Numerical-modeling-of-time-dependent-behavior-of-soft-clay-treated-with-stone-columns.pptx

Numerical-modeling-of-time-dependent-behavior-of-soft-clay-treated-with-stone-columns.pptx

1. Numerical modeling of time dependent behavior of soft clay treated with stone columns Eng. Eman ahmed

2. Presentation Outlines Introduction of soft clay problems Previous work in the presented topics The proposed research objective Research Methodology Research Plan

3. Failure and poor quality in construction of soft soil without using improvement techniques at soft clay

4. Introduction Soft clay problems. The importance of studying improving soft clay with stone columns technique. Types of stone columns affecting on soft clay properties and consolidation time.

5. Literature Priebe (1976) . proposed a method to estimate the settlement of foundation resting on the infinite grid of stone columns . He assumed that lateral deformations in soil at the boundary of unit cell are zero and considered the stone columns material is incompressible Poorooshasb and Meyerhof (1996) . proposed the performance ratio, which is defined as the ratio of the settlement of the improved ground to that of the unimproved ground under identical surcharges. They considered linear elastic behavior for stone column .

6. Balaam et al. (1978) . proposed a finite element approach for soft clay treated with granular piles and reported the effect of stiffness of granular pile on load deformation behavior. Han and Ye (2001) . estimating the rate of consolidation of the stone column reinforced foundations accounting for the stone column soil modular ratio. He proposed that during the process of consolidation the stress on stone column increases with time, whereas the stress on soil decreases.

7. The proposed Research Objective Investigating the effect of stone column on soft soil behavior. Critique analysis of current settlement prediction equation. Verify of numerical model that capable of predicting behavior of improved soft clay using stone column. Parametric study to investigate the effect of stone column diameter, spacing, length and embedment length.

8. Research Methodology By collecting data from literature, we can propose in this paper the following sequences: First, the simulation of numerical model for stone column in soft soil in plain strain is introduced. Second, verify the numerical model using the measurements data and doing parametric studies to investigate the effect of stone column diameter, spacing, length and embedment length. Finally, analytical and comparing results with existing theories.

9. Research Plan Topic Duration (Month) 1 2 3 4 5 6 7 8 9 10 11 12 Collecting data from literature Comparative study between standards Learning (Plaxis , Mate flow)2D Building the 2D model Parametric study Case study back analysis and model validation Thesis writing Thesis defense

10. Reference [1] A. Zahmatkesh & Asskar J. Choobbasti . (2010) "Settlement evaluation of soft clay reinforced with stone columns using the equivalent secant modulus" @ Saudi Society for Geosciences. [2] W.Edward & Polf P.Brenner . (Soft Clay Engineering) .New York. El Sevier scientific publishing company.(1981),History of civil engineering in soft clay ,(92/97).  [3] Aboshi H, Ichimoto E, Harada K, Emoki M (1979) The composer-a method to improve the characteristics of soft clays by inclusion of large diameter and columns. Proc., Int. Conf. on soil Rienforcement . E.N.P.C., 1, Paris 211-216 [4] Ambily AP, Grandhi SR (2007) Behavior of stone columns based on experimental and FEM analysis. J Geotech Geoenviron Eng ASCE 133(4):405–415 

11. (5] Balaam NP, Booker JR (1981) Analysis of rigid rafts supported by granular piles. Int J Num Anal Methods Geomech 5:379–403  [6] Balaam NP, Poulos HG, Brown PT (1978) Settlement analysis of soft clays reinforced with granular piles. Proc., 5th Asian Conf. on Soil Engineering, Bangkok, Thailand, 81–92 [7] Elkasabgy MA (2005) Performance of stone columns reinforced grounds. M.Sc. Thesis, Zagazig University, Faculty of Engineering at Shobra , Cairo

12. Thank You