From the standpoint of the installation process, steel structures have a number of specific features. They, as a rule, have large geometric dimensions, which very often conflict with the rigid parameters of both rail and road transport. This does not allow to increase the factory readiness of assembly units, causes the need for their pre-assembly integration and, in addition, in some cases leads to an under-utilization of the carrying capacity of vehicles and installation tools.
The flexibility of metal structures in the installation process is much greater than that of reinforced concrete or wood, which has to be taken into account in KM drawings (developed by the design organization) and, in particular, KMD (developed by the manufacturer). In the project, the parameters of dispatch marks and the location of the consolidation and assembly joints should be defined.
According to the SNiP, in the process of designing metal structures, it is necessary to take into account both the specific technology of their factory production and the requirements determined by the installation technology, starting with the process of delivering the structures to the construction site. The organization developing KMD drawings is responsible for their conformity to the KM drawings, for the design strength of all factory and installation connections of structures not provided for by KM drawings, for the correct sizes of the structural elements and their linking with each other, as well as for the fulfillment of the requirements of the installation works . Deviations from the drawings of CM, as a rule, are not allowed.
In the design of metal structures (the development of drawings KM and KMD) special attention should be paid to the manufacturability of their manufacture, transportation and installation.
When installing structures of great height (columns, towers, masts, etc.) and large spans (beams, trusses, crossbars, arches, etc.), it is necessary to carefully follow the observance of the maximum flexibility of structures.
Stability of the upper compressed belt of the trusses in the process of temporary detachment and alignment can be ensured by installing braces (when mounting the first truss) or the struts stipulated by the project, which are placed at the ridge in the middle of the span of the truss and between the ridge and the ends of the truss, while ensuring the flexibility of the upper belt in the areas between the anchorage points from the plane of the truss no more than 220.
The joints of metal structures are capable of relatively quick, in comparison with reinforced concrete, to perceive installation and permanent loads, which can significantly increase the rate of installation work. However, one should not forget about the main rule of installation - ensuring the stability of the mounted part of the building, for which purpose the permanent and installation links provided for by the project should be made immediately after the installation of the building or structure structures in the design position. For the same reason, during installation, metal frames of extended or high buildings and structures are divided into installation sites in accordance with expansion joints and spans, installation work is performed by a comprehensive or combined method (a differentiated method of mounting structures is rarely used).
In domestic practice, the characteristic features of the installation of metal structures are:
- installation of structures enlarged blocks, often construction and technological;
- production of construction and installation works in a flow-combined method;
- the work of complex teams, performing along with the main processes auxiliary and related.
Three-layer panels with insulation, lined on both sides with sheet material, often referred to as sandwich panels due to its multi-layer structure. Sandwich panels can be wall and roofing according to their purpose, they represent a single system of pre-fabricated buildings. We will consider only wall products. Wall sandwich panels are produced mostly self-supporting, but special designs are also offered that can be used as facing products.
The use of sandwich panels with effective insulation is promising because it provides:
- short installation time;
- low costs for capital construction (due to the low weight of the panels for installation, no special equipment is needed, a lightweight foundation is required, etc.);
- the possibility of dismantling (with preservation of the structures of its properties);
- A rich selection of finishes and colors.
Sandwich panels from leading manufacturers, as a rule, have anti-corrosion finishing coating, low weight, high strength, moisture resistance, fire resistance and high noise insulation characteristics. Another of the undoubted advantages of sandwich panels is their manufacturability. Manufacturers offer computer-aided design services in the CAD system, which provides a flexible and fast calculation of building structures. The complete development of the necessary technical documentation with the calculation and delivery of all the necessary components for the installation of panels (corners, splatters, fasteners, sealants) practically reduces the work on the construction site to assembly according to the principle of the designer.
Fig. 11.3. - Pre - fabricated buildings using sandwich panels
during installation
Sandwich panels are used in the construction of objects of various purposes - from industrial and administrative buildings to sports facilities. They are widely used for the construction of car service facilities, car washes, gas stations, and storage facilities. There is a sandwich panel application and for the device of warm contours around drying chambers, etc. Ideal for the manufacture of refrigeration systems of various sizes. Dozens of large low-temperature storage warehouses were built from sandwich panels. For these buildings, such technical qualities of the panels are particularly important as excellent thermal insulation properties and high resistance to moisture absorption.
Such distinctive features of sandwich panels as surface hygiene and ease of maintaining cleanliness are extremely important for the food industry, where the lining should be insensitive to processing with special detergents and should be well tolerated in both wet conditions and elevated temperature. Sandwich panels are suitable as non-load-bearing elements for construction in seismic areas.
Sandwich panels can be factory-made or assemble directly on the object (the so-called “element-by-assembly” panels). The most widely used panels in Russia were factory-made panels (supplied both from abroad and produced in rather large quantities in Russia).
findings
1) Reconstruction is a complex of construction works and organizational and construction measures related to changes in the basic technical and economic indicators (the quantity and quality of apartments, the construction volume and total area of a building, capacity, throughput, etc.) or its purpose, to improve living conditions, quality of service and increase the volume of services.
2) Restoration is a complex of works carried out on architectural monuments, in order to prolong their life, includes elements of both repair and conservation.
3) Construction processes for reconstruction and restoration are called production processes that take place on a construction site and have the ultimate goal of building, renovating, restoring, repairing, disassembling, moving buildings or structures. Objects and tools of labor are involved in any construction process. With the help of tools, workers work on the object of labor; For this purpose, various mechanized tools and construction machines are used. In many construction processes, workers use assistive devices and fixtures.
Что бы оставить комментарий войдите
Комментарии (0)