Application of Shape Memory Alloys in Retrofitting of Masonry and Heritage Structures Based on Their Vulnerability Revealed in the Bam 2003 Earthquake

Abstract

For decades, one of the most critical considerations of civil engineers has been the construction of structures that can sufficiently resist earthquakes. However, in many parts of the globe, ancient and contemporary buildings were constructed without regard for engineering; thus, there is a rising necessity to adapt existing structures to avoid accidents and preserve historical artefacts. There are various techniques for retrofitting a masonry structure, including foundation isolations, the use of Fibre-Reinforced Plastics (FRPs), shotcrete, etc. One innovative technique is the use of Shape Memory Alloys (SMAs), which improve structures by exhibiting high strength, good re-centring capabilities, self-repair, etc. One recent disastrous earthquake that happened in the city of Bam, Iran, (with a large proportion of masonry buildings) in 2003, with over 45,000 casualties, is analysed to discover the primary causes of the structural failure of buildings and its ancient citadel. It is followed by introducing the basic properties of SMAs and their applications in retrofitting masonry buildings. The outcomes of preceding implementations of SMAs in retrofitting of masonry buildings are then employed to present two comprehensive schemes as well as an implementation algorithm for strengthening masonry structures using SMA-based devices.

Sustainability of Civil Structures through the Application of Smart Materials: A Review

“…Figure 6. SMA stress-strain graphs depicting schematic crystal formations at different temperatures [26] (figure is taken from [47]).…”

“…Due to its high energy absorption capacity, the suggested model with a 2% pre-strain SMA wire model demonstrates the biggest reduction of the lateral deflections of the church and significantly lowers impact (from destruction to mild damage level) in the event of powerful earthquakes. The schematic of the proposed system with SMA strands for connection bonds [79]; (b) the schematic of the proposed system and SMA strand in the isolation system of masonry constructions [80] (figures are taken from [47]).…”

“…Pseudo-dynamic, in-plane tests on masonry wall sneer with cavities indicated that SMA devices used in conjunction with steel cables to prestress the masonry may absorb about 30% of the seismic energy produced and therefore enhance a structure's seismic resistance. Giorgio church bell tower that were anchored to the foundation and the roof [82] (figures are taken from [47]).…”

“…Figure 18. (a)The schematic of the proposed system with SMA strands for connection bonds[79]; (b) the schematic of the proposed system and SMA strand in the isolation system of masonry constructions[80] (figures are taken from[47]). …”

“…Figure 20. (a) Retrofitting scheme of the San Paolo Eremita church[76]; (b) installation of four pre-tensioned steel tie bars and SMA devices in the interior corners of the S. Giorgio church bell tower that were anchored to the foundation and the roof[82] (figures are taken from[47]). …”