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. 

Buried high-density polyethylene pipelines subjected to normal and strike-slip faulting — a centrifuge investigation

2008 ◽  
Vol 45 (12) ◽  
pp. 1733-1742 ◽  
Author(s):  
Da Ha ◽  
Tarek H. Abdoun ◽  
Michael J. O’Rourke ◽  
Michael D. Symans ◽  
Thomas D. O’Rourke ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Ground Deformation ◽  
Interaction Force ◽  
Strike Slip ◽  
High Density ◽  
Normal Faulting ◽  
Centrifuge Tests ◽  
American Society ◽  
Permanent Ground Deformation ◽  
Soil Pipe

Permanent ground deformation is arguably the most severe hazard for continuous buried pipelines. This paper presents results from two pairs of centrifuge tests designed to investigate the differences in behavior of buried high-density polyethylene pipelines subjected to normal and strike-slip faulting. The tests results show that, as expected, the pipeline behavior is asymmetric under normal faulting and symmetric under strike-slip faulting. In the case of strike-slip faulting, the soil–pipe interaction pressure distribution is symmetric with respect to the fault. However, in the case of normal faulting, there is a pressure concentration close to the fault trace on the up-thrown side, with much lower soil–pipe interaction pressures at other locations on the pipe. The soil–pipe interaction force versus deformation relationship (i.e., the p–y relationship) was obtained based on the experimental data. The p–y relationships for both the strike-slip and normal faulting cases were also compared with the relationships defined within the American Society of Civil Engineers (ASCE) guidelines. It was found that, for the case of strike-slip faulting, the experimental p–y relationship is generally consistent with the ASCE guidelines. In contrast, the experimental p–y relationship is much softer than that defined by the ASCE guidelines for the normal faulting scenario.

Ground deformation related to slip and afterslip of the 29 December 2020 Mw 6.4 Petrijna earthquake (Croatia) imaged by InSAR

2021 ◽  
Author(s):  
Athanassios Ganas ◽  
Sotiris Valkaniotis ◽  
Panagiotis Elias ◽  
Varvara Tsironi ◽  
Ilektra Karasante ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Moment Tensor ◽  
The South ◽  
Seismogenic Fault ◽  
Fault Surface ◽  
Seismic Fault ◽  
Vertical Fault ◽  
Horizontal Ground Motion ◽  
Dip Angle ◽  
The Right

<p>On December 29, 2020, at 11:19 UTC, a strong (M6.4), shallow earthquake occurred in the central region of Croatia. The epicentre was located near the town of Petrinja, about 40 km to the south of the capital, Zagreb. Here we present a preliminary analysis of the geodetic data (differential InSAR & GNSS) and preliminary estimates of the slip that occurred on the fault during the earthquake and subsequent aftershocks. We picked InSAR data to invert for the seismic fault assuming linear rheology and Okada-type dislocation (rectangular) source with non-uniform slip. The interferograms show an asymmetric, four‐lobed pattern, centered on a NW‐SE oriented discontinuity that is in agreement with the right-lateral plane of the moment tensor solutions for the mainshock. We found that the Petrijna earthquake ruptured a segment of a strike-slip fault zone that is shorter (8 km) than average and with larger slip (~ 3 m). All parameters of the seismic fault are well constrained by InSAR modeling due to the full azimuthal coverage with both ascending and descending data of good quality. The fit to the fringes is better with a steep dip angle (76°) than with a purely vertical fault. The upper edge of the modeled fault is at a depth of ~1 km, this means that the slip drop from 3 to 0 m in the uppermost kilometer and our geodetic analysis cannot assess whether the fault reached the surface in some sections of the fault, however should this be the case, we expect ruptures at the surface in the range of 0.1 to 0 m for consistency with our model and the structure of the fringes pattern. In particular, preliminary modelling results with distributed fault-slip show that the slip reached a peak of more than 2.5 m at a depth of about 2 km. We also found that, differently from what reported in the European database of seismogenic sources (EDSF), the seismic fault dips westward instead of eastward. Additionally, the 2020 rupture and the InSAR mapped trace do not match the EDSF composite seismogenic fault surface trace. Kinematic analysis of GNSS waveforms at station BJEL (about 70-km east of the epicentre) revealed that horizontal ground motion reached 7-cm (peak-to-peak). The InSAR data revealed a 7 km of right-lateral afterslip on the NW-edge of the rupture, and 5 km to the south of the main fault rupture. In particular, the afterslip data on the NW edge of the rupture document the curved shape of the post-seismic deformation, that highlights the non-planarity of faults in nature and possibly indicating the existence of a ramp structure connecting to the neighboring segment towards north.</p>

An investigation of methods for Fault Displacement Hazard Assessment for offshore studies

2020 ◽  
Author(s):  
Emilia Fiorini
Keyword(s):  
Hazard Assessment ◽  
Ground Deformation ◽  
Surface Displacement ◽  
Warning System ◽  
Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard Assessment ◽  
Surface Rupture ◽  
Permanent Ground Deformation ◽  
Fault Displacement

<p>The expected surface displacement in the aftermath of an earthquake is an important issue to consider, among others, for pipeline damage. While estimates of permanent ground deformation after an earthquake event is often performed nowadays through the acquisition of Interferometric Synthetic Aperture Radar (InSAR) scenes, this method is only applicable to onshore regions.</p><p>In this work we explore possible methodologies for fault hazard assessment to be applied in offshore regions.</p><p>Methods to estimate the surface rupture hazard for faults of known location and geometry are reviewed, such as the Okada equations available in the Coulomb3 software. However since fault data may be lacking or scarce in offshore areas we also explore the availability of methods to estimate a probabilistic surface rupture assessment, to be applied within the same framework of Probabilistic Seismic Hazard Assessment studies. A simple application of both methods is presented in a hypothetic case study where an early warning system for pipeline damage inspection is required.</p>

scholarly journals GLOBAL RELATIONS BETWEEN SEISMIC FAULT PARAMETERS AND MOMENT MAGNITUDE OF EARTHQUAKES

2004 ◽  
Vol 36 (3) ◽  
pp. 1482 ◽  
Author(s):  
B. C. Papazachos ◽  
E. M. Scordilis ◽  
D. G. Panagiotopoulos ◽  
C. B. Papazachos ◽  
G. F. Karakaisis
Keyword(s):  
Seismic Moment ◽  
Strike Slip ◽  
Fault Slip ◽  
Moment Magnitude ◽  
Empirical Formulas ◽  
Seismic Fault ◽  
Fault Parameters ◽  
The Moment ◽  
Fault Length ◽  
Global Relations

The most reliable of the globally available relative data have been used to derive empirical formulas which relate the subsurface fault length, L, the fault area, S, and fault width, w, with the moment magnitude, M. Separate such formulas have been derived for earthquakes generated by strike-slip faulting, by dip-slip faulting in continental regions and by dip-slip faulting in lithospheric subduction regions. The formula which relates the fault area with the magnitude is combined with the definition formulas of seismic moment and moment magnitude to derive also relations between the fault slip, u, and the moment magnitude for each of the three seismotectonic regimes. For a certain magnitude, the fault length is larger for strike-slip faults than for dip-slip faults, while the fault width is small for strike-slip faults, larger for dip-slip faults in continental regions and much larger for dip-slip faults in regions of lithospheric subduction. For a certain magnitude, fault slip is about the same for strike-slip faults and dip-slip faults in continental regions and smaller for dip-slip faults in regions of lithospheric subduction.

Co-seismic deformation, field observations and seismic fault model of the Oct. 30, 2020 Mw=7.0 Samos earthquake, Aegean Sea

2021 ◽  
Author(s):  
Panagiotis Elias ◽  
Athanassios Ganas ◽  
Pierre Briole ◽  
Sotiris Valkaniotis ◽  
Javier Escartin ◽  
...  
Keyword(s):  
Fault Location ◽  
Normal Fault ◽  
Aegean Sea ◽  
Rock Falls ◽  
Seismic Fault ◽  
Fault Parameters ◽  
Northern Shore ◽  
Loose Sediments ◽  
Dip Angle ◽  
Seismic Deformation

<p>On 30 October 2020 11:51 UTC a large Mw = 7.0 earthquake occurred offshore of the island of Samos, Greece. In this contribution we present the characteristics of the seismic fault (location, geometry, geodetic moment) as inferred from the processing of geodetic data (InSAR and GNSS). We use the InSAR displacement data from Sentinel-1 interferograms (ascending orbit 29 and descending 36) and the GNSS offsets from eleven (11) permanent stations in Greece and Turkey to invert for the fault parameters. Our inversion modeling indicates the activation of a normal fault north of Samos with a length of 32 km, width of 17 km, average slip of 2.1 m, a moderate dip-angle (37°) and with a dip-direction towards North. The inferred fault is located adjacent to Samos northern coastline, with the top of the slip ~1 km below surface, and ~2 km off-shore at its closest to the island. The earthquake caused the permanent uplift of the island up to 10 cm with the exception of a coastal strip along the NE part of the northern shore (near Kokkari) that subsided 2-6 cm. The effects of the earthquake included liquefaction, rock falls, rock slides, road cracks and deep-seated landslides, all due to the strong ground motion and associated down-slope mobilization of soil cover and loose sediments.</p>

Mechanical behavior of buried steel pipes crossing active strike-slip faults

2012 ◽  
Vol 41 ◽  
pp. 164-180 ◽  
Author(s):  
Polynikis Vazouras ◽  
Spyros A. Karamanos ◽  
Panos Dakoulas
Keyword(s):  
Mechanical Behavior ◽  
Strike Slip ◽  
Steel Pipes

Fault parameters determined by near- and far-field data: The Wakasa Bay earthquake of March 26, 1963

1974 ◽  
Vol 64 (5) ◽  
pp. 1369-1382 ◽  
Author(s):  
Katsuyuki Abe
Keyword(s):  
Effective Stress ◽  
Stress Drop ◽  
P Wave ◽  
Slip Angle ◽  
Polarization Angle ◽  
S Wave ◽  
Seismological Data ◽  
Fault Parameters ◽  
Wakasa Bay ◽  
Dip Angle

Abstract The source process of the Wakasa Bay earthquake (M = 6.9, 35.80°N, 135.76°E, depth 4 km) which occurred near the west coast of Honshu Island, Japan, on March 26, 1963, is studied on the basis of the seismological data. Dynamic and static parameters of the faulting are determined by directly comparing synthetic seismograms with observed seismograms recorded at seismic near and far distances. The De Hoop-Haskell method is used for the synthesis. The average dislocation is determined to be 60 cm. The overall dislocation velocity is estimated to be 30 cm/sec, the rise time of the slip dislocation being determined as 2 sec. The other fault parameters determined, with supplementary data on the P-wave first motion, the S-wave polarization angle, and the aftershocks, are: source geometry, dip direction N 144°E, dip angle 68°, slip angle 22° (right-lateral strike-slip motion with some dip-slip component); fault dimension, 20 km length by 8 km width; rupture velocity, 2.3 km/sec (bilateral); seismic moment, 3.3 × 1025 dyne-cm; stress drop, 32 bars. The effective stress available to accelerate the fault motion is estimated to be about 40 bars. The approximate agreement between the effective stress and the stress drop suggests that most of the effective stress was released at the time of the earthquake.

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.

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