Abstract:
Long oil and gas pipelines inevitably cross mountainous regions with complex geological environment and are threatened by various geological disasters, the most severe of which is landslides. To achieve early-warning of pipeline landslide hazards, multiple monitoring and early-warning indicators are typically established. However, the failure to account for the correlation between various indicators has led to a high frequency of false alarms. Based on the analysis of the dynamic evolutionary process of pipeline landslide hazards, this study proposes four stages of pipeline landslide hazards: (1) rainfall on the landslide leads to surface infiltration; (2) the groundwater level rises increasing the slope self-weight increases and reducing the geotechnical parameter; (3) the slope has undergone local deformation; (4) the landslide slides entirely and threatens pipeline safety. Three key monitoring indicators of landslide hazard deformations, external induced indicators, and pipeline stress-strain were extracted to construct a monitoring index system for pipeline landslide hazards. On this basis, a multifactor coupled early-warning model for pipeline landslide hazards is proposed. This model integrates the relationships between landslide deformation indicators, external triggers, and pipeline mechanical responses, creating a multidimensional early-warning criterion. This early-warning model was applied in a natural gas pipeline landslide in Guizhou Province, and successfully issued blue, yellow, and red early-warning information, providing sufficient time for emergency response and rescue of the landslide, ensuring the safe operation of the pipeline. This model can avoid the problem of high early-warning levels due to excessive rainfall, further improving the accuracy of pipeline landslide hazards early-warning and making the early-warning results more realistic. This tudy can provide a valuable reference for the monitoring and early-warning work on pipeline landslide hazards.