Geometrica domes have changed the landscape in Asia with storage solutions for bulk stockpiles, writes Melanie Saxton of Geometrica. These rugged domes, vaults and space frames, known as Freedomes®, take advantage of 3-dimensional structural behaviour to withstand brutal snow loads, typhoon- force winds, torturous slopes and corrosive saltwater environments.

ALL-TERRAIN TECHNOLOGY

Geodesic domes are an obvious choice to cover stockpiles, yet traditional construction systems for these domes may not translate to a low-cost solution. Manufacturing and construction complexities can offset material savings.

Geometrica has reversed this problem by creating Freedomes that are:

 

  • designed and prefabricated by computers to withstand brutal snow loads, hurricane force winds, punishing slopes and corrosive saltwater environments;
  • bar-coded, packaged and shipped in small units that can be manually unloaded in remote locations;
  • assembled by local labour without special equipment or welding;
  • assembled over a stockpile while the pile remains in operation — no downtime; and
  • custom-designed for irregular or sprawling stockpiles and uneven terrain.

 

DOMES OF ASIA

Freedomes are especially suited for established facilities that need to contain an existing open air stockpile. Siam Cement hired Geometrica in the late 1990s to build a dome in Surat Thani,Thailand — an initial project that segued into a project in Cambodia.

Kampot Cement: Cambodia is home to Kampot Cement Co. Ltd., the largest cement producer in the country. It was established as a joint venture between Geometrica’s prior client, Siam Cement, and Cambodia’s top construction and engineering firm, the Khaou Chuly Group. Geometrica is known for its expertise in the enclosure of limestone blending beds and environmentally friendly design, sparing the surrounding landscape from dust and loss of material during the rainy season.

The plant’s pre-blending bed was planned in a circular configuration to hold 25,000 tonnes of limestone (equivalent to ten days of production for the new plant). Domes help maintain the consistent chemical composition of the quarried raw material before it is fed into the kiln. Design and installation of the Kampot Cement dome was conducted in three languages: English,Thai and Cambodian.

Freedomes provide the most efficient shape for a stockpile enclosure because they are lightweight and can span large areas without intermediate supports. The most common dome shape is a segment of a sphere, but it is more economical to use varying radii of curvature for the meridian of the dome. The goal is to have the dome ‘hug’ the clearance line of the stacker- reclaimer. This results in a smaller dome surface area and better clearance for vehicles around the perimeter. With this in mind, Geometrica designed and installed a circular dome for Kampot Cement spanning 86m that now helps facilitate the production capacity of 950,000 tonnes of cement per year.

Lucky Cement: Lucky Cement Corporation in Taipei, Taiwan manufactures and sells Portland, ground granulated blast-furnace slag, fly ash, and blast-furnace slag cement. The company needed two domes to cover its bulk materials. One required a highly irregular design to accommodate a sprawling stockpile, while the other required a long span of 104m to cover more than 35,000 tonnes. Both domes were built while the stockpile was in operation — no downtime.

FERTILIZER INDUSTRY

After carefully considering the fluctuations of the natural-gas market in recent years, PT Pupuk Kalimantan Timur (Pupuk- Kaltim), Indonesia’s largest fertilizer producer, in Bontang, East Kalimantan, launched a project to diversify its fuel with a coal boiler in 2009. In addition to adhering to government policies that encourage the use of coal as a substitute for natural gas, Pupuk-Kaltim executives noted substantial economic benefits. 

Geometrica was selected to design and construct a coal storage dome for Pupuk-Kaltim based on the ability to meet very specific logistical and environmental needs.

POWER INDUSTRY

Any visitor to Kaohsiung Hsien will notice four massive solid fuel silos. When Taiwan’s state-owned Energy Company,Tai Power, decided to expand and cover its raw material stockpiles, it relied on Geometrica’s design expertise. The challenge was to design silos that could resist corrosive saltwater spray and typhoon winds. Gibsin Engineers LTD, a specialist company hired by TaiPower, determined that four long span concrete silos with metal dome covers would be required.

Geometrica designed and installed the domes with a ‘perimeter-in’ method of construction: the first nodes and tubes were laid on the supporting concrete wall. Each three to five tubes were joined to one node forming a ‘spider’. Each spider was then raised to the work front and tapped into place, creating rings around the base that grew one on top of the other until the whole skeleton was formed. Co-ordination with other suppliers was easy, as the area under the dome was free of obstacles. Neither scaffolding nor other special equipment were required, and the project was completed with a perfect safety record.

REVOLUTIONARY TECHNOLOGY

Freedomes are built of lightweight and strong galvanized steel or aluminium, comprised of prefabricated tubes using Geometrica’s computer-based manufacturing system. The tubes are bar-coded, packaged and shipped to the job site. They are connected on site with patented aluminium hubs comprised of an extruded aluminium cylinder with several threaded slots. Each tube is flattened at the ends into a pattern that slides into a hub’s slot. The connection of tubes and hub is compact, simple and very efficient — no welding required. When all tubes for a hub have been assembled, the joint is finished with washers and a single bolt. When completed, Geometrica’s patented hub connection is stronger than the tubes themselves.