If the water table is high in loam, sand, clay or mixed soils, the Foundation should be constructed at a depth that exceeds the level of soil freezing. This makes the withdrawal of groundwater, this event is considered mandatory in these conditions.
In the case where the depth of soil freezing is less than level with the water, you can not make allowance for soil type, Foundation plan, considering only the load of the building. While carrying out calculations, corrected for groundwater level (GWL) from half a meter to a meter in the direction of increasing the real level. For this reason, the strip foundations are excluded from the possible designs, as its price will be very high, and the erection of a bulky and costly.
In the calculation of foundations on soils with a high groundwater table make allowance for the subsidence of weak soil. If there is a risk of seasonal flooding, it is recommended to erect buildings using monolithic reinforced concrete structures. The pile should be below the level of potential soil erosion.
The technology of construction of the Foundation under high groundwater table
First dig a trench to the depth of the Foundation, then the ground leveled and dried. To do this, the perimeter of the site to dig a ditch with a space of 50 cm, its depth is 30 cm and a width of about 20 cm, the Ditch is designed to accumulate and drain moisture. The Foundation does not pitch in groundwater as high risk of leaching solution and attenuation of the constructed plate.
Then at the construction site, conduct soil compaction and concrete preparation. This layer is required for leveling pad and placement of waterproofing. After drying, it is covered with two layers of roofing material overlap each layer of 10-15 cm of Sand and gravel without using and fixing do, with ordinary bitumen is brought to a working condition.
The Foundation will be located below the groundwater level, therefore, concrete slabs, walls and ceilings must be isolated from moisture. Placing of the roofing material need to extend beyond the screed to protect the slab and make the overlap on the erected walls of the base of the Foundation.
Then mount design of wire mesh products and accessories, it will need to pour the solution. Recommend to create a slab thickness of 15, 20 or 30 see What the plate will be thicker, the better it will keep the Foundation and walls of the building. After standing plate, you can start constructing the Foundation. It is best to use concrete blocks, which form a monolithic structure. Once the work is finished, will only protect the Foundation from groundwater using mastic based on bitumen or film of waterproofing.