The wind resistance of transmission towers is not only affected by wind load, but also by service environment. This study uses the world's second Ultra High Voltage Direct Current transmission project - Xinjiang & PLUSMN;800 kV Tianzhong Line UHV DC transmission project - to develop a fragility analysis method for transmission towers in saline soil under wind loads to investigate the change of wind loads fragility of transmission towers in long-term service in the saline soil environment. It develops a tower-line-foundation (3 T-2L-F) system model considering soil-structure interaction. In addition, this research addresses the durability damage of the transmission tower using field investigation data and material degradation models and analyzes the influence of various durability damage components on the natural vibration mode of the basic of 3 T-2L-F model. Finally, it builds the structure-wind samples utilizing a Latin hypercube sampling method and explores the time histories analysis, the pushover analyses, and the time-varying fragility analyses considering the uncertainty of materials and wind loads. The findings indicate that the 3 T-2L-F model accurately simulates the actual situation of the transmission tower. The fragility of a transmission tower subjected to wind loads is proportional to the degree of material damage and the strength of wind loads.

The deformations revealed by us in the ancient buildings of the village of Tsymyti indicate very strong seismic oscillations. The displacement of a block weighing 25 t against the slope of the relief indicates very strong accelerations of the soil-more than 1 g. Thus, the local intensity of seismic oscillations is at least Il = IX-X. In the walls of ancestral towers and burial crypts, it is possible to identify a significant number of extended interblock cracks, tilts, and collapses of walls and their parts. Rotations of building elements and deformations of window openings are also revealed. The distribution of the tilts of the walls shows their general declination to the west. According to the same azimuth, the abovementioned multiton block was ejected. The deformation of the window openings also took place in the walls of the sublatitudinal orientation, i.e., possibly from the western direction. The age of the towers in Tsymyti has two periods: 15th-16th centuries (use in the construction of dry masonry without cement) and 16th-17th centuries (use of masonry with cement mortar). It is possible that the change in the type of construction was caused by a seismic event. The same earthquake, apparently, damaged the Dzivgis fortress, located lower down the valley of the Fiagdon River. The trend of the outer wall of the fortress coincided with the direction of seismic oscillations (along the east-northeast-west-southwest axis), which approximately coincides with the sublatitudinal direction of seismic oscillation in Tsymyti. The first earthquake probably also damaged the Gutnov family tower in Dzivgis, built in the 15th-16th centuries. The tower was mostly repaired, and the cracks visible in the walls of the tower to this day appeared in it during the second earthquake, which apparently caused the destruction of buildings in the village of Dzivgis. The age of these buildings dates back to the 18th-19th centuries. The age of the necropolis in Tsymyti was determined by archaeologists as the 17th-18th centuries. Heavily destroyed crypts are apparently a consequence of the second earthquake in the region. The crypts that received minor damage are probably the result of the third earthquake. In Dzivgis, in the 19th century, the third earthquake led to a rockfall that deformed the metal cemetery fences; this seismic event occurred after 1878. Additional field and desk studies are necessary for a more complete parameterization of ancient seismic events, as well as the localization of ancient epicentral zones in certain structures of the crust of the region.

Recently, several UHV transmission lines that have been operational for over 15 years, transmitting power from Yunnan and Guizhou to Guangdong Province, suffered severe damage to their tower foot due to soil corrosion. Consequently, this study conducted accelerated corrosion simulation research on the UHV transmission tower foot in a laboratory setting. The electrolytic corrosion acceleration simulation method and the dry and wet cycle acceleration simulation method were proposed as two approaches to simulate tower foot corrosion in this study. The corrosion morphology and products resulting from electrolytic and natural corrosion of the carbon steel substrate exhibited remarkable similarities. Notably, the acceleration ratio of electrolytic corrosion exceeded 100, thereby adhering to the fundamental principles and evaluation characteristics of accelerated corrosion. The experimental design involved a simulation test that replicated the on-site environmental conditions, specifically targeting the dry and wet cycles. This test effectively mimicked the corrosion process of metal surfaces and generated rust layers exhibiting similar characteristics to those observed in field corrosion. By conducting an analysis of the polarization curve for the rusted sample, a comparison was made regarding the corrosion rates observed in different sections of the tower foot. The outcomes obtained from AC impedance analysis revealed that soil corrosion predominantly relied on diffusion processes, thereby enabling us to derive equivalent circuitry and component parameters pertaining to carbon steel soil corrosion.

Almost 2 billion people depend on freshwater provided by the Asian water towers, yet long-term runoff estimation is challenging in this high-mountain region with a harsh environment and scarce observations. Most hydrologic models rely on observed runoff for calibration, and have limited applicability in the poorly gauged Asian water towers. To overcome such limitations, here we propose a novel data-driven model, SM2R (Soil Moisture to Runoff), to simulate monthly runoff based on soil moisture dynamics using reanalysis forcing data. The SM2R model was applied and examined in 20 drainage basins across seven Asian water towers during the past four decades of 1981-2020. Without invoking any observations for calibration, the overall good performance of SM2R-derived runoff (correlation coefficient & GE;0.74 and normalized root mean square error & LE;0.22 compared to observed runoff at 20 gauges) suggests considerable potential for runoff simulation in poorly gauged basins. Even though the SM2R model is forced by ERA5-Land (ERA5L) reanalysis data, it largely outperforms the ERA5L-estimated runoff across the seven Asian water towers, particularly in basins with widely distributed glaciers and frozen soil. The SM2R approach is highly promising for constraining hydrologic variables from soil moisture information. Our results provide valuable insights for not only long-term runoff estimation over key Asian basins, but also understanding hydrologic processes across poorly gauged regions globally.