When designing for wastewater and treatment plants SWJ are often asked to design the access platforms required for maintenance, inspection, and the operation of tanks and equipment. Their design involves several critical calculations to ensure they not only have structural integrity but that they durable and can withstand the pressures of the environment they are built in, so they remain safe for the plant staff.
Load-Bearing Capacity. We need to ensure that the platforms can withstand the dead load, the weight of the structure itself, the live, operational loads of workers and their equipment and also the dynamic loads from the weights, vibration and movement of surrounding machinery and equipment.
Lateral stability and the access platform’s ability to resist lateral pressure from wind loads is a crucial part of the design, the same as if we’re designing wastewater tanks. We would complete a through site and topographical survey to ensure we understand what surrounding structures might affect the wind loads and therefore the lateral pressure.
Structural Stability and Support. Structurally we have several options when it comes to supporting the access platforms, but it depends on the layout of the site, the access and the space we have around the platform as to whether we’d recommend steel or concrete columns and beams, cantilevered or braced frames, or/and anchoring to surrounding structures.
When designing access platforms, we tend to keep sections small so we can get them onsite more easily and fit them around the surrounding structures. The nature of water treatment plants often means we are working in a very congested site, where access is an issue, and we have to make the most of the space we have. We are often trying to ‘squeeze’ in a tank, access platform or balancing chamber around structures and machinery above ground, and buried services including communications ducts and electronic monitoring equipment below ground. How we get the materials in to build the platform and where we place columns has to take this ‘congestion’ into consideration.
Safety and Compliance Standards. There are safety standards we need to ensure we are meeting including minimum handrail heights and guardrail requirements, anti-slip flooring materials to prevent accidents, and structural redundancy to ensure the platform can resist accidental events, such as the loss of a supporting column due to vehicular impact, and will remain stable enough for an emergency exit by site workers.
Fatigue and Corrosion Analysis. Access platforms, as well as the tanks are often exposed to harsh environmental conditions, and we need to ensure that the materials used for the platform and supports will not fatigue. Generally, all access platforms are made from galvanised steel platform, as the galvanisation process offers a robust form of corrosion protection, read more about galvanised steel here.
Designing an access platform may seem like a relatively simple task but there are a lot of calculations required to keep platforms stable, safe, compliant and durable, not to mention the challenges of getting the materials on site and finding the space for adequate support.
By not making assumptions and leveraging precise calculations and advanced engineering methodologies SWJ Consulting have been able to provide the most efficient solutions for local water authorities.
If you would like to speak with us about access platforms, wastewater treatment tanks or foundations please give SWJ Consulting a call on 01993 225085 Oxfordshire office, 02381 920656 Southampton, or email mail@swjconsulting.co.uk
