Uncomplicated to the quality of the soil and at the same time a rapidly erected load-bearing structure is considered a columnar foundation. If you intend to build such a foundation for the house, then general provisions on the technology of erection and recommendations for improvement can be found here.
Content
For which soils it is recommended to use columnar foundation
Increased interest for the construction of houses on the pitted ground causes a columnar foundation. Among the various foundations, in the case of the exclusion of the negative effect of frost heaving, the columnar foundation is less susceptible to such influence. With a considerable depth of soil freezing, anchoring columnar and reinforced concrete columnar foundations are considered effective.
The preferred conditions for using the foundation are:
• light houses or buildings without cellars
• brick walls, requiring a considerable depth of laying: from 1.6 to 2.0 m.
• in case of mandatory exclusion of negative effects of frost heaving
• in the case where the design loads of soils involve the draft of the belt foundation.
We add that the laboriousness of the costs of erecting a column foundation is almost twice as economical as a belt one.
What is the foundation
The column foundation is represented by a system of pillars located at the points of intersection of the bearing walls, in the corners of the house or building, as well as in other places where the load is concentrated. On the columnar foundation, the effect of the ground punching forces is insignificant. This is explained by the fact that the forces of frost heaving affect the side surface of the basement, and the columns are erected from the calculation of the minimum cross section.
The pillars of the foundation are located in areas that, according to the calculation of the foundation, require increased attention and stability, for example, the area of internal partitions and walls. When the foundation is built, the distance between the columns standing alone is 1.5-2.5 m. To make the columnar foundation represent a single structure, a grill is arranged between the poles.
Grillage (randbalki and strapping beams) helps to avoid horizontal displacement or overturning of the structure. The main working function of the grill is the rigid fixation of the foundation of the house, which excludes the displacement along the horizontal plane. In this case, the use of grillage distributes the load from the design of the house evenly across all established posts, increasing the resistance and resistance to destruction.
The foundation on the pillars can be called universal, because such a foundation is quickly erected on any natural terrain, excluding hydro-and thermal insulation measures for the arrangement.
Types of columnar foundations
The well-known types of columnar foundations are:
• concrete and reinforced concrete
• brick
• Reinforced concrete
• stone.
The most popular type of columnar foundations in construction can be called reinforced concrete foundation.
Concrete and reinforced concrete columnar foundations are made of heavy concrete grade B15-B25.
Brick columnar foundations are built from burnt red brick, because badly burned brick is short-lived. The minimum cross-section of pillars of foundation brick with brickwork is 380 mm.
Butobetonnyetypes of columns have a section of about 400 mm.
The minimum cross-section of poles with masonry is 600 mm.
Methods of manufacturing columnar foundations
By the method of manufacture and the materials used, the following types are distinguished:
• monolithic
• prefabricated
• columnar
• foundation with grillage.
Structurally, the columnar monolithic foundation is a seamless pillar with a sole, made using reinforced concrete and reinforcement technology. Has high strength and load-bearing capacity.
The prefabricated columnar foundation has a structure consisting of reinforced concrete blocks, bricks and stone. High speed of erection does not stand competition. However, you should not flatter yourself - in this design the seams are not sufficiently reliable.
Supporting-columnar foundation is preferable for wooden houses that do not have deep cellars and basements. The simplicity of construction in this case is justified by the insignificant price of the foundation.
Foundation pillars are installed at the corners of the house, at the intersection of heavy walls and partitions. Sand-gravel padding is also required.
And, at last, the columnar foundation with grillage is considered the most preferable.
Depending on the method of making the foundation, an approximate calculation is made.
Calculation of the column foundation
It is recommended to make a calculation before installing the foundation. The main calculated values will be:
• depth of columnar foundation
• The weight of the house and the weight of the columnar foundation
Based on the data of geological studies of soils and calculated data, it is possible to calculate the PC by first downloading a special program from the Internet. The result of the calculations will be the values of the bearing capacity of the pillars, their size and cross-sectional area, as well as the minimum number of poles for erecting the foundation.
Technology of self-construction of a foundation
The erection of a columnar foundation with one's own hands, according to the algorithm of work, does not differ from the installation of a pile or tape foundation.
Therefore, with their own hands on the site for construction, the following stages of work are carried out:
• preparatory
• Creation of a drain cushion
• waterproofing works of the pillar
• erection of formwork
• pillar reinforcement
• pouring the column with ready-mixed concrete.
In order to establish a single pillar, it is necessary to prepare a pit of a given diameter for its placement. Then put a sheet of ruberoid on the bottom of the prepared pit. Preliminarily prepare the reinforcement frame for the height of the future foundation. We cut the cylindrical tube of the design diameter from the roofing material. We tie the barrel of the future column with wire and fix the wire. We put into the prepared pit a tube and reinforce it.
Then we begin to gradually fill the tube of the column with concrete, while simultaneously filling the column with soil from the outside. This will be the first pillar of the foundation. The subsequent pillars of the foundation are erected in a similar way. More detailed information is offered in the video.
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