Document Type


Date of Award

Fall 10-31-1997

Degree Name

Doctor of Philosophy in Civil Engineering - (Ph.D.)


Civil and Environmental Engineering

First Advisor

Robert Dresnack

Second Advisor

Paul C. Chan

Third Advisor

Su Ling Cheng

Fourth Advisor

Eugene B. Golub

Fifth Advisor

Robert P. Kirchner


Accidental rupture of natural gas transmission pipelines with subsequent ignition of the escaping gas can result in the loss of life and property. In the United States, current means of protecting both the pipeline and the public include the establishment of class locations, in which specific pipeline design, construction and operation requirements must be attained. In addition, distances at which the pipelines can be safely set back from the community, called safe separation distances, have been developed in some European countries (e.g., Great Britain, the Netherlands) through use of risk assessment principles. However, to date there has been no simple, consistent method for determining these distances.

A method for evaluating safe separation distances is proposed herein, in which the point source method for determining heat flux is coupled with relationships for predicting both the mass release rate from the rupture and the flame height of the ignited gas. The method is utilized to develop charts for predicting safe separation distances based on pipeline operating pressure and nominal pipeline diameter. The method is compared to information from both actual pipeline accidents reported upon by the National Transportation Safety Board and from the work of prior researchers utilizing other methodologies. The comparisons reveal that the method proposed in this thesis can produce results that are consistent with the above sets of data tested.



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