Abstract

In this research, the response of high voltage transmission towers under wind load patterns is discussed from the point of view of structural reliability. The paper focuses the attention on the response of two existing tension towers that are part of the 400 kV circuit at the perimeter of Mexico City. Two hundred nonlinear pushover analyses were carried out in detailed models in order to study peak demands in the critical structural elements in tension, compression and in the critical support to establish the vulnerability as a function of the: i) variability of the lateral load pattern and ii) the material overstrength from commercial profiles available in the local market. Based on the results, the global buckling of the elements in the mid-height led to a fragile collapse mechanism, regardless of the applied loading profile. This observation represents a research opportunity in the design practice for the existing towers. The study identifies a dependency between the collapse mechanism and the structure height, which is not currently considered by the specialized codes.

摘要

在这项研究中，从结构可靠性的角度讨论了高压输电塔在风荷载模式下的响应。本文重点关注作为墨西哥城周边 400 kV 电路一部分的两个现有张力塔的响应。在详细模型中进行了 200 次非线性 Pushover 分析，以研究关键结构元件在拉伸、压缩和关键支撑中的峰值需求，以确定脆弱性作为以下函数的函数：i) 横向载荷模式的可变性和ii) 当地市场上商业型材的材料强度过高。根据结果​​，无论施加的载荷分布如何，中高处元件的整体屈曲都会导致脆弱的坍塌机制。这一观察结果代表了现有塔楼设计实践中的研究机会。该研究确定了倒塌机制与结构高度之间的依赖关系，目前专业规范并未考虑这一点。