Prof. Sarosh H Lodi NED University of Engineering and Technology What Works and Does not Work in the Science and Social Science of Earthquake Vulnerability, January 28-29, 2011

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. 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. INRTODUCTION

Typical Urban Buildings

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

COMPARISON OF BARE FRAME AND INFILL FRAME

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

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

MODELING PARAMETERS OF INFILL (STRUTS) a = Depth of strut t = Width of strut t c = Thickness of shortcreteE c = Modulus of Elasticity of shortcrete E m = Modulus of Elasticity of infillE fe = Modulus of Elasticity of frame h col = Depth of column I c = Moment of inertia of column h inf = Height of infillL diag = Diagonal length of infill  Inclination angle of infill For retrofitted strut: For ordinary strut in above equation use: E c = 0 and t c = 0

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

TIME PERIOD AND BASE SHEAR FOR BARE FRAME FOR INFILL FRAME

COMPARATIVE ANALYSIS OF STRENGTH BASED ON PERFORMANCE BASED ANALYSIS

FAILURE MECHANISM BARE FRAME FOR INFILL FRAME

COMPARATIVE ANALYSIS OF STOREY DISPLACEMENTS

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

RETROFITTED MODELS a)BY MAKING STRONGER COLUMN AND BEAM WHICH ARE TO BE FAILED IN PREVIOUS ANALYSIS i.RCC OR STEEL JACKETING OF COLUMNS ii.RCC OR STEEL JACKETING OF BEAMS b)BY INTRODUCING A SPINE

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

COMPARATIVE ANALYSIS OF STRENGTH OF RETROFITTED MODEL

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

COMPARATIVE ANALYSIS OF STOREY DISPLACEMENTS

Campaign

Typical Rural Buildings

Typical Construction

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.

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.

PLAN OF SCHOOL

VIEW OF SCHOOL A view of school is shown in figure below.

TYPICAL SECTION OF WALL Typical wall section of the construction in the area is shown in figure below. X Y Z

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

ANALYTICAL MODELLING Axial behaviour is modelled as follows

ANALYTICAL MODELLING Shear behaviour is modelled as follows

ANALYSIS OF RETROFITTED SCHOOL A view of the mathematical retrofitted model is shown in figure below

ANALYSIS OF RETROFITTED SCHOOL A view of retrofitted long wall is presented in figure below which shows the jacketing scheme around the openings.

ANALYSIS OF RETROFITTED SCHOOL A view of retrofitted short wall is shown in figure below which displays a typical wall without openings.

PROGRESS IN RETROFITING WORK

STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3 PROGRESS IN RETROFITING WORK

STRUCTURAL RETROFITTING OF GGPS NAYASHER # 3

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