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TANK FOUNDATIONS
CIRCULAR BOLTED "STRIPSEAL" WATER TANKS
Several types of foundations can be used for circular bolted "Stripseal" water tanks. The type of foundation will be determined by a number of factors including:
Tank size
Soil type
Availability of materials
Wind speed region
Seismic rating
Customer requirements
In all cases it is recommended that a site inspection and soil test be carried out by a consulting engineer to determine the type of foundations suitable to the site.
Types of foundation:
The types of foundation suitable for use with circular bolted "Stripseal" water tanks (subject to suitable site conditions) are:
Compacted Gravel Base: All sizes of water tank can be installed on compacted gravel bases but their use is usually limited to rural or short term installations.
Corrugated Steel Mound Ring: Limited to use with 1 .8m and 2.4m high tanks, mound rings are formed from curved galvanised corrugated iron sheets bolted together to form a continuous ring which is then filled with compacted sand. The tank is assembled on this mound and the additional height allows the full tank to be drained when supplying cattle troughing or similar applications. Additional block footings for roof support posts may be required, depending on tank size and wind loads.
Reinforced Concrete Ring Beam: As the name implies, this type of foundation consists of a ring formed of reinforced concrete to suit the bottom ring of the tank. This is then filled with gravel and compacted to form the base for the tank. Additional block footings for roof support posts may be required, depending on tank size and wind loads.
Reinforced Concrete Slab: For appearance and installation purposes, it is preferable that tanks be installed on a concrete slab. The flat concrete surface provides an ideal base for the tank bottom ring and tank hold-down clamps1 where required. Slab type bases are preferred for reactive soils or areas with low allowable soil bearing pressures.
Foundations for "Sides Only" Tanks: Where a suitable waterproof concrete slab can be provided, tanks up to and including 4.8m high may be erected without steel bottoms using a special sealing strip and clamps to form a seal between the bottom ring and the slab. Each application must be referred to Ellis Tanks with full details of site conditions and tank size.
Note: When considering tank foundation type, there are some situations which require particular attention, for example:
(a) Where ground water is present, above or just below ground level.
(b) On sites where large scale filling without compaction has taken place, as uneven settlement may occur.
(c) Light friable sandy soils subject to erosion, or heavy black clays, subject to expansion when wet with characteristic cracking in dry periods. In cases like these, particular care must be taken in the choice of foundations.
For elevated water storage, Steel water tanks can be mounted on galvanised steel tankstands. Refer to Tankstand page
Site Considerations | Foundations | Warranty
