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Pre - disaster Mitigation Strategies - Special Reference to Pakistan

What Works and Does not Work in the Science and Social Science of Earthquake Vulnerability , January 28-29, 2011. Pre - disaster Mitigation Strategies - Special Reference to Pakistan. Prof. Sarosh H Lodi NED University of Engineering and Technology . INRTODUCTION.

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Pre - disaster Mitigation Strategies - Special Reference to Pakistan

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  1. What Works and Does not Work in the Science and Social Science of Earthquake Vulnerability, January 28-29, 2011 Pre - disaster Mitigation Strategies - Special Reference to Pakistan Prof. Sarosh H Lodi NED University of Engineering and Technology

  2. INRTODUCTION • Most of the buildings in the urban areas are semi – engineered non-ductile reinforced concrete moment resistant framed structures with very stiff masonry walls but not designed and detailed to resist seismic forces. • Most of the buildings in the rural areas are non – engineered load bearing stone/ brick masonry structures with no resistance to seismic forces.

  3. Typical Urban Buildings

  4. Typical Urban Buildings

  5. Typical Urban Buildings

  6. Model 1 Model of infill to increase seismic resistance a cost effective solution

  7. COMPARISON OF BARE FRAME AND INFILL FRAME

  8. MATERIAL PROPERTIES f’c= 21 MPa fy= 415 MPa Fcm= 2.1 MPa GEOMETRIC PROPERTIES

  9. PARAMETERS USED FOR ANALYSIS BARE FRAME FRAME WITH INFILL Soil profile type =SD Ct = 0.03 (For moment resisting frame) R = 5.5 Zone = 2B Soil profile type = SD Ct = 0.02 (For all other building system) R = 5.5 Zone = 2B

  10. MODELING PARAMETERS OF INFILL (STRUTS) For retrofitted strut: For ordinary strut in above equation use: Ec = 0 and tc = 0 a = Depth of strut t = Width of strut tc = Thickness of shortcrete Ec = Modulus of Elasticity of shortcrete Em = Modulus of Elasticity of infill Efe = Modulus of Elasticity of frame hcol = Depth of column Ic = Moment of inertia of column hinf = Height of infill Ldiag = Diagonal length of infill q = Inclination angle of infill

  11. STRENGTH OF INFILL (STRUTS) For Compression strut: For Tension tie:

  12. TIME PERIOD AND BASE SHEAR FOR BARE FRAME FOR INFILL FRAME

  13. COMPARATIVE ANALYSIS OF STRENGTH BASED ON PERFORMANCE BASED ANALYSIS

  14. FAILURE MECHANISM BARE FRAME FOR INFILL FRAME

  15. COMPARATIVE ANALYSIS OF STOREY DISPLACEMENTS

  16. Model 2 Addition of strength to the infill to increase seismic resistance

  17. RETROFITTED MODELS • BY MAKING STRONGER COLUMN AND BEAM WHICH ARE TO BE FAILED IN PREVIOUS ANALYSIS • RCC OR STEEL JACKETING OF COLUMNS • RCC OR STEEL JACKETING OF BEAMS • BY INTRODUCING A SPINE

  18. RETROFITTED MODELS Retrofitted columns and beams with infill Retrofitted infill wall 2” thick shortcrete with 12”c/c steel 3” thick shortcrete with 8”c/c steel 6” thick shortcrete with 8” c/c steel 8 “ th RCC wall & 4” thshortcrete with 6”c/c steel Retrofitted Elements Retrofitted Elements

  19. COMPARATIVE ANALYSIS OF STRENGTH OF RETROFITTED MODEL

  20. FAILURE MECHANISM OF RETROFITTED MODELS Retrofitted columns and beams with infill Retrofitted infill wall

  21. COMPARATIVE ANALYSIS OF STOREY DISPLACEMENTS

  22. Campaign

  23. Typical Rural Buildings

  24. Typical Rural Buildings

  25. Typical Construction

  26. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 INTRODUCTION School buildings are vital for a society They are places of learning They also play a significant role in the relief operation in post-disaster situations. These buildings can be used as temporary shelters. Assessment of seismic vulnerability of school buildings is essential to ensure safety of children and teachers.

  27. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 DESCRIPTION OF SCHOOL School consists of 4 classrooms. These have been divided into 3 blocks. Load resisting system consists of cavity walls of stone rubble masonry. These provide resistance against gravity loads. Roofing system consists is of timber trusses and corrugated metal sheeting. Construction inherently lacks resistance to lateral loads.

  28. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PLAN OF SCHOOL

  29. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 VIEW OF SCHOOL A view of school is shown in figure below.

  30. Y X Z STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 TYPICAL SECTION OF WALL Typical wall section of the construction in the area is shown in figure below.

  31. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 ANALYTICAL MODELLING A mathematical model of the school was developed. Finite Element Program SAP was employed. Individual blocks were modelled as solid brick elements. Mortar was modelled using non-linear springs. Non-linear properties of mortar were defined using existing constitutive models. Geometric non - linearity were also taken into account. Ground shakings were simulated using El-Centro ground accelerations

  32. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 ANALYTICAL MODELLING Axial behaviour is modelled as follows

  33. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 ANALYTICAL MODELLING Shear behaviour is modelled as follows

  34. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 ANALYSIS OF RETROFITTED SCHOOL A view of the mathematical retrofitted model is shown in figure below

  35. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 ANALYSIS OF RETROFITTED SCHOOL A view of retrofitted long wall is presented in figure below which shows the jacketing scheme around the openings.

  36. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 ANALYSIS OF RETROFITTED SCHOOL A view of retrofitted short wall is shown in figure below which displays a typical wall without openings.

  37. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

  38. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

  39. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

  40. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

  41. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

  42. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

  43. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

  44. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

  45. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

  46. STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3

  47. Thanks!

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