Collecting the information
Within the framework of collecting the information, documents pertaining to a given location are gathered and analyzed. This includes, apart from aerial photography, mainly geological and hydrogeological maps, as well as topographic maps and climate data. Knowledge of the local conditions, obtained in this manner, serves as a basis for the development of a catalogue of questions for the early topographic works. In this manner, it is possible to ensure precise design with reference to a given objective.
Preliminary survey of the location
On the basis of the initial knowledge obtained while collecting information, a survey of the local conditions is conducted. Usually, it includes the following works:
- engineering measurements on site in order to determine the local morphological conditions
- determination of near-surface geological conditions using microprobes inserted to the maximum depth of 3 m below the ground level, including soil sampling
- determination of depth of loose clastic rock using probes inserted to maximum depth of 3 m below the ground level
- development of a map of hydraulic conditions, that is, the drainage system
- getting familiar with the local flora and fauna
- a description of sociological conditions (settlements) and use of land (agriculture, mining)
Soil samples collected during field works are laboratory tested.
Chemical analyses determine the level of aggressiveness towards steel in the soil layers considered for the installation of piles. The particle size distribution of loose clastic rock is determined on the basis of sieve and slurry tests.
The results of data collection, site survey and laboratory tests are the basis for the report, and they are subject to interpretation and assessment from the perspective of the planned solar installation. At the same time, soil indicators that are necessary for further design are specified and the guidelines for the performance of works as well as recommendations for the topography of land and waste management are given. Moreover, a preliminary measurement of the necessary probe insertion depth for steel piles is conducted, together with a quality assessment.
For the purpose of the final dimensioning of the insertion depth after the assessment of the ground conditions, pull-out tests are conducted in representative points within the planned installation site.
In addition to the first report, an expert report is performed with a description of the ground conditions, the necessary insertion depth and the minimum weight of the profiles inserted, providing the parameters of pressure distribution in the soil and structure necessary to perform static calculations of the structure.