load for short piles.
|article #2212; publication #1020 (INDIA-2016)|