Why manual breaking of bored piles is prohibited

Health protection (vibration)

The manual breaking of pile heads with pneumatic hammers is a traditional method in civil engineering, but it poses considerable health risks. Daily use of pneumatic hammers can lead to serious health problems, in particular hand-arm vibration syndrome (HAVS). The European Union has also recognized this problem and has introduced the EU Directive “Directive 2002/44/EC – Vibration” defines protective measures and vibration limit values. Compliance with these guidelines on the construction site is not the sole responsibility of the contractor. The Construction Site Ordinance and the Occupational Health and Safety Act emphasize the shared responsibility between contractor and client for occupational safety on the construction site.

Health risks of pneumatic hammers

Manual hand pile breaking

Pneumatic hammers generate strong vibrations that can lead to hand-arm vibration syndrome (HAVS) if used regularly. HAVS is a condition caused by prolonged exposure of the hands and arms to vibrations. The symptoms are varied and can include painful and disabling disorders of the nerves, blood vessels, joints and muscles. The most conspicuous symptom is the so-called “white finger”, a circulatory disorder.

Consequences of the HAVS syndrome

The consequences are constant numbness, tingling, pain and joint stiffness in the fingers, hands and arms. The numbness and joint stiffness can mean that those affected are no longer able to hold a coffee cup. In the worst case, this can lead to complete incapacity to work. There is no cure for HAVS. Treatment is limited to alleviating the symptoms.

EU regulation

The European Union has also understood how dangerous hand-arm vibration syndrome is to health and has passed a corresponding law: Directive 2002/44/EC – Vibration. The aim of the Directive is to ensure the safety and health protection of each individual worker and to provide a minimum level of protection for all workers in the Community by the timely detection of harmful effects on health which arise or may arise from exposure to vibration, in particular HAVS diseases.

Limit values for hand-arm vibrations

The EU Directive defines exposure limit values for hand-arm vibrations on the basis of a standardized eight-hour reference period that simulates a working day. For hand-arm vibration, the exposure limit value is A(8) = 5 m/s² and the exposure action value is A(8) = 2.5 m/s². The maximum daily exposure can be calculated on the basis of the exposure limit value A(8) = 5 m/s², the action value A(8) = 2.5 m/s² and the acceleration a (m/s²) of the device in use.

Calculation acceleration jackhammer

A jackhammer has an approximate acceleration a of 15 m/s².

The table below shows that at an acceleration a of 15 m/s² the daily limit value for vibrations is already exceeded with an exposure time of one hour. This means that one person may only spend a maximum of one hour per day manually processing piles. The manual processing of bored piles by groups of people who carry out this activity exclusively throughout the day is therefore illegal according to the applicable EU Directive 2002/44/EC – Vibration.

Vibration intensity vs. exposure time

Joint responsibility of the client

It is not only the contractor who is responsible for compliance with occupational safety. The Construction Site Ordinance and the Occupational Health and Safety Act emphasize the shared responsibility for occupational safety on the construction site. According to the Construction Site Ordinance, the principles of the Occupational Health and Safety Act must already be observed during the planning and execution of a construction project. This means that the client must play an active role in creating safe working conditions. He is obliged to organize the work in such a way that hazards to the physical health of the workers are avoided, taking into account the current state of the art. The client therefore bears a significant share of responsibility for ensuring that occupational safety standards are complied with and that the necessary technical and organizational measures are implemented to guarantee a safe working environment.

EU-compliant pile head tendering

You can find a legally compliant tender template for pile head processing here: Tender template

This template is designed to take into account all relevant safety requirements and legal provisions without being limited to specific products or processes. In this way, they can ensure that the invitation to tender includes the necessary safety criteria and encourages bidders to take these into account in their bids and in the subsequent execution. The use of such a template helps to ensure that as a client you fulfill your obligation to promote a safe working environment and ensure compliance with health and safety legislation.

Do you have any questions about health protection (vibration), the EU Directive 2002/44/EC – Vibration or an EU-compliant pile head tender? Do not hesitate to contact us.

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