Famous Gothic buildings
The basis for determining a constructive solution of large-panel residential building is its structural diagram.
In practice, the design and construction of large-panel buildings used a significant amount of different design schemes, because of the large variety of space-planning decisions, different levels of development of building materials industry and production of precast products, security of construction sites lifting and transport equipment. The importance in the choice of structural schemes is their techno-economic evaluation. Depending on the constructive scheme of the building materials are defined and the nomenclature of assemblies, depend on it the methods of construction of buildings and technical-economic indicators of large-panel construction.
On the constructive scheme of the large buildings, divided into the frame, and frameless buildings with an incomplete skeleton.
Prefab large-panel houses main structure has a frame consisting of columns and beams. The columns of frame are available both at external, n internal walls; girders can be placed transversely or along the building. An important advantage of timber frame is the ability to erect buildings of great height, and, owing to the separation of functions between curtain walls and bearing all the load columns to make the walls very light, and the columns run from high-strength concrete.
To nedostatochnoe-panel houses are a large number of Assembly elements, degraded the interior of the rooms due to the protruding edges of columns and beams in the corners and over walls. Figure 2-9 .
Fig. 2-9. The constructive scheme of the frameless large-panel houses
a — with load bearing external walls and transverse and longitudinal partitions;—with load bearing external walls and transverse partitions;—c bearing external and internal longitudinal walls; g—with bearing transverse walls
Frameless home consist of brick exterior and interior walls, partitions, overlappings. The constructive idea of frameless buildings is to use the carrying capacity of external and most internal walls having a known strength. This applies primarily to reinforced concrete insulated panels and internal walls between apartments, which by the terms of soundproofing do the hard, and therefore durable. Therefore, the rejection of the frame n using the bearing capacity of the walls is quite appropriate.
Frameless large-panel buildings can be divided into the following two groups: a) with load bearing external walls and internal load-bearing transverse and longitudinal bulkheads, floor panels are based on the contour or with transverse partition walls and load bearing external walls, in this case, the floor panels rely on three sides; b) with longitudinal load-bearing external and internal walls or transverse walls with leaning slabs on both sides. For a design scheme with transverse bearing walls a possible solution to exterior walls type self-bearing or hinged design * .
In homes with an incomplete skeleton missing columns in exterior walls; the design scheme they occupy an intermediate position between framed and frameless buildings. In homes with such a scheme is used load-bearing capacity of exterior walls, which are made of materials that can take the load of the ceiling.
Fig. 2-10. Constructive schemes of frame-panel houses
a —frame with a transverse; b — longitudinal frame; b—with a beamless slab, simply supported on four points; e part —time (internal) frame and load bearing panels exterior walls
Spatial rigidity and stability of buildings with incomplete inner frame and frame the scheme is provided directly by the frame, connections or panels mounted in the plane of the frame, as well as free-standing walls forming the vertical shear. In frameless buildings stability is ensured by transverse and longitudinal load-bearing brick walls.
In large-panel construction is widely used in the most economical and easy to install structural scheme with bearing transverse walls, which rationally is not only used in a massive 5-storey housing, but has been used successfully in the design and construction of high-rise buildings (9-12 storeys or more). Currently being implemented in the practice of large-panel construction scheme with rare cross location of bearing walls, which provides a certain freedom of layout of apartments.
In a massive 5-story large-panel housing construction in the past has spread scheme with an incomplete inner frame, the application of which is not currently recommended. Now for the construction in Moscow, Leningrad, Kiev and other large cities developed large-panel buildings and large high-rise, decide on frame scheme.
Frameless schemes with cross-section and longitudinal bearing walls shown in Fig. 2-9. and frame-panel with incomplete skeleton diagram — in Fig. 2-10; beamless slab is shown in Fig. 2-10, V.
In the frameless large-panel buildings floors are arranged by type beamless structures along with support of panels directly to the vertical pillars; in frame buildings slab are solved with transverse or longitudinal girders.
Analysis of structural schemes used in massive 5-storey building, showed that the cost of living area in houses with internal transverse bearing walls, spaced at b m, approximately 2% higher than in homes with frequent step inner wall. This appreciation caused by increasing the span of the slab (3 to 6 m) and increased by 10 cm the height of the floor due to the increased thickness of slabs.
Comparison of structural diagrams of houses with longitudinal bearing walls showed that the cost of living area of the house with longitudinal internal supporting wall is 1.5% higher than in the house with an internal frame are often located. This is due, as in the previous case, the presence of large-span ceilings and increased floor height in the house from the inner longitudinal load-bearing wall. Large buildings with three longitudinal walls are used mainly in areas where local materials in their construction and the technical characteristics is most appropriate to use for load-bearing exterior walls.
Mention should be made of panel-frame or so-called frame and panel structural design, in which the spatial frame of the building creates zamonolichivanie vertical and horizontal contour elements of the frames of adjacent panels. This system is not widely used in our construction, but was applied in Czechoslovakia.
Frame-panel scheme has a transverse longitudinal load-carrying structural system (Fig. 2-11, a). In Czechoslovakia also received the use of a structural diagram, in which the transverse bearing walls alternate with lateral beamless frame (Fig. 2-11, b).
Fig. 2-11. Design scheme applied in the former Czechoslovakia
a —frame-panel scheme; b— combined scheme: 1 — transverse load-bearing walls; 2—the load-bearing piers; 3 —columns
With this scheme, the walls of stairwells together with a transverse bearing walls and ceiling create the rigidity and stability of the building.
* External walls apply three types;
bearing that perceives the vertical load from self weight of the walls and from the overlying structural elements of the building;
self-supporting, perceiving vertical load only from its own forest walls;
mounted resting on the frame members or cross walls.
When zamonolichennyj joints, ensure joint operation of external longitudinal and transverse load-bearing panels, designed self-supporting walls are actually load bearing.