From：Serve (Xiamen) New Energy Co., Ltd. Release time：2019-09-06
Overview：List of advantages and disadvantages of basic selection of photovoltaic power station photovoltaic support
List of advantages and disadvantages of basic selection of photovoltaic power station photovoltaic support
01, reinforced concrete independent foundation
A reinforced concrete independent foundation is respectively arranged under the front and rear columns of the photovoltaic support, and is composed of a basic bottom plate (cushion) and a basic short column above the bottom plate. The top part of the short column is provided with embedded parts (steel plate or anchor bolt) connected with the upper photovoltaic support, which requires a certain depth of burial and a certain base area; the foundation floor is covered with soil, and the basic self-weight and foundation cover soil gravity are used together to resist environmental load. The upper pull force uses a larger base area to disperse the vertical load of the photovoltaic support downward, and the horizontal load is resisted by the friction between the base bottom surface and the soil and the resistance of the base side and the soil.
The transmission path is clear, the force is reliable, the scope of application is wide, the construction does not require special construction machinery, and the ability to resist horizontal loads is the strongest, and it is resistant to flood and wind.
The required amount of reinforced concrete is large, artificial, and the earthwork excavation and backfilling volume is large, the construction period is long, and the damage to the environment is large. The limitations of this foundation are too large and are rarely used in today's photovoltaic power plants.
02, reinforced concrete strip foundation:
By setting the foundation beam between the front and rear pillars of the photovoltaic support, the foundation center of gravity is moved between the front and rear columns, and the basic anti-overturning force arm is increased, and the photovoltaic support overturning moment can be resisted by the self-weight only against the wind load; the strip foundation It has a large contact area with the foundation soil and is suitable for areas where the site is relatively flat and the groundwater level is low. Because the surface area of the foundation is relatively large, it is generally buried between 200 and 300 mm.
The earthwork excavation volume is small, no special construction tools are needed, and the construction process is simple.
It requires a large area of field level, which has a great impact on the environment, a large demand for concrete, and a long maintenance period, requiring a lot of labor. The foundation depth is not enough to resist flooding.
03. Spiral steel pile foundation:
The hot-dip galvanized steel pipe pile with spiral blades is used under the front and rear columns of the photovoltaic support. The rotating blades can be large or small, can be continuously interrupted, and continuous welding is used between the rotating blades and the steel pipe. During the construction process, professional machinery is used to screw it into the soil.
The upper part of the screw pile foundation is exposed to the ground, and a screw connection is adopted between the upper pile and the upper bracket. Through the side friction between the side of the steel pipe pile and the soil, especially the bite force between the rotating blade and the soil resists the pull-up force and the vertical load, and the pile-soil between the pile, the spiral blade and the soil The effect is against horizontal loads.
The construction speed is fast, no need for site leveling, no earthwork excavation, maximum protection of the field vegetation, and the site is easy to restore the original appearance, convenient to adjust the upper bracket, and the height of the bracket can be adjusted with the terrain. The impact on the environment is small, the labor required is small, and the screw pile can be used for secondary use.
The cost is relatively high, and special construction machinery is needed. The most important thing is that the basic horizontal bearing capacity is closely related to the compactness of the soil layer. The screw pile foundation requires the soil layer to have a certain compactness, especially the shallow soil layer close to the ground. Can be too loose; the screw pile foundation has poor corrosion resistance, although thick hot dip galvanizing can be used, but it is difficult to adapt to a strong corrosive environment.