It has been projected the expansion of a wind farm in Becerril del Monte (Palencia, Spain) in which it is planned to use a hybrid tower type, consisting of a section of concrete composed of segments (precast concrete) whose height can reach 50 meters and a length of steel cash. Considering the particularities of the tower, to the study of the foundation, the geotechnical investigation survey performed consisted of:
- Geotechnical drillings.
- MASW seismic test for determining the speed of shear waves (Vs) .
- Identification laboratory tests, strength and deformability test.
- Chemical tests for determining the aggressiveness of ground against the concrete.
The geotechnical study aims to determine the nature and properties of soil aspects necessary to design the structure, surface improvements and the type of foundation, considering the following objectives:
-. Identify constraints and geotechnical problems of the site under study.
-. Study of natural hazards. Identify and define the geological risks and assets geomorphological processes that may affect the new project. Geomorphological mapping include the following: escarpments or unstable areas, drainage channels, alluvial fans, processes of rapid erosion or deposition, dissolution or subsurface forms acarcavamiento, endorreicas surface areas with accumulation of salts: sabkkhas, salt and salt crusts, discharges due to human activity, rocky outcrops and evaluation of the effects of weathering processes, presence of unstable soils or very low bearing capacity).
-. Provide knowledge of geotechnical characteristics of the land, according to the project structure.
-. Existing zoning different lithologies in order to define the most appropriate foundations in each project area.
-. Determine the geotechnical parameters of each lithology detected for project design, where different solutions according to the foundation load stresses are discussed.
-. Recommendations for foundations of structures. Findings in relation to the overall stability of the foundation bearing capacity against the vertical ground failure, uprooting, horizontal ground failure, and structural failure.
-. Determine levels of corrosion and aggressiveness of the land to the maximum depth of execution of foundations.