Computational Technology Resources - CCP

Keywords: earthquake, seismic load, seismic acceleration, wave propagation, soil-structure interaction, Rayleigh damping, soil models, Plaxis.

Summary

The problem of dynamic interaction of the construction with the basement soil is very important for dynamics and the seismic resistance of structures [1,2]. It is known that the dynamic characteristics of structure and, consequently, its response to dynamic action significantly depends on the sub-soil properties.

In the work, described in this paper, the results of the numerical modelling of the behaviour of engineering structures under the action of seismic loading are presented. The modelling was executed with the dynamics module of Plaxis-2Dv8 program . Plaxis is a finite element code for analysis in geotechnical engineering. The Plaxis-2Dv8 program enables: soil-structure interaction to be taken into account; the use of different soil models (both linear and nonlinear) and the application of different surface configurations and different soil layer inclinations [3]. Most of these features are absent in other programs. In Plaxis-2Dv8 the axisymmetric model and also the plane strain model are available, in the dynamic module of Plaxis special earthquake boundary conditions are used in order to absorb waves, reaching the boundaries and to create prescribed displacements at the bottom of the mesh.

The purpose of the work described in this paper, is to examine the behaviour of the soil-structure system subject to seismic load. For the solution of this problem three soil models are examined: a linear-elastic body (LE), a Mohr-Coulomb model (MC) and a nonlinear hardening soil model (HS).

The paper then discusses the following problems: the dynamic behaviour of an ordinary five-storey building subject to seismic loading, a retaining wall and a water reservoir embankment. For all of these problems plain strain analysis can be performed because the length of both the building and constructions is much more than their width, and the earthquake should have a dominant effect across the width. The sizes of the soil domain are taken as ten times the overall size of the base of the building. The seismic dynamic action is modelled by imposing a prescribed displacement to all bottom boundaries of the mesh. A real accelerogram of an earthquake recorded by the U.S. Geological Survey in 1989 is used for the analysis, that provided by the Paxis-v8 library.

The building having five floors and a basement, is modelled as plane elements and the material of the building is assumed to be linear elastic. The retaining wall, of a height of 4m, supports granular media and is modelled as a concrete slab with soil contact. The water reservoir embankment with the height of water at 5m is modelled as a soil cluster. Physical damping in the structure and the subsoil is simulated by means of Rayleigh coefficients.

As a result of the calculations: displacements, velocities and accelerations of control points on structural elements and in the soil were obtained; the internal forces in the structural elements were determined. The results are different for every soil model; some results are compared with existing recommendations and this comparison shows the coincidence of these recommendations with the results of the MC model.

References

1: R.W. Clough, J. Penzien, "Dynamics of Structures", New-York, 1975.
2: Y.M.A. Hashash, J.J. Hook, B. Schmidt, J.I-C. Yao, "Seismic design of underground structures", Tunnelling and Underground Space Technology, 16/4, 247-293, 2001. doi:10.1016/S0886-7798(01)00051-7
3: Plaxis b.v. Delft, the Netherlands, 2007.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £50 +P&P)

	Computational & Technology Resources an online resource for computational, engineering & technology publications
	not logged in - login
Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 100 PROCEEDINGS OF THE EIGHTH INTERNATIONAL CONFERENCE ON ENGINEERING COMPUTATIONAL TECHNOLOGY Edited by: B.H.V. Topping Paper 115 Numerical Modelling of Engineering Structures subjected to Dynamic Seismic Loading S.N. Polukoshko¹, V.F. Gonca² and E.V. Uspenska² ¹Engineering Research Institute "Ventspils International Radio Astronomy Centre", Ventspils University College, Latvia ²Institute of Mechanics, Riga Technical University, Latvia doi:10.4203/ccp.100.115 purchase the full-text of this paper Full Bibliographic Reference for this paper S.N. Polukoshko, V.F. Gonca, E.V. Uspenska, "Numerical Modelling of Engineering Structures subjected to Dynamic Seismic Loading", in B.H.V. Topping, (Editor), "Proceedings of the Eighth International Conference on Engineering Computational Technology", Civil-Comp Press, Stirlingshire, UK, Paper 115, 2012. doi:10.4203/ccp.100.115 Keywords: earthquake, seismic load, seismic acceleration, wave propagation, soil-structure interaction, Rayleigh damping, soil models, Plaxis. Summary The problem of dynamic interaction of the construction with the basement soil is very important for dynamics and the seismic resistance of structures [1,2]. It is known that the dynamic characteristics of structure and, consequently, its response to dynamic action significantly depends on the sub-soil properties. In the work, described in this paper, the results of the numerical modelling of the behaviour of engineering structures under the action of seismic loading are presented. The modelling was executed with the dynamics module of Plaxis-2Dv8 program . Plaxis is a finite element code for analysis in geotechnical engineering. The Plaxis-2Dv8 program enables: soil-structure interaction to be taken into account; the use of different soil models (both linear and nonlinear) and the application of different surface configurations and different soil layer inclinations [3]. Most of these features are absent in other programs. In Plaxis-2Dv8 the axisymmetric model and also the plane strain model are available, in the dynamic module of Plaxis special earthquake boundary conditions are used in order to absorb waves, reaching the boundaries and to create prescribed displacements at the bottom of the mesh. The purpose of the work described in this paper, is to examine the behaviour of the soil-structure system subject to seismic load. For the solution of this problem three soil models are examined: a linear-elastic body (LE), a Mohr-Coulomb model (MC) and a nonlinear hardening soil model (HS). The paper then discusses the following problems: the dynamic behaviour of an ordinary five-storey building subject to seismic loading, a retaining wall and a water reservoir embankment. For all of these problems plain strain analysis can be performed because the length of both the building and constructions is much more than their width, and the earthquake should have a dominant effect across the width. The sizes of the soil domain are taken as ten times the overall size of the base of the building. The seismic dynamic action is modelled by imposing a prescribed displacement to all bottom boundaries of the mesh. A real accelerogram of an earthquake recorded by the U.S. Geological Survey in 1989 is used for the analysis, that provided by the Paxis-v8 library. The building having five floors and a basement, is modelled as plane elements and the material of the building is assumed to be linear elastic. The retaining wall, of a height of 4m, supports granular media and is modelled as a concrete slab with soil contact. The water reservoir embankment with the height of water at 5m is modelled as a soil cluster. Physical damping in the structure and the subsoil is simulated by means of Rayleigh coefficients. As a result of the calculations: displacements, velocities and accelerations of control points on structural elements and in the soil were obtained; the internal forces in the structural elements were determined. The results are different for every soil model; some results are compared with existing recommendations and this comparison shows the coincidence of these recommendations with the results of the MC model. References 1 R.W. Clough, J. Penzien, "Dynamics of Structures", New-York, 1975. 2 Y.M.A. Hashash, J.J. Hook, B. Schmidt, J.I-C. Yao, "Seismic design of underground structures", Tunnelling and Underground Space Technology, 16/4, 247-293, 2001. doi:10.1016/S0886-7798(01)00051-7 3 Plaxis b.v. Delft, the Netherlands, 2007. purchase the full-text of this paper (price £20) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £50 +P&P)
Back to top	©Civil-Comp Limited 2023 - terms & conditions