The Project involved the structural analysis and design of a 12 storey high building, plus 2 basement floor, located in Lima, Barranco District, with an average height of 49m. It is fitted with a seismic protection system, consisting of 145 elastomeric insulators with a lead core and 4 sliders located in the first basement and strategic zones.
The New Headquarters of the Engineering and Technology University are located in Malecon Armendariz, between the Av. Grau and la Av. Paseo de la República, Barranco district, (Lima- Peru) in a plot of approximately 15,000 m2.
The architectural design is the result of a Public International Contest, awarded to the firm Grafton Architects (Ireland) .
The first stage of the project has a built area of 34,000 m2. GCAQ participates in the project since 2012, being involved in three areas:
- Project Management.
- Structural Engineering
- Project Supervision
This construction will accommodate approximately 2.000 undergraduate students in the first stage, and to obtain the LEED certification is one of the main goals.
STRUCTURE PROJECT DESCRIPTIVE MEMORY
The building from the structural point of view has quite complex and atypical geometry and features in comparison to previously designed buildings, such as the following:
- Irregular floor structure
- Irregular elevation structure
- Flexible diagrams
- Gardens and trees in upper floors
- Long spans of post tensioned beams with reduced effects of camber (21m)
- Large cantilevers with post tensioned beams (Over 6m)
- Great mass of interior concrete partitions responding to architectural requirements
- There are no typical plants, between floor plants
- The completely breached system following the longitudinal axis of the building
Elastomeric seismic insulators, with a lead core, were used as a consequence of the mentioned reasons, looking to reduce the seismic acceleration and thus the seismic demand on the reinforced concrete structure. These detached to a great extend movement from floor to the structure, reducing in such a way accelerations and demands on the elements of the structure.
Mitigation of the effects of the irregularities characteristic of the super structure was achieved due to the incorporation of these insulating devices, simplifying and highlighting the transitional vibration modes along the longitudinal and transversal axis of the building, eliminating or reducing to a considerable extent the torsional modes. On the other hand, drifts in mezzanines were also quite reduced.
The system for earthquakes, resistant in the transversal direction, is made up of concrete walls and reinforced beams known as Wallbeams. In the longitudinal direction the building is basically breached.
The UTEC foundation stands on gravel from Lima. It is made up of separate footings, connected and combined and of strip foundation.
The structural analysis was done following the parameters established by the study of seismic risk, ground mechanics study and the parameters of analysis and design established in the National Building Regulations. Also, as currently there is no Peruvian structure regulation that gives guidelines for the design of structures with insulation systems the American Regulation (2010) ) “Minimum Design Loads for Buildings and Other Structures”. ASCE/SEI 7-10 American Society of Civil Engineers, Virginia, USA, was used.
Due to the complexity of the structure, all kind of structural analysis were carried out. Analysis which ranged from the most simple ones to the most complex ones; starting with static structural analysis to obtain the order of magnitude that can be expected, followed by spectral analysis and with non-linear time history analysis lastly, flexibility of the diagrams in each of the
mezzanines in the last two being considered.
The specified reinforcing steel supports a fluency effort of fy= 4200 Kg./cm2. Different qualities of concrete were used such as f’c = 245Kg/cm2 in foundations, f’c =280 Kg/cm2 in columns, slabs, beams, walls, slates and stairs, and f’c =350 Kg/cm2 for post-stressed beams. To ensure the properties of the insulators specified in the project, each of the insulating devices was tested in the laboratory of Dynamic isolation systems en Reno – Nevada, United States.
It´s worth mentioning that the New regulation of seismic insulation is in process of being developed. This will have the guidelines established by the ASCE regulation for a basis, which was used for developing this innovating project, which sets a historic milestone in Peruvian engineering.
To complete this project was not an easy thing to do; it demanded the effort of teamed structural engineers and draughts men, all working in the same direction. To carry out the project with the highest quality, safety and economic efficiency standards, preserving the original architectonic concept, resulting in a new icon in the city of Lima.
View Original