Simplified Analytical Models for Pipeline Deformation Analyses Due to Permanent Ground Deformation

2020 ◽  
pp. 183-204
Author(s):  
Gregory C. Sarvanis ◽  
Spyros A. Karamanos ◽  
Polynikis Vazouras ◽  
Panos Dakoulas ◽  
Kyriaki A. Georgiadi-Stefanidi
Keyword(s):  
Ground Deformation ◽  
Analytical Models ◽  
Permanent Ground Deformation

Deformation capacity of buried hybrid-segmented pipelines under longitudinal permanent ground deformation

2020 ◽  
Author(s):  
Gersena Banushi ◽  
Brad Wham
Keyword(s):  
Water Distribution ◽  
Large Scale ◽  
Ground Deformation ◽  
Lateral Spreading ◽  
Analytical Models ◽  
Axial Deformation ◽  
Pipe System ◽  
Pull Out ◽  
Pipeline Systems ◽  
Permanent Ground Deformation

Innovative hybrid-segmented pipeline systems are being used more frequently in practice to improve the performance of water distribution pipelines subjected to permanent ground deformation (PGD), such as seismic-induced landslides, soil lateral spreading, and fault rupture. These systems employ joints equipped with anti-pull-out restraints, providing the ability to displace axially, before locking up and behaving as a continuous pipeline. To assess the seismic response of hazard-resistant pipeline systems equipped with enlarged joint restraints to longitudinal PGD, this study develops numerical and semi-analytical models, considering the nonlinear properties of the system, calibrated from large-scale test data. The deformation capacities of two hybrid-segmented pipelines are investigated: (1) hazard-resilient ductile iron (DI) pipe, and (2) oriented polyvinylchloride (PVCO) pipe with joint restraints capable of axial deformation. The numerical analysis demonstrates that, for the conditions investigated, the maximum elongation capacity of the analyzed DI pipe system is greater than that of the PVCO pipeline. The implemented semi-analytical approach revealed that the pipeline performance strongly improves by increasing the allowable joint displacement. Comparison of the numerical results with analytical solutions reported in recent research publications showed excellent agreement between the two approaches, highlighting the importance of assigning appropriate axial friction parameters for these systems.

Failure Analysis Of Buried Gas Pipelines Crossing Seismic Faults

2020 ◽  
Vol 3 (2) ◽  
pp. 781-790
Author(s):  
M. Rizwan Akram ◽  
Ali Yesilyurt ◽  
A.Can. Zulfikar ◽  
F. Göktepe
Keyword(s):  
Ground Deformation ◽  
Warning System ◽  
Strike Slip ◽  
Gas Pipelines ◽  
Steel Pipes ◽  
Seismic Fault ◽  
Fault Parameters ◽  
Dip Angle ◽  
Permanent Ground Deformation ◽  
Recent Earthquakes

Research on buried gas pipelines (BGPs) has taken an important consideration due to their failures in recent earthquakes. In permanent ground deformation (PGD) hazards, seismic faults are considered as one of the major causes of BGPs failure due to accumulation of impermissible tensile strains. In current research, four steel pipes such as X-42, X-52, X-60, and X-70 grades crossing through strike-slip, normal and reverse seismic faults have been investigated. Firstly, failure of BGPs due to change in soil-pipe parameters have been analyzed. Later, effects of seismic fault parameters such as change in dip angle and angle between pipe and fault plane are evaluated. Additionally, effects due to changing pipe class levels are also examined. The results of current study reveal that BGPs can resist until earthquake moment magnitude of 7.0 but fails above this limit under the assumed geotechnical properties of current study. In addition, strike-slip fault can trigger early damage in BGPs than normal and reverse faults. In the last stage, an early warning system is proposed based on the current procedure. 

Steel Pipe Wrinkling due to Longitudinal Permanent Ground Deformation

1995 ◽  
Vol 121 (5) ◽  
pp. 443-451 ◽  
Author(s):  
Michael J. O'Rourke ◽  
Xuejie Liu ◽  
Raul Flores-Berrones
Keyword(s):  
Ground Deformation ◽  
Steel Pipe ◽  
Permanent Ground Deformation

Bridging the Gap Between Qualitative, Semi-Quantitative and Quantitative Risk Assessment of Pipeline Geohazards: The Role of Engineering Judgment

2015 ◽  
Author(s):  
R. S. Rod Read ◽  
Moness Rizkalla
Keyword(s):  
Ground Deformation ◽  
Lateral Spreading ◽  
Quantitative Risk Assessment ◽  
Assessment Approach ◽  
Assessment Engineering ◽  
Hazard And Risk ◽  
Pipeline Route ◽  
Permanent Ground Deformation ◽  
Fault Displacement

Geohazards are threats of a geological, geotechnical, hydrological or seismic/tectonic nature that can potentially damage pipelines and other infrastructure. Depending on the physiographic setting of a particular pipeline, a broad range of geohazards may be possible along the pipeline route. However, only a limited number of geohazards such as landslides, fault displacement, mining-induced subsidence, liquefaction-induced lateral spreading, and hydrological scour, which can result in permanent ground deformation or exposure of the pipeline to direct impact, typically represent credible threats to pipeline integrity. Identifying potential geohazard occurrences and estimating the likely severity of each occurrence in relation to pipeline integrity is an integral part of geohazard management, and overall risk management of pipelines. Methods for identifying and assessing the potential likelihood and severity of geohazards vary significantly, from purely expert judgment-based approaches relying largely on visual observations of geomorphology to analytically-intense methods incorporating phenomenological or mechanistic models and data from monitoring and field characterization. Each of these methods can be used to assess hazard and risk associated with specific geohazards in terms of qualitative, semi-quantitative, or quantitative expressions as long as uncertainty and assumptions are understood and communicated as part of the assessment. Engineering judgment is highlighted as an essential component to varying degrees of each geohazard assessment approach.

scholarly journals LARGE SCALE EXPERIMENTS OF BURIED STEEL PIPELINES WITH ELBOWS SUBJECTED TO PERMANENT GROUND DEFORMATION

2003 ◽  
Vol 20 (1) ◽  
pp. 1s-11s ◽  
Author(s):  
Koji YOSHIZAKI ◽  
Thomas D. O’Rourke ◽  
Masanori HAMADA
Keyword(s):  
Large Scale ◽  
Ground Deformation ◽  
Permanent Ground Deformation

Wave Propagation Versus Transient Ground Displacement as a Credible Hazard to Buried Oil and Gas Pipelines

2000 ◽  
Author(s):  
Douglas G. Honegger
Keyword(s):  
Wave Propagation ◽  
Southern California ◽  
Oil And Gas ◽  
Ground Deformation ◽  
Gas Pipeline ◽  
Tensile Failure ◽  
Northridge Earthquake ◽  
Research Activity ◽  
Research Project ◽  
Permanent Ground Deformation

In 1997, a research project was initiated by Southern California Gas Company, Pacific Gas and Electric Company, with support from Tokyo Gas, Osaka Gas, and Toho Gas, to investigate the cause of natural gas pipeline damage during the 1994 Northridge earthquake. As part of this research activity, extensive field and laboratory investigations were performed on a 1925 gas pipeline that suffered several girth weld failures in Potrero Canyon, a remote and unpopulated area just north of the Santa Susana Mountains. The pipeline is operated by the Southern California Gas Company, one of the principle sponsors of the gas utility research project. The investigations into the performance of the pipeline were largely prompted by questions regarding the cause of pipeline damage. Although ground cracking and sand boils were observed in Potrero Canyon following the Northridge earthquake, there were no clear signs of permanent ground deformation near the locations of pipeline damage. Pipeline damage, consisting predominantly of girth weld tensile failure and two instances of buckling of the pipe wall, indicated that significant relative pipe-soil deformation might have occurred. Field investigations were unable to identify surface evidence of permanent ground deformation near the locations of pipeline damage and attention focused on the possibility that the damage could have been caused by wave propagation. This focus was based on the assertions of past researchers that pipelines with poor-quality oxyacetylene girth welds are susceptible to damage from wave propagation. The detailed investigation of The pipeline has concluded that wave propagation was not a significant factor in the pipeline damage and raises questions regarding wave propagation effects as a causative mechanism for pipeline damage in past earthquakes. A simple analytical model of the transient ground deformation that may have occurred in the vicinity of the pipeline damage was found to provide insight into the cause of the ground cracking observed at the margins of Potrero Canyon, approximate magnitudes of differential ground displacements that may have occurred during the earthquake, and the reasons for the spatial distribution of pipeline damage. This model is proposed as the basis for identifying locations where similar earthquake effects can be identified in future hazard assessment studies.

Estimating co-seismic subsidence in the Hutt Valley resulting from rupture of the Wellington Fault, New Zealand

2016 ◽  
Vol 49 (3) ◽  
pp. 283-291
Author(s):  
Dougal B. Townsend ◽  
John G. Begg ◽  
Russ J. Van Dissen ◽  
David A. Rhoades ◽  
Wendy S. A. Saunders ◽  
...  
Keyword(s):  
New Zealand ◽  
Sea Level ◽  
Ground Deformation ◽  
Mitigation Strategies ◽  
Societal Implications ◽  
Vertical Deformation ◽  
Ground Shaking ◽  
Mean Values ◽  
Permanent Ground Deformation ◽  
Strong Ground

Ground deformation can contribute significantly to losses in major earthquakes. Areas that suffer permanent ground deformation in addition to strong ground shaking typically sustain greater levels of damage and loss than areas suffering strong ground-shaking alone. The lower Hutt Valley of the Wellington region, New Zealand, is adjacent to the active Wellington Fault. The long-term signal of vertical deformation there is subsidence, and the most likely driver of this is rupture of the Wellington Fault. In 1855 the Mw ~8.2 Wairarapa Earthquake resulted in uplift of the lower Hutt Valley area and created an expectation that future earthquakes would do the same. However, sediments beneath the lower Hutt Valley floor up to c. 220 thousand years old provide data that when combined with the international sea level curve demonstrate cumulative net subsidence of up to c. 155 m during that period. Recent refinement of rupture parameters for the Wellington Fault (and other faults in the region), based on new field data, has spurred us to reassess estimates of vertical deformation in the Hutt Valley that would result from rupture of the Wellington Fault. Using a logic tree framework, we calculate subsidence for an “average” Wellington Fault event of ~1.9 m near Petone, ~1.7m near Lower Hutt City, ~1.4 m near Seaview, and ~0 m in the Taita area. Such a distribution of vertical deformation would result in large areas of Alicetown-Petone and Moera-Seaview subsiding below sea level. We also calculate and present “minimum” and “maximum” credible subsidence values, which are approximately half and twice the mean values, respectively. This ground deformation hazard certainly has societal implications, and we are working with local and regional councils to develop a range of mitigation strategies.

Adapting Hazus for seismic risk assessment in Canada

2014 ◽  
Vol 51 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Miroslav Nastev
Keyword(s):  
Natural Hazards ◽  
Structural Damage ◽  
Best Practice ◽  
Ground Deformation ◽  
Physical Damage ◽  
Ground Shaking ◽  
Emergency Managers ◽  
Damage States ◽  
Earthquake Model ◽  
Permanent Ground Deformation

Although earthquakes have been recognised as major natural hazards with the potential to cause loss of life, property damage, and social and economic disruption in Canada, most risk and emergency managers still lack the necessary tools and guidance to adequately undertake rigorous risk assessments. Recently, Natural Resources Canada (NRCan) has adopted Hazus, a standardized best-practice methodology developed by the US Federal Emergency Management Agency (FEMA) for estimating potential losses from common natural hazards, such as earthquakes, floods, and hurricanes. Hazus combines science, engineering knowledge, and mathematical modelling with geographic information systems technology to estimate physical damage and economic and social losses. Besides the ground shaking, the earthquake model considers landslide, liquefaction, and fault rupture susceptibilities. Depending on the severity of the resulting transient ground motion and permanent ground deformation, five potential damage states (none, slight, moderate, extensive, complete) are employed to estimate the amount of structural damage and consequent economic and social losses. This note reports some of the typical features of the recently adapted Hazus earthquake model, with an emphasis on the considerations of earthquake-induced hazards, and overviews the ongoing activities and potential challenges in implementing this model in Canada.

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