Structures of external walls of civil and industrial buildings. Self-supporting walls Site preparation and foundation marking

Load-bearing wall (Fig. 1)– main load-bearing enclosing vertical design building, resting on and transferring the load from the floors and the own weight of the wall to the foundation, separating adjacent rooms in the building and protecting them from impact external environment.

Self-supporting wall (Fig. 2)– external enclosing vertical structure protecting interior spaces building from the influence of the external environment, resting and transferring the load from its own weight to the foundation.

Fig.2. Self-supporting wall (outer wall rests on the foundation, and the ceiling is adjacent to the wall)

Curtain wall (Fig. 3)- an external wall resting on the ceiling within one floor with a floor height of no more than 6 m. (at a higher floor height, these walls are considered self-supporting) and protect the building from the outside from the influence of the external environment.

Partition- an internal vertical enclosing curtain wall resting on the ceiling and separating adjacent rooms in the building.

In buildings with self-supporting and non-load-bearing external walls, loads from coatings, ceilings, etc. transferred to the frame or transverse structures of buildings.

In a house, the walls that stand on the foundation and on which the ceilings rest will be carriers.

And walls standing on a foundation without the ceiling resting on them will be self-supporting.

Fig.3. Curtain wall (external wall rests on the floor slab)

Walls of different structural purposes carry different loads. To provide the necessary bearing capacity For different walls choose a certain wall thickness and the strength of the materials used.

For example, it is recommended to make internal and external load-bearing walls of buildings made of aerated concrete blocks with a height of up to 3 floors inclusive from blocks of classes of compressive strength not lower than B2.5, with glue or mortar of a grade not lower than M75; at a height of up to 2 floors inclusive - not lower than B2 with glue or mortar of a grade not lower than M50.

For self-supporting walls of buildings up to 3 floors high, the class of blocks must be at least B2.

Walls are structural elements of buildings that serve to separate a room from the outside space (external walls) or one room from another ( interior walls).

According to the nature of the work, walls are divided into: load-bearing, self-supporting and mounted .

Load-bearing walls perceive the load from their own weight and other structures and transfer it to the foundations.

Self-supporting walls carry the load only from their own weight along their entire height and transfer it to the foundations.

Curtain walls walls are fences that rest on each floor on other elements of the building (frame) and only support their own mass within one floor.

They are presented to the walls the following requirements: they must have sufficient strength and stability, have the necessary heat and sound insulating properties, be fire-resistant, durable and economical. Sound insulation requirements apply mainly to the walls of residential buildings.

Optimal thickness walls must be no less than the limit determined by static and thermal calculations.

Since January 1997, Amendments to SNiP 11-3-79 “Building Heat Engineering” came into force: the required heat transfer resistance for residential premises has been doubled, and since 2000 it has been increased by 3.45 times. If you follow the letter of the law, then brick walls should be built 1.5 meters thick, so it is advisable to use combined designs external walls: load-bearing part of the wall, minimum thickness, plus effective insulation and decorative finishing.

Depending on the type of material, the walls can be stone, wood, or combined (sandwich type). Stone walls According to their design and method of construction, they are divided into masonry, monolithic and large-panel walls. Combined walls– various panel-frame houses.

Masonry is a structure made of individual wall stones, the seams between which are filled masonry mortars. To create a durable monolithic system The rows of masonry are made with mismatched vertical seams, that is, with their bandaging.

Monolithic wall. The wall structure consists of a reinforcement frame and concrete. To pour concrete, you need to set up the formwork. The formwork can be removable or permanent.

Panel-frame Houses. Panel houses As a rule, they are manufactured in factories and assembled at the customer’s site. Panel materials: core insulation (expanded polystyrene or mineral wool), “clad” on both sides with LSU or OSB sheets.

Frame houses . Such houses have many options (manufactured in a factory or built on the site).

Load-bearing walls are erected in buildings without frames or with an incomplete frame. They are made of brick, small and large blocks. Performing both load-bearing and enclosing functions, such walls absorb loads from the roof, ceilings, wind forces and sometimes loads from handling equipment. Load-bearing walls rest on foundations. Self-supporting walls carry their own weight within the entire height of the building and transfer it to the foundation beams. Wind loads, affecting the walls, is perceived by the building frame or half-timbered frame. The wall filling is connected to the frame with flexible or sliding anchors that do not interfere with the settlement of the walls. The height of self-supporting walls is limited depending on the strength of the material and the thickness of the wall, the pitch of wall columns, the magnitude of the wind load, etc. Self-supporting walls are made of brick, blocks or panels.
Non-load-bearing (curtain) walls perform mainly enclosing functions. Their mass is completely transferred to the columns of the frame and half-timbering, with the exception of the lower sill tier, which rests on the foundation beams. Columns support mass curtain walls through strapping beams, half-timbered crossbars or supporting steel tables.

Lightweight curtain walls, not being a load-bearing structure, have one purpose - to protect premises from atmospheric influences. Application effective insulation materials and thin sheet cladding allows the low weight of curtain walls to ensure their high heat-shielding properties, and their manufacture without wet processes ensures satisfactory humidity conditions in the premises from the first days of operation of the buildings.

Curtain walls made of frame panels two floors high were used in the building of the Institute of Scientific and Technical Information in Kyiv. The frame of the panels, measuring 2.8X7.2 m, is made of extruded aluminum profiles, glazing is made of double-glazed windows. The blind areas of the panels are lined with outside stemalitis, with internal - particle board. Semi-rigid mineral wool slabs are used as insulation. The joints between the panels are filled mineral wool and covered with aluminum protective and decorative elements.

The thickness of the walls with insulation made of foam glass, semi-rigid mineral wool slabs, phenolic-resol foam FRP-1 is approximately 100-120 mm, which makes it possible to reduce the cubic capacity of the building (without changing the area of ​​​​the premises) and, accordingly, the consumption of materials. All other things being equal, this helps reduce the cost of 1 m 2 of buildings.

In buildings erected in the Far North, lightweight panels are mainly used, consisting of two outer aluminum sheets 0.8-1.5 mm thick, between which there is insulation (polystyrene PSB foam plastics, PSB-S phenolic FRP-1, Vilares-5 or polyurethane PPU-ES, PPU-308, density 35-80 kg/m 3); such panels in most cases have framing ribs. In the conditions of the Far North, the use of lightweight panels sharply reduces their thickness to 150 mm, and therefore their weight (for comparison: the thickness of lightweight concrete walls reaches 600 mm, brick walls - 770 mm)

Wall panels dimensions 1.3x3.5 m and 1.3x4.5 m with cladding made of aluminum sheet 1.5 mm thick, with framing ribs that absorb lateral loads, baked plywood 10 mm thick and polyurethane foam insulation used in single-story residential buildings in the north.

When constructing houses, both multi-storey and private country houses, load-bearing or self-supporting walls can be erected. The first type of enclosing structures experiences serious loads from the floors and roof. Self-supporting walls are vertical elements of a building on which nothing rests. During the operation of the house, loads in such structures arise only from their own weight.

What are they?

Basic distinctive feature Self-supporting walls, in comparison with loaded ones, is that they have a small thickness. Accordingly, less material is used during their construction. The thickness of the walls of this type, depending on what they were built from, can range from 50-380 mm.

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During the construction of the rear, among other things, non-load-bearing enclosing structures can also be assembled. Such walls also do not take the load from the elements of the house located above. In another way, structures of this type are called hinged. They are always built within the same floor. However, if their height exceeds 6 m, they can already be considered self-supporting. Their design and calculations are carried out accordingly.

Self-supporting walls are basically only external enclosing structures. Such elements of the building simply protect its interior from wind and precipitation, adjacent to the main frame. Ceilings to such walls are attached to the side on all floors in height. When building houses, both single-layer and multi-layer self-supporting enclosing structures can be erected. If walls of this type are located inside the building, they only serve as partitions.

Features of operation

According to SNiP standards, in such structures when performing redevelopment in multi-storey and country houses It is allowed to make openings or expand them to the required parameters. Also, walls of this type, in some cases, can even be dismantled and rebuilt without the risk of collapse of other building structures.

Calculation

Before starting the construction of any house, of course, it is also drawn up detailed project. At the same time, an operation such as the calculation of self-supporting, non-load-bearing and loaded walls for stability is also performed. For brick structures, for example, such calculations are made taking into account data from several tables from paragraphs 6.16-6.20 of SNiP II-22-81. In any case, when calculating the stability of a self-supporting wall, the compliance of the ratio of its thickness to height with a given geometry with standard values ​​is determined.

Features of construction

It is possible to build such enclosing structures from almost any materials. Self-supporting walls are elements of a building that can be constructed from wood, brick, or blocks. In any case, such structures are assembled exclusively on strong supports. Their foundations are poured simultaneously with the foundation of the building itself.

Self-supporting brick, block walls, etc. are combined with other types of enclosing structures exclusively using flexible connections. When using rigid ones, due to unequal degrees of loading, building elements may subsequently crack and become deformed. Accordingly, living in the house will become unsafe.

Self-supporting walls are structures that, when laid with bricks or blocks, are required to be reinforced according to standards. However, such enclosing parts of buildings are usually strengthened not as thoroughly as loaded ones. When constructing walls of this type, rods are inserted through large quantity rows of masonry. According to the standards, reinforcement for such structures can be used with a diameter of 1-2 mm.

Materials for multi-storey buildings

When constructing high-rise buildings, self-supporting external walls can be constructed from:

• hollow, porous, solid ceramic bricks;
• sand-lime brick.

When constructing buildings with not too many floors, blocks are sometimes also used:

• arbolite;
• ceramic;
• made of foam or aerated concrete;
• expanded clay concrete and any other large format.

A feature of such materials in comparison, for example, with the same brick, is a relatively low degree of strength. Therefore, their standards allow the use of them, depending on the type, when constructing houses no more than 3-5 floors high.

I wrote this article in April. And I put it aside in the hope that I would select illustrations, and perhaps break them into small blocks - more suitable for the format of this LJ.
But it’s already January next year - and I don’t know when I’ll do this.
That's why I'm posting it in its entirety, without illustrations, and if someone makes it to the end - tell me about it - I'll sign you up as a hero :)

Walls:
The walls of buildings are load-bearing, self-supporting and non-supporting.
What are the differences, how does it work and how does it manifest itself externally and in architectural aesthetics.

A load-bearing wall is a wall that supports the roof structure (or balconies, or any other load) - this wall that is structural element. Part of a working structure. Like a post or beam in a post-and-beam system.
A self-supporting wall is a wall that does not carry anything additional - but has its own weight. That is, it bears its own weight, at least. The higher it gets, the greater the weight, the more similar its properties are to a load-bearing one.
A supportable wall is a wall that is supported not by what is below, but by what is on the side or above. That is, if it’s quite simple, it’s either a thing suspended on something, or nailed to a certain structure like a cladding. Such a wall has mainly an enclosing function - almost unrelated to the structure.

And just imagine load-bearing wall made of brick or stone.
Ideally, stones and bricks lie flat in it, the load presses from top to bottom. The lower, the greater the load - it’s normal if the wall begins to expand and strengthen towards the bottom. Perhaps the wall will have a slope - like the walls of fortresses - narrower at the top.

If the wall is loaded and it becomes load-bearing (or a very large self-supporting one), this whole ideal picture will not work. Because a lot of additional loads will appear in the wall - which, although according to the design, should act strictly vertically - in reality - due to non-ideal density, due to loads that have some lateral shifts, etc. – a lot of stress will occur inside the wall. Of the obvious and understandable ones, all sorts of lateral moments will accumulate towards the edge of the wall, towards the corner of the building and the greatest load will be placed on the corner. Therefore, the corners seem to be strengthened and thickened in even simple buildings. Often it is necessary to remove excess load from window and doorways– to make the jumper easier. Sometimes during the construction process a certain tension accumulates that needs to be removed.
Load-distributing arches, etc. appear in the wall. things.

This is the picture for all load-bearing and self-supporting walls. The corners are reinforced, the masonry is complex so that there are dressings, the load accumulates towards the bottom and the wall thickens.
This is good for traditional materials- stone and brick. The same picture applies to all kinds of modern blocks (in fact, these are the same stones - just artificial). The same picture for reinforced concrete (monolithic) walls. Only there internal stresses they are immediately used as reinforcement and the strength is much higher than that of natural stone. But the principle is the same.
It’s a little different with wood, because you can’t install a distribution arch in it. But they don’t build from wood and very high or heavily loaded walls. But greater force is exerted on the angle, structures that lighten the jumpers appear - that is general principles are saved.

There is an architectural - aesthetic - expression for load-bearing and self-supporting walls. Just as an order is the ideal expression of a post-and-beam structure in stone and wood, so for a wall there is architectural element– rust. Rust is an image of large masonry blocks in a wall. Sometimes it is made of stone, sometimes it is purely decorative - made of plaster. When doing rustication, the architect tells us that the wall is load-bearing. Well, or at least self-supporting. The more powerful the rust, the more likely it is that it is a load-bearing wall. Making a pronounced rust on a wall that is clearly self-supporting is quite strange. Can. But less justified. And rustication (even exaggerated decorative) on supported panels is simply not an understanding of its essence and design in general.

Remember, we talked about whether the order on the Colosseum is decorative or not. (link)
So - in the Renaissance, almost the same combination of two structural systems on the facade. On the one hand, the wall is rusticated, that is, telling the viewer that it is load-bearing. On the other hand, pilasters appear, which seem to show that there is some kind of post-and-beam frame inside.
And researchers talk about the contradiction of these systems. Or - that the order on such facades is purely decorative.
Firstly - for some reason no one says that this could be a real carnassus - and the filling with a wall between is self-supporting (well, they don’t say - because this really is not the case - at least in the Renaissance, although I think if you dig deeper - in the 19th century such mixed structures already existed - when the frame was connected to the wall)
Secondly – ​​as with the Colosseum – these systems complement each other and are intertwined.

How it happens in this design: in its most primitive form - A leveling beam is placed on the load-bearing wall, which distributes all further loads evenly. On it, with a certain step, transverse beams are placed on which the ceiling is supported. If there were no beams, the beams would press pointwise and the internal loads in the wall would be more varied.
But nevertheless, the beams do not press evenly on every cm of the wall.
Secondly, what we said is that the corners bear a large load.
And thirdly, if the building has transverse walls - and there are more than 2-3 windows on the facade - then at the points of their connection with the main wall there is also a large horizontal load (and, by the way, a smaller vertical one - if the transverse wall is also load-bearing, but it is usually self-supporting)
So the appearance of certain vertical elements on the façade - half-columns, pilasters - seems to be justified by a post-and-beam system. Of course - if they express internal layout buildings and repeat the internal walls - this is doubly justified. But often you have to cheat somewhere and add extra ones - for an even step or for the beauty of the facade.
Nevertheless, it is impossible to call these purely decorative elements. They are tectonic.

Working in monolithic reinforced concrete, we can absorb all these loads with reinforcement. And make a perfectly smooth, even wall. However, this flat wall will be just decoration - not reflecting the inner work.
Perhaps, in order for a reinforced concrete wall to be a truly pronounced structure, its reinforcement should, as it were, “shine through” - like the veins on a person’s arms or read like a skeleton. Seeing a living creature, we cannot draw its skeleton. But imagine the main load-bearing structure inside - we can completely. However, the principle of operation reinforced concrete wall not much different from stone (yes, stronger, yes - you can make more complex things, larger protrusions and lintels - but the principles are the same - the load acts from top to bottom)

So - at the beginning of the 20th century, designs appeared that made it possible to simply hang a wall on them. And make any wall. Glass. From lightweight foam etc. Loose walls appear.

It must be said that in architecture, a load-bearing, self-supporting or self-supporting structure is a very important criterion. They are often sharply different, painted radically different colors– like black-and-white half-timbered or white-colored classicism.

Therefore, if the wall is unsupported, it is very important to show and emphasize (well, because we remember that tectonics is the basic principle of architecture - and exceptions only confirm the rules)

That is, there are two options - to identify and aestheticize modern hanging structure. Or deliberately abandon the principle of tectonics - and create something completely different. What do deconstructivists do? But this must be done a) masterfully b) clearly. Like a bright trick, a theatrical performance. Or pure decorativeness - with bright color. Ideally, an elegant joke. So far, I don’t see any application or path for this in mass architecture. This is a separate conversation, of course...

So - if the wall is unsupportable - then it would be good to identify and emphasize this. How can I do that?
1. identify and show load-bearing frame making the wall almost invisible. For example glass. So at Foster - in a cucumber. The frame has been revealed. Glass is portable. By the way, Koolhaas too (despite the fact that he is a deconstructivist and, in general, the Chinese skyscraper does not come from the design). Any buildings “just pieces of glass” do not meet this criterion, because the frame is not revealed.
2. develop a decorative expression that the wall is supported not by what is below, but by what is on the side (or suspended). It could be rivets. (or any other fastenings based on the principle - nails, screws, etc.) These could be some kind of latches around the perimeter - similar to glass in frames. Such options were made by Otto Wagner for cladding (by the way, this can all concern simply decorative cladding walls) - this is not rustication - these are panels “nailed” to the wall or frame. IN modern architecture This option has not been developed at all.
3. Look for the aesthetics of the curtain walls in the old curtain walls. For example, in skins that were stretched over the frame of yurts, etc. dwellings... To go by demonstrating that the wall is flexible and cannot hold without an internal supporting frame - it means it is there. Perhaps the time has not yet come for this - and not yet modern technology flexible fabric for walls. Especially something involving windows. Although I think that this is quite possible. But this is a question for technologists... partly this is expressed by Zaha Hadid - in her flexible walls.