The world's population is growing exponentially every year. The housing issue is becoming more and more urgent for hundreds of families who want to have a house or apartment of the required size and, most importantly, in a "decent" place.
For million-plus cities, this is the most burning issue. After all, there are fewer and fewer areas suitable for building, and more and more apartments are required. Many developers have begun to use all available sites, regardless of geological features.
Thus, the city authorities readily give swampy lands, groundwater sites, etc. for new construction. In order for houses to be built not only quickly, but also with high quality, developers often use piles for such cases.
What are piles?
Piles are supports made of various materials: metal, concrete, reinforced concrete structure, frame, soil or sheet pile. They are used so that the structure has a more stable, less prone to groundwater and corrosion foundation.
Depending on the structural features of the soil on which the foundation is being poured, the developer can use different methods of installing such supports. The main criterion is the weight of the entire structurebuildings, as well as the density of the land on which it will be built.
To do this, they can use a pile driver, a diesel hammer, a vibratory pile driver, a hydraulic hammer and a pile driving machine. In special cases, when rocky layers are possible, a drill is used.
Pile heads
Even the most experienced master cannot install piles in such a way that their upper part, which will hold the entire foundation, is on the same level. These bearing parts are called pile heads.
The shape of the head depends on the pile that is used for installation. It can be round, square, rectangular. In addition, for the convenience of mounting the base, various fastening methods can be used.
To fill the base for the foundation at the desired level, the master needs to install a frame (grillage) on the columns, which is fixed with the help of caps.
Types and features
The pile heads differ not only in shape, which corresponds to the shape of the installed pile, but also in size. At the same time, do not forget that when using a screw or concrete pile, the tip will also be different.
An important nuance in the choice of heads is its shape: it can be T-shaped or U-shaped. When mounting the grillage on the T-shaped head, you can install both the formwork and the slab for pouring the foundation.
Only beams can be used with U-shaped heads, and their diameter must match the width of the tip.
Sizes
The most popular on the market for a long time are screw and reinforced concrete piles. Their cost, reliability and long service life make them the most sought after.
When choosing a material, the developer is guided not only by the characteristics of the soil, but also by the magnitude of the load in the form of the room to be installed. Taking into account all the nuances, they also choose the design for mounting the grillage.
The average size of the head of a screw pile in diameter, in its pipe part, ranges from 108 mm to 325 mm. And the diameter of the head itself can vary from 150 mm to 200 mm.
The smallest in diameter is a tube of 57 mm. Such a base can withstand a load of eight hundred kilograms. Most often they are used for the construction of light outbuildings (garage, gazebo, barn).
Wider pile with 89mm head diameter. Pillars with this diameter are used on peat or wetlands for the construction of cottages, baths, garages, fences.
Piles with a head size of 108 mm are the most "hardy". They easily support three and a half tons, are mechanically mounted and are suitable for almost all types of soil.
The concrete head of the piles has a square shape with a side length starting from twenty centimeters. The greater the load, the longer the reinforced concrete pile.
Screw or reinforced concrete?
The question of choosing the material for piles remains open primarily because of the size of the building. Forindustrial-scale orders (high-rise buildings, commercial and administrative buildings, bridges) use reinforced concrete poles.
They are durable, resistant to corrosion, perfectly tolerate temperature changes. The disadvantage of this type of piles is the high cost of installation. It is produced using special equipment.
Screw piles are less expensive to install. They can be installed using only human resources. Therefore, screw piles are most often used during the construction of country houses, small cottages.
Chop or cut?
In order for the structure to have an even foundation, after installation, the piles are cut at the desired level. Pile head cutting is done using:
• jackhammer (small amount of work);
• hydraulic logging (construction of residential complexes or shopping malls).
To perform all the necessary manipulations, the master marks the desired height at which the pile will be cut. And then, if it is a concrete structure, with the help of improvised means, they make a furrow and chip off excess concrete.
Leave only the metal frame, which is cut with hydraulic shears and a jackhammer. If necessary, craftsmen can "tie" the remaining rods and foundation formwork.
This method of removing "excess" is quite laborious and can take a lot of time. Masters process no more than fifteen heads per shift.
More budget anda quick way is to cut the ends. This method is convenient and economical. Suitable for working with various types of piles. A big plus is the high-speed processing of the ends, which significantly reduces the time for arranging the grillage.
For trimming, improvised cutting tools are used - a grinder, with an installed tape or disk circle; abrasive saw.
Before starting work, mark the cut line with a marker or chalk, for an even cut, make a furrow around the circumference. If the tool or pile starts to heat up, they are cooled down and only then continue to work.
The disadvantage of this method of processing is the complete unsuitability after cutting the reinforcement, as well as the quick wear of the working tool. Which may entail additional costs for the purchase of consumables.
How to properly prepare for assembly?
If metal piles were chosen for the foundation equipment, it is necessary to carry out preliminary work so that the pile heads last longer.
After cutting at the level of two or three centimeters from the saw cut, you need to remove the coating layer that protects the material from environmental factors. For this, a metal brush or a special attachment for a grinder is perfect.
Installation
Installation of pile heads also has its own characteristics. The main criterion for installation is the type of pile and the material from which it is made. If a screw pile was used during construction, its heads will necessarily be metal and fastened by welding.
This can be a T-shaped head in the formplates with a round base, which is put on a pile and fastened with a weld. In addition, if a channel or an I-beam is used to mount the grillage, they are welded to the end of the pile in a special way.
The I-beam is fixed for welding in the form of a square plate, and the channel is turned over with the "wings" down, welding to the base. If, according to the architect's idea, the building is being built from a wooden beam, the first "line" of logs is connected to the head with a metal rod.
For welding use electrodes with a size of 3 millimeters, the current value is not more than 100 amperes.
If a concrete pile head is used to install the grillage base, its installation begins after the pile head has been cut to the desired level. Heads of this type are mounted in concrete mortar during the pouring of the foundation into the formwork installed on piles.
And now for the good stuff
The use of piles in construction is not new. But there is a possibility that not all customers have encountered their use in life. Many are confused by the lengthy process of their installation, as well as the rather laborious method of installing the grillage.
It is worth noting that the use of this type of foundation saves the owners of the home from many negative factors. This is:
- Spring-autumn floods.
- Soil instability (peatlands, swamps, quicksand, quicksands).
- Ease of installation, regardless of weather conditions (frost, heat, etc.)e.).
- Building buildings on uneven surfaces;
- Distribution of the weight load along the contour of the foundation.
There are many projects in the world, in the construction of which the foundations installed on screw and concrete piles were used. Most of them are eco-projects, the function of which is to preserve the pristine beauty of the places chosen for construction. The protected corners of Norway and Finland were enriched with unusual buildings "on chicken legs". They have not only become cozy dwellings for their owners, but also an attraction for curious tourists.
Beautiful, comfortable, and most importantly, safe homes amaze with their simplicity and original design. What type of piles and heads will become the basis of your home is up to you. The main thing is that this foundation should serve more than one generation of your family.
