Secrets to a prefect dwarf wall construction for Gs / Grp Sectional panel tanks

Once you've been in the tank game as long as we have, you've pretty much seen it all!

In this piece, we aim to draw upon our extensive 35 years of tank installation experience to enlighten our service partners and empower them to navigate these challenges effectively.

The primary issue often stems from the disparity between the approaches of steel and civil engineers. Civil engineers typically operate within a 20 mm tolerance, whereas their steel counterparts aim for precision within 2 mm.

Recognizing this dissonance is key to staying ahead in the game.

Let's delve into some cautionary tales, dissecting the reasons behind mishaps and outlining crucial do's and don'ts to steer clear of similar pitfalls.

DESIGN ISSUES

Imposed loads exert the most pressure on the outer edges of sectional steel tanks, especially the initial and final walls. This pressure also extends to all outer edges perpendicular to internal walls. Short dwarf walls exacerbate this issue, particularly when the rebar cover is dangerously close to the tank edges. The tank's flanges act like blades, creating stress points, leading to catastrophic cracking of the walls—an issue rooted more in design oversight than construction error.

ALIGINMENT ISSUES

Another prevalent issue lies in construction techniques, particularly misalignments at wall-panel junctions. This error can lull contractors into a false sense of security due to the perceived insignificance of minor misalignments. However, the ramifications amplify with scale. Contractors often introduce errors during measurement, sometimes resorting to unreliable tools like Chinese fabric tape measures or measuring walls individually instead of holistically.

HIGH SPOTS - LEVELS & OUT OF SQUARE

Moreover, uneven wall levels and out-of-square constructions compound these challenges. As Ross Perot aptly remarked, "A good carpenter measures twice and cuts once," emphasizing the importance of meticulous measurement practices.

The secret lies in meticulousness—measure, double-check, then proceed with concrete casting.

Here's a step-by-step guide:

1. Design - or ask us for a QcP plan and check list before you start - A properly functional Method statement

2. Equip yourself with a reliable, long steel tape measure (25-50 meters). Always measure with a buddy ! - 4 eyes are better than two

3. Invest in quality steel shutters to minimize errors during construction.

4. Streamline your construction process with pre-aligned and pre-shuttered systems for easy checks on squareness, levels, and panel alignment.

5. Incorporate running measurements across the foundation's entire length, marking panel joints on the shutters for reference.

6. Consult with the manufacturer to address any concerns regarding sealant or gasketing between panels, especially with huge tanks

7. Ensure a minimum 250 mm overlap on walls to maintain structural integrity within the tank's load points.

By adhering to these meticulous practices, you can significantly mitigate the risk of common tank installation mishaps.