Page 445 - Advanced Design Examples of Seismic Retrofit of Structures

P. 445

Chapter 6

Examples of Nonengineered

Buildings

Mohammad Yekrangnia
Department of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran

Aims
By reading this chapter, you are introduced to:
l adobe buildings characteristics and failure modes;
l introduction to several simple, feasible and economical retrofitting techniques
suitable for adobe buildings;
l good experiences from around the world in seismic retrofit of adobe buildings;
l an introduction and implementation of the “stability-based” retrofit method;
l comparison of seismic performance of several test specimens retrofitted with various
methods; and
l performance of the retrofitted adobe buildings in past earthquakes.

6.1 INTRODUCTION

The term “nonengineered” buildings refers to buildings with poor seismic
performance which cannot meet codes’ minimum requirements. These build-
ings are usually constructed by common-practice and their material properties
and constructional details vary significantly. Construction of nonengineered
houses has been among the most typical construction technique in many
third-world countries. Also, there are numerous cases of old buildings which
had been constructed at the time when no seismic design code was available;
hence they are categorized as nonengineered buildings. The collapse of these
buildings has been and still remains as one of the main causes of loss of human
lives and of economic devastation following strong earthquakes [1]. An exam-
ple of large-scale collapse of these nonengineered houses after the 2008 Ziarat
earthquake in Pakistan is shown in Fig. 6.1.
Nonetheless, observations from past earthquakes, for example, the 2003
Bam earthquake in Iran, prove that if these nonengineered buildings are con-
structed according to the uniformly accepted construction concepts with
good-quality materials and workmanship, their seismic performance is superior

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