How can transmission line towers improve their disaster resistance through structural design in areas prone to strong winds or earthquakes?
Publish Time: 2025-11-07
As the "backbone" of the power system, transmission line towers bear the heavy responsibility of supporting conductors and ensuring electrical clearances and mechanical safety. In coastal areas prone to strong winds or seismically active zones, these towers not only need to withstand conventional loads but also face the severe test of extreme natural disasters. To ensure the continuous and stable operation of the power grid in harsh environments, modern transmission line towers have significantly improved their wind and earthquake resistance through multiple design strategies, including scientific structural optimization, material upgrades, and connection reinforcement.1. Wind-resistant design: From aerodynamic shape to overall stiffness optimizationIn areas with strong winds, wind load is the most significant lateral force acting on the tower. To reduce wind resistance and suppress vortex-induced vibration, engineers employ various structural countermeasures: First, optimizing tower type selection—for example, widely using cat-head or goblet-shaped towers in typhoon-prone areas, whose symmetrical, streamlined crossarm layout effectively disperses wind pressure and reduces windward area; second, conducting wind tunnel tests and CFD simulations on angle steel components, adjusting the density and angle of the members to avoid resonant frequencies; furthermore, increasing the proportion of diagonal members in the tower body and setting up cross-bracing systems can significantly improve the overall stiffness and torsional performance of the space truss, preventing local instability. Some ultra-high voltage lines also introduce tuned mass dampers or flexible cable systems to actively suppress tower top swaying caused by strong winds.2. Seismic Design: Ductile Structure and Foundation SynergyUnder seismic loading, transmission line towers need to possess good ductility and energy dissipation capabilities. Traditional rigid connections are prone to brittle failure in strong earthquakes; therefore, modern seismic-resistant towers generally adopt semi-rigid node designs, allowing controllable micro-deformation at bolted connections to absorb seismic energy. Meanwhile, the use of Q355 and higher strength low-alloy steel not only improves load-bearing capacity but also enhances material toughness, reducing the risk of low-temperature brittle fracture. More importantly, the towers and foundations form a collaborative "structure-foundation" system: in soft soil or liquefiable ground areas, deep pile foundations or enlarged pile caps are used to enhance overall stability; in high-intensity earthquake zones, some projects pilot seismic isolation bearings or friction energy dissipation devices to dissipate seismic input energy at the foundation level, protecting the upper tower structure.3. Connection and Redundancy Design: Enhancing System RobustnessTransmission line towers are assembled from hundreds of angle steel components using high-strength bolts, and the reliability of these connections directly determines overall safety. In disaster-prone areas, the design emphasizes redundant force transmission paths—even if individual members fail, the load can still be transmitted through other paths, preventing cascading collapses. Simultaneously, thickened node plates, double shear connections, or pre-tightened monitoring bolts are used at key nodes to ensure they do not loosen or fail under repeated dynamic loads. The thickness of the hot-dip galvanized layer is also increased accordingly, supplemented with sealant to fill gaps and prevent corrosion from weakening the connection strength.4. Intelligent Monitoring and Resilience AssessmentWith the development of digital technology, transmission line towers are equipped with strain gauges, inclinometers, and accelerometers at key locations such as tower legs and crossarms to transmit wind vibration response and displacement data in real time. Combined with meteorological early warning and earthquake rapid reporting, this enables pre-disaster load pre-adjustment and rapid post-disaster assessment, significantly improving grid resilience.In summary, the disaster resistance capability of transmission line towers in areas prone to strong winds or earthquakes does not rely on a single measure. Instead, it is achieved through the integration of multiple technologies, including aerodynamic optimization, material reinforcement, nodal ductility design, foundation coordination, and intelligent sensing, constructing a resilient structural system that is "resistant, stable, minimizes damage, and recovers quickly." This not only ensures the safety of the nation's energy artery but also provides a solid model for infrastructure construction in an era of frequent extreme weather events.
