The structure and construction requirements of the storage tank foundation

The structure of the storage tank foundation mainly includes the insulating and anticorrosive layer on the top surface of the foundation, the tank wall support, the edge retaining structure, the sand cushion, the oil and water barrier, the detection signal tube and other structures. The construction materials and requirements of each basic structure of the storage tank are different.

1. Insulation and anti-corrosion layer on top of foundation
The asphalt sand cushion or asphalt concrete cushion laid on the top surface of the foundation is mainly used to block underground capillary water and moisture, and protect the bottom plate.

2. Tank wall support
The storage tank wall support structure is mainly composed of reinforced concrete ring beams or gravel ring beams. The main function of the tank wall support structure is to act as an installation support for the tank wall and its lower ring plate to adjust the uneven settlement of the foundation.

3. Edge retaining structure
For a flexible foundation constructed mainly of bulk materials, it is necessary to set up a foundation edge retaining structure, which is usually composed of reinforced concrete ring beams or slope protection.

4. Sand and gravel cushion
The main function of the sand-gravel cushion is to disperse and transfer the upper load to the foundation through the cushion. The uppermost sand cushion is generally not less than 30cm, and the lime soil and plain soil cushion is controlled according to the conventional compaction coefficient.

5. Oil barrier and waterproof layer
Mainly aimed at foundations that are afraid of oil and water soaking, such as collapsible foundations, swelling foundations, foundations with large water permeability, etc. This layer is usually paved 10-20cm below the oil spill signal pipe with lime soil, clay, asphalt sand or asphalt concrete. The thickness of lime soil or clay layer is generally not less than 30cm, and the thickness of asphalt sand or asphalt concrete is not less than 10cm.

6. Oil leakage signal pipe and others
Oil leakage signal pipes are embedded in the reinforced concrete ring beam every 10-15m along the circumferential direction, mainly to detect oil leakage. The rest also includes water dispersion, slope protection, settlement observation points, etc.

After the structure of the storage tank foundation is built in accordance with the construction requirements, the settlement of the storage tank foundation needs to be observed, and the uneven settlement value of the storage tank foundation should be within the allowable safety range.