Simplified method for predicting the internal forces in strut‐and‐tie model of cable pylon anchorage zone in a cable‐stayed bridge

Abstract

The mechanical behavior of cable pylon anchorage zone in a cable‐stayed bridge is complex due to high localized stresses. A strut‐and‐tie model (STM) has been introduced in this paper, which is recommended as an efficient way to analyze the disturbed region. However, predicting the internal forces in the tie members in the STM by integrating stresses was time‐consuming and inefficient. To address this issue, the principle of minimum strain energy was used to analyze the STM of the cable pylon anchorage zone. A simplified method was presented to assess the internal forces in the cable pylon anchorage zone. Moreover, an actual bridge (Cao'e River Bridge) was employed to be analyzed, and the prestressed steel strands in the bridge were obtained by the simplified method. A full‐scale test model of the bridge was fabricated to validate the accuracy of the simplified method. Furthermore, based on the simplified method, the effect of the thickness of front wall, the length of inner opening straight section, the thickness of side wall, the thickness of inner wall and the width of inner opening straight section on the internal force in the tie members in the STM was studied. The results show that the length of inner opening straight section has negligible effect on the internal forces in all tie members. Compared with the thickness of the side wall, the thickness of inner wall and the width of inner opening straight section have limited effect on the internal force of tie members. This study was expected to promote the design of cable pylon anchorage zone.