While excavating a hole onsite that is anything more than 120cms in depth can be relatively straightforward, depending on the make-up of the soil or ground cover, maintaining the depth and structure of the trench for any real length of time often requires planning. Trench sheets play an important role in this regard, ensuring that trench walls remain in position and reducing the risk of cave-in to almost zero, providing correct installation.
|Cave-ins can be directly and indirectly caused by a number of external influences. One of the most common is by excessive or unaccounted-for weather systems bringing in heavy rain, or other extremes such as snow. Another common issue that often leads to the structural shape of a trench failing is insufficient regard for surface ground proximity, with groundwork preparations poorly planned in advance of excavation. Both of these potentially catastrophic occurrences can easily be avoided with the inclusion of correctly installed trench shields.|
In most cases, trench shields should be braced with props to help keep the sheets in position, and working effectively. These props are designed to work either at angles to the 90 degree face of the shield, or horizontally, bracing a trench sheet against a solid wall, or an opposing sheet.
Incorrect fitting of trench sheets can have disastrous consequences with personnel carrying out work within a trench, and particular attention should be observed during times of extreme weather, or with heavy plant machinery maneuvering around or working inside the trench.
Subsequently, all work carried out in this manner must be planned in accordance with an experienced health and safety advisor, and to specified standards. Particular attention must be given to the dimensions of the trench, any other external influences such as the water basin in the area, the expectation of extreme weather fronts during the course of the work.
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