BACK TO PORTRAIT ORIENTATION
+

STRUCTURE

400N Lake Shore Drive

location

400N Lake Shore Drive

project completion

Competition 2016

size

2,889,628 sf

type

Residential



Architecture | STLArchitects
Engineering | ARUP
Exterior Wall | ENAR

STRUCTURE We approached the design of the structural system understanding that the structural and architectural design of a supertall building should work together to provide optimum performance at the lowest cost, in the least amount of time, and with the least architectural impact. We set out to design a tower with the structural efficiency and elegance that would allow the architecture to attain its maximum expression without compromising the flexibility of alternative development scenarios.

Developing the required program on a site of such modest proportions while taking advantage of its unmatched views requires buildings with tall and slender proportions. When the height to width ratios of these slender buildings surpass 1:10, the structure dedicated to resisting wind loads and vibration begins to increase dramatically. In order to provide the most efficient structural design possible, STL enlisted the assistance of Arup Engineers, one of the premier engineering firms in the world and a firm with whom we’ve worked very successfully in the past.

We approached the design of the structural system understanding that the structural and architectural design of a supertall building should work together to provide optimum performance at the lowest cost, in the least amount of time, and with the least architectural impact. We set out to design a tower with the structural efficiency and elegance that would allow the architecture to attain its maximum expression without compromising the flexibility of alternative development scenarios.

Developing the required program on a site of such modest proportions while taking advantage of its unmatched views requires buildings with tall and slender proportions. When the height to width ratios of these slender buildings surpass 1:10, the structure dedicated to resisting wind loads and vibration begins to increase dramatically. In order to provide the most efficient structural design possible, STL enlisted the assistance of Arup.

The Game Changer: Viscous damping The result of our collaboration has yielded an extraordinarily efficient structure boasting a state-of-the art viscous damping wind-resistance system. This viscous damping system allowed us to eliminate all of the tuned mass dampers from the project, and also to eliminate the buttress walls on the majority of the residence floor plates, resulting in open, unobstructed floors. Preliminary analysis indicates about 10-15% of the concrete for the wind-resisting system was eliminated from the traditional buttress walls + tuned mass damper approach. The resulting concrete savings are in the realm of $5 to 6 million in the North Tower and $3 to 4 million in the South Tower, with an estimated 10 weeks of reduction in construction time for each tower.

Eliminating the tuned mass dampers provides substantial advantages. First, removing the tuned mass dampers and replacing them with viscous dampers eliminates material from the project. These enormous concrete masses, required to be placed at the top of the building, are time consuming and costly to construct. The system allows $4 to 5 million in savings on each tower (cost difference between TMD and Viscous Dampers). In addition, eliminating tuned mass dampers from the tops of the buildings takes the most valuable real estate and returns it to usable space.

Eliminating the buttress walls results in open, unobstructed floor plates that can be divided flexibly depending on market needs at the time of sale. This allows for unlimited options for buyers to combine units if desired

partners in charge

Luis Collado

Jose Luis de la Fuente


technical director

Tracy Salvia


project director

Beatriz Gonzalez


director designer

Jose Luis Perez-Griffo


team

Marta Bueno

Ignacio Espigares

Andrea Kamilaris

Brian Koehler

Andrew Paul

Logan Springer