Drawings of the strip foundation for the house. We build together a prefabricated strip foundation from blocks - an affordable solution. General rules for making sections
It is he who must take on the entire load and “carefully” transfer it to the layers of soil. Building strip foundation implies the laying of a reinforced concrete strip completely around the perimeter of the object. A reinforced concrete strip is laid under the walls from the inside and outside of the building along the perimeter.
It is used in houses with walls made of brick, stone and concrete. high density(over 1250-1300 kg/cu.m.). If it is laid correctly, then it is able to correctly “redistribute” the load on the walls and permanently eliminate the appearance of cracks.
Before construction, you need to choose a suitable foundation. At the same time, the most low prices on a strip foundation should not “play” a decisive role, since an incorrect design of the foundation and excessive savings on everything can lead to distortion, cracks or even uneven shrinkage and breakage of the building.
What is the relationship between the process of building a strip foundation and the service life of the future structure?
The service life of the future structure directly depends on the quality of the materials that you use in its construction:
- base - on cement can last about 150 years;
- "brick" tape - from 40 to 50 years;
- prefabricated concrete structure - from 60 to 75 years.
Drawing of a strip intermittent prefabricated monolithic foundation
drawing of a shallow strip reinforced concrete foundation
If we consider the design feature of the base, then they can be divided into 2 types:
- monolithic, which is being built on the construction site itself;
- prefabricated from massive and non-lifting blocks-packs of reinforced concrete, which are mounted directly on the construction site by a crane.
A competent and clear drawing of a strip foundation is the success of a durable and reliable construction
Before starting laying the slabs, it is extremely important to correctly and thoroughly draw up a drawing of the strip foundation. There will be few “blurry” calculations for its compilation, it is extremely important to observe all the accuracy in the calculations and take into account possible resistance to future loads.
For such a base, reinforced concrete, a foundation slab and a block, as well as brick and rubble concrete, are suitable.
strip foundation drawing
recessed strip foundation
strip foundation drawing
strip foundation
The width of the "sole" of the base must be calculated based on the composition of the soil, as well as from its pressure on the foundation. To find the width of the "sole", you need to clearly calculate the base. For example, with excellent bearing capacity the width will be 40 cm, while with the same load on subsiding soil, it increases by 2 times.
If it is not provided for in the future house, and the slabs will be laid no more than 1.5 meters, then when building a tape support, the mills must be made of concrete (without reinforcement). When building a house with a basement, monolithic walls must be reinforced, while the reinforcement and the thickness of the wall itself directly depend on the deepening of the basement.
It is simply impossible to do without during the construction, regardless of the chosen walls. This is necessary then to avoid the dampness of the walls and the appearance of mold with fungus.
What is the price of a strip foundation?
As for the price of a tape support, it ranges from 3000 rubles. ($85) per sq. meter, the base of cement blocks with tape will cost 2 times cheaper than 1500 rubles. ($42) for one sq. meter.
To lay this foundation, you will need:
- concrete B15 - from 4300 rubles. ($120) /m3;
- concrete B7.5 - from 3800 rubles. ($105) / m3;
- fittings 10 and 12 - from 35,000 rubles. ($980) / t;
- masonry - 130 rubles. ($3-4)/ bag;
- FBS 24-5-6 - from 3500 rubles. (95-99 $)/ for 1 block.
When drawing up a drawing of a strip base, it is necessary to calculate the future expected load, which consists of the weight of floors, roofs and load-bearing walls. When accounting, it is necessary to take into account the estimated weight of the snow cover, which lingers on the roof of the building in winter. Accurate calculations will help you calculate the required volume of solution required for pouring, cubature earthworks and required for reinforcement footage of rolled metal.
You can save on laying slabs only with the right materials. It is not worth saving on the materials themselves, choosing analogues cheaper, since such “savings” can cause cracks on the walls over time and you just have to do a major overhaul or a complete restructuring of the foundation.
- Preparatory work
- Final stage
Who in the world does not know a monolithic strip reinforced concrete foundation? 8 out of 10 houses on the planet stand on such a foundation, because it is built quickly, is relatively inexpensive, and at the same time withstands quite serious physical and thermal stress.
Drawing 1. Strip foundation made of monolithic concrete.
To build a strip foundation, the drawing must be made quite serious, but many can do without it.
Simplicity in manufacturing is ensured by the logic of the whole design.
Making a precast foundation is a little easier, but the system remains the same. For example, you can disassemble drawing 1, which is designed for brick one-story buildings located in the southern parts of the country (the small width of the foundation will not allow laying 2 bricks).
Preparatory work
You will need the following tools and materials:
Drawing 2. Reinforcement of the strip foundation.
- shovel;
- wheelbarrow for soil;
- roulette;
- gravel;
- sand;
- geotextile;
- edged board;
- wood saw;
- hammer with nails;
- ruberoid;
- broken brick.
The first step is to mark the site on which all further activities will be carried out. The terrain plan indicates exactly where this should be done, and the drawing will tell you the exact parameters.
The width of the trench is 0.55 m, and the depth is 1.2 m. As the width increases, the strength capabilities also increase. If the strength of the foundation is sufficient, and the area of \u200b\u200bsupport on the ground is insufficient, then an extension can be artificially made from below (drawing 2). If a depth of 1 m is not enough to go below the freezing layer, then you need to continue deepening, but usually this is enough.
Do not forget that the trench goes not only along the outer perimeter of the building, but also under all load-bearing walls. Sometimes there are no load-bearing walls in the house, but in this case a crosshair is made from below to increase the strength of the structure.
When digging a trench, you need to be careful enough, since in the end not only the vertical surfaces, but also the bottom should be even. If this is not the case, then the force of gravity will be distributed unevenly.
After the work of digging and leveling is completed, a layer of fine gravel for drainage is covered on the bottom, the thickness of which is 10 cm. Geotextile is laid on the gravel to separate it from what will happen from above.
Scheme of formwork strip foundation.
The next layer is laid out a 10 cm sand cushion, which is compacted with a vibrating plate or watered with water to shrink. Continuation of work is possible only after the sand has dried, i.e. after 2-3 days. Gravel and sand display drawing 3.
In the meantime, the sand dries, you can prepare the formwork. For this you need to use edged board from conifers (deciduous trees quickly rot from moisture), which is hammered together with nails into wooden shields. The shields themselves are installed in trenches and rise above the ground level by only 0.2 m. This height is quite enough for convenient operation of the house, and there will also be no overspending on the strip foundation.
Due to the fact that the thickness of 1 board is 3.5 cm, the width of each shield is 7 cm. As a result, only 41 + - 1 cm of usable space remains in the tunnel.
A roofing material is laid on the bottom and walls for waterproofing. After the formwork is removed, the roofing material will remain on the foundation.
Before you start reinforcing, you need to scatter broken bricks or plastic plates to the bottom. This will completely eliminate the contact of metal and moisture.
With constant exposure to moisture on the reinforcement system, the latter begins to rot.
Reinforcement of a monolithic foundation
- reinforcing rod 12 mm;
- hacksaw or grinder;
- welding machine;
- roulette.
Drawing 3. Sand cushion device.
This process is the most difficult from the technical point of view. Tying with wire in the standard way is not possible here, so you have to make a slight indulgence in quality and resort to welding. If desired, there is an option to use a harness at certain points, but mixing 2 options is inconvenient. Despite the standard drawing, it is better to slightly strengthen the structure, which will increase the margin of safety by at least half.
For reinforcing reinforced concrete bases, it is better to take a 12 mm rod, because. 10 will not give the desired strength indicators.
First of all, 12 parallel rods are laid in increments of 10 cm. The length of each of them is equal to the length of the base wall for which they will be used.
Perpendicular to these rods, another 1 layer is laid out in increments of 20 cm. The length of the perpendicular ones is 110 cm, which turns out to be exactly end-to-end joins the first. After laying the 2nd level, all places where the rods are in contact with each other must be welded using electric arc welding. It is advisable not to forget about 1 joint in order to achieve maximum quality.
After completing the crate, you need to make another one in the same way. At the second crate, even the joints will be located opposite, otherwise it will not be possible to complete the work. Between all parallel joints at 2 battens, segments of similar reinforcement are laid, but their length is 30 cm, after which each joint is securely tacked by the same welding.
After all the joints are made, you need to manually check each of them. Such reinforcement tunnels are made absolutely for each wall. Once all of them are prepared and installed in their places, you can proceed to the next stage of work.
Making mortar and pouring
Scheme of laying the strip foundation.
- Concrete mortar m300 (water, cement, sand, gravel);
- concrete mixer;
- water;
- polyethylene film.
To fill a monolithic strip foundation, automixers are usually ordered in order to meet the shortest possible time. Ideally, the timing should be limited to one light day, although it is very difficult to achieve such a performance. This will require not only automixers, but also hoses to deliver the solution directly to the site.
But this pleasure is expensive, besides, there is no guarantee that the supplier will provide exactly m300, and not m250, so most craftsmen in private construction prefer mixing on the spot. In practice, it takes much more time, but when a team of 8 people (2 concrete mixers) is working, the difference becomes illusory.
There is a lot of controversy on the topic of which cement to choose for concrete m300, because. it is easier to make it from m400, and m500 is 20% more economical. As a result, we will stop at m500, and the calculations will be carried out by volume in relation to 10 liters of dry cement.
Water is the main dilution material, which will require 6 liters. Used only drinking water without impurities, so that this does not affect the quality of concrete, and if there are a lot of impurities, then the solution will turn out to be completely fragile.
Sand is a fine dry aggregate. The larger its granules, the more the base material (cement) is saved, but the savings rarely reach 10%. In this case, 25 liters will be required. It is used exclusively in washed form.
Gravel (crushed stone) - its quantity in this case is 12 liters. Gravel particles never exceed a size of 7 cm, but they are never less than 0.5. It is he who allows you to save a lot when pouring, because. if you do without it (you will already get a solution of cement), then the price immediately rises by 30-35%. Apply only washed.
So, from 10 liters of cement, you can get 53 liters of high-quality m300 mortar. Sometimes, in order to save money, craftsmen increase the amount of large and small aggregates, but this makes the final design of a monolithic strip foundation much weaker due to the level of fragility.
The solution is poured into the trench in layers of 15-20 cm. After pouring each layer, it must be plowed up to release the accumulated air. Such an action will significantly affect the quality of the reinforced concrete foundation.
After all the concrete is poured to the brim, the work is still not considered complete. The entire monolithic strip foundation, erected during the first 12-14 days, is watered. The reason for this is simple - when hardening, concrete absorbs moisture at a high rate, which is why it dries unevenly, and microcracks may appear.
But only at the slightest hint of precipitation, the solution is covered with plastic wrap, because. already at this stage, rain can begin to erode the reinforced concrete monolith. The time of complete solidification of the tape monolith is 28 days.
Final stage
After excavations have been carried out, the installation of forms, all kinds of protection measures, reinforcement and pouring of the strip foundation, then its full maintenance during hardening, we can assume that the foundation is ready.
In order to further secure it, you need to take additional precautions - storm water and a blind area are mandatory, but insulation and ring drainage are made as necessary on heaving soils or flooded areas. But it is better to take these precautions already when the house is built, because. at the same time it is impossible to do it physically.
Now the manufacture of the tape base is completed completely, it remains to cover it with waterproofing, and you can start building a house.
Drawing of a monolithic strip foundation and its manufacture
A drawing of a monolithic strip foundation allows you to make a high-quality base for a house. When working, you need to strictly adhere to the indicators of the drawing, and there will be no problems.
8 out of 10 houses on the planet stand on such a foundation, because it is built quickly, is relatively inexpensive, and at the same time withstands quite serious physical and thermal stress.
Drawing 1. Strip foundation made of monolithic concrete.
To build a strip foundation, the drawing must be made quite serious, but many can do without it.
Simplicity in manufacturing is ensured by the logic of the whole design.
Making a precast foundation is a little easier, but the system remains the same. For example, you can disassemble drawing 1, which is designed for brick one-story buildings located in the southern parts of the country (a small one will not allow laying 2 bricks).
Preparatory work
You will need the following tools and materials:
Drawing 2. Reinforcement of the strip foundation.
- shovel;
- wheelbarrow for soil;
- roulette;
- gravel;
- sand;
- geotextile;
- edged board;
- wood saw;
- hammer with nails;
- ruberoid;
- broken brick.
The first step is to mark the site on which all further activities will be carried out. The terrain plan indicates exactly where this should be done, and the drawing will tell you the exact parameters.
The width of the trench is 0.55 m, and the depth is 1.2 m. As the width increases, the strength capabilities also increase. If the strength of the foundation is sufficient, and the area of \u200b\u200bsupport on the ground is insufficient, then an extension can be artificially made from below (drawing 2). If a depth of 1 m is not enough to go below the freezing layer, then you need to continue deepening, but usually this is enough.
Do not forget that the trench goes not only along the outer perimeter of the building, but also under all load-bearing walls. Sometimes there are no load-bearing walls in the house, but in this case a crosshair is made from below to increase the strength of the structure.
When digging a trench, you need to be careful enough, since in the end not only the vertical surfaces, but also the bottom should be even. If this is not the case, then the force of gravity will be distributed unevenly.
After the work of digging and leveling is completed, a layer of fine gravel for drainage is covered on the bottom, the thickness of which is 10 cm. Geotextile is laid on the gravel to separate it from what will happen from above.
The next layer is laid out a 10 cm sand cushion, which is compacted with a vibrating plate or watered with water to shrink. Continuation of work is possible only after the sand has dried, i.e. after 2-3 days. Gravel and sand display drawing 3.
In the meantime, the sand dries, you can prepare the formwork. To do this, you will need to use a cutting board made of conifers (deciduous trees quickly rot from moisture), which is hammered together with nails into wooden shields. The shields themselves are installed in trenches and rise above the ground level by only 0.2 m. This height is quite enough for convenient operation of the house, and there will also be no overspending on the strip foundation.
Due to the fact that the thickness of 1 board is 3.5 cm, the width of each shield is 7 cm. As a result, only 41 + - 1 cm of usable space remains in the tunnel.
A roofing material is laid on the bottom and walls for waterproofing. After the formwork is removed, the roofing material will remain on the foundation.
Before you start reinforcing, you need to scatter broken bricks or plastic plates to the bottom. This will completely eliminate the contact of metal and moisture.
With constant exposure to moisture on the reinforcement system, the latter begins to rot.
Back to index
Reinforcement of a monolithic foundation
Prepare the following:
- reinforcing rod 12 mm;
- hacksaw or grinder;
- welding machine;
- roulette.
Drawing 3. Sand cushion device.
This process is the most technically difficult. Tying with wire in the standard way is not possible here, so you have to make a slight indulgence in quality and resort to welding. If desired, there is an option to use a harness at certain points, but mixing 2 options is inconvenient. Despite the standard drawing, it is better to slightly strengthen the structure, which will increase the margin of safety by at least half.
For reinforcing reinforced concrete bases, it is better to take a 12 mm rod, because. 10 will not give the desired strength indicators.
First of all, 12 parallel rods are laid in increments of 10 cm. The length of each of them is equal to the length of the base wall for which they will be used.
Perpendicular to these rods, another 1 layer is laid out in increments of 20 cm. The length of the perpendicular ones is 110 cm, which turns out to be exactly end-to-end joins the first. After laying the 2nd level, all places where the rods are in contact with each other must be welded using electric arc welding. It is advisable not to forget about 1 joint in order to achieve maximum quality.
After completing the crate, you need to make another one in the same way. At the second crate, even the joints will be located opposite, otherwise it will not be possible to complete the work. Between all parallel joints at 2 battens, segments of similar reinforcement are laid, but their length is 30 cm, after which each joint is securely tacked by the same welding.
After all the joints are made, you need to manually check each of them. Such reinforcement tunnels are made absolutely for each wall. Once all of them are prepared and installed in their places, you can proceed to the next stage of work.
Back to index
Making mortar and pouring
- Concrete mortar m300 (water, cement, sand, gravel);
- concrete mixer;
- water;
- polyethylene film.
To fill a monolithic strip foundation, automixers are usually ordered in order to meet the shortest possible time. Ideally, the timing should be limited to one light day, although it is very difficult to achieve such a performance. This will require not only automixers, but also hoses to deliver the solution directly to the site.
But this pleasure is expensive, besides, there is no guarantee that the supplier will provide exactly m300, and not m250, so most craftsmen in private construction prefer mixing on the spot. In practice, it takes much more time, but when a team of 8 people (2 concrete mixers) is working, the difference becomes illusory.
There is a lot of controversy on the topic of which cement to choose for concrete m300, because. it is easier to make it from m400, and m500 is 20% more economical. As a result, we will stop at m500, and the calculations will be carried out by volume in relation to 10 liters of dry cement.
Water is the main dilution material, which will require 6 liters. Only drinking water without impurities is used so that this does not affect the quality of concrete, and if there are a lot of impurities, then the solution will turn out to be completely fragile.
Sand is a fine dry aggregate. The larger its granules, the more the base material (cement) is saved, but the savings rarely reach 10%. In this case, 25 liters will be required. It is used exclusively in washed form.
Gravel (crushed stone) - its amount in this case is 12 liters. Gravel particles never exceed a size of 7 cm, but they are never less than 0.5. It is he who allows you to save a lot when pouring, because. if you do without it (you will already get a solution of cement), then the price immediately rises by 30-35%. Apply only washed.
So, from 10 liters of cement, you can get 53 liters of high-quality m300 mortar. Sometimes, in order to save money, craftsmen increase the amount of large and small aggregates, but this makes the final design of a monolithic strip foundation much weaker due to the level of fragility.
The solution is poured into the trench in layers of 15-20 cm. After pouring each layer, it must be plowed up to release the accumulated air. Such an action will significantly affect the quality of the reinforced concrete foundation.
After all the concrete is poured to the brim, the work is still not considered complete. All, erected during the first 12-14 days, are watered. The reason for this is simple - when hardening, concrete absorbs moisture at a high rate, which is why it dries unevenly, and microcracks may appear.
But only at the slightest hint of precipitation, the solution is covered with plastic wrap, because. already at this stage, rain can begin to erode the reinforced concrete monolith. The time of complete solidification of the tape monolith is 28 days.
The drawing of which in a simplified form is a top view with linear dimensions.
Features of the strip foundation
The strip foundation belongs to the class of monolithic foundations, but is more economical than slab foundations. With a reduction in the consumption of concrete and reinforcing structures, such supports remain highly reliable for low-rise housing construction and are also used in the construction of fences, utility and household buildings of various types.
Types of supports
This type of foundation plan can represent two types of support structures:
- monolithic, during the production of which the solution is poured into a trench with filling,
- made with laying of finished reinforced concrete products.
The depth of the trench in both cases is greater than the level of soil freezing, and the width is calculated taking into account the load.
Rice. 2. A simple and understandable schematic representation of a monolithic strip support with dimensions.
Influencing factors
When performing engineering calculations, the following factors are taken into account:
- the total weight of the structure (during the construction of buildings, the materials from which the construction will be made, the internal layout, the number of floors, the number and size of window and door openings are taken into account),
- type of soil that affects the degree of shrinkage,
- the magnitude of the load during operation.
Features of building a plan
The plan of tape-type supports is created according to certain rules.
- The scaling is 1:100 or 1:400.
- Before construction, axial marking is performed.
- If there are columns, their location is indicated on the diagram.
- The general outlines of the structure are applied in lines of 0.5-0.8 mm.
The full plan includes images of the footing and soles, indicating the places of depth differences characteristic of uneven surfaces, and openings for the entry of utilities. The latter can be represented in two ways:
- with a full schematic representation and indication of data on the low point,
- axial point by transferring the main data (diameter, parameters of the lower point) to the explication.
Communication holes and ledges are depicted by shading or contour, broken lines. If necessary, such images are clarified with explanations or footnotes.
Image of difficult areas
If the plan depicts a prefabricated or monolithic foundation of a complex configuration, it is difficult to convey the nuances of the device in a single complete diagram. In this case, more complex planning methods are used:
- apply additional images of cuts to the main drawing, ensuring their axial correspondence,
- if necessary, make such cuts larger, they are performed on separate supplement sheets indicating all the necessary data (numerical, explanations, arrows indicating the type of cut, etc.).
In accordance with the complexity of the sections, scaling 1:20, 1:25 or 1:50 is selected.
On additional sections indicate:
- ground level,
- floor level,
- general outline of the supporting structure,
- thermal and waterproofing.
Possible additions to the general scheme
If a monolithic or prefabricated strip foundation is planned, for the most complete information needed by the builders, the general plan is accompanied by:
- a reinforcement scheme drawn up taking into account the load and geometric parameters (the reinforcement is laid in the lower and upper parts in the horizontal direction, with a total support height of more than 1.5 meters, additional vertical reinforcement is required),
- notes containing information about the nuances of the design,
- recommendations for preparatory work,
- information about hydro and thermal insulation,
- tables indicating the load standards for a specific supporting structure.
Degree of deepening
The depth of the strip foundation is determined in accordance with the purpose of the support. There are two main types of structures - buried and shallow. This feature is necessarily reflected in the plan.
- Shallow types are used in the construction of small brick or concrete structures, as well as in the construction of wooden buildings on soils of a slightly heaving type. The depth of the trench in this case is 50-70 cm.
- Recessed types of strip foundations with reinforced reinforcement are suitable for large houses that have basements or basements, heavy floors. The optimal trench depth is 20-30 m more depth soil freezing.
The plan always contains information about the degree of penetration of the tape.
The consumption of materials for the implementation of buried supports is much higher.
Differences between the drawings of prefabricated and monolithic supports
The principle was described above, according to which a plan is drawn up for any strip foundation, whether it is monolithic or prefabricated. At the same time, the drawing, which shows the prefabricated type of support, has a characteristic difference - the images indicate the mark of whole and corner reinforced concrete blocks.
Independent calculations
Without experience and qualifications, it is not difficult to create a plan for supporting structures if the prefabricated foundation is calculated for outbuildings or fencing. To do this, it is enough to take into account the following parameters:
- soil shrinkage vertically,
- load from the weight of the main structure,
- the load from the roof with a rafter system, when it comes to utility or household buildings,
- earth pressure load acting from the sides.
For insurance, the obtained load values \u200b\u200bare increased by 2%.
professional planning
Plan strip support for a residential building requires more detailed calculations and professional execution. When performing calculations, the specialist takes into account the current provisions of SNiP and takes into account the slightest nuances, including operational loads, the possible weight of a snow cap on the roof, weight reduction when making window and door openings.
Schema Requirements
Plan the foundation of the tape type must meet the following requirements:
- easy readability,
- completeness of information on the main scheme,
- Availability additional information in applications
- sufficiency of data for construction without the need to perform additional calculations.
A detailed and complete drawing of any type of support structure is easy to implement. It eliminates the possibility of discrepancies and errors at the stage of preparatory work and installation.
Strip foundation plan, drawing updated: February 26, 2018 by: zoomfund
In private and public housing construction, a tape-type bearing base is often used. It is considered the most practical and does not require large financial costs, as well as the use of heavy special equipment. But first it is necessary to properly plan the strip foundation, drawing, project and miscalculation - this is what any foundation requires in order to be really strong and ensure the stability of the entire structure.
Calculation of the depth and width of the strip foundation
Design works with basic parameters, so before creating a house plan, you need to know the characteristics of the soil, the dimensions of the future building. For a large residential facility, the foundation should be buried below the freezing point of the soil up to 0.6 m, while the total depth of occurrence can reach 2-3 m, especially on soft and moving soils. A light secondary structure or wooden structure can be deepened up to half a meter. Homogeneous and strong soils allow deepening of the foundation by 0.45 m.
The project takes into account the layout, dimensions and width of the external, internal load-bearing walls, under which a monolithic or block foundation. The minimum width of the supporting base must be no less than the width of the walls. It is permissible to hang a wall element over the foundation, but not more than 13 cm, and when arranging only one type of bearing base - this is a reinforced concrete foundation. It has greater strength in comparison with the materials of the wall structure, therefore it has the ability to withstand massive loads. A narrowed foundation will save on the cost of materials and fittings.
Depending on how wide the foundation will be, its sole, the total width of the supporting structure is calculated. To do this, the project reflects all the loads (sum) that put pressure on the foundation. Therefore, the preliminary plan of the house will come in handy, as well as the conclusion of the geologists, which indicates the main points: soil properties, freezing level and the height of aquifer soil layers.
Advice! If there are reference books on geological exploration data, then the freezing point of the soil and the heaving, the severity of the soil can be found from there. In this case, it is not necessary to order geological exploration. But in heaving soils there is a possibility of a change in the level of groundwater, so it is better to play it safe so as not to redo not only the project, but also the foundation of the house itself.
Do not forget that a sand or gravel fine-grained cushion up to 10-20 cm wide is necessarily arranged under the supporting base, so the trench is dug out taking into account this depth. You can take a sand-gravel mixture in a ratio of 40:6.
The width of the supporting base is calculated from the total load of wall panels, ceilings, roofs and the net weight of materials. To this mass is added the weight of the furniture and everything that will be in the premises, so the plan of the house should also provide for such nuances.
Important! The dimensions of the base of the foundation are calculated so that the magnitude of the loads does not exceed the allowable weight on the soil layers of the construction site! The design soil resistance should not be less than specific gravity building mass pressure.
If the house plan involves a construction in the form of a rectangle or square, then calculating the required volume and size is quite simple, another thing is pouring complex bases. Here you will have to divide each node into basic elements and calculate the volumes and sizes from them, then adding the resulting values. After calculations, it is easy to think over the amount of materials needed for the construction of the foundation, concrete mix, reinforcement, formwork and other things.
Calculation of the bearing capacity of the foundation
Bearing capacity is the maximum possible load on the foundation, which it can withstand without loss of quality and strength characteristics. As a rule, the indicator includes certain times for the formation of deflections, the level of stiffness and the width of the crack opening.
Ground masses consist of particles filled with water and air. Under the influence of the load, the particles are compressed, changing their shape, so the soil in the total mass also changes and can sometimes even protrude from under the bearing base. This is called shifts, as a result of which even a monolithic foundation can warp, the house settles, loses its stability. Therefore, when starting to think over a project or building plan, it is important to take into account such factors.
Important! Knowing the maximum load on the ground is necessary to calculate the mass of the building. If the indicators are exceeded, the soils are displaced by an unacceptable amount. The settlement of a monolithic, block or piled strip foundation is determined by the ratio of deformation and stress calculations - this is the average value of the pressure that has its effect on the soil masses.
Features of a shallow foundation
This type of carrier base does not need to be made high so as not to exceed the allowable stiffness standards. A sufficient height is considered to be 40-50 cm. In addition to imparting unnecessary qualities, a high foundation entails an overrun of reinforcement and concrete mix. A low load-bearing base is a more economical and fairly durable structure.
Thermal, waterproofing materials will help improve the performance and reliability of the building. Therefore, when designing a house plan, it is worthwhile to thoroughly consider each node based on actual values, indications and characteristics.
An example of planning, calculating materials and the size of the foundation of a house
Building materials required for work:
- Pure sand of fine-grained fraction;
- Crushed stone, fine gravel;
- Cement;
- Reinforcing rod, wire, steel rods;
- The basis of the underground part of the foundation: rubble stone, wire, metal pieces.
Any bearing base consists of ground and underground parts. Measurements of length, width, height are necessary for calculating the dimensions of a monolithic reinforced concrete foundation. In order to determine the volume of the flooded area of the above-ground part, the length of the trench around the perimeter is summed up, multiplied by the width and planned height, it is better to reflect this in the plan of the house. Example: if the total length of the supporting base is 30 m, the width is not more than 30 cm, and the total depth is 1 m, then the volume of the foundation is 9 m3.
The same data will help you buy the right amount of sand and cement, but you need so much reinforcement to lay 2 times around the entire perimeter of the foundation, that is, the length of the bearing base is multiplied by 2 and it turns out 60 m. Here 60 meters of reinforcement is needed. But at the same time, the reinforcing bars pass in a vertical position in a cut of 1 meter (height). The pitch of the rod is 50 cm, which means that you will have to buy 60 reinforcement rods of 1 meter in length. Bottom line: 60 m + 60 m = 120 meters of reinforcing bar is necessary for the foundation of our building. And all this should be taken into account in the project.
In addition, it is necessary to calculate the number of formwork boards. It's easy: multiply the height of the above-ground part of the supporting base by the length of the formwork and another 2. Thus, an estimate is calculated according to the plan of the future structure, where each node, connection is indicated and trifles and nuances are taken into account.