Here, Dave Holland, National Engineering Director at Mabey Hire, explains how you can best safeguard your project’s temporary works in the event of unplanned site suspensions.
All across the country, construction workers are beginning to put down their tools and sites are temporarily closing, in light of the ongoing COVID-19 global pandemic. However, while sites may be closed, temporary works, including groundworks, propping and bridging, will remain in-situ to ensure that the site or structure remains safe.
By their very nature, temporary works are designed to be exactly that - temporary. Some temporary groundworks, for example, are designed on an assumption of lasting less than twelve weeks. So, when construction sites are unexpectedly forced to close for an unknown period of time, it’s important that you are aware of the steps to take in order to mitigate potential risks. Failing to do so could lead to costly structural or environmental damage and serious health and safety hazards.
For example, the engineered design of a short-term temporary works system may only encounter a small amount of water, due to rainfall, or a slight amount of wind damage. But, when you increase the length of time that the temporary works equipment is in-situ, it is only logical that the likelihood of it being affected by extreme events also increases. Will ground anchors remain stressed after a significant number of wet and dry cycles in the soil? Will falsework, propping or bracing systems be able to cope with a greater number of load cycles from wind and temperature changes? These are all important questions that our customers have been asking us.
While it is good industry practice to inspect the area and construction equipment on an active site before the start of each working shift, what happens when the site is temporarily closed? Depending on how long a site shutdown lasts, it could result in projects being left uninspected for a long period of time. To ensure that the site and temporary works equipment remains safe and stable, it’s important to continue these regular inspections, even if construction work has been halted.
So what should you be looking out for?
General
- Ensure that all bolted or pinned connections remain in place and are not loose
- Check for deformation of equipment, particularly at connection locations
- Check the overall condition of equipment for signs of deterioration
- Ensure there has been no weakening of the system due to vandalism and/or theft
- Check all items are still installed as per the original construction or scheme drawings
Groundworks
- Assess the soil properties on site, as different soils can present different risks
- Ensure that drainage and dewatering systems are operating normally
- Check for any “creep” in structures by regularly marking off and recording the positions of, for example, hydraulic rams, struts and ties, thrust blocks etc.
- Check and maintain anchor systems
- Check for ground erosion, as this can be an early indication of a potential failure
- Visually check for any bowing or bellying of trench sheets and sheet piles
Propping and Jacking
- Check bolted connections between prop units and prop units to screw jacks. Are the bolts tight?
- Ensure that screw jacks at the top of props are tight, with maintained contact between timber packs and steel soffits
- Check bracing members are straight with no defects or damage
- Ensure all scaffolded couplings are tight and that, where installed, the edge protection system is complete
Bridging
- Visually inspect parts for interference, particularly where adjacent to vehicle or rail passage
- Ensure all mesh panels, where required, are in position with no visible signs of damage
- Ensure all sway braces and vertical braces are securely bolted in position
- Ensure all bearings are clear of debris and free to expand
If anything doesn’t look quite right, it is important that you don’t try to fix or modify the fault yourself. Make sure you speak to your temporary works supplier first. To help our customers, we’ve recently set up a dedicated Emergency Response team, who are there to help should you need emergency support on site.
To read our full guide, please click here.
