Analysis of the Cracking Mechanism and Prevention and Repair Strategies for the Foundations of High-Voltage Transmission Line Towers in a Mountainous Area

Taking a practical 220kV transmission line with foundation cracking issues as a case study, this paper summarizes five typical crack patterns and proposes an analysis method for transmission tower foundation cracking based on multi-dimensional performance testing in three areas. The method involves core sampling and sectioning, along with crack observation, compressive strength testing, alkali-aggregate reaction testing, and carbonation depth measurement, employing microscopic optical, mechanical, metallographic, and chemical analysis techniques. This systematic analysis investigates the crack formation mechanisms in the tower foundation and categorizes typical crack prevention and repair strategies. The results indicate that the numerous defects within the tower foundation concrete, coupled with the uneven quality and low local strength, lead to cracking under temperature stresses caused by daily temperature fluctuations, hydration heat, and dynamic loads from the upper tower, ultimately causing the foundation to crack and continue to deteriorate under normal climatic conditions.