Five Causes of Trench Accidents
Trenches are a common sight in the construction industry and present several dangers. These include falls, cave-ins, dangerous fumes and gases, and worker vulnerability to falling loads from above. The greatest danger however, is a cave-in on the workers inside the trench. Here are five factors that cause cave-in trench accidents:
Inadequate Protection Systems in Place
A vertical wall of soil is generally unstable. Although it may initially hold up when the soil conditions are right, disturbances such as vibration or changes in the soil’s moisture can cause the wall to collapse. To ensure worker safety, appropriate protection systems are required. Depending on the soil type, soil moisture, trench depth, and other factors, one of four types of protection systems are used:
- Benching. Unstable vertical walls of trenches are cut back into a stair-like pattern of steps.
- Sloping. The trench wall is cut back at an angle to form a constant slope.
- Supports and shoring. A trench wall can be stabilized using timber supports, or held in place with hydraulic cylinders that push against shoring made of aluminum or steel.
- Trench boxes. Trench boxes protect workers from cave-ins and do not support the trench wall. The space between the cave wall and trench box is minimized and backfilled.
Vibration from nearby traffic, equipment, and construction operations can move and destabilize the soil in the trench wall. The choice of protection systems should take vibration into account.
Stress Loading the Soil
Heavy loads and construction equipment located too close to the trench can stress the trench wall soil to the point of failure and cause a collapse. Avoid stressing the soil by keeping heavy loads and equipment a safe distance away.
Excavated Materials Located Too Close to the Trench
Pushing these materials back from the trench will prevent their collapse back into it.
Failure to Inspect the Trench before Each Shift and after Weather Events
The properties of soil change with moisture content and other environmental factors. An overnight rain can make the trench walls unstable for example. If heavy construction equipment accidentally gets too close to the trench, its walls should be inspected.
At Frekhtman & Associates, an experienced construction accident lawyer can advise you of your legal options on getting compensation for a work injury suffered by you or a loved one. Contact us for a free consultation.