Behavior of Underground Piping Joints Due to Static and Dynamic Loading

摘要

This report describes the procedures and results of an empirical data research program designed to determine the static and dynamic behavior of some typical restrained and unrestrained underground pipe joints, such as their axial and rotational stiffness, axial force capacity, and moment bending capacity. Pipelines have suffered damage and failure from past earthquakes and have been shown to be vulnerable to seismic motions. It has been well documented that a majority of pipeline failures have occurred at unrestrained pipe joints while restrained joints have a capacity to resist pull-out, and therefore, both unrestrained and restrained pipe joints need to be examined and their axial and rotational stiffness and their strength characteristics need to be investigated in order to help mitigate potential damage and failure. Five different material types with eight different joint types and several different pipe diameters were used in this testing program. The test results are given as load-displacement plots, moment-rotation plots, and tables listing the axial and rotational stiffness, force capacities, and bending moment capacities. A comparison is made between static results and dynamic results to determine if static testing is sufficient to characterize the dynamic behavior of pipe joints. This report also suggests methods to use the test results for a finite element pipeline system analysis and for risk assessment evaluation.