Regarding the gap thickness between the storage tank bottom plate and the concrete platform
Thread Content
As the title suggests, I would like to ask what typical thickness the gap between the edge of a storage tank floor and the concrete base can be, due to deformation. . Thank you all! ~
Let’s first look at the size of the storage tank. I’ve seen tanks with a capacity of 100,000 units, and the maximum gap in those cases was between 15mm and 20mm; this gap exists during the water testing process. In reality, it depends on the levelness of the foundation. If the deformation is caused by welding, it probably won’t be that large – 10mm seems like a considerable amount to me. Of course, this is just my opinion; there’s no theoretical basis for it
Due to precision issues in civil engineering work, the ring foundations surrounding the storage tank are not entirely level. Before the foundation is poured, it is required that the civil engineering team level it according to the design elevation; however, there are still slight discrepancies, which are even greater in the case of larger tank foundations. This aspect needs to be taken into account before the foundation is inspected. The welds between the edge plates of the tank and the base ring are single-sided welds that cause contraction, which inevitably leads to the upward bending of the edge plates. To control this upward bending, a set square is used for positioning before welding, thereby reducing deformation. The misalignment between the edge plates and the foundation under water pressure is caused by the combined effect of these factors. In such cases, it is necessary to use non-shrinking concrete to fill the gaps, so that the bottom plate can fit tightly against the foundation and distribute forces evenly
Mm-hmm, professionally speaking, I have a question: does the welding sequence for the large corner joints also affect the warping of the edge plates? I was wondering, is it generally done from the inside out or from the outside in? Thank you
The specifications require that the base plate should fit tightly against the foundation, which is achieved through grouting.
I didn’t really want to say anything, but the so-called grouting that is done later is actually just the plastering of the foundation ring beams; without exaggeration, the thickness of this layer is 20 mm or more. Sand (epoxy coal tar pitch) is usually used for filling, and the process is carried out from the inside out. In reality, the surface isn’t level at all, and anyone who works on this knows that. The design slope should be 0.8 per thousand or less