A brief discussion on mountain solar mount system and foundation
Publish Time：2022-10-13
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Solar power generation is one of the ways to utilize new energy in the world today. A large proportion of the areas with sufficient sunlight in my country are mountainous areas. In addition, the land policy has become more and more strict in recent years, and mountain photovoltaic power plants have become a new direction for photovoltaic power station construction. At present, among the photovoltaic power station projects under construction and proposed by our company, the proportion of mountain photovoltaic power stations is also showing an obvious increasing trend.
As the site of a solar power plant project, the mountain area has the advantages of abundant light resources, low land rental cost, convenient management, little disturbance to residents' lives, and high land utilization rate. At the same time, the mountainous area is far away from the densely populated areas and the main traffic roads in the city, which also causes many difficulties to the overall construction deployment during the construction period: the mountain surface is often covered with plants and forests, the surface is undulating, the terrain height difference is large, and it is easy to form mountain winds, bearing capacity The design value of and pull-out resistance should be higher than that of general areas; mountain terrain and slopes are dangerous, and personnel, equipment, and large-scale machinery enter the site for large-scale site leveling, especially when construction is carried out in sloping mountainous areas, the risk is very high; the rainy season landscape Confluence is likely to cause soil collapse and landslides, and corresponding preventive measures should be considered.
Due to the complexity of geological conditions in the construction of photovoltaic power plants in mountainous areas, the focus and difficulties are mainly concentrated in the construction of basic engineering.
1. Design features
(1) Geological disaster prevention design: The geological conditions in mountainous areas are complex and changeable, and geological disasters such as mountain torrents, landslides, soil collapses or debris flows are prone to occur. Therefore, strict geological disaster prevention measures should be taken when designing photovoltaic power plants, and slopes should be well prepared. Support and drainage facilities.
(2) Structural stability design: the uplift resistance of the foundation meets the requirements to ensure the stability of the soil around the foundation.
2. Construction characteristics
(1) Different geology, different construction methods. In order to save costs and improve efficiency, if the conditions are met, try to choose spiral steel piles. Corresponding construction methods shall be adopted for rock formations or other formations that are not suitable for rotating piles. Generally, the construction technology of anchor concrete pile and the construction technology of down-the-hole cast-in-place pile can be selected.
(2) The surface forms are different, and different equipments are used. If the terrain is flat and large-scale machinery and equipment can be driven into it, mechanical construction should be done as much as possible. Miniaturized equipment can be selected for steep slopes and difficult access for large machinery.
(3) During the construction process, attention should be paid to equipment production safety, personnel safety, lightning protection and fire prevention.
In the design, selection and installation of solar module mount in mountainous areas, fixed types are usually used in mountainous areas. When the photovoltaic array adopts a fixed arrangement, the optimal inclination angle should be combined with the local multi-year monthly average irradiance, direct component irradiance, scattered component irradiance, wind speed, rain, snow and other climatic conditions and technical and economic comparisons. design.
The load of the component support structure design mainly includes the self-weight of components such as the component, the wind pressure load, and the snow load. When calculating the support structure, the largest load is the wind load, and the wind load has a controlling effect on the photovoltaic support. For example, in Ningxia, my country, most of the battery array damage occurs in strong winds. Therefore, the wind load quasi-permanent value coefficient is taken as 1.0 in the load calculation of the photovoltaic support.
The support array needs to consider the lateral stability. Adding oblique upward tie bars on the side and back of the support will reduce the vibration of the support array and increase the stability of the support. If some windproof structural measures, such as windshield walls, are added to the windproof surface of the support array, the wind load coefficient of the photovoltaic array will be greatly reduced, thereby reducing the impact of wind load on the module support.
Wind load information acquisition. The basic wind pressure is generally obtained by querying the attached table of GB5009-2012 of the "Code for Loads of Building Structures". When the project site is not within the query range, it can be obtained by calculating the difference between the wind load values at nearby locations, or by using the local annual maximum wind speed data through the primary Nouri Equation Calculation. Basic wind pressure w0=1/2 *ρ*v2*S where ρ is the air density, v is the wind speed, and S is the windward area.
The design and construction of mountain power stations should be based on the actual situation of the construction site, and follow the principles of reducing investment, improving system efficiency, and ensuring system operation safety. The brackets and foundations must be able to adapt to changes in complex terrain, and should have certain adjustment capabilities. As far as possible, the square array and the terrain must have a high degree of matching, and their strength must meet the relevant technical specifications and standards.
Due to the complexity of geological conditions in the construction of photovoltaic power plants in mountainous areas, the focus and difficulties are mainly concentrated in the construction of basic engineering.
1. Design features
(1) Geological disaster prevention design: The geological conditions in mountainous areas are complex and changeable, and geological disasters such as mountain torrents, landslides, soil collapses or debris flows are prone to occur. Therefore, strict geological disaster prevention measures should be taken when designing photovoltaic power plants, and slopes should be well prepared. Support and drainage facilities.
(2) Structural stability design: the uplift resistance of the foundation meets the requirements to ensure the stability of the soil around the foundation.
2. Construction characteristics
(1) Different geology, different construction methods. In order to save costs and improve efficiency, if the conditions are met, try to choose spiral steel piles. Corresponding construction methods shall be adopted for rock formations or other formations that are not suitable for rotating piles. Generally, the construction technology of anchor concrete pile and the construction technology of down-the-hole cast-in-place pile can be selected.
(2) The surface forms are different, and different equipments are used. If the terrain is flat and large-scale machinery and equipment can be driven into it, mechanical construction should be done as much as possible. Miniaturized equipment can be selected for steep slopes and difficult access for large machinery.
(3) During the construction process, attention should be paid to equipment production safety, personnel safety, lightning protection and fire prevention.
In the design, selection and installation of solar module mount in mountainous areas, fixed types are usually used in mountainous areas. When the photovoltaic array adopts a fixed arrangement, the optimal inclination angle should be combined with the local multi-year monthly average irradiance, direct component irradiance, scattered component irradiance, wind speed, rain, snow and other climatic conditions and technical and economic comparisons. design.
The load of the component support structure design mainly includes the self-weight of components such as the component, the wind pressure load, and the snow load. When calculating the support structure, the largest load is the wind load, and the wind load has a controlling effect on the photovoltaic support. For example, in Ningxia, my country, most of the battery array damage occurs in strong winds. Therefore, the wind load quasi-permanent value coefficient is taken as 1.0 in the load calculation of the photovoltaic support.
The support array needs to consider the lateral stability. Adding oblique upward tie bars on the side and back of the support will reduce the vibration of the support array and increase the stability of the support. If some windproof structural measures, such as windshield walls, are added to the windproof surface of the support array, the wind load coefficient of the photovoltaic array will be greatly reduced, thereby reducing the impact of wind load on the module support.
Wind load information acquisition. The basic wind pressure is generally obtained by querying the attached table of GB5009-2012 of the "Code for Loads of Building Structures". When the project site is not within the query range, it can be obtained by calculating the difference between the wind load values at nearby locations, or by using the local annual maximum wind speed data through the primary Nouri Equation Calculation. Basic wind pressure w0=1/2 *ρ*v2*S where ρ is the air density, v is the wind speed, and S is the windward area.
The design and construction of mountain power stations should be based on the actual situation of the construction site, and follow the principles of reducing investment, improving system efficiency, and ensuring system operation safety. The brackets and foundations must be able to adapt to changes in complex terrain, and should have certain adjustment capabilities. As far as possible, the square array and the terrain must have a high degree of matching, and their strength must meet the relevant technical specifications and standards.