Latest blasting techniques for rehabilitation of dam walls_approved | 28.04 KB | Download | |
Preview | At Hazelmere, the existing spillway crest, piers, lintel beam, and bridge decks were demolished. | 2.84 MB | Download |
Dam walls are some of Jet Demolitions most innovative projects to date | 2.47 MB | Download | |
Preview | Hazelmere Dam saw the compilation of specific demolition-control guidelines. | 1.49 MB | Download |
Preview | Jet Demolition Contracts Manager Kate Bester | 395.02 KB | Download |
Preview | Jet Demolition has developed new blasting techniques to retain the structural stability of dams. | 5.95 MB | Download |
Preview | Jet Demolition used cranes to lower the demolition excavators onto the Hazelmere Dam wall. | 4.4 MB | Download |
Preview | The Full Supply Level (FSL) of Hazelmere Dam was raised by replacing the original Radial Arm Gate design with a Piano Key Weir. | 1.82 MB | Download |
Rehabilitation of dam walls usually requires demolition of redundant portions of monolithic blocks and associated concrete structures. Dynamic energy imparted by the demolition process has the potential to cause damage to concrete located just across the demolition boundaries and beyond. While it is essential to avoid damage to remaining concrete, it is also important to carry out the demolition works in a productive and cost-effective manner.
Hence, informed and judicious selection of demolition methods and their application techniques are vital to a controlled and productive project – which is where Jet Demolition’s extensive experience stands it in good stead, explains Contracts Manager Kate Bester. “Our work at Hazelmere Dam allowed for the compilation of specific demolition-control guidelines to be developed for dam rehabilitation projects.”
Here a combination of explosive, mechanical, and diamond-cutting methods were employed. It was demonstrated that explosives can be used as the primary method of demolition on dam rehabilitation projects in a safe, productive, and controlled manner, without causing damage to the remaining mass concrete and concrete structures.
Located on the Mdloti River in KwaZulu-Natal, the Hazelmere Dam was built in the 1970s. It was designed originally to accept radial arm gates to raise the Full Supply Level (FSL). However, a subsequent redesign showed that the FSL would be achieved optimally via a Piano Key Weir (PKW).
To clear the way for new construction works, demolition of the existing spillway crest, piers, lintel beam, and bridge decks required the controlled removal of 5 300 m3 of concrete up to 3 m in thickness. The key requirements were to demolish the redundant structures in a safe, rapid, cost-effective, and controlled manner, without residual damage.
The traditional demolition method for projects with large volumes of mass concrete is explosives, with large hydraulic hammers used for the smaller concrete sections and for secondary breakage. Finishing work is typically undertaken by small hydraulic hammers and handheld breakers.
Despite the advances in diamond-cutting technologies, this method is usually not practical nor cost-effective to apply in isolation. The use of drilling and blasting is unrivalled in terms of speed and cost-effectiveness. However, for obvious dam-safety reasons, maintaining the structural integrity of the remaining concrete is a perennial concern when demolition works are carried out on a dam structure, or in nearby rock.
When considering safe blasting vibration levels for a particular project, it is critical to consider the prevailing site conditions and geometrical configurations. “At Hazelmere Dam, our production blasting programme and demolition methods achieved all of these objectives successfully,” concludes Bester.
Pull quote
“Our work at Hazelmere Dam allowed for the compilation of specific demolition-control guidelines to be developed for dam rehabilitation projects.” – Kate Bester, Contracts Manager, Jet Demolition
Do you want to use this press release on social media?
#JetDemolition has developed new blasting techniques specifically to retain the structural stability of dams themselves, with no wasted effort.
Ends
Connect with Jet Demolition on Social Media to receive the company’s latest news
Facebook: https://www.facebook.com/JetDemolition/?ref=br_rs
LinkedIn: https://www.linkedin.com/company/jet-demolition-pty-ltd/
Notes to the Editor
To download hi-res images for this release, please visit http://media.ngage.co.za and click the Jet Demolition link to view the company’s press office.
About Jet Demolition
Jet Demolition has been undertaking industrial demolition works since 1994, and is the leading, largest, and most technically advanced demolition company in Africa. It offers in-house, full-range demolition services, including advanced mechanical solutions and controlled implosions. It actively pursues ongoing development of skills and equipment suited to the changing needs of the industry.
Jet Demolition is a technically based company, with various staff members holding MSc, BSc, and BTech Degrees, as well as National Diplomas, in various engineering fields. This expertise gives it the technical foundation to successfully engineer solutions for large and complex demolition projects, and furthermore fuels its drive to deliver quality projects safely. Jet Demolition strives to offer its clients innovative and technical solutions to demanding demolition challenges.
Jet Demolition Contact
Kate Bester (NDip Civil Engineering - PMP)
Contracts Manager
Phone: (011) 495 3800
Cell: 072 811 5310
Email: kate [at] jetdemolition [dot] co [dot] za
Media Contact
Rachel Mekgwe
NGAGE Public Relations
Phone: (011) 867 7763
Fax: 086 512 3352
Cell: 074 212 1422
Email: rachel [at] ngage [dot] co [dot] za
Web: www.ngage.co.za
Browse the NGAGE Media Zone for more client press releases and photographs at http://media.ngage.co.za