Detta examensarbete har gjorts i syfte att få fram förankringslängder till ett bergförankrat vindkraftverk. Målet med examensarbetet har varit att få fram längder på förankringstag och en prövning av flera olika stagvarianter har gjorts. Det dimensionerande momentet och egentyngden på vindkraftverket har tagits från ett tidigare projekt beläget i Solberg. Dessa krafter har fördelats ut till stagen och förankringslängder har tagits fram. De delar som har hanterats i rapporten utöver dimensioneringen är stagvarianter, borrning av stag, injekteringsbruk och provdragning. En bottenplatta i form av en oktogon har använts i dimensioneringsprocessen. Stagen har placerats i en cirkulär form i ett lager. Tre olika metoder har använts för att få den dimensionerande längden på förankringen. De tre metoderna hanterar: Vidhäftning mellan berg      och injekteringsbruk Vidhäftning mellan stål      och injekteringsbruk Bergkonsmetoden En analys har gjorts mellan dessa. För att lösa problemet har en litteraturstudie i olika böcker och eurokoder gjorts. Intervjuer med personer från olika företag med anknytning till förankringar har varit en bra grund till examensarbetet. Efter avslutade litteraturstudier har formler för beräkning av problemet tagits fram och fyra excel-modeller har upprättats för beräkning av förankringslängder. Ett beräkningsexempel på ett stag från Pretec har gjorts och förankringslängder har tagits fram. I resultaten har dragkraften i varje stag varierat mellan 1725 – 3747 kN, detta kan ses i tabell 6. Förankringsdjupet för de olika lastfallen varierar mellan 3 – 10 meter. De slutsatser som har gjorts är att förankringslängden ökar med sprucket berg då vidhäftningen är försämrad och att förankringslängden ökar med ökad påfrestning hos stagen. Metoden där förankringslängden bestäms med hjälp av bergkonsmetoden kan uteslutas vid homogent berg. / This master’s dissertation has been made in order to gain a deeper knowledge of how to design anchors to a wind turbine on rock. The goal of the master’s dissertation has been to produce lengths of anchors and trials of several different anchors have been made. The design overturning moment and the weight of the construction that occur in wind turbine has been distributed to the anchors and anchorage lengths have been calculated. The areas that have been handled are anchor variants, drilling, grouting and testing of the anchorage. A bottom plate in the form of an octagon has been used in the design process. The anchors have been placed into a circular shape in one layer. Three different methods of solution were used to design the length of the anchorage. The three different methods manage: Bond between rock and grout Adhesion between steel and grout Rock cone method An analysis has been made between them. To overcome this, a literature study in various books and Eurocodes have been made. Interviews with people from various companies related to the anchorages have been a good foundation for this master’s dissertation. After completing literary studies, the formulas for calculating the problem has been developed and several Excel models have been established for calculating the anchorage length. The results of the pulling force varied between 1725 - 3747 kN. Anchor lengths that have been calculated vary between 3-10 meters. A calculating example of an anchor from Pretec has been made and the anchorage length has been produced. The conclusions are that the anchor length increases with fractured rock where the adhesion is impaired and that the anchoring length increases with increased tension in the anchors. The method in which the anchor is determined by the length of the rock cone is very conservative and may be omitted.

The objective of dissertation is to find the approaches for processing the data extracted from the reports that document the performing of acceptance tests of ground anchors. The purpose of this activity is to allow further utilization of this data for designing practice. 795 test records were collected. It is essential for the correctness of analysis, that the whole anchor bond must be placed in homogeneous material. The records for anchors that don’t fulfilled this condition were removed. The set of 379 records of anchors installed in six different soil types during construction work in Czech Republic remained. All those anchors were tested according the demands of european standard ČSN EN 1537:2001, valid until 2013. The methodics based on the mathematical statistics, regression analysis and probability methods were compiled during solving the task defined above. The major result of data processing that was performed via methodics based on combination of mathematical statistics and probability simulation methods is the set of bond shear stress parameter values elaborated for variety of soil types. The regression model for determination of the force-displacement curve and the model predicting the creep behavior of loaded ground anchor were constructed, where the creep value is dependent on the tendon bond length, tendon free length and on the level of prestressing force. The description of full-scale experiment, whose results were used for verification of assumptions incorporated in relevant methodics, is included. The example of determining the probability of failure of anchored structure using the stochastic simulation technique is mentioned also, where the previously obtained results are used as input values for this calculation. Moreover, the software application serving for automatization of processes associated to conducting of the tests of ground anchors and to creating the test report is introduced.