Numerical Simulation and Fatigue Analysis of the Grout Layer Replacement for Horizontal Joint of Wind Turbine Prestressed Concrete Tower

There are many engineering applications of prestressed concrete tower as the wind turbine support structure, and the concrete tower has the advantages of applicability and economy with good prospects. This paper proposes a grout layer replacement scheme for the problem of grout missing in the horizontal joint of concrete tower segments, and conducts a series of numerical simulation and fatigue analysis. The simulation results show that, for the case of grout missing, there is an obvious stress unevenness in the local area of severe grout missing. The concrete compressive stress decreases, tensile stress increases, tensile damage zone develops, and steel rebars stress increases, which can lead to local concrete cracking and blocks falling. For the case of grout filling and replacement completion, using no expansion grout for repair makes little contributions to the recovery of concrete stress, while using slight expansion grout can restore the concrete local stress to an even state. The fatigue analysis results show that, for the case of grout missing, the fatigue damage factors greatly exceed the limit, indicating a short fatigue life and the potential risk of local failure. For the case of grout filling and replacement completion, using no expansion grout cannot decrease fatigue damage, while using slight expansion grout can decrease fatigue damage and improve fatigue life. This paper provides the investigation into the effectiveness of grout layer replacement for horizontal joint, and the presented results can provide technical supports for the analysis and solution of grout missing problems.