The device of the pit for the foundation

The foundation is the main part of any structure, therefore, the duration of operation of the building depends on the quality of its manufacture. The initial stage in the construction of the foundation is the digging and arrangement of the pit. The shape of this element directly depends on the type of foundation. We offer to get acquainted with the features of the preparation of the pit for the foundation.

The main varieties of pits for the foundation

Depending on what type of foundation is used during the construction of the house, the type of pit, its size and depth are determined. There are certain criteria for dividing pits into certain subspecies. We offer to familiarize themselves with them:

slopes - their number or absence;
the need for the construction of angular mounts;
the presence of inclined vertical walls;
A pit or a trench, this factor is determined by the foundation: tape or slab.

If the tape type is built on the site, then the pit is a trench that passes along the perimeter of the house and at the places of installation of the load -bearing walls. During the construction of a slab foundation for the house with a basement, you should dig a pit around the perimeter of the house and at the site of installation of the basement.

Before starting work, certain work of the earthly nature should be carried out, which include:

determination of the type of soil that is present on the site, conducting a special examination, this stage is mandatory, since it is with its help that it is possible to determine the optimal depth of the foundation, which will ensure its strength and reliability during operation;
The analysis of the building, which will be built on the site, in this case, determines the weight of the building, its load on the foundation, at this stage, the smallest parts should be provided up to the materials for decorating the roof, walls and floors;
performing the calculation of the depth of the pit, this stage depends on previous calculations and is preferable if it is carried out by specialists;
Conducting an analysis of the climate condition of the region, determining seasonal movements of the soil.

Calculations and development of a pit for the foundation

If you plan to arrange a foundation pit yourself, then keep in mind that in this matter, you need a lot of effort, patience and time. However, in this case, it will be possible to save significantly.

The work begins with the implementation of calculations of the depth of the pit for the foundation. In order to determine the volume of the pit, use the following formula:

v \u003d n/6 (2a+a1) in+(2a1+a) B1

In this case:

n - determines the height of the pit;
a and B - the value of the sizes of the parties;
a1 and B1 the length of the pit at the top;
t is the coefficient of the slope.

After calculating the foundation of the pit for the foundation, the process of determining the volume of backfill follows. To do this, you should subtract the total volume from the volume of the pit itself.

Keep in mind that the depth of the pit determines the soil and its bottom directly, and not a black mark. Before starting soil seizure, the depth on which the digging will be made is determined. It is this value that determines the depth at which the digging will be produced. This value determines the soil and its composition, as well as the load that comes from the house itself. To calculate the pressure of the building for the future foundation, use the following formula:

a \u003d f/a (MN/m*m)

In this case, the load from the house is divided into the area of \u200b\u200bthe lower part of the foundation.

In order to determine the area of \u200b\u200bthe sole of the foundation, the load should be divided into a certain value of the soil and the level of its permissible load. After determining the size of the pit for the foundation, it should be digging it.

In the process of digging the pit, several stages should be distinguished:

preparation of the site for the foundation, removing its upper layer, about forty cm in size;
in the presence of additional moisture or cages, their removal from the site;
Removing the soil to a previously certain depth, at a depth of the pit in more than 125 cm, special supports should be installed in the form of bars, they will help prevent the soil to slide along the walls of the pit;
At soil depth of about 500 cm, certain steps should be equipped in the pit, the depth of which is determined only by specialists.

DIY foundation foundation for the foundation: manufacturing technology

Digging the pit under the foundation is a rather difficult process, for which one person will not be enough. Of particular complexity is the work in the depths of the Earth, since the soil slide should be feared. We offer to get acquainted with the main stages of work on the pit:

1. Removing the fertile soil layer. Since this type of soil is characterized by high biological activity, it cannot perform the function of the supporting base. Since from time to time, it changes in volume, so it cannot serve as a reliable basis for the foundation. To remove this layer, use ordinary tools or special construction equipment. The choice of one or another option depends directly on the material capabilities of the owners of the future house.

2. In the presence of a basement under the house, the pit is equipped throughout the area of \u200b\u200bthe house. In this case, special equipment will be required. The soil seizure process is carried out gradually, while building equipment is installed at least 80 cm from the beginning of the foundation. All soil is laid near specialized equipment.

3. In the absence of a basement on the site, it is enough to equip a conventional strip foundation, the depth of the laying of which depends on the type of soil and the load on the building. In this case, the pit is equipped directly around the perimeter of the walls and at the installation sites of the load -bearing walls. This version of the foundation device is much cheaper than installing the foundation of the plate type.

The pig of the pit should be treated with particular caution. Its depth is determined by the type of soil and the following indicators:

If the soil consists of sand or gravel, the minimum foundation value is 100 cm;
The soil tie implies the arrangement of the foundation with a depth of 125 cm;
loam and clay - 150 cm;
Particularly dense soil requires a deeper base, with a depth of 2 meters.

In order to prevent soil shedding during digging the pit, you should equip a certain slope on the walls of the foundation. If the height of the walls of the foundation is about 150 cm, then the following values \u200b\u200bshould be applied:

If the work is carried out on sandy soil, then the slope is about 60 degrees, and the ratio is one to half, and if the slope of the soil is about 45 degrees, then the ratio is one to one;

If the soil is characterized by a large amount of sandy loam, then with a slope of 75 degrees the ratio is one to one quarter, and with a slope of 55 one to half;
If the soil consists of clay or is characterized by hardness, then the ratio at a slope of 90 degrees is one to zero.

Before the pouring of the pit, to prevent soil sliding, it is recommended to use special woods made. In this case, building them with your own hands is quite easy. In addition, the process of filling the sinuses should be provided. This process is very important, since it is carried out with minimal soil pressure. The backfill is carried out gradually, while the material is thoroughly compacted. The optimal thickness of each layer during the backfill process is 20 cm. The soil compaction is carried out only by manually.

The manufacture of the blind area is carried out from the onset of soil compaction. Do not forget to waterproof the pit, before starting to install the formwork. For these purposes, roofing material or material in the form of flat sheets from asbestos cement is suitable.

The device of the pit for the foundation: Recommendations

To equip the pit should be equipped in the ratio with normative legal documents, such as SNiP. It clearly indicates the permissible norms of the size of the pit for each type of soil. In addition, all work should be carried out with special security and technologically correct methodology. If you do not adhere to the rules for the construction of a pit, then the building will eventually turn out to be unreliable and low -quality.

It is preferable to entrust the pit of the pit to experienced specialists. Since without experience in this industry, you can make irreparable errors that will lead to vain time and forces. Please note that the degree of load on the horizontal walls of buildings located near the site directly depends on the depth of the pit.

At the depth of the pit of more than three meters, a special fence made of stainless steel, the diameter of which is about 30 centimeters, should be installed. When digging a pit of five six meters, it will be necessary to build a special underground wall with a thickness of about 60 cm. If the depth of the pit is more than seven meters, the wall thickness will be more than one meter.

In order for the pit to be performed reliably and efficiently, you should also correctly determine the type of soil located on the site. Before the start of excavation, the soil is given for examination. In this case, it will be much easier to determine the depth and dimensions of the pit.

If there is a soil with a high level of softness on the site, then for compaction of the pit should be equipped with a cerebr him or pebbles pillow in it. In this case, the walls of the pit will acquire additional resistance.

When working with too moist soils, you should take care of arranging a special moisture removal system from the site. For this, the presence of drainage in the form of a gravel is required.

In addition, pay attention to the reliability of the sloping parts and corners of the pit. Speech is set from the initial part of the foundation of the pit, pay special attention to the fixation of the struts. In order to avoid the appearance of slipping, use brackets or a guard beard to fix the struts.

Keep in mind that at the depths of the pit at more than 4-5 meters, you should not only install the brackets, but also carry out additional protection of the walls from the crowning. To strengthen this design, a strapping beam should be used, which is fixed on the walls using bolts and linings, in this case, it will be possible to provide reliable protection of the walls from the shrinkage of the soil.

Using uck puffs, it is possible to strengthen the foundation pit arranged in the process of erecting the foundation under the house with the basement. At the same time, the anchor is installed at the place of double height of the sloping installation. The steep slope is determined by the depth of the pit and the type of soil. For example, in the process of building a house on a bulk type soil, at a depth of the pit is about 150 cm, the lower slope section is set 1 m from the walls of the pit. Therefore, the degree of its steepness depends on the type of soil and depth of the pit. The optimal value of this indicator is from 25 to 60 degrees. The amount of excavation, which is carried out on the site, depends on the increase in the angle of the instrumentation of the slope. The higher the angle of slope of the slope, the more money you will need to dig a pit.

It is preferable to perform work associated with the digging of the pit in the summer or autumn. In this case, the level of soil moisture will be minimal. The cost of the pit for the foundation dug in the winter is several times more than the work carried out in the summer. In the spring or late autumn, the level of groundwater is at the maximum level, therefore, these periods are also not suitable for work on digging a pit.

Pit for the foundation price and features of arrangement

When arranging a strip type or column foundation, an option of an independent digging of a pit is possible. Otherwise, it will require specialized equipment.

Particular attention should be paid to safety in the process of making the foundation. All walls of the pit must be fixed. Digging the pit is based on the removal of the upper soil layer, while another meter should be added to the perimeter of the house on which the blind area will be located.

The entire soil, which is located on the site after digging the foundation pit is subject to disposal. For this, special equipment is used. However, keep in mind that some of the soil will be required to perform backfill.

After digging the pit for tape or slab foundations, the process of its waterproofing, the installation of formwork follows. Next, reinforcement is installed, which is poured with concrete solution.

Remember that each of their stages of erecting the foundation should be carried out in compliance with certain technological requirements, only in this case, it will be possible to get a reliable base for the house.

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