What formulas are used to calculate a pile foundation and online services for calculations

Pile foundations are essential for creating a sturdy and stable building foundation, particularly in regions with difficult soil conditions. By uniformly distributing a structure’s weight to the soil below, these foundations guard against settlement and maintain structural integrity over time. Comprehending the computation of pile foundations entails comprehending multiple essential equations that engineers employ to ascertain the quantity, kind, and arrangement of piles required for a particular undertaking.

The soil bearing capacity, the site’s geology, and the weight of the structure are all often taken into account by the formulas used to calculate pile foundations. One basic formula is based on the idea that the dimensions, type of pile (e.g., concrete, steel, or timber), and soil’s capacity to support the load without excessive settlement all affect a single pile’s load-bearing capacity. In order to make sure the foundation can handle unanticipated stresses, engineers also account for safety margins.

Accurate pile foundation calculations are essential for people working on building and remodeling projects. Thankfully, software tools and internet services exist expressly for this purpose. These instruments streamline the intricate computations required to ascertain pile dimensions, lengths, and spacing according to project requirements. To give engineers and architects exact recommendations, they consider soil data, structural loads, and local building codes.

Online tools for calculating pile foundations are practical and effective, helping designers to minimize mistakes and streamline their workflows. These tools allow engineers to quickly produce reports and recommendations that direct the construction process based on site-specific data. This ensures the safety and longevity of the buildings they support while also saving time and improving the foundation design’s overall accuracy and dependability.

Parameters for calculating the base

An examination of the site’s geology and climate is required prior to beginning foundation calculations.

You will require the following details in order to proceed:

• type of soil, as well as its chemical composition, physical and mechanical properties, humidity;
• the depth of freezing of land masses and the level of underground sources under the reference area;
• risks of flooding, landslides, etc.P.;
• map of the site showing landscape features, as well as utility lines.
• average precipitation in the region.

The acquired data will form the foundation for the pile foundation calculations, which are elaborated in the Rules from SNiP 52-01-2003 (2018 edition), Nos. 3.03.01-87 and 2.02.03-85.

Parameters like these are determined through calculations.

• foundation laying depth;
• number of piles and optimal spacing between them;
• the weight of the structure that presses on the foundation;
• permissible load on power elements;
• soil resistance.

To calculate the total loads from the design structure, it is necessary to have its plan in order to know:

1. floor area;
2. height of floors, wall thickness;
3. building materials used.

From the aforementioned SNiP, all acceptable and corrective factors are extracted.

What the pitch depends on?

Based on the number of piles, their diameter, the pile field scheme, and the design features, the distance between the closest support elements is determined separately. The design loads and the soil’s bearing capacity are taken into consideration when choosing the number of supports and their specifications.

Favored schemes for pile fields:

• single piles – placed at the corners of the structure and in places where the soil is subject to maximum loads;
• strip placement – piles are arranged along the perimeter at a minimum distance;
• makeshift arrangement – groups of several supporting elements are placed in the most loaded places, and the step does not matter;
• continuous pile field – support pillars in 1 m increments are located along the entire perimeter of the structure.

Pitch selection is very important to designers because an excessive gap between load-bearing components can cause the structure to collapse. An unsuitably short step results in high labor and material expenses.

Optimal distance

The range that works best is between 1.5 and 3 m. The lowest step that can be taken, which is equivalent to three support diameters, is determined by regulatory requirements. A maximum step of six pile diameters is taken.

The following circumstances could be exceptions:

1. The pitch is 1.5 diameters if the supports are installed in groups and at an angle.
2. Construction is carried out on a site with a large slope, then the distance is selected according to the minimum allowable.
3. According to the project, the foundation will rest on stable and high-density rocks, then the step can be increased to 4Ø.

How to determine the amount of material for a private house?

Divide the total design loads by the load-carrying capacity of one pile to find the number of supports required for a load-bearing structure. SNiP No. 2.02.03-85 lays out the tabular coefficients and calculation principles.

Calculation of the bearing capacity of an individual support

The following formula can be used to determine the load-bearing element’s capacity:

• Y_c – indicator of working conditions;
• Y_cr – coefficient that takes into account soil resistance to loads;
• R – calculated soil resistance under the sole area;
• D – diameter of the load-bearing element;
• P – cross-sectional perimeter of one pile;
• Y_cri – indicator reflecting the soil pressure on the pile wall;
• F_i – soil resistance relative to the surface of the load-bearing element;
• L – pile length.

The following condition can be used to confirm a structural element’s load-bearing capacity in relation to the design parameters:

1. N – design load on a single support;
2. γ_n – reliability coefficient based on the responsibility class of the structure (determined by GOST 27751);

The soil reliability coefficient, denoted as γ_cd, is equivalent to:

• 1.2 – if the load-bearing capacity of the pile is determined by field testing when transferring statistical loads;
• 1.25 – if the F index is found based on the results of dynamic tests taking into account elastic deformations of the soil;
• 1.4 – if the load capacity is determined by calculation using a set of rules from SNiP, as well as tabular coefficients;
• 1.5 – if the permissible load on the support is determined using computer programs.

Calculation of design load

Depending on the kind of foundation, use the following formula to determine the maximum load on a support for independent calculations:

Type of power structure	Formula	Unknown quantities
Bored pillars	F=R×D+∫ Y_cf ×F_i×H_i	R – design soil resistance;

D stands for pile diameter.

The coefficient of soil action conditions on the support’s lateral surfaces is represented by Y_cf.

The thickness of the soil in contact with the pile’s surface is represented by H_i;

For different soils, c_1 is the coefficient of linearity or specific adhesion;

Y_1, the soil’s specific gravity above the screw portion;

H_1 is the pile’s subsurface portion’s size;

The rod’s overall length, or h;

Calculation of the load from the building structure

Finding the total mass of the house and multiplying the value by the safety factor (1.1–1.25) will yield the load that the structure is supposed to transfer to the ground through the foundation, as per the plan.

In order to determine a building’s weight, you must know:

• the area of ​​all walls and ceilings;
• type of roof and its dimensions;
• specific gravity of the building material used;
• payload that can be exerted by people and interior items (for residential buildings is taken equal to 150 kg/m2);
• mass of snow cover (regional average).

The values are added up once the weight indicators for the furniture, people, walls, ceilings, and roof have been located and the load of the snow cover has been calculated. You will be able to ascertain the number of supports and confirm that the parameters you have chosen are accurate based on the computations’ outcome.

Calculation of the required amount of material

Dividing the structure’s weight by the load capacity of a single pile yields the number of power elements.

Maximum loads that can be used to pre-select the number of elements are indicated by support manufacturers in the technical documentation.

One of the designer’s responsibilities is to use the bearing capacity of the supports formulas, which are provided in the material above, to compare the pile’s characteristics with the specified parameters. There is no other way to be certain that the computations are accurate.

By counting the number of support elements, you can confirm that the selected scheme is correct; to do this, you’ll need:

1. Divide the total weight of the structure (house and foundation) by the supporting area.
2. The second indicator is found based on the cross-sectional shape and number of piles. For example, for products with a round cross-section, the classic formula is used .

Calculate the calculated soil resistance (R0) from SNiP 2.02.01-83 and compare the resultant value with the known pressure the structure applies to a square centimeter of soil. They believe that the number of piles was appropriately calculated if the structure’s weight does not exceed value R0. If not, choose products with a greater cross-sectional area or add more supports.

Depth of installation of supports and pitch between them

The freezing point (d_f), which can be found in reference books, is below the soil where the pile foundation is located. However, it is more convenient to compute this value yourself using the following formula:

1. T – average monthly subzero temperature for the entire winter in the region;
2. d_0 – coefficient that is selected according to the type of soil:
3. 0.23 – clay soils;
4. 0.28 – silty sands;
5. 0.30 – middle fraction sands;
6. 0.34 – gravel and coarse rocks.

The final step in the engineering calculations is to determine the support element spacing.

The supports are positioned as per the plan, keeping a 1.5–2.5 m optimal gap and giving particular attention to the locations where the structure puts the most pressure on the soil, which are as follows:

• at the corners of the structure;
• at the entrance group;
• under load-bearing walls;
• under existing stoves and fireplaces;
• under heavy equipment, etc.d.

In the realm of construction and renovation, understanding the formulas behind calculating pile foundations is crucial. Pile foundations provide essential support for buildings on soil that may not bear heavy loads well. Engineers use specific formulas to determine factors like load-bearing capacity and depth of piles needed, ensuring the stability and durability of structures. Additionally, online services now offer convenient tools for these calculations, making the process faster and more accessible. These services allow engineers and builders to input site-specific data and receive precise calculations promptly, streamlining the design and construction phases significantly. This article explores these formulas in practical terms and highlights how online tools are revolutionizing pile foundation calculations in today"s construction industry.

Obtaining data using online calculators

Power structure calculations are labor-intensive, but they can be made easier by using online calculators and specialized services.

The following portals are the most widely used of all the ones that currently exist:

1. moi-domostroi.ru – a simple house weight calculator. To calculate, you will need to know the shape of the house, the dimensions of all structural elements, types of building materials, type of roof, and specify the region.
2. gvozdem.ru – service for determining the number of support elements. Allows you to find out the need for concrete and reinforcement, knowing the parameters of the pile.
3. screw-piles.ru – a service for determining the need for piles, based on the design features and soil type.

Since all programs that are publicly available use approximations of coefficients and average conditions, the outcomes of these computations are only suitable for initial planning.

Useful video

Expert video recommendations for computations:

For any building project to be stable and long-lasting, it is essential to comprehend the formulas used to calculate a pile foundation. When the soil close to the surface isn’t strong enough to support the weight of the structure, pile foundations are used. To calculate the required number, length, and diameter of piles, engineers utilize a number of important formulas. The soil’s ability to support a given weight, the structure’s weight, and the depth at which stable soil layers start are all taken into consideration by these formulas.

A basic formula relies on the idea that a pile’s ability to support a load is determined by both the soil’s bearing capacity and its cross-sectional area. By dividing the total load that the foundation must support by each pile’s load-bearing capacity, engineers can determine the necessary number of piles. This computation guarantees that no pile will eventually sink or shift in order to efficiently support its portion of the building’s weight.

In addition, geotechnical studies and soil tests are used to calculate pile length formulas. These tests evaluate the characteristics of the soil at varying depths to identify the start of stable, load-bearing layers. In order to guarantee the stability of the foundation against settlement or subsidence, piles are subsequently engineered to extend deeply enough to reach these stable layers.

Thanks to modern technological developments, these computations are now easier to access through online services. These platforms provide tools that, depending on input parameters like building dimensions, anticipated loads, and soil type, automate complicated calculations. They considerably expedite the design and planning stages of building projects by giving engineers and architects prompt, accurate results.

Construction experts can efficiently and economically design pile foundations that satisfy structural requirements by utilizing these formulas and online tools. By combining theoretical formulas with real-world applications, it is ensured that infrastructure and buildings are constructed on strong foundations that can withstand environmental challenges and the test of time.