NZ Dairy Spring 2021

Earthquakes have the ability to cause significant disruption to the dairy industry. But thanks to a Kiwi innovation dairy silos can now be safeguarded against an event by protecting product, people, infrastructure and the environment. The ONGUARD seismic anchoring system was developed in response to New Zealand’s propensity for earthquakes. Lab tested and earthquake proven it is now used worldwide for the protection of liquid storage silos. ONGUARD New Zealand General Manager Derek Liddington, says that the ductile anchors absorb the seismic energy and provide protection to the silo walls and foundations. “The ONGUARD anchors are welded to the silo around its base and connected to the silo’s foundation slab. Unlike traditional tank anchoring systems that only work in a one-pull tension direction, ONGUARD anchors provide controlled yielding in both tension and compression throughout cycling earthquake accelerations. This gives excellent energy dissipation, produces a more stable silo response and provides additional resilience to withstand earthquakes that are larger than the design case.” Each ONGUARD application is carefully designed by ONGUARD engineers, along side companies it works closely with, such as NDA Engineering, specifically for the seismicity hazard at the client’s location and to ensure that all other elements of the silo system have sufficient strength to remain undamaged. Derek says that a holistic design approach is required, which considers the silo, anchors, foundation slab, and catwalks, to ensure efficient seismic performance. ONGUARD can work with clients in a variety of ways. It can provide silo fabricators direct with design solutions for anchors and silo wall thicknesses. ONGUARD can also provide design requirements for the foundation slab and catwalks, or can work with the client’s foundation and catwalk designers to achieve the desired outcome. The ONGUARD system can be specified from the ground up. It can also be retrofitted to existing silos using gathered information such as silo geometry, material thicknesses and foundation construction. ONGUARD engineers are then able to calculate the earthquake strength of an existing silo system, quantify the level of risk it poses and specify a customised ONGUARD system to replace the silo’s existing anchorage. “Product is the lifeblood of a business and ONGUARD ensures it is held securely within its silos during an earthquake and subsequent aftershocks ensuring performance, protection and peace of mind.” DESIGNED FOR NZ’S PROPENSITY FOR EARTHQUAKES.