Upon project award or even during the design and procurement stage, manufacturers and suppliers will do a site survey and provide an installation guide based on site-specific conditions. To ensure the safety and quality of the bollard installation process, an installation safety checklist and method statement is required especially if HVM measures will be implemented in developed urban areas. Factors to consider before installation include:
- Planning, Procurement, and Work Permits
- Underground Services
- Installation Safety
- Bollard Foundation
- Installation Process
- Quality Assurance
Planning, Procurement, and Work Permits
Good planning will enable projects to run smoothly and reduces unnecessary costs due to delays, double-handling, statutory requirements, and if necessary, shifting. Time is critical for industries and sites that require urgent high-level security barriers. Once the site vulnerabilities are identified and highlighted, traffic departments and safety and security departments in malls, airports, hotels, petrol stations are ordered by the management to have bollards that can be installed in a few hours rather than days. As a result, security teams are under pressure to find qualified manufacturers and suppliers of HVM bollards that can provide immediate solutions without sacrificing quality.
Once the supplier or manufacturer is identified, project teams need to work with the procurement team for the delivery of materials, obtain a work permit for excavation, temporary traffic diversion, and any other site-specific requirements. They also need to make sure that cordoning off an area for excavation will only be for a few hours to avoid blocking the existing traffic flow. The team needs to ensure that materials are on hand and delivered to the site especially for materials imported from other countries.
Installing bollards will require excavation work except in the case of surface-mounted bollards or bolt down bollards.
HVM bollards or crash-rated bollards require a considerable depth to serve as a structural foundation for a physical barrier that can withstand vehicle-borne attacks. For sites where excavation cannot be done due to critical underground services, shallow-mounted bollards can be employed.
Before doing excavation work, the team needs to consider site-specific safety issues such as the proximity and physical condition of nearby structures, overhead and underground utilities, situational factors such as traffic and any engineering constraints. It is important to avoid damaging underground services. Underground electrical cables can be hazardous and may cause injuries and fatalities.
If underground cables are within the vicinity, someone from the organization has to detect and locate them. Underground cables may need to be dead for the work to proceed safely. If so, be aware that utility companies require a certain number of days to notify customers in the area of the temporary disconnection. The site engineer needs to review the local building code for specific requirements and approvals.
Industry best practices require a depth of at least 30 cm for shallow-mounted bollards although the shallowest project successfully implemented had a record depth of 16 cm. Shallow-mounted HVM bollards also reduce installation time which makes this type of bollards a preferred choice for sites where installation time is critical.
Once the work permit is obtained, the area of the excavation is to be cordoned off with barricade as approved by the site safety manager. Appropriate safety signs, warning lights, safety tape, green mesh, fire blanket, fire extinguishers, and other fall protection requirements must be prepared on-site. All personnel will need to comply with the necessary safety precautions including undergoing a safety induction and the daily toolbox talk.
All electrical cables need to be taped properly to avoid tripping hazards. Electrical power also needs to be taken from the site after obtaining approval from the site engineer. Once depth has been achieved, excavated soil will be dumped to the approved yard. Compaction of the excavated loose soil will also be done to the approved standard.
Prepare and clean the surface to receive the concrete base foundation of the bollard. It is necessary to remove any obstruction to the line of sight during the placement of the pipe bollards such as dirt and debris. If necessary, use a pressure washer to clean the concrete surface prior to the pipe bollard installation. Ensure that proper safety resources are available to prevent accidents and injuries specifically when installing HVM bollards as they are heavy.
More often, the common cause of failure for most bollards is from over-turning or upsetting of the foundation than bending of the pipe. The material, whether it is concrete or asphalt pavement and the thickness surrounding the bollard’s fulcrum including the soil type plays a big part in the ability of a bollard to resist an anticipated impact.
Crash-rated or HVM bollards are designed and procured with their corresponding certified foundation. It is important to note that crash-rated bollards will lose its purpose and strength without the tested and validated foundation. Manufacturers will not provide the HVM bollards as a standalone product, it has to be procured along with the foundation.
As a reference, industry best practices employ a 3:2:1 concrete mix (cement, sand, gravel ratio). Assuming good soil conditions, a foundation of 400 x 400 x 600 mm deep is best for light to medium duty traffic. For heavy-duty service, an experienced structural engineer may have to determine a specific foundation design based on individual requirements, site conditions including the soil characteristics.
The installation process of bollards varies according to type. When setting the bollards into a concrete foundation, allow the concrete to cure for a minimum of 2–3 days before starting construction on the fresh concrete surface. Moisture in the environment and cool temperatures can slow the process of curing significantly. Clean the surface of the bollard with a cloth before the concrete cures. Once the curing process is done, adjustments to the bollards will not be possible.
Quality Control & Assurance
After installing the bollards, check for any signs of surface damage. Abrasions need to be covered as soon as possible to prevent rust and to maximize the life span of the bollard. To avoid debris, dust, and water from accumulating on the bollard’s flat top, it is recommended that pipe bollards are finished with a dome top. A bollard cap can also be installed into the concrete while it is still wet to provide an even, uniform dome surface finish.