NEHRP Clearinghouse
- Title
- Seismic Design Criteria for Buried Pipelines. (Seismic Vulnerability, Behavior and Design of Underground Piping Systems).
- File
- PB291415.pdf
- Author(s)
- Wang, L. R. L.; Fung, R. C. Y.
- Source
- National Science Foundation, Washington, DC. Applied Science and Research Applications., September 1978, 23 p.
- Abstract
- Overall aims of this research are to develop a systematic way of assessing the adequacy and vulnerability of water/sewer distribution systems subjected to seismic loads and to develop future design methodologies. To aid in the design of buried pipelines against earthquakes, this paper evaluates the reserve strength of buried pipes beyond normal stress/strain conditions. This reserve strength is the capacity available in buried pipes to resist seismic loads. In buried pipelines under combined conventional and seismic loadings, bi-axial stresses are developed since conventional loads produce mainly hoop stresses whereas the seismic effect is predominantly in the longitudinal direction. To evaluate the failure of buried pipelines consisting of non-homogeneous materials under a bi-axial stress state, a modified Von-Mises failure criterion is proposed. This paper evaluates parametrically the reserve strengths of a typical cast iron (rigid) pipe and a typical ductile iron (flexible) pipe with several important parameters such as aging (corrosion effect), laying and loading conditions, buried depth, dynamic effect, and trench load uncertainty factor in estimating vertical earth and truck loads. It is concluded that the seismic reserve axial strength of buried pipes is influenced by all the parameters investigated. The effects from corrosion, loading condition, and trench load uncertainty factor are more pronounced than those from buried depth, laying condition, and the earthquake induced dynamic water pressure effects.
- Keywords
- Seismic design; Earthquake resistant structures; Water pipes; Seismic waves; Buried pipelines; Subsurface structures; Biaxial stresses; Sewer pipes; Earthquake engineering; Earthquakes; Pipelines; Design criteria