I  Project Overview

1. Project Introduction：

The project is located in Xialuokema Township, Luhuo County, Ganzi Prefecture, with a total installed capacity of 20WM and an average altitude of about 4170 meters. The project adopts the model of "locally build photovoltaic power stations and local poverty alleviation" and is a key project for poverty alleviation development in Ganzi Prefecture.

2. Construction Geological Conditions：

The construction site of photovoltaic power station has high altitude, low temperature during construction period, and weak road transportation conditions. It is mainly composed of long ridge-shaped mountain tops and wide and gentle slopes. The middle and northern part of the site is micro-grooved. The altitude is 4137.5~4184.0m, and the maximum height difference is about 47m. There is spring water discharge in the micro-groove north of the middle, and the terrain is low in the rainy season. There is a short-lived water flow, which has a certain impact on the foundation and construction. The surface vegetation is plateau meadow. Seasonally frozen soil will affect the stability of the foundation to a certain extent when it is frozen and thawed. The foundation soil is mainly crushed silty clay, crushed stone and sandstone are all medium-soft soils, and the thickness of the overburden is less than 50m. There are seasonal water flowing gullies, which are the main drainage channels. Surface water and upper stagnant water are weakly corrosive to the concrete structure.

I  Project Features:

1. Seasonal frozen soil exists at the station site in winter, and the freezing depth is about 0.6-0.8m. Therefore, the foundations of inverters, box transformers and other constructions (structures) adopt multiple comprehensive foundation forms such as spiral piles and microporous piles. Take materials, dig out soft fillings, and backfill gravel, block stones, plain concrete or lime soil to enhance the strength, integrity, and stability of the foundation.

2. In view of its geological characteristics, the photovoltaic panel array adopts microporous cast-in-place piles, and the pile end bearing layer is on plastic silty clay, crushed stone or sandstone.

3. Seasonal frozen soil is distributed in the site in winter. The photovoltaic modules adopt a combination of soil and rock foundation, cut out the locally prominent bedrock, and set up a "cushion layer" to reduce uneven settlement.

4. The construction of the project has caused a certain degree of damage to the site environment. During the construction of the site, the waste soil should be piled up reasonably, and the areas with large water catchment should be avoided or drainage measures should be taken to protect the vegetation. The construction wound area should be restored as much as possible Vegetation.

5. The erection of the photovoltaic array should reserve a certain safe distance from the seasonal water gully to avoid submergence and erosion, or siltation caused by sludge flow. Cause damage to the components. The small gully increases the depth of the foundation, and adopts effective interception and drainage measures to restore vegetation as much as possible.

6. Take drainage and pit wall support measures to protect the building and component foundations to prevent stagnant water on the surface in the rainy season.

7. The roads in the station are mainly arranged along the contour lines, and the sections with high terrain and good surface drainage should be selected, and drainage measures such as retaining walls and culverts should be constructed. The slope rate method or retaining wall and other measures are adopted for treatment, and the foundation should be properly buried to reduce the possibility of scouring and collapse by storm.