The construction of any building begins with the construction of the foundation - the foundation of the entire building. It takes on the entire load of the structure, evenly distributing it over the ground. Thanks to him, the building will not move and deform under different climatic conditions. Depending on the design values, the type of soil and the features of the building, there are several types of foundation. All of them have their own merits.
Columnar types of foundation
Forces and stresses are generated inside the frame, which can lead to deformation of the structure if it is poorly anchored to the ground, in which the aforementioned forces and loads are transmitted. There are two types of loads: proper loads related to the weight of the materials of which the building itself is made up of its structural and perimetric parts, while random loads depend on the intended use and therefore on the number of users that it will act.
Precisely because of the presence of several factors, in order to lead to a structure that responds well to loads and stresses due to external forces such as wind and seismic events, we must be well acquainted with the principles of static and science of buildings, which by means of mathematical formulas, they return the dimensional parameters that must be observed for a correct design.
What types of foundations exist? What is the difference between them? What type of foundation to choose? You will learn all this from our article.
No. 1 - strip foundation
One of the popular options that is used in construction. Although the construction technology is simple, the base itself is massive, and the process is rather laborious. In addition, the material for work takes quite a lot. Most often used for the construction of private houses on a simple type of soil.
The first study, however, can be made to select the type of foundation to be taken, of course, to geological and geotechnical, consultation from a specialist who will analyze the structure, stratigraphy and all the possibilities of the site where you want to build this building.
Construction materials
Let's analyze Various types existing funds. They are divided into two classes: direct or superficial bases, indirect or deep bases. Straight stems are the most commonly used, for soils that don't have significant levels of conformity but do respond well to stresses. The skirting boards are included in them or parallelepipeds, armed with a square or rectangular section, the size of which depends on the load it insists on, and is made of concrete castings inside the formwork, usually of wood.
What is strip foundation? This is a tape or strip made of reinforced concrete that follows the contour of the entire building. Thanks to this device, the foundation is strong, able to withstand high loads. Tape is formed under each interior and exterior walls. It is recommended to use for stone, brick or concrete houses with a large weight. The peculiarity is that with this foundation you can build a garage or cellar under the house. Yes, labor costs are really high, but you will get a reliable foundation that can stand for more than 150 years. It is better to invest once and forget than to sell too cheap and often resort to repairs. But, this is only guaranteed if you adhere to the construction technology. By doing something wrong, you will significantly reduce the operational life and characteristics of the base.
They rest on a foundation slab and must always be connected to each other by curbs, which provide a more complete stress compliance. This standard has been introduced into the new anti-seismic regulations, which provide for the implementation of various systems used as anti-seismic devices.
Other types of straight bases are inverted beams, so named because they are tufted in the opposite direction, while kiosks, which are real mesh, are more resistant to stress. On the other hand, indirect foundations are accepted when the ground does not have a high degree of resistance, or when such a feature is present in deeper layers, or when a building with significant loads needs to be built. An example is a skyscraper.
Device technology
Typically, such a foundation is laid 0.2 m deeper than the location of the freezing point of the soil. The thickness varies and directly depends on the thickness of the walls with the finish and the planned pressure of the walls. There are two types of such a foundation:
A trench is dug for the device, which repeats the shape of the house and bearing walls. After that, everything is leveled and a sand cushion is arranged at the bottom. She is well rammed. The recommended layer of sand is from 10 to 20 cm, the layer of crushed stone is the same. The deeper the trench, the thicker the cushion layer is needed. After that, it remains only to make the formwork (removable or fixed), install a reinforcing mesh and pour everything with concrete. The scheme of the strip foundation can be seen below.
In the cases described above, pole or micropiles systems are used. Their functioning is associated primarily with the search for stable soil and the frictional forces created between the pile and the earth itself. Materials used: wood, concrete, prefabricated or cast in place, steel, in combination with special materials that increase the adhesion between the base and the ground.
The main types of foundation structures
The poles are inserted into the ground in various ways: they can either be beaten with piles or boring machines, i.e. they are made after removing the soil and then pouring reinforced concrete into the formwork. Instead, microsaws are used for small jobs and are classified as such when their diameter does not exceed 300mm when drilling and 150mm when used.
Advantages:
- Strength.
- Durability.
- Possibility to build a basement, cellar, garage.
- Withstands heavy loads, suitable for weighted structures.
Flaws:
- High cost.
- Big labor costs.
Slab foundations for the house
Finally, other sub-categories of funds are included, but they are rarely used as they consist of a high degree of specialization and are very expensive to implement. In short, in the construction process of a building, the choice of the foundation to be used is one of the most important design considerations.
Of course, many programs help us to understand the performance of forces, the characteristics of the characteristics of materials, but it is important to fully know all those elements and concepts of statics that describe the functioning of a building well. It is for this reason that, especially for highly important works, the design of structures is left to engineers or structural workers who represent the leading experts in this field.
No. 2 - columnar foundation
It differs from the first option in that fewer materials are required, since the foundation is not solid, but is made on the basis of pillars. These poles are installed at all corners of the building, at the intersection of the wall and at those points where there is a high load. A feature is reliability, efficiency, lack of waterproofing work. But, it cannot be used for heavy structures. Found application in private construction for the construction of small structures.
In fact, it is a serious mistake to underestimate the importance of funds, as well as all other auxiliary elements, to use poor materials or weakly strengthen structures, especially in a country like ours, which has large areas with a high seismic risk.
First of all, consider the type of land on the site and the design of the house. Remember that not all land is suitable for construction. To find out what the composition of the plot is in your area, ask the municipal office for geological or hydrological maps of the area.
Pillar foundations can be
You can also perform geotechnical testing to be sure. Their implementation is not mandatory, but thanks to them you will receive a complete set of information about soil layers and guidelines for the type of foundations. Also, take care of right foundation. It must be designed by a person with a building qualification. It should include, in particular, the bearing capacity, level ground water and freezing depth. To make the foundation strong and reliable, hire a proven team. Also try to get the right materials and accessories.
Device technology
In fact, this is a system of pillars that are located at the right points of the building (necessarily at the corners and places with increased load). They dig into the ground. The optimal distance between them is one and a half or two and a half meters. The pillars themselves can be made of bricks, stone, ordinary or rubble concrete. It is important to fill the remaining space between the pillars and the ground with sand and gravel and additionally concrete.
The foundation of the building can be done in several ways. Below are the most important ones. They work well in buildings with a basement as well as in homes without a basement. The first is to line the excavation with building foil and then pour it with concrete. The second requires the placement of a thin concrete foundation at the bottom of the excavation, as well as rebar and plank boarding. The foundation slab is a kind of building foundation that works on lands with low bearing capacity or high water tables. Thus, the created board can be both the foundation and the floor of the first floor. Foundations on piles - a foundation that works on poor soil. Reinforced concrete piles are laid, and then concrete is poured. It is worth remembering that this is a rather expensive solution. Borehole foundation is a type of foundation that is carried out on difficult ground. The base is mounted on special wells, which are made in the same way as a well for water intake. Wells can be concrete, brick or reinforced concrete. The cost of this type of foundation can be ten times higher than in the case of foundations.
- The basis of the foundations is a traditional and relatively cheap type of foundations.
- This is an excellent solution for lands with good bearing capacity.
- They can be made of concrete or reinforced concrete.
- They are laid in the formwork or directly on the ground.
- To increase their strength, appropriate reinforcement is used.
To preserve the heat of the space under the floor, as well as to protect against moisture and dust, a pick-up is made. What is this? The wall that connects the pillars. It is built of brick, concrete or rubble masonry. With heaving soil, a sand cushion is poured under the pick-up, with a layer of 15 cm. And the wall itself deepens into the ground by 15 cm.
They differ in properties and filling method. Self-compacting concrete is concrete that can be poured directly from a concrete mixer into an excavation. It is durable and insensitive to ground water.
- concrete mix- a traditional type of concrete with a very wide range of applications.
- It is durable and ductile, and, above all, inexpensive.
- Waterproof concrete is a specialized type of concrete.
- It is resistant to ground water.
Advantages:
- Profitability.
- Speed and ease of work.
- Reliability.
Flaws:
- Only suitable for low weight houses.
- There is no possibility of building a basement or garage.
glass type foundation
We would like to note that this type is a variation of this type of foundation. Their design is quite similar. It can be used for the construction of bridges, for the construction of industrial nuclear buildings and other industrial buildings. For private construction, a glass-type foundation is rarely used. The photo shows what it looks like.
Foundation walls can be divided according to the type of material used. With stacked hollow blocks - like brick walls, they are made up of concrete blocks or ceramite-like blocks. The difference is that the empty spaces are filled with concrete.
- Monolithic - they are completely made of ready-mixed concrete.
- Freemasonry - from brick and concrete blocks or expanded clay concrete.
- Sometimes stone walls are also found.
- This is a fairly popular solution in single-family homes.
No. 3 - monolithic foundation
Most often, these types of foundations are used for small buildings. To perform the work, you do not need additional expensive equipment. Such a foundation can be tape or columnar.
First, you need to define the outline of the building and then clear and level the ground. The surveyor must lay out the foundation walls. For this purpose, it should indicate the corner points of the house and the benchmark - a permanently stabilized height. Then determine the corner walls of the foundations and the excavation points. After completing these activities, you can look into the foundation. The depth of excavation should take into account the depth of the upper surface of solid foundations. The next step is to level the excavation area and prepare the ground for the benches.
Then you have to make longitudinal reinforcement and formwork. The excavation thus prepared is ready to pour out benches and foundation walls. Pay attention to the density of concrete. If it's liquid or semi-liquid, you'll need to thicken it. In the case of plastic or thick plastic, use a vibrator. Wait for the concrete to bond, then wipe and level the surface.
Tape looks like a reinforced concrete strip that stretches around the entire perimeter of the building. Shallow, monolithic base type forms a rigid frame in horizontal plane, which will ensure the stability of the foundation on heaving soil. Use the design for houses with a small weight of wood. As for the in-depth base, it is made for heavy structures for which it will be necessary to build a garage.
If we talk about a columnar monolithic foundation, then this is a building of pillars erected at each corner of the building and places with a high load. As for the space between the pillars, it is covered with sand, gravel and concreted.
In addition, for especially heavy houses, a solid monolithic foundation is made, which is completely arranged under the building area. The main advantage of this type of foundation is that when the soil is displaced, monolithic slab will move with her. As a result, the walls of the house will not crack and collapse. The foundation is strong and inexpensive, about 15-20% of the cost of the total.
No. 4 - pile foundation
Ideal for those who are faced with a difficult type of soil. The fact is that such a foundation can be made on heaving soil with a close location of groundwater. He is not afraid of any unstable soils. And most importantly - the cost of construction is minimal. This is one of the most economical options for building a private house. Piles are used as the basis - these are pillars with pointed ends that are screwed, driven or inserted into the ground. They transfer the load of the entire building to the ground, distributing it.
There are several types of this foundation, which depend on the type of piles. They are:
- Wooden.
- Concrete.
- Metal.
- Reinforced concrete.
The shape determines the round piles, ring, rectangular or square. If we talk about the installation method, then the products are:
screw foundation
Screw piles are easy to use for personal purposes. Their base is made in the form of a screw, so you can simply screw them into the marked places. The work is carried out without the involvement of additional special equipment. In this case, the size of the piles depends on the depth of groundwater and the level of soil freezing. All piles are screwed into the ground strictly perpendicular by hand or with special equipment.
A screw pile is a metal pipe with a welded blade of a certain configuration. For a screw foundation, they are screwed into the ground no less than 1.5 m. At the same time, heaving and subsidence soil is not a problem. Piles are set at one level, concreted, and a strapping is made on top.
Advantages
Why are screw foundations so valued? They have a high bearing capacity. The thing is that when the pipe is screwed in, the soil does not become loose, but, on the contrary, is compacted by the pile blade. In addition, the device of such a foundation does not require much effort, time, materials and funds. In just a few days, your foundation will be ready. While it takes 30 days to dry the strip foundation, plus the work on its construction. And the process can take place at any time of the year.
Driving foundation
If we talk about a driven type foundation, then the piles need to be driven or pressed into the ground with special equipment or by vibration. This makes the process more difficult. At home, making such a foundation will be difficult.
bored foundation
The middle option, which is also often used for building houses. The difference is that piles are made right on the construction site and installed in an already dug well.
The work consists in the fact that wells are dug in the designated places. This can be done both manually (hand bur) and mechanized. At the bottom of the well, a sand cushion is made and a pile is installed (steel frame, asbestos-cement pipe, etc.). Fittings are placed inside the pipe and everything is poured with concrete mortar. The space between the pipe and the ground is covered with sand and gravel and also concreted.
Note! Due to its simplicity and low cost, in Russia this type of foundation is used in 10% of cases when a pile foundation is chosen.
No. 5 - floating foundation
Scope of use - regions with a low occurrence of groundwater and weakly bearing, heaving, bulk soil. The design itself is quite simple, and the foundation itself perfectly protects the building from external factors and destruction.
Device technology
It all starts from digging a trench according to plan. Width - 50 cm, depth - 70 cm. Then a row of rubble concrete is installed along the entire length of the pit. After that, a strip of reinforcing mesh is laid on top, the width of which is 35-40 cm or 3-4 strips of reinforcement bars. All joints are seized by welding or tied with metal wire. After that, the second row of rubble concrete is laid out and the plinth is built on.
After everything is ready, the floating foundation should be infused for a week in a wet state, and for 3 days in a dry state. When it comes to floating foundations for small structures, the process is a bit different. The trench is dug 60 cm wide. Of these, 10 cm is covered with rubble, the remaining 50 with sand. The whole mass is thoroughly saturated with water so that the foundation gives a sediment. Then everything is filled up again to reach the previous level. At the ground level, concrete tiles are cast under the posts. After that, brick pillars are installed, the width of which is one and a half or two bricks. Small concrete blocks are allowed. Everything is covered with roofing material and a strapping is made from a board impregnated with an anti-rotting compound.
In this case, if there is water under the base, then it will be everywhere. The foundation will move evenly. So, you can deal with problem areas.
This article presents short review existing species foundations and their applications. The foundation should be chosen, first of all, based on the type of soil and the characteristics of the future structure. As for the design to match the surrounding landscape, you can implement design solutions in each of the presented types of foundation. So, let's move on to considering the types of foundation.
A very commonly used type of foundation for private construction. The strip foundation is a reinforced concrete strip of fixed height and width, located along the perimeter of the entire building. Such a foundation is well suited for houses with heavy walls (concrete, brick) and ceilings. If the house has a garage or basement, then this type of foundation is perfect for this.
Usually the strip foundation deepens to a depth greater than the depth of soil freezing, but there is also a shallow strip foundation, which is used in the construction of small houses, mostly wooden.
The columnar foundation is erected by placing pillars in all corners and intersections of the walls of the future structure. This foundation is much more economical than a strip foundation, but is applicable only for light houses and structures. A special fence is created between the pillars (made of brick, concrete, rubble masonry). This foundation is used on immovable soils that are not subject to swelling and movement. Also at column foundation basements are not created.
Monolithic foundations are also used in the construction of light wooden structures. Such foundations do not require the involvement of special equipment, and there will be no restrictions in the layout of the future building. A monolithic foundation is used in cases where the soil is highly compressed.
The main advantage monolithic foundation is the constancy of the position of the foundation slab in the event of soil movement, which saves the structure from destruction.
The pile foundation is intended for construction on unstable soils. Ideal for large construction projects. The construction of the pile foundation takes place with the help of piles - pillars (reinforced concrete, wooden and others) with a pointed end. Each of the piles can withstand a load of 2 to 5 tons. The upper parts of the piles are connected to the beams, forming the supporting base of the structure. This type of foundation is expensive and rarely used in private construction.
A slab foundation is a type of monolithic foundation in which a monolithic base can act as a floor. It should be noted that this is a rather expensive type of foundation, used mainly for small houses. The slab foundation has all the positive properties of a monolithic foundation.
A floating foundation is being built in areas with a low level of groundwater, as well as on bulk, heavy, weakly bearing and heaving soils. The main purpose of this foundation is to protect the building structure during soil deformation.
Foundations on screw piles, like a conventional pile foundation, are a wonderful foundation option, and for areas with a high level of groundwater, a screw foundation is simply ideal.
This foundation is indispensable for heaving soils, unstable soils and areas with complex landscapes.
Screw piles are steel pipe with welded blade.
Video
This video will tell you about the types of foundations.
Another topic for conversation.
