Concrete pipe falls, injures workers

Two Queensland excavation workers have been injured after a 1350 mm-diameter concrete stormwater pipe toppled over.

According to a Workplace Health and Safety Queensland incident alert, the workers were installing a 500 mm length of the pipe when the accident took place in October 2018.

It said the workers were abutting the pipe up to the end of a recently laid pipe, using timber and sandbags as chocks to support the pipe in position.

It appears one of the workers may have moved a sandbag and the pipe toppled over. One worker was trapped beneath the pipe for several minutes and his leg was broken. Investigations are continuing.

According to Workplace Health and Safety Queensland, excavation work introduces a number of risks that must be managed, including the risk of people working in the excavation being crushed by unrestrained or inadequately restrained pipes. In addition, weather conditions such as rain or wind can affect ground conditions and cause objects to become unstable.

The incident alert said control measures to prevent unrestrained or inadequately restrained objects in the excavation from toppling over include:

• temporarily securing or restraining concrete pipes or other objects to prevent them from moving and toppling over during installation, particularly short pipes that have a large diameter and relatively small area on the supporting surface (ie, ground or chocks). This could mean tying the object back to other stable elements of the installation or bracing the object from suitably designed footings;
• ensuring the ground surface, packers and chocks are suitable for supporting the pipes or objects being laid until final works and backfilling are completed;
• using suitable lifting attachments, such as C hooks, which will support shortened pipe sections until suitable bracing or restraint can be securely attached to the pipe to prevent unintended movement;
• where possible, designing the stormwater system connections to avoid installing short concrete pipes, particularly pipes of a large diameter;
• ensuring workers have adequate knowledge and training to perform the task safely (eg, young, new or inexperienced workers may be unfamiliar with a task);
• monitoring and supervising the workers who are required to be in the installation area and ensuring any exclusion zones are enforced;
• ensuring there are adequate procedures for all potential emergency situations.
   

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