During the overhaul and reconstruction of the building and facilities, the most difficult and crucial moment is the work on strengthening or replacing structures. All these measures are carefully considered on the basis of the analysis made during the technical inspection of the building and its structural elements.
The reconstruction project should provide for all the smallest comments on defects or structural defects. Special attention to the solution of structures is paid in the case when the load on the old structural elements increases in connection with the organization of a new function in the building. The project should include measures to ensure the strength, stability and fire safety of the building, in general, its individual elements and structures. If calculations showed that reinforcement of structures does not give a positive effect, then it is necessary to provide for the replacement of old ones with more efficient types of new structures.
When reinforcing structures, measures should be provided to ensure the joint operation of the reinforcement elements and the structures to be retained.
All structural calculations must be carried out taking into account the loads and effects set forth in the SNiP . Construction of building elements made of various materials (metal, reinforced concrete, wood, waterproofing carpet and other materials) should be carried out in accordance with the requirements of the building regulations. Structures that meet all the requirements of SNiP and do not imply the perception of new loads can be used in the reconstructed buildings.
Grounds and foundations should be checked and calculated on the basis of the requirements of SNiP.
In the process of surveying buildings, deformations of structural elements are most often observed due to uneven subsidence or swelling of the soil at the base of the foundations. Therefore, before starting work on the reconstruction of any building, it is necessary to carry out activities to strengthen the soil.
Artificial bases are arranged by forcing concrete mixtures into voids, the solution is injected into the cracks, and in sedimentary soils, they are calcined, smolyzized, silicified, and strengthened by an electrochemical process.
This is followed by an operation to strengthen the foundations of the reconstructed building, if there are unacceptable deformations in them. Foundation strengthening is carried out in cases where the load on the building structure will be increased by the calculation.
The effective means of strengthening foundations is the joint-molding of the walls of strip foundations with ferro-concrete clips - shirts. Shirts between anchors of reinforcing steel, channel and I-beams. This creates conditions for the joint work of the old and the new foundations. Cement mortar is pre-pumped into the cracks and voids of the “weathered” foundations. When damage is found in the lower parts of the foundation, it is reinforced with longitudinal reinforced concrete beams. This increases the footing area of the foundation to the base. To improve the load transfer to the beams, lateral buttresses are installed.
In case of strongly deformed buildings with columnar foundations, they carry out continuous homonolation of the foundation, turning it into a strip foundation. This tape is mated to the pillars by fastening clamps or anchors. In the case of "weathered", the bodies of the foundations are taken in solid reinforced concrete clips.
If you need to greatly increase the load on the building structure (replacement of wooden floors to reinforced concrete), then they unload the existing foundations at the expense of outriggers. These trailing piles are made by pressing in ready-made piles (but not by driving in order not to damage the building) or by injecting the solution into the wells under pressure. The pile is joined by a grillage, which is firmly connected to the existing foundation.
Old houses very often have ceilings over basements in the form of logs on beams.
If the reports are destroyed, they are restored by the following methods:
- partial rerun of the vault in circles;
- clearing the seams of the masonry with separate hooks and stripping them with a mortar;
- Riveting of the arches with copper wedges;
- injection of masonry vaults with special solutions;
- restoration of a laying of the arch with replacement of the destroyed bricks in certain places.
Basement waterproofing. Waterproofing coatings are strictly local and traditional device for protecting basements of buildings from groundwater. They have been used for centuries. Traces of coating with natural resins are found on the foundations of buildings built 200 years or more ago. She our ancestors outside protected underground structures from destruction under the action of groundwater.
Repair of such waterproofing is ineffective. With a constant wetting of the surfaces, and especially the influx of water, new layers of insulation do not adhere well to old coatings. The adjacency of a horizontal carpet to a vertical one is difficult to solve, since the foundation divides them. Therefore, new insulation is usually performed from the basement side.
If a stable groundwater table is located below the basement floors, then the insulation, which is designed to protect against overhead, is made lightweight. Mastic of the so-called painting insulation is applied on the surface in two times .
Sometimes they use plastering cement mortars with hydrophobic additives.
For removal from surface water walls, blind spots with a slope from the building are increased.
Paint and plaster insulating coatings are unreliable, therefore, if the groundwater level is above the basement, multi-layer insulating carpets are used. They stick on the walls and the base of the floor. In order to avoid separation by hydrostatic pressure, they are pressed from above by a protective structure made of concrete . Its thickness is taken depending on the water level in the attached ground. When the level is higher than the level of the floor by 0.8 m and more, the pressure structure is reinforced and the grids are laid.
Recently developed methods that are an alternative to the above. The industry has mastered the production of highly effective mastic solutions based on polymers with high waterproofing properties. Their injection into the wall material is widespread in industrialized countries. The reliability of such waterproofing is ensured by swelling of the composition in the pores. Due to this, all voids in the body of the walls are replenished (Fig. 9.8).
Engineering equipment in basements. The engineering system needs constant development and improvement. The need for reconstruction of engineering equipment and facilities also arises during reconstruction and requires a new quality of engineering support. The main difficulty lies in the significant deterioration of networks and structures of engineering systems. The main causes of damage to pipelines are significant periods of their service, without preventive repairs, low rates of renewal of pipes, sharp fluctuations in network pressure, intense external and internal corrosion, and poor quality of pipeline construction.
The organizational and economic aspects of the reconstruction of engineering services in new socio-economic conditions are becoming particularly relevant.
Recently, individual boiler rooms for residential high-rise and public buildings have become widespread.
When equipping residential buildings with elevators should provide noise insulation adjacent to the elevators of residential premises. Moreover, if houses are equipped with elevators with a lifting capacity of up to 400 kg, dimensions for elevator shafts, machine rooms and platforms in front of elevators can be taken within one meter. For platforms less than 1.2 m, the elevator doors must be sliding. If it is impossible to use standard elevators, it is allowed to use non-standard industrial elevators produced by the industry.
During the reconstruction it is allowed to use hydraulic elevators that do not require the device of machine rooms. It is allowed to keep the existing dimensions of the vestibules and not to design the lobby-hall in front of the elevators. If it is not possible to set up a vestibule, it is allowed to install double doors with opening in different directions, equipped with sealing gaskets and door leaf closers.
It is recommended to save existing chutes. With a building height above 14 m to the upper platform of the stairs it is necessary to equip new refuse chutes. At the same time it is necessary to ensure their airtightness and noise protection of the premises of the apartment, located next to the garbage can. The best option is the device of a pneumatic waste bin in each kitchen of the projected apartment.
Garbage chutes , as a rule, are installed next to elevators, but there are also cases when these elements of building engineering equipment are located on different sides of the staircase. Garbage chutes are also mounted on the interfloor platforms, removing the distributors of dirt and odor from the entrances to the apartments.
In the storerooms for the needs of the population, located in the basement and basement floors, it is allowed to maintain a clear height from the floor to the bottom of the protruding structures of the overlying ceiling of at least 1.7 m.
Что бы оставить комментарий войдите
Комментарии (0)