building structures -6 | trussed tube systems| tubular systems | lateral force resisting systems |

1. TRUSSED TUBET h e d i a g o n a l b r a c i n g s y s t e m s
BUILDING STRUCTURES – 6 || RIFQUTH S.B ||

2. 2
TRUSSED TUBE or BRACED TUBE
BRACING
INTERSECET
AT THE TOP
OF INTERNAL
COLUMNS
Trussed tube, the exterior face combines vertical, horizontal and
diagonal members all of which are rigidly connected.
•The diagonal members carry gravity loads as well as lateral
loads.
•The external tube resists entire shear as well as bending
loads.
•And the internal structure carries on gravitational load.
•The most efficient structure acting as a cantilever is the
exterior trussed tube system.
•The system is essentially a trussed tube with the fascia
diagonals not only acting as a truss in the plane, but also
interacting with the trusses on the perpendicular facades to
develop the tube action.
•The principal advantage of the trussed tube is that it
eliminates the need for the closely spaced columns of a framed
tube.
•The end diagonalized frame may be in the form of a channel
or "c" shape to provide wind resistance in both directions.
•The diagonalization can also vary from a broad "x" form to smaller
"x's", thus transforming each facade into a diagrid braced system.
BUILDING STRUCTURES – 6 || RIFQUTH S.B ||

3. 3
CHARACTERISTICS
• Further improvement of framed tube structures.
• Cross bracing frame with x braces over many stories.
• Diagonals of a braced tube connect columns at each
intersections.
• Shear lag is virtually eliminated .
• Spacing for columns are increased.
• Depth of girders are small.
• Large sized windows are allowed.
• Braces transfer axial load from highly stressed column to
low stressed column.
• Hence eliminates difference between load stress.
• Large scope of architecture.
• Uses a structural architectural concept.
BRACING POSSIBILITIES
BUILDING STRUCTURES – 6 || RIFQUTH S.B ||

4. 4
Lateral
loads
Load transfer through bracing
Column transferring
loads
Gravitational and soil loads
STRUCTURAL LOADING ON
TRUSSED TUBE
•Lateral loads such as wind,
earthquake, soil and water loads act on
the structure.
•The loads are initially transferred from
slabs to columns and also the external
braces transfer load to internal
columns.
•Loads from slabs, columns, bracings,
internal columns are transferred to
ground from various points.
BUILDING STRUCTURES – 6 || RIFQUTH S.B ||

5. 5
TRUSSED TUBE
STRUCTURES
S K Y S C R A P P E R S
Steel braced tubed structure
and columns are of steel I
sections
J O H N H A N C O O K C E N T E R
Completely concrete framed
structure braces act as
medium of aesthetics and
function to the structure
O N T E R I E C E N T E R
Combination of steel and
concrete is used.
B A N K O F C H I N A
BUILDING STRUCTURES – 6 || RIFQUTH S.B ||

6. 6
BUILDING STRUCTURES – 6 || RIFQUTH S.B || SAI YASHWANTH
EXAMPLES
JOHN HANCOCK CENTER , CHICAGO
•Architect :- Skidmore, Owings & Merrill.
•City :- Chicago
•Building Type :- Tower
•Number of Dwellings :- 700
•Date Built :- 1968-70
•Floor :- 100
• Floor area :- (260,126 m²)
STRUCTURAL DESIGN ASPECTS
•The building's distinctive x-bracing has made it an architectural
icon, and increases the flexibility of interior spaces by eliminating
the need for regular columns between the core and perimeter.
• The structure could resist the strong windforces more effectively
by having the forces absorbed by all three dimensions of the
building.
• The diagonals are connected to the exterior columns, making it
possible for the forces to be carried over from the braces to the
columns and back.
• The innovative construction also resulted in a 50% decrease of
required steel compared to skyscrapers built with interior columns.

7. 7
STRUCTURAL PLAN - JOHN HANCOOK CENTER
BUILDING STRUCTURES – 6 || RIFQUTH S.B ||

8. 8
EXAMPLES
ONTERIE CENTER , CHICAGO
•Designed by : skidmore, owings & merrill
•Completed : 1986
•Towers : 2
•Main tower: 60-story
•Auxiliary tower : 11-story
STRUCTURAL DESIGN ASPECTS
•Onterie Center is the first concrete high-rise in the world to use
diagonal shearwalls at the building perimeter.
• This type of design uses fewer columns and allows for a distinct
unit layout.
• This concept stems from the fact that instead of using closely
spaced perimeter columns, it is possible to stiffen the widely
spaced columns by diagonal braces to create wall-like
characteristics.
• Therefore, the columns can be more widely spaced and the
sizes of spandrels and columns can be smaller than those
needed for framed tubes, allowing for larger window openings
than in the framed tubes.
BUILDING STRUCTURES – 6 || RIFQUTH S.B ||

9. 9
STRUCTURAL DESIGN- ONTERIE CENTER
BUILDING STRUCTURES – 6 || RIFQUTH S.B ||

10. 10
BUILDING STRUCTURES – 6 ||
THE END
RIFQUTH S.B
DONE BY FACULTY
Eng. ASHWINI PATIL