Excavation Safety |Work Place Safety

INTRODUCTION

One of the hazardous activities on the construction site is an excavation and it is an unavoidable part of a construction job. Excavation is an essential part of construction activities and the safety officer must learn how to ensure safety during excavation work.

Excavation is disturbance or removal of land surface to the required depth and it can be in any form includes deep piles, trench, hole, pit, or open excavation. Each one is associated with a number of hazards that need to be controlled to ensure the safety of the worker and the property. Some of the most fatal accidents witnessed during excavation are cave-in of the excavated areas and suffocation of workers in deep excavated areas.

Through this article we will share all crucial and important information and practical knowledge through which a safety professional can make his working site safe during excavation activity.

GENERAL RECOMMENDATIONS

• Excavation more than 1.25 meters deep shall not permit unless safety measures are planned and ready to implement
• Excavation shall not be permitted without no objection certificate (NOC) from the respective department or agency regarding the underground installation
• Landmarking and barricading must be done prior to starting excavation work, these must be including hard barricading, warning signage, and safety rules notice boards
• All workers must be providing proper personal equipment includes safety shoes, hard helmets, gloves, safety goggles, reflecting jackets, etc.
• If excavation work is plain with help of a machine or power tool all machines and power tools must be certified or inspected by safety expert (In some companies third party safety certification is mandatory)
• The construction material/spoils should accumulate 2/more feet away from the edge of the excavated area and the accumulated material height must not be higher than 1.5 times the excavation height.
• Appropriate lighting must be installed in the excavated area and around to avoid any accidents due to dark spots.
• Access and egress must be provided with the help of stairs, ladders, or ramps – both entrance and egress must be marked and the ladder must be guard railed.
• The ladders must be 3 feet higher from the ground level and must be braced with the ground to avoid sliding hazard
• All protective systems must be inspected on daily basis and if found any damage or loose replace it on an immediate basis.

TRENCH SUPPORTING SYSTEMS

There are three supportive or safety systems which can be used to avoid cave-in hazard of the excavation sides. These systems include;

1. Sloping and benching system
2. Shoring system
3. Trench Shielding system

1. Sloping and benching system

Slopping is the technique through which the edges of the excavated area are cut-down to 40 degrees so that they minimize the pull of gravity by lowering the height of evacuation depth. This technique is very used full where the ground material nature is no sandy and the material stability is remained intact against wind and jerks of power tools or machines.

Benching is also called stepping technique this method of the protection system is adopted where the round is no sufficient around the excavated area and cut down the edges into multiple steps. It is recommended that each step must be at 1/3 of the excavation depth. The benching system is very effective where the excavated round is composed of hard soil.

2. Shoring System

Shoring is implemented where sloping and benching systems are impractical due to several reasons such as if the excavated area is located near the road site where vibration due to running vehicles can erode soil from edges of the excavated area. Or if the excavation is done in a muddy or high-water seepage area due to which soil stability cannot retain for long.

Wood or aluminum plates can be used for shoring and to fixed them in place horizontal jacks or brackets can be installed on appropriate distances.

3. Trench Shielding System

Trench shielding is the best protective system among all system because it not only provides safety against cave-in hazard but also provide a safe space to work for the workers inside the shielding system.

For the shielding system ready-made customize shielding structure is installed inside the excavated area with the help of a crane or hoist. These protective systems are mainly recommended in projects where the underground machine or system installation is required.

JOB SAFETY ANALYSIS FACTORS

• Soil Type/Soil assessment report
• Under Ground Utilities data and types
• Water level
• Traffic in surrounding 
• Weather forecast 
• Method of intended excavation
• Disposal of excavation material/spoils 
• Working hours/shifting

CONCLUSION

As safety is the responsibility of everyone including employer and employees and without coordination and accomplishment of their roles and responsibilities safety can not implement with its true spirit. In excavation activity, the safety counts from the planning phase to the box-up phase. Excavation can be made safer and easier to handle is we integrate safety in all parts of its process.

For Excavation Safety Checklist and other important safety, blogs visit the below link.

Excavation Safety Checklist

How to prepare Job Safety Analysis (JSA)

Important Parameter of Crane Lift Permit