A glued arch with resting on the foundation has reached.

Contents

1) Design and calculation of board flooring

2) Design and calculation of continuous twin span

3) Structural Design and Calculation

3.1) Selection of main frame elements

3.2) Geometric calculation of the arch

3.3) Determination of loads

3.4) Arch calculation in Lira

3.5) Selection of arch section

4) Design and calculation of design nodes

5) Comparison of options

6) List of literature used

Measures and methods to extend the service life of wooden structures.

Along with the construction of new, public and industrial buildings and structures, one of the most important tasks is the task of preserving existing ones, among which a significant part contains wooden bearing and enclosing structures. The correct operation of buildings and structures ensures their serviceability, i.e. the safety and failure-free operation of wooden and other structures within a minimum standard service life, and in many cases allows a significant increase in their service life. Normal operating conditions are such that wooden structures are not damaged, the loads acting on them do not exceed their carrying capacity, and the temperature and humidity do not exceed the permissible ones. If these conditions are violated, wooden structures can prematurely lose their carrying capacity and rigidity.

Thorough inspection of wooden structures should be carried out during their commissioning and subsequently repeated periodically, at least once a year.

An important role in extending the service life is played by premature protection of wooden building structures and parts from moistening, damage by woodblowers and woodblowers, damage by insects - pests, as well as from mechanical damage. Protection against humidification can be provided by painting the surfaces with appropriate moisture-proof paint materials. They are applied in liquid form with a thin layer with a brush or a sprayer on the surface of the operated wooden structure or part. The thickness of the paint coating layer should be 100250 μm, depending on the operating conditions, as well as on the type of protective material. In order to combat biodegraders, wood structures and elements are gas disinfected (fumigation) or wood is treated with hot air. Wood is treated with hot air, supplying it to a closed room, most often to an attic room. The wood must be heated within an hour so that the temperature inside it is reached, at which the death of the corresponding type of biodegrader occurs. Temperature control is crucial for the durability of wood structures, since its violation leads to humidification and decay or overheating and weakening of wood. To protect wooden structures and elements operating in high humidity or if the wood itself has high humidity, diffusion antiseptic pastes containing antiseptic (sodium fluoride, borax) and binding materials (coal varnishes, extracts of sulfite cheeks, latexes, polyvinyl acetate emulsions) are used.

In the first years of operation of the structures, the process of washing the loaded surfaces of the joints takes place, and in high-humidity structures, also drying, and reducing the size of the elements.

As a result, the density and monolithic nature of the connections can be compromised, the bolts can lose their initial tension, and gaps between the connecting elements appear. Loosened bolts must be tightened and the initial density restored. It should be borne in mind that in most cases the cause of the emergency condition of some wooden structures was the unsatisfactory quality of the joints, the presence of overload of the structures and their insufficient horizontal fixation, the presence of unacceptable deflections and exit from the plane. Reloading of structures, especially with a constant load, significantly reduces the reliability of their operation and their normal operation periods, since the long-term strength of wood is much lower than short-term. When inspecting structures, it is necessary to strictly ensure that the actual loads acting on the structures do not exceed the design ones. Thus, the durability of wood structures largely depends on premature protection from various types of damage and proper care of the structure.

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