Semi-Quantitative Assessment Technology of Geohazard Risk for Pipeline

Geohazard is one of the most serious threats to shallow buried pipeline. Based on the date of investigation, risk assessment and risk ranking are most important tasks of pipeline geohazard risk management. At the phase of investigation, qualitative assessment technology or quantitative assessment technology can't offer a risk ranking for thousands of geohazards. Semi-quantitative assessment technology can calculate the relative risk based on the simple date of investigation, and risk ranking can be made. According to the definition of the risk, a risk assessment model was established for pipeline geohazard. Analyze the major factors affecting the geohazard risk and index system of the geohazard susceptibility assessment was established. Meanwhile, it also considers the influences of the different index and gives the value of weighting factor. The possible state of each index on site is analyzed, and the risk is estimated which are expressed by values. The semi-quantitative assessment systems are established for the primary pipeline geohazards, such as landslide, rockfall, debris flow, mining ground subsidence, hydrotechnical hazards and loess collapse. The classification standards of the risk is established in accordance with the situation of geohazard prevention.