Category: Roads

  • AASHTO green book equation in wind farms road design

    I’ve been recently asked to justify the roadbed thickness for a wind farm I’ve designed. For several reasons (mainly because the majority of documents are redacted by non-civil engineers) the engineering companies supporting our customer ask for a written demonstration that the road design comply with the requirement of the famous AASTHO 1993 green book….

  • Wind farm internal roads bends additional widening

    One of the problems frequently found in wind farm project and construction is that road bends with a reduced radius often needs an additional widening to allow the passage of the trucks with the WTGs components. Normally the biggest problems come with the blades. I suggest using a commercial software such as AutoTURN to estimate…

  • Wind farm civil works projects: typical errors

    Here you have my collection of errors I frequently see when I check wind farm project developed by external companies. Being a quite peculiar sector is no surprise that I normally found several mistakes: here you have the most commons.   Error #1: two levels crane pad / foundation area designed without considering the slopes…

  • Floating roads on peat

    Floating roads are a solution developed in Scotland during the construction of several Km of internal wind farms roads on very poor, organic materials such as peat. It is an interesting constructive technology, developed on a very compressible, decayed material normally considered as the worst possible subgrade for road construction. In a normal highway project,…

  • Good practice during windfarm construction

    “Good practice during windfarm construction” is a document produced by several Scottish agencies (Scottish Renewables, Scottish Natural Heritage, and the local Environmental Protection Agency and Forestry Commission). It provides several useful advices on wind farm construction, based on the experience they gained with the development of several pretty big projects (for instance Whitelee W.F., with…

  • Tensar Triax geogrid use in wind farms

    Here you have a real world example of geogrid use. We are in a wind farm in southern Spain, and thanks to previous experience with this technology the client decided to use a Tensar Triax geogrid TX160. This is a triangular geogrid (the “old school” version was square). It seems that the triangular geometry guarantee…

  • Maximum wind farm internal road gradient

    This is another standard problem I found in the wind farm I’m working with: mountainous areas, with difficult access and very strong inclination. The standard maximum slope imposed by several manufacturers (for instance Repower and Gamesa) for safe transport on gravel roads is about 6% to 7%. Above 7% other technical solution may be necessary,…

  • Geotextile vs Geogrid: which is the best solution?

    This is a debate we are living each time we have to build internal roads on soils with a low (<5) to very low (<2) CBR. Basically when the others alternatives (mainly soil substitution and soil improvement) are not feasible we are adopting two different solution, either a strong geotextile with reinforcement and separation properties…