Award of Merit: Low-Rise Category
Maypo Office and Laboratory Building Seismic Upgrade
Mexico City, Mexico
Submitted by Sika Mexicana S.A. de C.V.
MAYPO S.A. de C.V.
Eng. Ma. Del Carmen
Quimec S.A. de C.V.
Sika Mexicana S.A. de C.V.
The Maypo office and laboratory building, located in Mexico City, Mexico, is a fourstory structure reportedly constructed in the early 1980s. To date, the use of the building has been for shops, offices, and medical and clinical laboratories.
Progress in the investigation of soil characteristics in Mexico City and state-of-the-art earthquake engineering have generated new design standards and construction methods that have improved the level of seismic safety of new buildings. However, existing buildings constructed with less stringent design standards present a challenge. Worried about the safety of their building, Maypo initiated a structural assessment and seismic upgrade for the property.
Because original building design information did not exist, diagnostic studies were performed, including planimetry and altimetry surveys to estimate the magnitude of differential settlements, bibliographic research of soil mechanics in the area, concrete excavation for steel reinforcement assessment, extraction of concrete cores, visual inspection, and three-dimensional computer modeling for a dynamic structural analysis.
The studies revealed that the nonstructural masonry walls interfered with the free deformation of the main structure; the concrete slabs exhibited cracking, deflections, and excessive vibration; and the beams exhibited shear cracking at their ends. Furthermore, the computer model revealed that the columns were overloaded.
To structurally strengthen and seismically upgrade the building, new steel beams were retrofitted to stiffen the concrete slabs and surface flatness was recovered by installing a reinforced concrete overlay. Beam cracking was epoxy-injected to restore structural stiffness and improve behavior. Carbon fiber-reinforced polymer (CFRP) fabric was installed at beams to increase shear strength and at columns to increase strength and ductility. The strengthening project lasted approximately 2 months at an approximate cost of $600,000 USD.