Tall Buildings – PIRMOZ STRUCTURAL ENGINEERING

We embrace challenges to maneuver our differentiators.

Tall buildings pose unique structural challenges, especially when they are located in coastal or seismic areas. Below are some of the projects that Dr. Pirmoz has designed for other firms and private owners before launching this company:

Atieh-II hospital:

The architectural design of this 36-story, 1.9 Million sq. ft. building in the high seismic zone of Tehran, Iran, could only be resolved using coupled steel plate shear walls with concrete-filled composite columns — the first use of this system in the country. Dr. Pirmoz introduced this system to the client, developed the concept and performed the full analysis-design of the structure. He also proposed and designed stiffened steel panels used in the three outrigger stories. He used composite floor slabs — comprised of steel plates connected to a reinforced concrete slab — to satisfy the concentrated strength and stiffness demands in the outrigger stories. The building has also special moment resisting frames and is equipped with Rotational Friction Damping devices. The contribution of other team members in the design of other parts of the structure including composite beams and producing construction drawings is acknowledged. The project management and the design of other disciplines was by Group 4 Consulting Engineers.

Pictures courtesy of B. A. T. Company

Tunnel-Form systems:

Unlike typical framed reinforced concrete structures with beams and columns, tunnel-form systems comprise only flat floor slabs and walls with a constant thickness throughout the full height of the building. The constraint in the thicknesses of the structural members (floors and walls) makes it challenging to achieve an optimum structural design. His experience and insight in the seismic response and design of concrete structures were effectively used in the design of numerous tunnel form projects for mass construction.

Dr. Pirmoz has designed the following projects between 2010 to 2011, purposefully considering an “increased shear demand” in the design of the walls of these buildings. Magnifying the design shear forces of seismic walls was not required in ACI 318-11, the reference design code for these projects at that time. Nearly a decade later, this requirement is now introduced in ACI 318-19.

Based on an energy-based concept and through an iterative analysis-design process, he considered the effective contribution of the coupled beams between the shear walls of the structure. This resulted in a significant reduction in material use, as well as a more favorable and controlled seismic response for these buildings. Reinforced concrete ductile coupled walls system has been recently introduced in ASCE 7-2022 and is recognized as seismically favorable.

Pictures courtesy of Naghsh Afarin Mehraaz Consulting Engineers

The Urmia complex:

This project had been initially designed by another engineering consult with its shear walls being 14″ (longitudinal direction) and 12″ (transverse direction). He reviewed the design of the super-structure as a third party consultant and noticed that as the wall thicknesses increase, the rate of increase in the seismic mass and forces are much higher than the associated increase in strength. He reduced the thickness of the walls and investigated the feasibility of designing the structure with 10″ and 8″ thick walls, respectively along transverse and longitudinal plan directions. This reduction in wall thicknesses resulted in significant savings of materials and expenses. The original consultant reviewed and accepted the change and completed the design process with the revised thicknesses.

Pictures courtesy of Naghsh Afarin Mehraaz Consulting Engineers

Mass construction:

The intent of using a fixed thickness for the walls and floor slabs is to use modular sliding forms for faster construction. This type of concrete structure significantly reduces the construction time and expenses and provides a favorable seismic performance, showing minimal structural and non-structural damage after seismic events. He has designed the following projects for mass construction in different cities of Iran. He also has done the peer review of several tunnel form structures ranging from 14-story to 18-story buildings in cities with a heigh seismicity.

Pictures courtesy of Naghsh Afarin Mehraaz Consulting Engineers

We embrace challenges to maneuver our differentiators.

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