Glass greenhouse structure mainly includes greenhouse foundation, greenhouse steel structure and aluminum alloy structure.
1. Basic classification The foundation of the glass greenhouse is divided into independent column foundation and strip foundation. Independent foundations can be used for inner columns or side columns, and strip foundations are mainly used for side walls and inner partition walls.
2. The basis of design requirements Before design, the geological data of the construction site should be carefully analyzed. One is the geological survey report of the site (for important large-scale greenhouse projects); the other is the construction site test (for general projects); The third is based on experience and reference geological data of nearby projects (for small projects). When designing the foundation, in addition to meeting the requirements of strength, it should also have sufficient stability and the ability to resist uneven settlement. The foundation connected with the column supports should also have sufficient horizontal force transmission and space stability. The bottom surface of the greenhouse should be located below the frozen soil layer, and the heating greenhouse can consider the influence of heating on the freezing depth of the foundation according to the climate and soil quality. Generally, the bottom of the foundation should be more than 0.5 meters below the outdoor ground, and the distance between the top of the foundation and the outdoor ground should be greater than 0.1 meters to prevent the foundation from being exposed and adversely affecting cultivation. Except for special requirements, the distance between the top surface of the greenhouse foundation and the indoor ground should be greater than 0.4 meters. The embedded parts connected with the steel structure of the greenhouse are all set on the top of the foundation, and the design of the embedded parts is also an important part of the foundation design. The connection between the embedded parts and the superstructure mainly includes hinged connection, consolidation and elastic connection. According to the different connection methods, the design and construction methods are also different, but all embedded parts must ensure a good connection with the foundation and ensure that the upper structure is transferred. The coming power is correctly transmitted to the foundation.
3. Foundation materials and construction characteristics
(1) Independent foundation. Reinforced concrete is usually used. From the construction method, the independent foundation can be divided into two methods: full cast-in-place and partial cast-in-place. Full cast-in-place adopts the method of construction site support and integral pouring; part of the cast-in-place method adopts the method of foundation short column prefabrication and foundation cushion on-site pouring. The two methods can be selected according to the specific situation. The cast-in-place method has the characteristics of good integrity and low cost; some cast-in-place methods have higher cost but fast construction speed, and the construction quality is easier to guarantee.
(2) Strip foundation. The masonry structure (brick, stone) is usually used, and the construction is also carried out by on-site masonry. A reinforced concrete ring beam is often set on the top of the foundation to install embedded parts and increase the stiffness of the foundation. In addition, the side wall foundation can also adopt a mixed use of independent foundation and strip foundation. With the coming force, the strip foundation is only used as a part of the partition member. (3) Precautions for foundation construction. During foundation construction, the correctness of the column height and axis position should be ensured. The equipment, pipeline openings and installation should be buried in time. It is strictly forbidden to gouge after construction to damage the foundation.
