Hospitals are regarded as some of the most important structures in society due to the service that they provide. Knowing this, governments spend large amounts of money on these facilities. Also, codes of design require to provide them more reserve capacity than that for conventional structures. However, large damages (such as collapses and permanent or temporary interruptions of their functionality) have still been observed in hospitals during strong earthquakes. Unfortunately, it is precisely after this type of event that their service is in high demand and failure in providing that service could lead to further disastrous or fatal consequences. Therefore, the use of protective technologies, combined with rational procedures of design, would help to reduce damage and probable losses of functionality in hospital structures. In this thesis, a procedure for seismic design of structures equipped with a type of protective technology, namely, buckling-restrained braces (BRBs), is proposed. Then, the results of experimental and numerical studies are presented to understand the benefits of using BRBs in structures. This study highlights that BRBs are very effective to dissipate seismic energy and can act as structural fuses, i.e. disposable devices that may be replaced after an earthquake without interruptions in the functionality of the structure. One of the advantages of the proposed procedure is that it takes into account explicitly the characteristics and contributions of both, the main structure and the BRBs. It is based on the assumption that a structure protected with BRBs can rationally be represented by a dual SDOF system whose parts yield at different displacement levels. Other advantages include: 1) better control of the displacement demands on the structure; 2) achievement of the fuse concept beforehand; and 3) rapid assessment of the probabilistic performance of the structure. The experimental studies consisted of testing steel and concrete models, with and without BRBs, on a shaking table. In addition to calibrate and validate the proposed method of design, the tests have helped to find that, due to BRBs: 1) the damping ratio is increased significantly; and 2) the dynamic response, to ground motions characteristic of the lakebed zone of Mexico City, is reduced in terms of lateral displacements, inter-storey drifts, floor velocities and floor accelerations. The numerical studies are: 1) a study of the response of typical hospitals improved with BRBs; 2) a study of residual displacements in conventional and dual systems; and 3) evaluation of the economic benefits of using BRBs in structures. On these studies, hypothetical hospitals located in the lakebed zone of Mexico City were considered. The results show that the use of BRBs is very beneficial in medium- and low-rise buildings, while adverse effects may be observed in high-rise structures.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:713567 |
| Date | January 2016 |
| Creators | Guerrero Bobadilla, Hector |
| Publisher | University of Manchester |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://www.research.manchester.ac.uk/portal/en/theses/seismic-design-and-performance-of-hospital-structures-equipped-with-bucklingrestrained-braces-in-the-lakebed-zone-of-mexico-city(5e7856c9-a9bf-47fa-a12f-f6db23dccba0).html |
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