The TISE foundation belongs to the group of pile supports. It is made using bored technology. This option is perfect for an individual house on heaving soils.
Frost frost
The phenomenon of frost heaving is characteristic of clay soils, which include:
- sandy loam;
- clay;
- loams.
Heaving occurs when two conditions are present simultaneously: cold and moisture. Clay does not pass liquid well and accumulates it. In winter, the soil freezes to different depths, for some areas of the country this mark is more than 2 meters.
With frost heaving, the soil increases in volume and pushes the foundations. The consequences will be uneven deformations, cracks on the walls, destruction.
Universal foundation TISE technology allows you to deal with this phenomenon. The house on the foundation of TISE as if hooks on the ground. This is possible due to the broadening in the lower part. For large buildings make the TISE strip foundation. This technology is a combined option. Here, poles hooked into the ground and a tape that reliably ties the entire structure together are included in the work.
Universal foundation TISE technology: benefits
The construction of foundations is an important component of work. Sometimes the estimate for the construction of the underground part is one third of the total cost. But with the right choice of grounds, you can significantly reduce labor and financial costs.
The foundation on piles of TISE has the following advantages:
- good bearing capacity;
- lack of need for heavy equipment;
- reducing the cost of transporting materials and structures;
- an effective way to combat frost heave;
- the ability to use at a high level of groundwater (GW);
- simplicity of technology.
Regarding the last plus, it is necessary to give explanations. During construction in marshy areas, temporary water reduction will be necessary for the duration of the work. This may require additional costs.
The design has other disadvantages. Disadvantages of the TISE foundation:
- the impossibility of arranging a basement or its high cost;
- increased costs when working on coarse soil;
- the need for special equipment (drill with folding knives).
Despite the shortcomings, the foundation of TISE with your own hands under your house is a reliable support for the building, good ecology and safety for humans.
Foundation calculation
The calculations consist in the selection of the optimal cross-section, step of supports and depth of support. For execution, you need to prepare the source data:
- type of soil on the site;
- load from the building.
The calculation is performed in the same way as for other bored types. To understand what soils are located on the construction site, you will have to perform geological surveys. To do this, carry out manual drilling or tear pits - deep holes. The foundation of the TISE foundation involves the study of the soil to a depth that is 50 cm higher than the estimated elevation of the sole.
For calculations, not only the layer on which the bearing is based is needed, but also all the overlying ones. The pile foundation is calculated taking into account the support on the base at the lower point and with the inclusion of lateral friction.
To collect the loads from the building, you need to add up the mass of all its structures:
- foundations (intended);
- walls;
- overlappings;
- partitions;
- roofing.
Also included here are payloads for floors from furniture, equipment and people, as well as snow on the roof. All values are multiplied by a safety factor, which is from 1.05 to 1.4, depending on the type of loading. The main regulatory document that is used in calculating the mass of the house is JV “Loads and Impacts”.
Construction technology
This method of building construction, which provides for broadening in the sole area, is not new to builders. The method has been used since the 18th century. But before it was not possible to use modern nozzles, so the well was developed using an unsafe explosive method.
Now on the construction market there are special tools that are equipped with folding knives. Upon reaching a certain mark, these devices recline, and the drill continues its work. The width of the extension is on average equal to 60 cm.
The foundation for TISE technology should be based below the freezing level. The exact mark of this level for each region can be found on special tables or maps.
TISE foundation technology is easier when working with sandy soils. Such material is easy to process. But most often on large or medium sands, simpler structures can be dispensed with: such bases are not prone to frost heaving. Things will be more complicated on clay soils, but it was for them that the option was created. Significant difficulties can cause large debris in the path of drilling, such as stones.
If groundwater is found close to the surface of the earth during geological exploration, water reduction will be required. Temporarily water can be pumped out by pumps. After pouring concrete, the water treatment plant does not matter, since the piles rely on considerable depth and work well in marshland conditions.
The foundation technology TISE practically does not differ from the conventional bored type. It includes several stages:
- clearing and marking the site;
- drilling of the wells;
- installation of reinforcing cages;
- pouring concrete;
- erection of grillage.
The territory under construction needs to be cleared of garbage. After that, a blind area is built around the perimeter of the future building, to which a cord will be attached, showing the direction of the axes or walls of the building. For the manufacture of cast-offs, wooden racks and jumpers are used.
Drilling of the wells
The construction of the foundation of TISE differs significantly only at this stage. The operator is drilling. After the tool reaches the mark defined by the project, a special knife is thrown out. This knife works on traction, he continues to choose soil, but with a large diameter.
Spent soil is collected in a special container and removed from the well. If necessary, lay a sand cushion at the bottom, and a pipe from roofing material is inserted into the well (from roofing - an outdated version). Such a pipe will prevent the flow of cement milk into the ground and the deterioration of concrete quality.
Reinforcement
The TISE pile-grill foundation is reinforced with reinforcing cages. Working rods are arranged vertically. They are designed to compensate for bending loads. Most often, 4-6 rods of class A400 with a diameter of 10-14 mm are installed. The exact values depend on the mass of the house: the larger it is, the more powerful the reinforcement is required.
To connect the working rods to each other, horizontal clamps made of reinforcement with a diameter of 6-8 mm are used. They are placed in increments of 200-300 mm over the entire height of the pile.
The following requirements are imposed on fittings:
- compliance with class and diameter;
- reliable fastening of frame elements to each other for welding or with knitting wire;
- absence of dirt, paint and rust on the surface.
If it is necessary to connect the reinforcement along the length, this is desired with an overlap, which is accepted at least 20 diameters. The ends of the rods should extend above the edge of the pile to connect with the grillage.
Concrete works
For concreting piles, it is recommended to use concrete B15. It can be prepared independently from cement, sand, gravel (gravel) and water, it is better to order the mixture at the factory. In this case, the material has a passport, and all proportions in the preparation are strictly observed.
Concreting of each element is done in one go. Interruptions in work will lead to the formation of seams - weakened areas. The work is performed in two ways:
- manually;
- using a concrete pump.
If the second option is selected, this must be reported to the concrete manufacturer. To work with special equipment, a material with a mobility grade of P4 or P5 is required. Otherwise, the mechanism may break.
After pouring, a compaction of the mixture is mandatory. This is necessary in order to remove air bubbles from the thickness. Compaction is done by vibration or bayonetting. For bayoning, only a reinforcement bar is required, which mixes the mass of concrete.
Making grillage
The TISE foundation with grillage allows you to build a reliable and rigid system. Since the technology is most often used for heaving soils, even in the manufacture of strapping it is worth remembering methods of dealing with heaving.
The grillage should not touch the ground. This is the only way to protect it from damage during frost heaving. Despite this, the design may be buried. For the manufacture of strapping, two methods are used.
The first is to raise the element above the ground. The size of the gap is taken equal to 10-15 cm. To do this, before pouring, a layer of sand of the required thickness is poured onto the surface of the earth. The grillage is made according to the usual technology with the use of formwork. After pouring the structure, you will have to wait several weeks for a set of strength. At the end, sand is taken out from under the foundation, and the resulting gap is closed with decorative material.
To make a buried grillage on heaving soil, a damper layer is placed under the tape. For its manufacture, polystyrene foam of low strength 10 cm thick is suitable. When buckling the soil, the material is crushed, but does not transfer the load above. Due to this, a detrimental effect on the grillage and its damage is prevented.
Monolithic strapping is done according to the type of strip foundation.
Working fittings with a diameter of 10-14 mm are placed horizontally. For vertical and horizontal clamps, 8 mm rods are used. For pouring the grillage, it is worth taking concrete of brands B15 — B20, depending on the loads and the distance between the piles.