EFFECT OF STRUTTED EXCAVATION CORNERS ON GROUND DEFORMATIONS IN CLAY

HASSAN, ASMAA M.

EFFECT OF STRUTTED EXCAVATION CORNERS ON GROUND DEFORMATIONS IN CLAY

Document Type : Scientific and technological

Author

ASMAA M. HASSAN

Assistant Professor, Civil Eng. Dept., Public Works Division, Cairo University, Giza, Egypt

Abstract

In the last decades, Deep excavations in populated urban areas had been become a traditional practice. One of the essential for such excavations is to prevent damage to the nearby existing buildings. In order to guarantee the security for the existing buildings and excavation site, it is needed to predict possible problems. In order to evaluate the wall deformation and soil displacements, numerical analyses and empirical methods shall be taken into consideration. In numerical analysis the use of 2D modelling computer programs considered that modelled section is continues infinitely with the same geometry through the perpendicular axis to the section. However, any variation the supporting conditions and stiffness of pit corner in this perpendicular axis effects the behaviour of the deformation. Therefore 3D modelling computer programs provide more realistic solution considering any effect of 3D behavior. In this paper, A 3D analysis computer modeling program PLAXIS 3D is used to study the corner effect on the behavior of the ground deformation around the braced excavation pit. It was found that the deformation decreased when go far from the center of excavation. The corner stiffness has a significant effect on the wall deformation.

Keywords

References

1- Beadman, D., Cheng, A., 2002. Geoguide 2002-06. Arup International Document

2- Burland, J.B., Simpson, B. & St. John, H.D., 1979. Movements around excavations in London Clay. Proc. 7th European Conf. Soil Mech. And Found. Eng., Vol.1, British Geotechnical Society, Lon-don U.K.13-30

3- Finno, R.J. & Blackburn, J.T. & Roboski, J.F., 2007. Three-dimensional effects for supported excavations in clay, J. Geotech. Geoenviron. Eng., 133 (1) 30-36

4- Fuentes, R., Devriendt, M., 2010.Ground Movements around corners of excavations: Emprical Calcula-tion Method J. Geotech. Geoenviron. Eng., 136 (10) 1414-1424

5- Lee, F.H., Yong, K.Y., Quan, K.C.N. & Chee, K.T. 1998. Effect of corners in strutted excavations: Field monitoring and case histories. J. Geotech. Geoenviron. Eng., 124 (4) 339-349

6- PLAXIS, (2014), “Reference Manual”, Delft University of Technology and Plaxis B.V., The Netherlands.

7- Ou, C.Y. & Chiou, D.C., 1993. Three-dimensional finite element analysis of deep excavations. Proc. 11th Southeast Asian Geotech. Conf. The Institution of Engineers, Malaysia, Kuala Lumpur, Malaysia, 769-774

8- Ou, C.Y., Shiau, B.Y. & Wang, I.W., 2000, Three-dimensional deformation behavior of the Taipei National Enterprise Center (TNEC) excavation case history. Can. Geotech. J. 37, 438-448

9- Simpson, B., 1992. Retaining Structure: displacement and design, Geotechnique, London, U.K., 42(7), 541-576

10- St. John, H.D. 1975. Field and theoretical studies of the behavior of ground around deep excavations in London Clay. Phd thesis in Cambridge Uni-versity, Cambridge, U.K.

11- Wong, L.W. & Patron, B.C., 1993. Settlements induced by deep excavations in Taipei, Proc. 11th Southeast Asian Geotech. Conf. The Institution of Engineers, Malaysia, Kuala Lumpur, Malaysia, 787-791.