I  Project Overview

1. Project Introduction：

 The total installed capacity of the project is 10MW. It uses a large area of tidal flat resources and wasteland that is not suitable for crops and trees. The solar energy resources are relatively abundant and the development prospects are broad. It is the first photovoltaic power station in China to apply screw pile technology.

2. Construction Geological Conditions：

The project is located in Dongying, Shandong, bordering the estuary of the Yellow River, which belongs to the coastal beach. The soil is mainly soft plastic and plastic cohesive soil, which has collapsibility and low bearing capacity. It is not suitable for the foundation supporting layer of traditional concrete buildings. The foundation soil is slightly corrosive to concrete and steel structures. The groundwater level of the site is high and it is close to the surface, which is prone to water storage in the rainy season.

I  Project Features:

The groundwater level is high and close to the surface. The main bearing layer is clay and plastic soft soil. The difference in bearing capacity is easy to collapse. Therefore, when designing the foundation, consider:

1. Backfill the foundation pits and trenches in the site, excavate the original soft plastic cohesive soil base and backfill the gravel, lay a layer of 200mm thick stones, and then carry out the foundation construction. Return to inspection after one year of operation, there are no obvious settlement points, the maximum settlement does not exceed 50mm, and the settlement area at each point does not exceed 1 square meter.

2. The photovoltaic panel array adopts an independent foundation. Buildings (structures) such as inverters and box transformers all adopt the method of increasing the height of the foundation. Steel pipes and supports are all hot-dip galvanized for corrosion protection, and drainage and pit wall support measures are taken at the same time.

3. Change its mouth-shaped cable trench pressure top to rectangular pressure top, adopt light concrete cover plate, both ends of the cover plate are flush with the outside of the cable trench, outdoor circuit breaker foundation and main transformer foundation are constructed with "mirror surface" concrete technology. The use of prefabricated concrete manhole covers instead of cast iron manhole covers improves the look and feel and durability.

4. "S"-shaped anti-sinking is set at the grounding down-conductor parts; the same axial structure and the support grounding wires are set on the same side to achieve a neat and consistent effect.

5. The pre-embedded cable pipe in the outdoor site and the inlet of the rear-mounted equipment mechanism box are connected by a metal movable sleeve to ensure that there is no exposed part of the cable between the cable pipe and the equipment. The use of heat-shrinkable tubing technology to make cable heads effectively solves the complex problems of plastic heading technology, large gaps in the cable arrangement, and aging. To

6. After the injection of plain concrete on the slope of the foundation pit is completed, the excavation of the drainage ditch by the side of the pit starts. The drainage ditch is set close to the side slope, and a water collection pit is set at the corner of the foundation pit. During the construction process, the road facilities must be drained smoothly to prevent the ground from draining underground or soaking the foundation pit, causing slope landslides and landslides.