Abstract:
The grouting layer of the wind turbine foundation of with prestressed anchor bolts often occurred cracking and fracturing near its edge. The fracture section is neat and smooth. The linear elastic fracture mechanics model of the grouting layer is developed by FRANC-2D to analyze the crack path and the history of the stress intensity factors. The simulation results show that the crack begins at the junction of the grouting layer and the steel plate,and then propagates almost horizontally to the outer edge. Subsequently,the crack develops downward along 45 degrees until reaches the edge of the grouting layer. The mode-I stress intensity factor decreases at first,then increases,and decreases again during crack propagation. A local minimum value occurs near 0.2 times the total length of the crack,which can be used to evaluate the ultimate bearing capacity of the grouting layer. The parametric analyses of different grouting layer thicknesses and extension widths show that crack propagation is easier with the increasing thickness,while more difficult with the increasing extension width. Moreover,the influence of the extension width is more obvious. Based on parametric analyses and dimensional analyses,the calculation formula for the ultimate bearing capacity of the grouting layer and the design suggestions for engineering practices are proposed. The validity and applicability of the formula are verified by the linear elastic fracture mechanics and fatigue fracture analyses of practical engineering.