Strut-and-tie model of the one-box–three-cell anchorage zone in cable-stayed bridges with three cable planes using a topology optimization method

Owing to the complex geometric configuration and mechanical behaviour of the one-box–three-cell cable–pylon anchorage zone, establishing an appropriate analytical model is conducive to the reinforcement design of the structure. This article proposes a tailored evolutionary structural optimization (ESO) method to generate a rational strut-and-tie model (STM) of the anchorage zone. In addition, a crack propagation model is presented to substantiate the effectiveness of the STM obtained by the tailored ESO method. The STMs of the one-box–three-cell and one-box–two-cell anchorage zones are compared. The influence of the thicknesses of the front walls, side walls and inner walls on the internal forces of the tie members in the STM is also explored. The results show that the thickness of the front walls has the greatest effect on the internal force of the tie members in the STM, whereas the thickness of the inner walls has almost no influence.