Assessment of the Structural Condition of a Hospital-Type Building in Mexico City Damaged in the 1985 Earthquake

• Published in: Key engineering materials 2017-09, Vol.754, p.349-352
• Main Authors: Avila, Jorge A., Avila-Haro, Jorge Arturo
• Format: Article
• Language: English
• Subjects: Aseismic buildings; Building codes; Compressibility; Concrete structures; Damage assessment; Decision making; Earthquake damage; Earthquake resistance; Earthquakes; Finishes; Friction piles; Ground motion; Lateral displacement; Nonstructural members; Reinforced concrete; Seismic design; Seismic engineering; Seismic response; Stiffness; Structural damage; Structural members; Three dimensional models; Urban planning; Vibration measurement
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.754.349

The seismic-resistant behaviour and the current structural condition against gravity loads of a hospital-type building is evaluated. The building fell into disuse due to the damages caused by the 1985 Mexico City earthquake. The structural assessment intends to ease the decision-making process regarding either to: 1) demolish the structure (including foundation) in order to build another tower-type structure in the same location; or 2) rehabilitate the structure (increase resistance and stiffness). The building consists in a reinforced concrete structure of the late 1960's, with five levels based on a rigid box foundation with friction piles, which was abandoned after the 1985 earthquake. It is located in a compressible seismic zone (site dominant vibration period, Ts ~ 2 seconds) and was designed according to the RCDF-66 [1] with seismic coefficients of 0.06 and 0.08 for the longitudinal (frames) and transverse (concrete walls of head axes) directions, respectively. Between 1971 and 1972 the foundation was reinforced with control piles. There are no reported damages of the main structural elements resistances but, because of the observed effects in the non-structural components within the building, important lateral movements can be induced, which are not recommended, nor desired, in hospital-type structures. Important deterioration problems can be observed in the non-structural elements and finishes as well as in the main structure (including foundation) after being abandoned for more than 30 years with scarce maintenance. The assessment was performed through spectral modal dynamic analyses, including three-dimensional models of the structure and foundation in conjunction in accordance with the current Code (RCDF-04) [2], as well as with a newer and stricter Regulation proposal of the Mexico City Building Code. Additionally, time-history analyses were performed with both site-representative ground motion records and 1985 earthquake records. The analytical results of the fundamental vibration periods were calibrated against the ambient vibration measured periods. Slump field measurements resulted under 1% with respect to height. In general, it complies with the failure limit state (resistances), but not with the lateral displacements and story drift limit.