Statistical Analysis for the Seismic Risk Assessment of Pipelines in India

Abstract

Pipelines are one of the most important lifeline facilities that play a vital role in maintaining the public safety and economic wellbeing of a nation. They traverse over a large area with nonuniform soil conditions and are susceptible to various earthquake hazards. The oil and gas pipeline infrastructure is relatively new in India as compared to the water pipeline networks in the country, which is more than a century old. For various reasons, they are mostly buried underground. Several buried pipelines in the country are exposed to significant risks as they pass over zones of high seismicity. Some major pipelines, including a few cross-country pipelines, are also being planned to be commissioned soon in India. With the ever-expanding pipeline networks in India, it is important to understand the risk associated with the pipelines and appropriate design strategies and mitigation measures to prevent imminent disasters due to potential future earthquakes. Therefore, the present study discusses various types of pipeline failures based on previous earthquake records that illustrate the seismic response of pipelines in India. In addition, based on materials used, the seismic behavior of pipelines in previous earthquakes around the world over the last 110 years (1906–2016) has been presented. Moreover, a detailed illustration has been put together to envisage the degree of vulnerability of the existing and proposed pipelines in India during future earthquakes. A new methodology has been proposed to qualitatively assess the risk potential of pipelines based on the seismic zone the pipeline is passing through and the population density in the region. Furthermore, seismic fragility analysis of pipelines in India has been conducted to quantify the seismic risk involved in terms of repair rates and monetary losses, along with a simple case study to illustrate the proposed methodology. Finally, a brief review of various mitigation measures in reducing the seismic risk to pipelines is presented.