WSH Alert – Collapsed Concrete Blocks Injured Workers

Incident

Four persons were injured when concrete blocks crashed into a site office they were working in. The blocks had been acting as a retaining structure for a stockpile of aggregates at a neighbouring site. Their collapse damaged the dividing boundary hoarding and the site office.

Preliminary findings showed that there was no reinforcement between the concrete blocks. The retaining wall could have given way under the high lateral pressure aggravated by the stocking up of the stockpile and the heavy rain that occurred before the incident.

Figure 1: Overview of the scene after the incident

Recommendations*

 

Stakeholders involved in similar set-ups should consider the following to help prevent an incident recurrence.

• Get a professional engineer (PE) to design the retaining structure and certify that it is adequate for its intended purpose;
• Ensure that the stockpile’s setup is proper, safe and not over stacked;
• Identify and control all possible hazards and risks associated with the works; and
• Establish proper water drainage for the stockpile to prevent build-up of hydrostatic pressure

 

Source: WSH Alert from WSH Council dated 6 October 2011