Preliminary calculation of loads on the foundation of a building should be comprehensive. Many mistakenly focus on the static load from the frame, adjusting the base structure for it. But this is only part of the total pressure force that acts on the foundation. Dynamic loads and, in general, ground movements can lead to more unfortunate consequences than minor miscalculations in the supporting racks of the frame. If these nuances were not taken into account during construction, then as part of the planned maintenance of the house, it will be necessary to strengthen the foundation in one of the ways suggested below.
How to strengthen the strip foundation?
In private housing construction, a tape bearing base is one of the most popular ways to build a foundation. But its design has many vulnerabilities. The basic reinforcement method in this case involves the implementation of shotcrete. A trench is dug along the line of laying the concrete tape, providing access to the surface of the structure. Further, rows of notches are made on the entire lower region, along which concrete is subsequently sprayed. For this operationyou must use a heat gun.
Another way to increase the stability of the foundation with the help of an adhesive mortar is grouting. Unlike the previous method, this technology does not require earthworks with digging a pit. To strengthen the strip foundation by grouting, a special injector unit is used, through which the concrete solution is supplied to the problem surfaces through the ground. But first, it is necessary to create pits with a depth of 50-100 cm. This technology allows you to fill cracks and voids in the foundation, increasing the density of the bond with the adjacent soil.
Options for reinforcing pile foundations
Also a popular type of supporting structure of the house, which, due to technical features, gives more room for the implementation of various strengthening options. In particular, experts recommend the following technologies:
- Apply girth. For the bearing racks, a reinforced concrete clip of a suitable size is selected, which captures the rod. For a medium-sized house, it is desirable to use a structure with a thickness of at least 10 cm, while allowing you to dive into the ground by 100 cm.
- Concrete shirt technology. In some ways, this approach is similar to the methods described above for band construction. A point reinforcement of the foundation is being implemented for each pile by pouring mortar into the created wells and trenches.
- Strengthening with additional columns. A more complex operation that requires detailed calculation. Near the existing problematic pile, another auxiliary support-rod is installed. The pole insertion technique can be driven or bored.
- Strengthening grillage. Injection of concrete mass by gunning. This is not about the part of the foundation immersed in the ground, but about the upper tier, where the transition to the lower floor of the house begins.
Both in the case of tape and column construction, combined approaches to increasing the strength of the supporting base are possible and even recommended.
Features of strengthening tiled foundations
The monolithic reinforced concrete structure is the most reliable and durable, but also the most problematic in terms of its strengthening. The difficulties lie in insufficient access to the central zone of the structure, which connects the soil and the grillage. The craftsman can only deal with the edges of the structure, preventing the frame from spreading and slowly peeling off the structure.
The main methods of strengthening foundations on a monolithic reinforced concrete slab come down to creating a prefabricated clip covering the entire perimeter of the structure. In other words, a reinforcing belt is formed around the house at the level of laying the foundation. It should enter the ground to the same depth as the slab. As for the strengthening materials, it is best to use wood. It is more flexible in installation, holds dynamic loads and is easily updated in case of serious damage. Fastening is carried out with anchor joints and strong steel brackets at the corners.
Now you can go touniversal reinforcement technologies, which in different variations can be applied to certain types of foundations.
Increasing the base area
This method is based on the principle of increasing the density of mutual load foundation-soil. Often problems with the destruction of the structure arise precisely because of the lack of reliable support from the outside. The task is to artificially increase the width of the foundation towards the ground. To do this, a new formwork is formed, which will temporarily open the space between the concrete and the adjacent earth. This task will be performed by construction jacks. In the process of retention, it is necessary to strengthen the foundation of the building with the help of concrete tides. Moreover, for greater reliability, they should be introduced with additional fixation with metal rods extending from the foundation niche. For reinforcing rods, holes are pre-drilled, followed by reinforcement with cement or other high-strength binder mixtures. At the final stage, after the tides have hardened, the jacks are removed, and the space is filled with dense soil.
Increasing the depth of laying the foundation
Technology is applicable only to lightweight platforms, which are usually used for the frames of wooden houses. The bottom line is to transfer the support sole to the underlying soil layer. The construction of a new platform will require the formation of a system of concrete blocks. The unloading of the former foundation structure is carried out using hydraulic jacks and end beams. Powerthe equipment raises the walls of the structure, after which approximately 2-meter pits are dug around the perimeter of the bookmark.
The bottom and walls of the formed ditches are reinforced with wooden blockings. Directly strengthening the foundation is realized at the expense of the support base, under which the well is being dug. Its depth should correspond to the height of the deepening of the base. Once the well concrete has cured, the hydraulic equipment can be placed under the walls in the new house placement configuration. The well is being compressed, the remaining gap is concreted and sprinkled with dense soil.
Introduction of support structures under the sole
Optimal solution for shallow foundations, which allows you to strengthen the supporting structure without building up the platform. The embedded element can be a reinforced concrete slab or a group of columns. The choice of one or another means will depend on the local conditions of the bookmark. Technically, reinforcement of bases and foundations with piping can be implemented without special equipment. In a simple stud configuration, a perimeter trench can be dug and screw piles can be installed by screwing in. They will rest on a reinforcing belt made of concrete platform, metal or even wood, pre-treated with protective impregnations.
Reinforcement with pillars
As you can see, pile elements are one of the most popular means of supporting the foundation. In this case, a universal technique for using columnar unloading is considered. To the advantages of this technologyincludes the complete exclusion of earthworks. Neither digging trenches nor creating wells will be required. In a bored way, a rod 10-15 cm thick is placed either close to the existing supports, or outside the perimeter of the base line. The traditional reinforcement of foundations with piles involves direct unloading of the carrier base. In this case, the possibility of transferring part of the pressure from the grillage to additional piles is also allowed. Again, it is desirable to use more than one column, but several - this is necessary so that the unloading of the mass is uniform and without distortion.
Foundation reconstruction
Sometimes, due to the obsolescence of the structure, foundation support aids no longer help. In this case, you can not do without a major revision of the structure. The work is carried out in two stages - dismantling with the cleaning of the old foundation and the installation of a new design. Accordingly, it will be necessary to use special equipment with a crane and hydraulic equipment, which will allow the structure to be lifted with minimal damage to the frame. Next, the current platform is liquidated. A new sole after reconstruction is created by pouring a monolithic screed. Moreover, strengthening the foundation of the house in such a scheme can be thought out and implemented even before the installation of the frame. The most effective way is dense reinforcement both inside the monolithic base with metal rods, and by laying the grid along the grillage.
Methods of strengthening the soil around the perimeter
Lowthe density of the soil surrounding the foundation often causes the destruction of the supporting structure. The following ways can help improve the stability of the adjacent land structure:
- Introduction of solutions. This is an extensive group of technologies that involve strengthening the soil with cements, silicate mixtures, bitumen and other building binders, which are introduced into the ground through the same pits and trenches.
- Improving the strength of backfills. If it is planned to strengthen the foundation indirectly around the perimeter and without the use of special building materials, then you can limit yourself to adding crushed stone with sand. With small indents from the building, wells are made with a depth of 1.5-2 m and filled with the above combination of bulk materials. The main thing is then to make a hard rammer.
- Installation of piles. Another way of deep reinforcement. Concrete or metal rods are introduced into the soil along the foundation line.
Foundation insulation
Exposure to moisture, frost and condensation adversely affects the concrete structure of any foundation. Integrated insulation will help protect the structure from such processes. If you plan to strengthen the foundation of a private building, then you can limit yourself to a standard set of thermal and hydroprotection tools. For insulation on the ceiling of the grillage, you can use expanded clay embankment, expanded polystyrene plates or mineral wool. On the sides outside, geotextiles, bituminous resin or traditional laying of a two-layer roofing material are usually used for waterproofing.
In conclusion
Strengthening the platform on which the house stands can be done in different ways. The simplest ones do not require the use of special machinery and equipment. For example, for a small building, you can use methods to strengthen the foundations due to piles or compacting fillings into the ground. They are cheap and do not require much physical effort. Difficulties may arise only with the reorganization of the tiled foundation or with the complete replacement of the carrier base. But in such cases, it is better to seek help from professionals.
