Page 151 - Advanced Design Examples of Seismic Retrofit of Structures

Example of an RC Building Retrofitted by RC Shear Walls Chapter 3 143

TABLE 3.7 The Main Causes of Vulnerability

Building with two independent, isolated building parts
Causes
l Improper arrangements structural system to withstand the seismic demands of a region
with very high seismicity
l Considerable irregularity in the plan of the building because of improper arrangements
of structural members, especially the RC shear walls
l Low ductility of the RC shear walls because of their details and using unribbed bars
l Low capacity of RC shear walls
l Pounding of the two northern and southern parts of the building during earthquakes
Conclusions
l The building is very vulnerable under Earthquake-1
Monolithic building
Causes
l Improper arrangements structural system to withstand the seismic demands of a region
with very high seismicity
l Irregularity in the plan
l Irregularity in the height of the building
l Low ductility of the RC shear walls because of their details and using unribbed bars
l Low capacity of RC shear walls
Conclusions
l The building is very vulnerable under Earthquake-1

3.4 PRELIMINARY DESIGN AND STUDY OF THE POSSIBLE
RETROFIT METHODS (PHASE-1, STAGE-2)
Based on the main causes of vulnerability of the building and the recommen-
dations in the previous parts of this chapter, three candidates for seismic retrofit
of the building are proposed and studied. These retrofit solutions are as follows.

3.4.1 Proper Connection of the Two Building Parts
l The main strategies are as follows:
– The method should be designed to make the best out of the building
potentials.
– The method should be feasible, preferably straightforward, and
economical.
– The method should improve the stiffness distribution in the plan of the
building.