Thạc Sĩ Seismic pounding effects in buildings

SEISMIC POUNDING EFFECTS IN BUILDINGS
A THESIS SUBMITTED IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR
THE DEGREE OF
BACHELOR OF TECHNOLOGY
IN
CIVIL ENGINEERING
By
ISHAN JYOTI SHARMA
ROLL NO-10401029
​

ABSTRACT
Major seismic events during the past decade such as those that have occurred in
Northridge, Imperial Valley (May 18, 1940), California (1994), Kobe, Japan (1995),
Turkey (1999), Taiwan (1999) and Bhuj, Central Western India (2001) have
continued to demonstrate the destructive power of earthquakes, with destruction of
engineered buildings, bridges, industrial and port facilities as well as giving rise to
great economic losses. Among the possible structural damages, seismic induced
pounding has been commonly observed in several earthquakes. As a result, a
parametric study on buildings pounding response as well as proper seismic hazard
mitigation practice for adjacent buildings is carried out. Therefore, the needs to
improve seismic performance of the built environment through the development of
performance-oriented procedures have been developed. To estimate the seismic
demands, nonlinearities in the structure are to be considered when the structure enters
into inelastic range during devastating earthquakes. Despite the increase in the
accuracy and efficiency of the computational tools related to dynamic inelastic
analysis, engineers tend to adopt simplified non-linear static procedures instead of
rigorous non-linear dynamic analysis when evaluating seismic demands. This is due
to the problems related to its complexities and suitability for practical design
applications. The push over analysis is a static, nonlinear procedure that can be used
to estimate the dynamic needs imposed on a structure by earthquake ground motions.
This project entitled “Seismic Pounding Effects in Buildings.” aims at
studying seismic gap between adjacent buildings by dynamic and pushover analysis
in SAP2000. A parametric study is conducted to investigate the minimum seismic
pounding gap between two adjacent structures by response Spectrum analysis for
medium soil and Elcentro Earthquake recorded excitation are used for input in the
dynamic analysis on different models The effect of impact is studied using linear
and nonlinear contact force on models for different separation distances and
compared with nominal model without pounding consideration. Pounding produces
acceleration and shear at various story levels that are greater than those obtained
from the no pounding case, while the peak drift depends on the input excitation
characteristics. Also, increasing gap width is likely to be effective when the
separation is sufficiently wide practically to eliminate contact. The results of
pushover analysis viz. pushover curves and capacity spectrum for three different
lateral load patterns are observed to study the effect of different lateral load pattern on
the structural displacement to find out minimum seismic gap between buildings.