Solving sway

Engineers know that high-rise projects pose design challenges including building sway, creep, and thermal expansion/contraction of piping systems. With the Burj Khalifa exceeding the height of any existing structure, those concerns became even more critical and high-profile.

03/16/2010


View the full story, including all images and figures, in our monthly digital edition
Upon its completion in January 2010, the Burj Khalifa (formerly known as the Burj Dubai) in Dubai, United Arab Emirates, seized a number of records from other prominent high-rise buildings. At 2,625 ft and 160 stories, the mixed-use structure is not only the world's tallest building, it also has broken two other significant records: tallest structure, previously held by the KVLY-TV mast in Blanchard, N.D. (2,063 ft), and tallest free-standing structure, previously held by Toronto's CN Tower (1,815 ft). In addition, the Burj Khalifa has the highest number of stories in the world, the highest occupied floor, and the highest outdoor observation deck. Its elevator has the longest travel distance in the world and it has the tallest service elevator in the world.

 

Engineers know that high-rise projects pose design challenges including building sway, creep, and thermal expansion/contraction of piping systems. With the Burj Khalifa exceeding the height of any existing structure, those concerns became even more critical and high-profile.

 

According to William Baker, partner and senior structural engineer at Skidmore, Owings & Merrill (SOM) in Chicago, wind behavior of the structure was a top structural design consideration for the engineers designing the Burj Khalifa. Regional estimates for wind load placed the expected sway at the top of the structure at up to 6 ft overall.

 

The question of accommodating sway in the chilled water, domestic water, and fire protection piping systems was not just about how much the structure would move, but also about how quickly it would move given acceleration of the movement. Taking into consideration these design challenges, SOM chose to specify grooved mechanical pipe joining systems for these piping systems.

 

Grooved piping and deflection

Grooved mechanical pipe joining systems are most often specified as an alternative to welding of pipe and can accommodate axial movement, angular deflection, or pipe misalignment due to building creep, settlement, or thermal transients, as well as building sway due to wind loads.

 

Grooved mechanical couplings are available in two distinct styles: rigid and flexible. Rigid couplings are designed to fix the joint in its installed position, which eliminates any movement at the joints. Flexible couplings are designed to allow controlled linear and angular movement at each joint that can accommodate deflection and settlement.

 

Joints using flexible couplings allow for expansion/contraction or angular deflection within the joint. The groove in the pipe is wider than the coupling key, permitting controlled movement. The coupling key fully engages itself within the groove, creating a self-restrained joint, capable of accommodating longitudinal and lateral stresses from internal pressure and external forces. The pressure responsive gasket design provides a positive seal, with the coupling housing fully encompassing the gasket, while reinforcing and securing the seal.

 

Flexible grooved mechanical couplings are an alternative to welded pipe expansion means. Flexible couplings accommodate angular deflection within the design capability of the coupling and can result in space savings compared to welded loops or welded offsets.

 

In the Burj Khalifa, Victaulic grooved couplings were specified on a per-floor basis to handle the piping design requirements. The systems were designed to be anchored at every floor, at the top and bottom. By installing anchors at every floor, any movement of the system would be directed to the joints between the anchors. The total piping system movement, including expected building creep, settlement, thermal expansion/contraction, and angular deflection, was calculated on a per floor basis. Flexible couplings were then installed between anchors to accommodate the total movement.

 

Accommodating building sway

Vertical riser piping in tall buildings is often subject to deflection due to swaying caused by wind loads. Where the pipe is rigidly fixed to the building structure, freedom of motion must be designed into the piping system, allowing it to move with the building.

 

The anchoring of the piping systems on a per floor basis with the use of flexible couplings between anchors provided the necessary freedom to allow the piping to move with the structure.

 

Accommodating for building creep

Deflection or linear movement imposed on a piping system may occur due to building creep. Building creep is defined as the amount a building will move due to settlement over a specified period of time. This is an important consideration for high-rise construction and especially in the Burj Khalifa design.

 

Building creep can be accommodated in different ways within mechanical piping systems: using a flexible connection system, a rigid system, or a combination of both.

 

In a grooved system using only flexible pipe joints, risers are installed with anchors at the top and bottom with the piping being guided every other pipe length to prevent angular deflection at the joints within the piping run. A sufficient number of flexible couplings must be used to accommodate the anticipated movement. Proper gapping of the pipe ends within the coupling is required to allow the riser to compress as the building settles.

 

In systems with only rigid mechanical joints, risers can be treated similar to a welded system, and where movement is required, expansion joints can be designed into the riser to accommodate movement and prevent damage to system components.

 

Risers using both rigid and flexible grooved joints can reduce guiding requirements and accommodate the expected movement.

 

The bottom line on the tallest building in the world

Engineers, owners, and contractors will undoubtedly look to the Burj Khalifa as an example for future high-rise construction. Structural and piping designs that include grooved mechanical joints may alleviate challenges associated with building sway, creep, and deflection.

 

Grooved couplings can be beneficial to engineers and contractors, by providing design flexibility and reducing scheduling pressures and labor challenges due to the ease of installation associated with grooved mechanical joints.

 

 

 

Acknowledgements

Information provided by Victaulic

 

 

 



No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
2016 Product of the Year; Diagnose bearing failures; Asset performance management; Testing dust collector performance measures
Safety for 18 years, warehouse maintenance tips, Ethernet and the IIoT, GAMS 2016 recap
2016 Engineering Leaders Under 40; Future vision: Where is manufacturing headed?; Electrical distribution, redefined
SCADA at the junction, Managing risk through maintenance, Moving at the speed of data
Safety at every angle, Big Data's impact on operations, bridging the skills gap
The digital oilfield: Utilizing Big Data can yield big savings; Virtualization a real solution; Tracking SIS performance
Applying network redundancy; Overcoming loop tuning challenges; PID control and networks
Driving motor efficiency; Preventing arc flash in mission critical facilities; Integrating alternative power and existing electrical systems
Package boilers; Natural gas infrared heating; Thermal treasure; Standby generation; Natural gas supports green efforts

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
This article collection contains several articles on the vital role of plant safety and offers advice on best practices.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.
This article collection contains several articles on strategic maintenance and understanding all the parts of your plant.
click me