The size design of ordinary steel truss span

According to the use and process requirements to determine the general 3M as a module.The roof span is 3 times, 12 m, 15 m, 18 m, 21m, 24 m, 27 m, 30 m, 36 m,also have a greater span.Triangular steel purlin roof structure is flexible, not limit by 3M modulus.

Steel truss span calculation: the roof supports distance force, generally take the distance between the axis of pillar minus 300 mm.

Roof height: according to the requirements of economic, stiffness, construction and transportation lines, roof slope and other factors to determine.Triangle truss height h= (1 / 4 ~ L / 6) L (span), in order to adapt to the requirements of materials with large roof roof slope.

Trapezoid truss relatively flat slope, the roof span height should meet the demand of stiffness, when the winding slope is 1 / 8 to 1 / 12, span height is generally (L / 6 ~ 1 / 10 L). The small value is taken when the span is large (or the roof load is small),otherwise large value.

End height: when the roof is hinged with the column is 1.6 ~ 2.2 m, when the rigid connection is 1.8 ~ 2.4 m; the large value is taken when the bending moment is large, otherwise small.

Height: according to the end height, roof slope, the maximum height should be less than the transport boundaries, such as railway transportation line is 3.85M.

Division of roof steel truss internodes should be determined according to the roofing material. When using a large house, the roof panel width is equal to the length of internodes, generally 1.5 m or 3 m; When using the purlin, according to the purlin spacing set, generally 0.8 ~ 3 m. Try to make the load of the roof effect directly on steel roof truss joints, avoid the top chord of local moment.

This blog is published by the steel roof truss manufacturer Jiangsu Andy Steel Structure Co. Ltd.

Advantages and disadvantages of double glazing curtain wall

Advantages：

1.Sound insulation: due to the skin of the shielding effect of the noise, double glass curtain wall reducing the impact of outdoor noise for the interior.It is in is particularly suitable for the construction using double glazing curtain wall which is in a very strong traffic noise environment in the city center area.At the same time, double glass curtain wall can still introduce natural ventilation in the strong noise environment, reducing the building energy consumption.

2.Insulation: in the winter, the existence of outer curtain wall strengthened the insulation performance of the outer envelope. The heat loss of the building surface can be reduced effectively by the preheating of the air between the double glass curtain wall. And because the inner curtain wall temperature is relatively high, it is advantageous to the indoor thermal comfort.

3.Night ventilation cooling: in the hot summer, the internal temperature of the umbrella building may be too high.And double glass curtain wall and not to directly open the ventilation mode, so it has safety protection function, which makes office buildings can use the cool night air to natural ventilation indoor cooling in the summer night after work.

Double glass curtain wall of the sun blind is installed in the interlayer, compared to the single glass curtain wall of the plug, this way is more conducive to the protection of the blinds.Especially some complex, expensive metal shutters, sun and rain will not only shortened service life, but also affect the shading and reflection effects. In addition, external blinds are often generated ambient noise. High technology park located in the outskirts of Munich, Germany, using a plug-in type metal shutters, ringing unceasingly in the breeze all day, while the double glass curtain wall shutter does not have this problem.Because of the existence of the outer curtain wall, the air pressure in the building is reduced, which makes it possible to open the window of the high-rise building, and the energy consumption of the mechanical ventilation is greatly reduced.In the architectural design, double glazed curtain wall due to the use of large areas of glass, making the building very high permeability.

4.Natural ventilation: a very important advantage of double glazing curtain wall is to allow natural ventilation. Natural ventilation can not only reduce the air conditioning energy consumption, but also to improve the environment of comfort, and enhance human health.

5.The layer of double glass curtain wall can be used as a fire passage.

6.Energy saving: as the double glazing curtain wall improves the performance of building heat preservation and heat insulation, and the umbrella can be natural ventilation for a long time, so that the building can save energy and reduce energy consumption.

Disadvantages:

1.Relative to the ordinary building, the cost of the external retaining structure is increased by 1.5-2 times.

2.In the strong summer sunshine, the temperature of air interlayer is often too high, especially when the double glass curtain wall between the interval is too small and the shading effect is poor, the temperature is sometimes higher than the outside temperature is,making the natural ventilation can not be achieved through the window.

3.Wall cleaning and maintenance costs of double glazing curtain wall are high.Double glass curtain wall based on the consideration of local climate and the special high altitude environment of high-rise building,umbrellas have a buffer and a weakening of the impact of the environment and the environment, and have the most basic use function at the same time,can maximum reduce dependence on non renewable energy.This design idea and starting point has far-reaching significance for saving energy, creating a sustainable development in the future. 

This blog is published by the double glazing curtain wall manufacturer Jiangsu Andy Steel Structure Co. Ltd.

Hanging type full glass curtain wall introduction

Hanging type full glass curtain wall, which glass rib and glass panel support by hanging, glass curtain wall weight by the structure of the upper beam bearing, so the glass curtain wall is vertical, smooth surface, reflection true.The more important is under the impact of the earthquake or wind, the glass is made of elastic deformation in a certain extent, avoiding the stress concentration caused by the broken glass.1995 January in Japan Osaka and Kobe earthquake, hanging type full glass curtain wall of intact rate is far greater than the seating type full glass curtain wall, besides the place type full glass curtain wall are generally less than 6m height.

After the survey, the main reason for hanging type full glass curtain wall is partially destroyed:
1.The damage of the whole curtain wall is caused by the destruction of the concrete structure;
2.An expansion bolt loose, weld fracture or combined steel clip fracture of hanging steel structure;
3.Glass edge of the original collapse or the use of drilling process;
4.The glass and metal rails distance is too small;
5.The bond between glass silicone adhesive failure.

What should be paid attention to the design of light steel structure workshop

After the light steel structural layout is finished, the section of the member should be estimated. It is assumed that the shape and size of the section of the beam column and support are assumed.

Can choose the channel, steel rolling or welding H steel etc.. According to the load and the bearing condition, the cross section height is usually between the 1/20~1/50 of the span. The complex calculation of the overall stability of the steel beam can be avoided when the flange width is determined according to the l/b value of the space of the lateral support of the beam. The section height and the width of the flange, the plate thickness according to the provisions of local tectonic stability prediction.

light steel structure workshop

Column section by the ratio of length and diameter ratio. Usually 50< λ <150, and the simple selection is near 100. According to the axial compression, bending or bending under the direction of the different, can choose the steel pipe or H steel section, etc..

Beginners should pay attention to the different structure, the specification of the structural requirements of the cross section is very different. The local stability of the plate part of the component which is unique to the light steel structure. There is a big difference between the standard and the light gauge steel.

In addition, the choice of the form of the member cross section has no fixed requirement, the light steel structural engineer should be based on the stress of the component, reasonable choice of the safety of the economic aesthetic section.

The origin of arched corrugated metal truss roof

In the forties of the last century, some American structure designers inspired from the structure and the shape of the natural plant skin texture began to seek a sheer material through the corrugated stiffening which methods of large span structures.They build a mechanical model of thin steel plate, and analyze the reasonable structure in theory.On the way to achieve this structure, the structure division and the mechanic come together.Structural requirements of the mechanical engineer to develop the production of a corrugated thin wall structure of the unit,which is a metal truss roof molding machine.In 1955, the United States used this metal truss roof for military (fighter base, barracks, etc.).Low cost, amazing construction speed, good construction effect, metal truss roof attracts more and more researchers and users.This kind of structure develops quickly, especially the introduction of computer numerical control make the structure of the metal truss roof simple and fast.However, due to various reasons (such as the economy, etc.), the scientific research and the development of the sturcture production unit is limited to a number of major companies (such as the United States MIC) of United States, Britain and other countries.Therefore, the international market of this structure is a monopoly of these companies, which is very bad for the development of metal truss roof and further promote the development.

metal truss roof

In the last century 80's, china had sent commissioners to the United States to investigate, but the introduction of foreign technology is very difficult: first, the cost of equipment is very expensive; Secondly, foreign technology is not in line with China's comprehensive technical standards (such as material, load, etc.); and the United States retained in the structural analysis of the key technologies.

This blog is published by the metal truss roof manufacturer Jiangsu Andy Steel Structure Co. Ltd.

Performance of low level light steel structure house

1.Earthquake resistance, wind resistance, high reliability.The excellent physical properties of steel made the light steel structure house with the characteristics of the overall rigidity, the strength of the component, the light weight of the structure,its performance in the earthquake or hurricane or other rare case of disaster is far better than other structural forms of residential.For the weak foundation area, the steel structure residence can reduce the basic cost, and reduce the probability of the occurrence of uneven subsidence.Steel structure system can be accurately designed and analyzed,making the structural reliability of the steel structure housing is better than that of brick masonry building.

2.Anti-corrosion, fire prevention, durability.The use of corrosion resistant galvanized steel in steel structure, greatly enhanced the anti-corrosion and durability of the main structure of the construction, reasonable structural measures to ensure the fire resistance of light steel structure;Structural creep, flooding and damage to the termites, rodents and other pests will not appear in the steel structure residential.

light steel structure house

3.Heat insulation, sound insulation, energy saving.Light steel structure residential composite wall structure ensures the requirements of heat insulation, moisture, sound insulation. The use of insulating glass to make the sound insulation index of 40 weighted above, in addition to greatly reduce noise pollution, but also save a lot of energy.

4."Space free combination" residential.The flexible selection of lightweight high strength steel structure , provides the greatest degree of freedom for the combination of residential space. On the one hand, the steel structure can provide very large shared space,at the same time, the architect can no longer stick to the position of bearing wall, layout of the functional space freely according to the design need.

Effect of glass curtainwall on birds

Since the sixties of the 19th century, with the rapid economic development of Toronto, each big financial magnated to headquarters located here and many skyscrapers have sprung up.

While at the same time in several migratory route of the high-rise belt has become a great threat to birds, reflective structural glass curtain wall high-rise buildings around the scenery make birds can not fully aware of the immediate danger, often too late to slow down against the glass.According to bird protection volunteer organization FLAP (Fatal Light Awareness Program) statistics, each year there are one million to nine million of migratory birds die from these glass fin curtain wall in Toronto.

FLAP's volunteers collect these birds that are injured or killed in the streets of the tall building area every day, and the birds will be brought to the Ontario Lake nearby;And the wounded will be sent to animal rehabilitation center, bodies of all dead birds were frozen in the freezer provided by the caring people.

FLAP is actively promoting the promotion of new type of structural glass wall, new type glass curtainwall can be avoided by projection method and other to avoid birds, but due to the high cost of the problem, the effect is not very optimistic.At the same time, the organization is also on the issue to the government to seek legislative support.

This blog is published by the China steel structure manufacturer Jiangsu Andy Steel Structure Co. Ltd.