Analysis of Freeze Damage in Drainage Pipe Networks in Cold High-Altitude Regions and Engineering Mitigation Practices

Abstract

Drainage pipe networks in cold high-altitude regions are continuously affected by low temperatures, frozen ground, and freeze–thaw cycles, making them susceptible to ice blockage, frost-heave deformation, joint cracking, and manhole freezing, which compromise the safe and stable operation of drainage systems. Existing studies have primarily focused on frozen-soil mechanisms or individual anti-freezing measures, while systematic research on freeze-damage diagnosis, integrated mitigation strategies, and effectiveness verification throughout the entire engineering process remains limited. Therefore, based on the operational characteristics of drainage systems in cold high-altitude regions, this study adopts an integrated approach combining field investigation, risk identification, indicator-based evaluation, and engineering validation to systematically analyze the characteristics and causes of freeze damage in drainage pipe networks. A freeze-damage risk identification framework consisting of environmental, engineering, and operational factors is established. Furthermore, a whole-process anti-freezing technical system featuring “source prevention–process control–operation assurance” is proposed, together with a hierarchical and integrated mitigation scheme. Engineering practice demonstrates that, after implementing zoned and graded anti-freezing measures, the number of freeze-damage incidents during the freezing period in the treated area decreased from 12 to 2, achieving a freeze-damage improvement rate of 83.3%. The internal temperature of high-risk pipeline sections was maintained above 0°C, and the winter operational stability of the drainage system was significantly enhanced. The research establishes a closed-loop framework integrating freeze-damage risk diagnosis, mitigation measure selection, and operational performance evaluation, providing practical guidance for the planning, design, rehabilitation, operation, and maintenance of drainage pipe networks in cold high-altitude regions.