Masonry structure is those structures which are built by individual units together with the help of mortar. Easy of construction, Low cost and Highly durable, Fire resistance, Architectural appearance, Heat & Sound insulation and freely available materials are some of the advantages of masonry based buildings. Masonry structures are widely used in most of the developing countries. In early periods, masonry buildings were built with a less priority against seismic risks. But from the last few decades losses due to severe earthquake all around the world shows that the importance of resistance against the Seismic load in masonry buildings.
Sri Lanka is located in an aseismic zone away from major 12 or 13 plate boundaries or any active faults. However, there was an incident which cost more than 2000 deaths & collapses of more than 200 houses due to the earthquake on 14th April 1615 in Colombo. since this earthquake, there were several minor earthquakes were observed within the region around Sri Lanka. Also, the formation of a new plate boundary dividing Indo-Australian plate increase the possibility of the earthquake events. Considering above facts, Sri Lanka is no more in the safety region against seismic attacks. So, the study on masonry walls against seismic loads and retrofitting methods in masonry walls become more important. This research mainly focusses on the In-Plane & out-plane seismic behavior of the Junction Wall (L-shaped) with(GFRP) and without reinforcement.
“Traditional masonry structures without any special reinforcement or retrofitting method are highly vulnerable against to the seismic load”. Failure can be assured both In-plane failure & Out-of-plane failure. The major disadvantage of Masonry brick wall is it is low resistance against tensile stresses and lateral loads. The walls which are perpendicular to the seismic wave subjected to out-of-plane bending results in out-of-plane failure featuring vertical cracks at the wall corners and middle of the walls which may due to the inadequate flexural strength of unreinforced masonry or due to lack of integrity of an adjoining structural. Only a few researchers revealed the out-of-plane behavior of the masonry walls/ buildings due to the inability of taking account of wall interaction with the other part of the building and fragile nature of the brick masonry. So, it is necessary of analyzing the seismic behavior of the brick masonry wall junction (“L-shaped”) in terms of crack initiation, lateral drifts and failure patterns and comparison between the reinforcement wall and reinforcement (GFRP) wall.
SIGNIFICANCE OF RESEARCH
Generally shaking table test and seismic behavior of masonry wall was investigated against in-plane direction or out-of-plane direction. Sometimes the whole structure was investigated against the seismic load in the presence of facility to carry the large-scale tests. Both direction ‘(in-plane and out-of-plane) behavior against seismic load for the same wall is important to do the analysis of horizontal shear failure, corner or junction failure and failure of out-of-plane walls initiated by junction failure. Commonly corner or junction is identified as the weakest part of unreinforced masonry structures, so that proper technique of reinforcement method and comparison between both reinforced and unreinforced wall junction collapse analysis is important in the industry.
SCOPE OF THE STUDY
For the last few decades, dynamic response of masonry structure has been a focus of many researchers all around the world. Most of the researcher’s done the experiment in single wall panels or sample masonry buildings/houses against the seismic load. Most of the studies revealed that the dynamic response of the reinforced strengthened masonry walls in terms of fundamental frequency, crack patterns and directions, shear strength & energy absorption separately for each plane (in-plane and out-of-plane). So it is necessary to pay attention impact of reinforcement arrangement in URM walls to increase both in-plane and out-of-plane seismic performance of the wall junctions.
AIMS AND OBJECTIVES OF THE RESEARCH
The main goal of the research is proposed the building masonry technique withstand against severe seismic attacks. The main objective of this experiment is, seismic analysis of two scaled masonry L-shaped wall junctions constructed using both URM(unreinforced) and (GFRP or CFRP) reinforced masonry walls.
• Construct the proto-type model with respect to the proper scale, with the study of proto-type modelling.
• Analyse the results and outline the final conclusion.
• Familiar with the Shaking Table machinery and study on the software which operates the shaking table.
• Finally applied the seismic load on to the models and short out the final results.
• Identify the parameters which are going to be measured to compare the final conclusion.
• Literature reviews on previous experimentation done under seismic behaviour of masonry structures & find out the different reinforcement techniques.
Work Break Down
Preliminary Literature review
Study on R-200 software
Semester 6B Examination
Model a Porotype with scaled dimensions
Construct the Prototype model
Analyzing the models under shaking table
2- Base plate for shaking table
2- L-shaped masonry Walls(proto-type)
0.5m2 of GFRP or GFRP