本研究基于斜拉桥和矮塔斜拉桥的拉索安全性评估，为比较斜拉桥和矮塔斜拉桥提供了新的观点。由于二者都使用拉索，人们通常认为这两种类型的桥梁具有相同的结构。但是，国际桥梁设计标准规定了二者各自的拉索安全系数。为了纠正这一误解，本研究通过考虑各种异常因素和破坏因素（如过载、钢索损耗和钢索腐蚀）的影响，对在疲劳和极限状态下的拉索的安全系数进行了比较。本研究的主要目的是解释两种类型桥梁之间的结构差异，并通过采用确定性和非确定性方法来评估其结构冗余。为了实现这一目标，根据日本现行的拉索设计指南，本文建立了两座桥的三维模型。在达到桥梁模型的平衡状态之后，以参数化方式对拉索的不同安全系数进行了静态分析。最后，采用一阶可靠性方法和蒙特卡洛方法确定了拉索的可靠性指标。分析结果表明，在相同的荷载条件下，斜拉桥和矮塔斜拉桥在不同安全系数下具有不同的结构冗余度。此外，随着拉索的安全系数的增加，其结构上的冗余大大增加。

This study provides new insights into the comparison of cable-stayed and extradosed bridges based on the safety assessment of their stay cables. These bridges are often regarded as identical structures owing to the use of inclined cables; however, the international standards for bridge design stipulate different safety factors for stay cables of both types of bridges. To address this misconception, a comparative study was carried out on the safety factors of stay cables under fatigue and ultimate limit states by considering the effects of various untoward and damaging factors, such as overloading, cable loss, and corrosion. The primary goal of this study is to describe the structural disparities between both types of bridges and evaluate their structural redundancies by employing deterministic and nondeterministic methods. To
achieve this goal, three-dimensional finite-element models of both bridges were developed based on the current design guidelines for stay cables in Japan. After the balanced states of the bridge models were achieved, static analyses were performed for different safety factors of stay cables in a parametric manner. Finally, the first-order reliability method and Monte Carlo method were applied to determine the reliability index of stay cables. The analysis results show that cable-stayed and extradosed bridges exhibit different structural redundancies for different safety factors under the same loading conditions. Moreover, a significant increase in structural redundancy occurs with an incremental increase in the safety factors of stay cables.