Soil dynamics and earthquake geotechnical engineering Geotechnics for transportation and infrastructure Centrifuge Modeling of Buried Pipelines Response Due to Normal Faulting M. Rojhani & M. Moradi & A. Galandarzadeh Department of Civil Engineering, University of Tehran, Iran ABSTRACT: Buried pipelines are commonly used to transport water, gas and oil. They are classified as lifelines as they carry materials essential to the support of human life. Due to the importance of lifelines survivability, it is of prime importance to study their threats to mitigate damages. Permanent ground de- formation (PGD) such as fault crossing and lateral spreading are some of the most important threats for pipelines. Especially, localized PGD or faulting is a severe hazard for them. Many analytical, numerical and statistical researches have been done since almost four decade ago, but their results must be evalu- ated and verified by records of field case histories. As well-documented field case histories are quite lim- ited, physical modeling can be used for verification. Physical modeling includes 1g modeling (full-scale or near full-scale) and centrifuge modeling. Centrifuge modeling is somehow preferred to 1g modeling for its accuracy, validity and expense point of view, especially for pipeline modeling with very long ef- fective unanchored length. This study focuses on behavior and response of buried continuous pipelines subjected to normal faulting using centrifuge modeling technique. In this technical paper laboratory equipments, modeling setup and procedure and split-box container are demonstrated. Especially, physical characteristics of the university of Tehran centrifuge are described. Finally the recorded strains induced in model pipelines are presented. 1 INTRODUCTON Buried pipelines often serve as lifelines in that they may carry resources that are essential to the support of human life and this is the reason to retain them in serviceable condition in every situation. Among vari- ous kinds of natural hazards, earthquakes happen to be the most serious threats for lifelines serviceability. They can damage lifelines through faulting, perma- nent ground deformation (PGD) and deformations due to seismic wave’s propagation. Faulting can af- fect pipelines in various ways (Fig. 1) and cause se- vere damages (Fig. 2) depending on faulting move- ment direction. Considering mentioned hazards, lots of statistical, analytical and numerical studies have been conducted since 1970s in order to predict pipelines response and vulnerability level and also to investigate methods of damage mitigation; but it has been a difficult and somehow impossible way to evaluate theoretical and analytical research results due to loss of accurate and efficient records about pipelines response to faulting in actual case histories of earthquakes (Choo et al. 2007). In order to compensate such a gap, studies turned towards applying experimental and physical modeling of this phenomenon. Since 2003, signifi- cant a) Horizontal Faulting b) Normal Faulting c) Reverse Faulting Fig. 1 Different ground rupture patterns and pipelines’ re- sponse researches have been started in U.S.A. and Japan with support of companies and institutes such as To- kyo Gas Company, US lifelines Agency, National Science Foundation in U.S.A, Earthquake Engineer- ing Research Center and etc. Most of mentioned conducted studies have been focused on strike-slip faulting. So, still there is lack of studies on normal and reverse faultings’ effects and this puts them in prime importance of research priority. As a very long unanchored length of pipeline is af- fected due to faulting, 1g physical modeling of pipe-