Civil Foundations for Weighbridges: What to Consider

If you’re considering a weighbridge installation, it’s essential to work with a civil construction contractor who understands the specific requirements of weighbridge foundations. This includes knowing the allowable tolerances that apply to weighing instruments, which differ slightly from those typically used in regular construction projects. Let’s dive into what you need to know.

1. Understanding Weighbridge Foundation Requirements

Before any physical work begins, it’s critical that all dimensions are checked and controlled on-site. These measurements must be precise, as discrepancies can lead to misalignments that affect the performance and accuracy of the weighbridge. Any discrepancies in dimensions must be reported immediately, as no claims will be granted for issues arising from these errors. So, make sure that the measurements are spot on before proceeding with the foundation work.

2. Allowable Tolerances for Weighbridge Foundations

The tolerances for weighbridge foundations are much stricter than those for regular civil or mining construction. In fact, weighbridge foundations must be constructed with an allowable tolerance of no more than 5mm. This is a critical factor for accurate weighing. The slightest deviation in the foundation could affect how the weighbridge measures the weight of the vehicles, leading to incorrect readings that could cause a variety of problems.

For this reason, it’s important to hire a civil construction contractor who understands these specific tolerances and how they impact the overall performance of the weighbridge. These tolerances are vital, as they directly influence the structural integrity of the platform and the accuracy of the weight readings.

3. Proper Setting Out and Plinth Construction

The process of setting out the weighbridge foundation is another important step. Setting out to be done from the center line outwards ensures the foundation is correctly aligned. The plinths (the support columns or pads that the weighbridge sits on) must be straight and level. Bolts must be cast insitu, which means they need to be placed directly in the concrete during the pouring process, ensuring they’re securely embedded. Using grout or topping isn’t allowed, as this can compromise the integrity of the foundation.

4. Soil and Reinforcement Considerations

When constructing the foundation, the soil underneath must have a suitable bearing pressure to support the weight of the weighbridge and any vehicles that will be on it. Additionally, the plasticity index (P.I.) of the soil should be taken into account when designing the foundation. The soil conditions, along with the reinforcement provided as per the issued drawings, are the responsibility of the civil contractor. A properly designed foundation with the right soil conditions ensures long-term stability for your weighbridge.

5. Weighbridge Office Construction

Another important consideration is the weighbridge office. It must be constructed in such a way that the person operating the indicating mechanism has a clear and unobstructed view of the entire weighbridge platform. The layout and positioning of the office are crucial for smooth operations.

6. Electrical and Drainage Considerations

A standard 3-point electrical socket (isolated) providing clean 220VAC power with no more than 3 ohms resistance between earth and neutral must be installed in the office. Electrical connections for the weighbridge are the customer’s responsibility.

Moreover, adequate drainage is essential, and it’s best to ensure natural drainage around the foundation to prevent water pooling that could affect the structure over time. For the load cell cable, PVC conduit must be installed 500mm below the surface from the center of the foundation to the weighbridge office. This conduit should be placed well away from other cables, at least 450mm apart.

As a SANAS accredited company, Clover Scales is recognised for its commitment to accuracy and precision in all aspects of weighbridge installation. This accreditation ensures that we operate with the highest standards in the industry, giving you peace of mind that your weighbridge foundation will be built correctly from the ground up. Clover Scales understands that achieving accurate weighbridge readings starts with the foundation, and our team ensures that the foundation is constructed with exacting standards, using the right soil and reinforcement materials tailored to your specific needs.