Leader drilling allows you to install piles in an upright position in areas with dense soil. This method is most relevant in the winter, because it facilitates the process of hammering the tongue when laying the foundation.
The popularity of such technology is increasing annually. Leader drilling allows not only to reduce soil resistance, but also to immerse the structure to great depths. In addition, when performing work, the level of noise and vibration is reduced. This is one of the advantages of the method.
Features
At the design stage, specialists determine the method of laying the foundation, and also specify the requirements for technology and performers.
Leader wells are drilled only after preparatory work. First of all, the sizes of piles are determined. The diameter of the leader wells should be 3-5 centimeters smaller than the diameter of the reinforced concrete structure.
All work must be carried out in accordance with SNiP. Leading drilling of wells is carried out before driving reinforced concrete structures into the ground. This technology is used very often due to the reduction of vibration and noise. After all, piles are driven into the ground quickly and without much difficulty.
The diameter of the screw, which is used when drilling wells, depends on what soil is in the base. The depth should be about 1 meter less than the immersion depth of the pile. It is worth noting that the clogging of reinforced concrete structures, as well as preliminary drilling, are carefully planned by many experts. This allows you to fully comply with the technology and optimally place piles in each case.
What situations require such drilling?
Leading well drilling under piles is often used when laying foundations based on piles. Moreover, the design can be of any volume and varying complexity. Most often, this method is used in the following cases:
- If during the geological survey revealed a layer of compacted sand. With shock laying such a ground is almost impossible to pass. As a result of this, leader drilling under piles is carried out.
- If the topsoil is dense. With the shock method of laying piles, destruction of the reinforced concrete structure or its deformation can occur. Preliminary drilling allows to pass through the problematic soil layer without complications.
- If work is carried out on the forever frozen ground. Such soil is quite dense. Leader drilling is recommended to avoid problems.
- If the site is dominated by rocky soil. Rock formations are an insurmountable barrier for a driven technique.
- If the piles will be placed at a considerable depth. In this case, pile failure may occur. As a result of this, it is not possible to reach the desired level without drilling wells.
- If in the area where the foundation is laid, dispersed soil prevails with a minimum density. In this case, the guiding function of the drilling is especially appreciated.
Application
This method of laying piles is often used when arranging the foundation on a site close to buildings. This method allows you to reduce the noise level during the work, as well as reduce the vibration during clogging of reinforced concrete structures. Leader drilling can be carried out in densely populated areas located within the city.
This technology allows you to significantly speed up the process of laying a pile foundation. Such drilling does not violate the integrity of reinforced concrete structures. Moreover, the technology allows you to achieve the desired depth, while ensuring the rapid passage of dangerous and problem areas at the construction site.
How does drilling under piles
Leader drilling of wells is carried out with the help of pile machines equipped with drilling rotators. They replace pile hammers. The key to this is vertical. Only in this case can the work be done qualitatively. This is provided by drill rotators.
During the work, soil removal is required. Manual manipulation is performed. If this is not done, then excess soil will not allow the installation of piles. Due to the cleaned soil, the mark increases by about 50 centimeters.
Work stages
The leader drilling process and laying the piles can be divided into several stages:
- On the site are marked with points the places where the piles will be clogged.
- Special equipment is installed. Units are mounted in marked locations.
- The technique is prepared, verticality indicators are checked.
- Wells are being drilled using special pits.
- The reinforced concrete structures are driven into the ground.
- An examination of each installed pile is carried out. They are being delivered to a representative of technical supervision.
When performing leader drilling, several types of screws can be used: continuous and composite construction. In the first case, the creation of a well is a non-stop process. This saves time, and also provides high quality work performed.
Technology benefits
The popularity of leader drilling can be explained by its advantages. Among the advantages of this technology are:
- Possibility to install piles on a site with various types of soil, as well as with any technical characteristics.
- The technology can significantly increase the depth of laying reinforced concrete structures.
- Compliance with all rules for installing piles. The verticality indicator is taken into account.
- High quality of work.
- Vibration reduction for neighboring buildings when driving piles.
Technology disadvantages
The disadvantages of leader drilling include:
- Tangible material costs arising from overcoming some bureaucratic obstacles.
- Attraction of specialists, as well as the use of equipment.
Despite the large number of advantages, the technology has another minor drawback. This is the price of the work. The cost of leader drilling depends on several indicators. First of all, this is the depth of the bookmark, as well as the type of soil on the site. On average, this figure is 300-1500 rubles per 1 meter.
In conclusion
Leader drilling technology is constantly being improved. After all, such a method is applied in those places where it is impossible to do without additional soil treatment. This technology is relevant when driving reinforced concrete structures in problem areas. Special equipment greatly facilitates the process of laying the foundation of the future foundation. The main thing is to follow all the recommendations of specialists and follow the rules when performing work.