Dynamic Response of Historical Masonry Minaret under Seismic Excitation

Takwa A Khider,Hayder A Al-Baghdadi

doi:10.28991/cej-2020-03091459

Abstract

In order to study the dynamic response of historical masonry structures, a scaled down brick masonry model constructed in civil engineering department at Baghdad University to simulate a part of a real case study, which is Alkifil historic minaret. Most of the previous researches about masonry structures try to understand the behavior of the masonry under seismic loading by experimental and numerical methods. In this paper, the masonry units (bricks) simulated in scale (S= 1/6) with the exact shape of the prototype bricks. Cementitious tile adhesive was selected to be the mortar for the modeling. The height of the model designed to be 1.5 m with a 0.5 m diameter. Detailed construction steps were presented in this paper. Experts built the model with high accuracy. A shaking table and other dynamic testing facilities were used at the University of Baghdad. The model was tested using the time-compressed El Centro 1940 NS earthquake at different amplitudes. The first ground motion of (PGA= 0.05g) which considered as weak ground motion was used to check the adequacy of the conventional behavior of the masonry model and the limit of the elastic behavior of the model during weak earthquakes. Moderate ground motion (PGA=0.15g) was performed to investigate the response of the model with minor to moderate damages. The severe ground motions were not appropriate to use in such circumstances because of the possibility to overturn the model. The experimental results showed very adequacy of the model to withstand the weak and moderate earth motion with no observed cracks.

Highlights

Masonry has been known as one of the oldest construction types and there is a high stock of masonry buildings around world including historical monuments which have being used for thousands of years or even up to now
The first step for the retrofitting of this type of structure is a deep understanding of their structural characteristics, vulnerabilities, and dynamic response
The potential resistance of such structures is adequate to resist the seismic forces with no damage

Summary

Introduction

Masonry has been known as one of the oldest construction types and there is a high stock of masonry buildings around world including historical monuments which have being used for thousands of years or even up to now. It is estimated that more than 70% of the worldwide building inventory is masonry type. Availability of materials and workmanship, enough local knowledge of constitutes like a brick, stone, timber and mortar have made masonry construction an attractive choice for building owners. Masonry can be considered strong and durable for gravitational loads. Due to the inherent structural deficiencies and material weakness of masonry, it has been proved that they are extremely vulnerable during earthquake events which resulted in a high number of casualties. This type of building should be considered for retrofitting and strengthening against earthquake-induced loads. The first step for the retrofitting of this type of structure is a deep understanding of their structural characteristics, vulnerabilities, and dynamic response

Objectives

Methods

Conclusion