Substructure Health, Safety & Environment

How will operatives, the public and the environment be protected during substructure works?

A good starting point when it comes to Health and Safety (H&S) is to visualise how subcontractors will carry out the required works.

Excavator loading muck away wagon

The main questions to think about are:

Substructure construction is a high risk activity which should be undertaken by specialist contractors.

As with all other elements of work, Subcontractors responsible for the substructure need to submit a Risk Assessment Method Statement (RAMS) prior to works commencing.

RAMS are to be read and signed by any operatives involved with the works to acknowledge understanding on how risks are to be mitigated and any site specific hazards.

Ensuring the operatives are competent carry out the works can significantly reduce the chance of an incident or accident occurring. The level of competence should be outlined for key roles in the RAMS and a check conducted at Site Induction.

Some of the main risks associated with Substructure construction include:

1. Striking of underground services - almost all services in the UK are routed under the ground.

When digging with heavy machinery or even by hand using the incorrect tools it is very easy to hit a service and damage it. This is known as a service strike.

This can be serious ramifications: death if a high voltage cable or financial implications for damaging the service.

Example of underground services

There are a number of things which can be done to reduce the risk of this happening:

- Permit to dig to be issued by main contractors before digging commences. This checklist prompts questions such as are the operatives competent and is the equipment correct for the job.

- Utility drawing - A company conducts a ground penetration radar survey and plots results on a drawing so rough location of services are known. Note: this is not 100% accurate, it's a guide.

- Cable avoidance tool (CAT) and Signal Generator (Genny) - To be used by trained operatives only to identify any services that may be in the ground before starting excavation works.

CAT and Genny - uses a signal to identify services underground

2. Falls into excavations - when constructing the substructure it's necessary to excavate ground. This introduces the risk of someone falling down into an excavation and injuring themselves.

This can be controlled by:

- Barriers - suitable for purpose. Act as a physical barrier to stop anyone entering the excavation area. As a general rule the closer to the excavation barriers are the more resistant to force they need to be as there is a chance they could be pushed into the excavation.

- Communication - in the collaboration meetings which happen on site it is important to identify where excavations will be taking place. This information should be shared with other operatives working on site so they are fully aware.

3. Collision with machinery - large excavators, dumpers and rollers are often required to carry out works. There is a risk that people may collide with plant and become injured.

Mitigation for this could be:

- Exclusion zones - remove this risk by fully segregating the plant from any operatives.

- Banksman - a trained operative on site who supervises the use of vehicles and heavy machinery

- Thumbs up policy - where full segregation is not possible, a policy could be introduced where anyone looking to pass equipment needs to make eye contact with the driver and give them a thumbs up before passing.

4. Hot works - cutting of steel reinforcement could cause flames which could lead to fires.

This can be controlled using:

- Alternative cutting method - if the size of the reinforcement isn't too large it may be possible to use cold cutting methods which eliminates this risk

- Hot works permits - to be issued to subcontractors before any works which could lead to a fire start. Prompts questions like are the correct fire extinguishers present? Are there combustible materials close?

Environment

I recommended reading the Environmental Impact Assessment (EIA) to see what measures have been put in place to reduce the impact of building the substructure on the surrounding environment.

These include:

1. Soil Erosion - excavation and grading can disturb the soil, making it vulnerable to erosion. This can lead to sediment runoff into nearby water bodies, which can harm aquatic ecosystems and reduce water quality.

2. Habitat Destruction: often clearing land is necessary, this can result in the destruction of natural habitats for plants and wildlife and lead to a loss of biodiversity.

3. Stormwater Runoff: Rainwater can pick up pollutants from construction sites and carry them into stormwater drainage systems. Effective stormwater management is essential to prevent pollution of local water bodies.

4. Noise and Air Pollution: Construction equipment and machinery can generate noise pollution and emit air pollutants. This can have adverse effects on air quality and the health of nearby residents.

5. Contaminated Soil and Water: Groundworks may uncover or release hazardous materials, such as asbestos, lead, or petroleum products, which can contaminate soil and groundwater if not properly managed.

6. Greenhouse Gas Emissions: The transportation of materials and operation of heavy machinery, can contribute to greenhouse gas emissions, contributing to climate change.

Definitions

RAMS - document outlining how works will be conducted. Should record hazards, assess the likelihood and severity of the risk and address how these will be reduced or mitigated

Site Induction - a presentation given to any new operatives attending a construction site explaining the site rules and giving site specific health and safety information

Plant - Construction plant refers to machinery and equipment used in projects for tasks like excavation, lifting, and material handling

EIA - Environmental Impact Assessment evaluates potential effects of the project to make informed, eco-friendly decisions.

Grading - the process of manipulating and leveling the ground to achieve a desired slope, or elevation.

Posts to Follow

We plan to go into more details about Substructure and add sections on:

·       Quality

·       Programme

·       Commercial

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