About half of the total building stock in Turkey is masonry type building.
Masonry buildings in Turkey, especially in rural areas, are constructed without any
engineering knowledge mostly by their own residents. They generally have heavy
roofs. Masonry type buildings also have thick and heavy wall materials. Heavy
roof and wall material generate large inertial forces in the case of an earthquake.
Brittle failure of walls leads to total failure of whole system followed by sudden
collapse of heavy roof. The aim of this thesis is to understand failure mechanisms
of brick masonry walls, prevent their brittle failure and allow the walls to dissipate
energy during an earthquake. Furthermore, ultimate capacity increase was also
targeted by using low cost and easy to obtain material.
In order to find an economical and effective way in strengthening of brick masonry
walls in their in-plane direction, steel rebars were used as post-tensioning materials
in brick masonry walls and house tests. Springy connections were utilized in the
reinforcing and post-tensioning bars in order to prevent early loss of post-tension
due to wall cracking or rebar yielding. Separate tests were conducted with and
without rebars and springs in order to compare their results.
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The test results indicated that the ultimate lateral load capacity of 6m long brick
masonry house increased up to about 6 times with respect to its nominal value.
Energy dissipation also increased up to about 10 times of the original house.
Lateral load capacity increase in 2m long rebar post-tensioned brick masonry walls
were measured as about 17 times when compared with the original wall. The
energy dissipation capacity was also increased about 30 times the nominal value.
A general procedure was developed to assess the vulnerability of single storey
masonry houses, which calculates the earthquake demand acting on each wall
segment. Comparison of capacity versus demand enables evaluation of wall
segments and leads strengthening calculations if necessary. Derived formulas were
used to calculate post-tensioning force and design vertical and diagonal rebars. The
procedure was demonstrated using properties of an existing house and
strengthening cost was found to be about 10% of the building cost.
The results of the conducted tests have shown that rebar post-tensioning of brick
masonry walls is an effective and cost-efficient way of strengthening the walls in
their in-plane direction and can be used as an economical and simple technique for
seismically vulnerable masonry houses. Spring based connection detail has
improved the post cracking performance of the walls at large deformations by
keeping the wall reaction higher after ultimate strength has reached as well as
increased the energy dissipation capacity of the walls.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12610114/index.pdf |
| Date | 01 October 2008 |
| Creators | Erdogdu, Murat |
| Contributors | Turer, Ahmet |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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