On the basis of the safe use of buildings and economy, the relevant building responsible persons must strictly control the quality of curtain wall materials and master the key points of curtain wall design so that the construction quality of curtain wall can be guaranteed. So today I would like to introduce to you common problems in curtain wall design.

Analysis of Common problems in Building Curtain Wall Design

Embedded parts:

Some building engineering main bodies do not design embedded parts, so they have to be remedied with expansion bolts and chemical bolts during construction. However, because of embedded parts specifications and steel price welding and Anchorage length, it is difficult to meet the requirements of the construction code.

Parts of columns and beams:

The model of column mechanics calculation is difficult to meet the needs of practical engineering, in addition, the characteristic parameters of column and beam section are not calculated accurately or misapplied, and even some section shapes can not meet the requirements of force at all; some columns are even designed as compression members, although the strength of the bar is checked but the stiffness of the member is not checked. There are also some who do not check the calculation according to the most disadvantageous grid and the largest span.

Where the curtain wall is connected to the host:

The strength of the weld of the support and plate does not meet the requirements of the construction code, and only one bolt is installed in the connection position, which makes the bending moment of the angle code too large and difficult to strengthen.

The fixed position of the plate:

There is no bracket under the plate of the hidden frame curtain wall, the spacing of the pressure plate is too large, and the strength of the pressure plate itself can not meet the requirements of the construction code.

Fire and lightning protection parts:

The thickness of waterproof cotton used is difficult to meet the requirements of the construction code, while the waterproof partition is relatively thin, and the waterproof joint is not strict enough, which leads to the failure to deal with the lightning protection joint in the telescopic position of the column.

the key points of control in the design of curtain wall

Because of the high professional requirements of architectural curtain wall design, it is often architects who first put forward design ideas and design effect drawings in the design process; secondly, the specific design is organized by architectural decoration companies, which is characterized by discontinuous design process. Combined with practical work experience, the common problems and improvement measures in curtain wall design are summarized as follows.

Key points in the design of curtain wall as a whole

The curtain wall is the outer structure of the building, and its functions mainly include: bearing the dead weight and the seismic action and wind load acting directly on it, because it does not share the earthquake or load borne by the main structure, so the curtain wall should meet the following requirements in design:

1. It should have certain stiffness, bearing capacity, stability and displacement capacity relative to the main structure.

2. The connection between its members and columns and beams can reliably transfer seismic and wind loads and the dead weight of curtain wall members.

3. The concrete strength grade of the main structure of the connection should not be lower than C25 to ensure the reliability of its connection with the main structure.

4. The connection between it and Anchorage must be safe and reliable, and leave room appropriately, especially when it is necessary to determine its bearing capacity, physical tests should be carried out.

5. When the curtain wall is connected with the masonry structure, steel beams and columns or reinforced concrete can be added to the main structure. Here, the lightweight filling wall is not considered as the supporting structure of the curtain wall structure, because its deformation capacity and bearing capacity are relatively small.

6. Measures against Rain Water's leakage performance should be taken in curtain wall design, especially for some curtain wall projects with shutters and glass lighting roofs, special attention should be paid to the construction of structural complex parts such as connection with the periphery, roof pressing and so on. when it is found that the sealing is bad and the material performance can not meet the requirements, timely rectification or replacement should be carried out, and the water test of anti-Rain Water leakage performance should be carried out layer by layer if necessary to prevent leakage.

Key points of structural design of curtain wall

1. The curtain wall structure must have sufficient ability to adapt and absorb displacement, so that the curtain wall members can be effectively prevented from being damaged by the displacement caused by the horizontal force of the main structure, and there is room for movement between the curtain wall components and the columns and beams.

2. In order to make the curtain wall deformable in its own plane, a movable joint can be set up on each floor of the post, which also makes it possible to move up and down the post.

3. The gap between the upper and lower column joints should not be less than 15mm, so as to meet the requirements of the error of the column installation, the temperature deformation of the column, and the axial deformation of the main structure column bearing vertical load.

4. The column should be designed as an axial tension or eccentric tension member, and the construction method should choose the hinged joint to hang at the upper end and the lower end to select the joint form that can be deformed up and down, so as to reduce the adverse impact on safety when the column is designed to work under complete pressure. at the same time, it also prevents horizontal load from bending.

Design points of Lightning Protection system for Curtain Wall

Through the setting of lightning protection system, curtain wall can effectively reduce the loss of personal and property caused by lightning. Through the scientific setting of the curtain wall lightning protection system, the ideal lightning protection effect of the curtain wall can be achieved, so as to prevent or reduce the personal injury and property loss caused by lightning striking the building curtain wall. The setting of lightning protection system should follow the principle of safety and reliability, but also have a certain sense of advance, so as to build a technologically advanced building curtain wall lightning protection system. In the lightning protection design of the building curtain wall, we should also make full use of the lightning connectors, down wires and grounding devices of the building, through the scientific application of these devices to realize the connection of the vertical keel, the horizontal keel and the building lightning protection net of the building curtain wall. finally, a relatively perfect whole of lightning protection is constructed. Through this design, the huge amount of electricity caused by lightning can be quickly transmitted to the ground, thus protecting the building curtain wall from lightning damage. In the design of the building curtain wall, most of the cover plate of the building curtain wall is designed as the curtain wall lightning connector, which makes the lightning current received by the curtain wall lightning connector can be led down through the lightning equalizing ring and lightning protection of the curtain wall. safely lead the lightning current to the lightning protection net of the building, so as to achieve a more ideal lightning protection effect.

Key points in the design of curtain wall

1. the curtain wall is a replaceable structure, and the service life of the structural design is not less than 25 years. The embedded parts are not easy to replace and should be considered according to 50 years. The structural design service life of long-span and large-scale supporting steel structure should be considered according to the main structure.

2. correctly understand and implement the standards and norms. The standard is the summary of mature experience, not the prospect of new technology. The specification does not limit the application of new technologies.

3. The safe selection of glass is a key problem in curtain wall design and structural design. Different types of safety glass and different properties should be selected according to the different requirements of different parts.

4. Curtain wall energy saving has become an important part of building energy saving in our country. The energy-saving design of curtain wall should consider the thermal insulation design in winter in cold areas, cold areas and mild areas, and the thermal insulation design in hot summer and cold winter areas and hot summer and warm winter areas. In the design, it should be considered that the energy-saving effect of insulating glass is much greater than that of single-layer glass. Adopting the structural form of heat-breaking curtain wall is the most effective way to save energy in curtain wall buildings.

All in all, in the design of curtain wall engineering, we should choose those highly qualified professional companies, so as to ensure that the design can achieve a more ideal effect. In addition, in order to improve the design level of the curtain wall, it is necessary to strictly review the design audit of the curtain wall project, and finally ensure the structural safety of the curtain wall project through the implementation of the relevant calculation and structural design of the curtain wall. to achieve a more ideal function. In order to achieve a good curtain wall design effect, it is necessary to strengthen the control of design, material selection, manufacture and installation, and finally achieve the ideal curtain wall engineering quality through the strict control of the whole process of curtain wall production.