The first step in laying a strong foundation for any building is figuring out how many piles a pile-screw foundation requires. This kind of foundation is widely used in construction because of its reputation for stability and adaptability to different soil conditions. Precise calculations are the first step towards ensuring a sturdy foundation, whether you’re building a small structure, a new home, or even a deck.
Important elements including the necessary load-bearing capacity, the makeup of the soil, and the distribution of structural weight are evaluated during the process. The ideal number of piles is determined in part by each of these factors. Usually, the computation starts with determining the overall load that the foundation needs to bear, taking into account both the static and dynamic loads that the structure will place on the earth.
To determine the soil’s bearing capacity, testing is then necessary. This stage guarantees that the soil will be able to sustain the planned structure over time without experiencing too much settlement or instability. Plotting and quantity of piles should be done differently for different types of soil, from sandy to clayey, which highlights the importance of precise soil analysis.
Engineers use the proper formulas and methods to determine the pile spacing and depth after evaluating the load and soil properties. By distributing the structural load evenly across the foundation, this calculation seeks to reduce the possibility of uneven settling or structural damage. The ultimate objective is to create a foundation that can dependablely support the structure for its whole life.
Calculation methods
The primary components of this kind of foundation are metal screw piles, the diameter and length of which can vary based on the anticipated load on the piles as well as the technological requirements. You can order a professional, complex calculation of the pile-screw foundation from specialized companies and design bureaus. This calculation will include many design features and parameters, and it will also account for the soil’s bearing capacity on the site where the future house will be built. Based on our hands-on experience building these kinds of structures, we suggest taking the easier route and computing screw piles.
Determining the diameter of the supports
Screw piles come in diameters of 57, 76, 89, and 108 mm and are used in the installation of foundations for both residential and commercial buildings. The weight of the completed structure is taken into consideration when choosing this parameter:
- 57 mm – used for the construction of the simplest and lightest structures (fences and fences made of chain-link mesh);
- 76 mm – chosen as a base for lightweight outbuildings or fences made of wood or corrugated board. The bearing capacity of such elements does not exceed 3000 kg;
- 89 mm – used where the load-bearing load will not exceed 5000 kg. This is an excellent solution for the construction of a one-story building (frame or panel), baths, summer kitchens, sheds and massive fences;
- 108 mm – foundation a site for the construction of a house made of foam blocks, wooden beams, frame (1-2 floors) with light weight. The bearing capacity of screw piles of this diameter reaches 7000 kg.
Factors affecting the length of supports
The accuracy with which the piles are measured will determine how strong the final structure will be; if these crucial foundational components are determined to be too short, the house may collapse under its own weight once it is occupied. The following factors are taken into consideration when determining the length of the piles:
- Soil density.
- Height difference between different points on the site.
Soil density
The best way to analyze soil is to base your work on local geological studies. If there are no studies on the properties of the soil in a particular area, you can calculate the density of the soil using a more straightforward method.
Therefore, at the site’s lowest point, you must dig a shallow ditch up to one meter in depth. It is preferable to choose piles with a maximum length of 2.5 meters if you notice a clay mass or sand at this depth. You will need to keep going deeper until you reach hard rocks if you come across low-density rocks (peat), quicksand, or groundwater. In this instance, piles are installed with a length that matches the drill’s length.
This table lists the different soils’ densities and carrying capacities.
| Type of soil | Dense soil | The soil of medium density |
|---|---|---|
| Sand (large fraction) | 6 | 5 |
| Sand (middle fraction) | 5 | 4 |
| Suite (in dry form) | 3 | 2.5 |
| Plastic sandy loaf (wet) | 2.5 | 2 |
| Sand (small fraction) | 4 | 3 |
| Wet sand (small fraction) | 3 | 2 |
| Clay | 6 | 2.5 |
| Clay is wet | 4 | 1 |
| Loam | 3 | 2 |
| The loam is wet | 3 | 1 |
Road between the heights of the site
As was previously mentioned, knowing the difference in elevation between various points on the site is essential to accurately calculating the length of piles and avoiding mistakes. If you are certain that there is a difference and that 2.5 m long piles are appropriate based on the soil’s density, they have to be installed in the upper row.
The length of the supports that will be installed in lowlands should be greater than the height difference between those points. Using a water level or level with a plumb line and roulette, the difference is computed. It is advised to increase the length of the foundation piles by 50 cm if there is a noticeable height difference (greater than 0.5 m), as the foundation piles’ height may not even reach 20 cm in the lowest locations.
(function(s, t, w, d, n)) We have w[n] = w[n] || []; w[n]. push(function()) Rendering Ya.Context.AdvManager (blockId:"R-A-510923-1",renderTo:"yandex_rtb_R-A-510923-1",async:true>);>);t=d.getElementsByTagName("script")[0];s=d.createElement("script");s.src="//an.yandex.ru/system/context.js";s.async=true;t.parentNode.insertBefore(s,t);>).
Calculation method
The dimensions and weight of the house that will be placed on the foundation are taken into consideration when calculating the number of screw piles. Generally speaking, the separation between piles can be:
- up to 2 m if a structure is built from aerated concrete and foam concrete blocks or slabs;
- up to 3 m, if it is planned to build a wooden house from timber, logs, etc.d.;
- up to 2.5 m – also chosen for wooden structures. They also work with such piles in regions where there is a large wind load;
- up to 3.5 m – for the construction of lightweight fences and fences.
In order to accurately calculate the number of supports needed for a pile-screw foundation, the following steps need to be completed:
- draw up a project for the future foundation or first level of construction;
- place screw supports at each corner of the future building;
- install piles where the load-bearing partitions of the house will intersect;
- between the located piles it is now necessary to install additional piles along the perimeter of the load-bearing walls with the condition that the distance from one to another element does not exceed what was previously recorded (taking into account the weight and type of building);
- the remaining space for the foundation is filled with piles so that the distance between adjacent supports does not exceed that specified in the calculations (2 – 3 m);
- where a stove or fireplace will be installed, provide at least a pair of screw supports, again, taking into account the size of the heating structure, otherwise a critical load on the foundation cannot be avoided;
- in case a terrace or any other extension is built, the locations for fixing the supporting elements are designated according to the previously agreed upon principle, taking into account the optimal step distance;
- Now that the distance between the piles has been determined, all that remains is to count all the screw supports marked on the plan diagram.
| To calculate the number of piles needed for a pile-screw foundation: | 1. Determine the total load that the foundation will bear. |
| 2. Check the soil conditions where each pile will be placed. | 3. Calculate the allowable load per pile based on soil type. |
| 4. Divide the total load by the allowable load per pile. | 5. Round up to the nearest whole number to determine the minimum number of piles required. |
A pile-screw foundation’s pile count is determined by following a few crucial steps that guarantee the project’s stability and longevity. Examine the soil conditions in the area where the foundation will be built first. In this first step, the kind and quantity of piles needed to properly support the load are determined.
The structure’s weight and dimensions that the foundation will support should then be taken into account. These variables affect the piles’ depth and spacing, making sure they can support the expected load without settling or moving over time.
During this process, it is essential to consult with a structural engineer or foundation specialist. In order to optimize pile placement and number in order to meet safety and performance standards, they can offer comprehensive calculations based on soil tests and structural plans.
Finally, take into account environmental factors like water table levels and frost depth. These factors influence the pile-screw foundation’s design, guaranteeing its stability and functionality in the face of climatic fluctuations and environmental strains.
This tutorial will take you step-by-step through the process of figuring out how many piles are required for a pile-screw foundation, which is an essential part of creating stability for a variety of constructions. We hope to deconstruct the calculation methods into manageable steps so that both construction professionals and do-it-yourselfers can understand and utilize them. Comprehending these computations guarantees that your foundation is robust and dependable, customized to your project’s particular needs without needless complications.
