A 3-Dimensional Continuum ALE Model for Soil-Pipe Interaction

2008 ◽  
Author(s):  
Abdelfettah Fredj ◽  
Aaron Dinovitzer ◽  
Joe Zhou
Keyword(s):  
Large Scale ◽  
Large Deformations ◽  
Ground Deformation ◽  
Ground Movement ◽  
Soil Movement ◽  
3 Dimensional ◽  
Ale Methods ◽  
Permanent Ground Deformation ◽  
Pipeline Design ◽  
Soil Pipe

Soil-pipe interactions when large ground movements occur are an important consideration in pipeline design, route selection, guide monitoring and reduce the risk of damage or failure. Large ground movement can be caused by slope failures, faulting, landslides and seismic activities. Such conditions induce large deformations of both the soil and pipe. Analyses of such behavior pose a significant challenge to capabilities of standard finite elements as the capability to analyze large deformations is required. This requirement is difficult to meet for Lagrangian-based code. New developments using ALE methods make it possible to determine soil and pipe deformation confidently for large displacements. This paper describes a study performed to investigate the mechanical behavior of a pipeline subjected to large soil movement. A 3D continuum modeling using an ALE (Arbitrary Eulerian Lagrangian) formulation was developed and run using LS-DYNA. The results are compared with published experimental data of large-scale test to verify the numerical analysis method. The analysis is further extended to analyze the soil-pipe interaction under permanent ground deformation such as those associated with surface fault rupture and landslides.

Recent Concepts for the Welding of High Strain Pipelines

2009 ◽  
Author(s):  
Brian D. Newbury ◽  
Martin W. Hukle ◽  
Mark D. Crawford ◽  
Joshua Sleigh ◽  
Steven A. Altstadt ◽  
...  
Keyword(s):  
Large Scale ◽  
High Strain ◽  
Soil Liquefaction ◽  
Operating Pressure ◽  
Line Pipe ◽  
Strain Capacity ◽  
Soil Movement ◽  
Specific Material ◽  
Pipeline Design ◽  
Design And Testing

Standard allowable stress-based pipeline designs (strain demand ≤ 0.5%) are now giving way to more complex strain-based designs (strain demand higher than 0.5%) as the locations of future pipelines move into regions of increased strain demand. The increase in required levels of strain demand are attributed to seismic activity, soil movement, soil liquefaction, frost heave, thaw settlement, ice scour or a combination thereof. Pipelines in high strain demand regions are typically limited by the strain capacity of the girth weld. As strain-based pipeline design has matured, it has become evident that specific material properties (both weld metal and line pipe), defect size, defect location, misalignment, and operating pressure each affect the strain capacity of the pipeline. This paper reviews proposed design and testing methodologies for the qualification of strain-based design welding procedures. These methods have been applied in the development and qualification of welding procedures for the construction of pipelines subject to longitudinal tensile strains in excess of 2%. Strain-based design requires considerably more effort than traditional design in terms of girth weld qualification and testing. To ensure adequate girth weld strain capacity for strain-based design the testing includes large scale and full-scale pressurized testing for design validation.

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.

Towards Robust Fragility Relations for Buried Segmented Pipe in Ground Strain Areas

2015 ◽  
Vol 31 (3) ◽  
pp. 1839-1858 ◽  
Author(s):  
Michael O'Rourke ◽  
Evgueni Filipov ◽  
Eren Uçkan
Keyword(s):  
Wave Propagation ◽  
Linear Function ◽  
Ground Deformation ◽  
Unit Length ◽  
Ground Movement ◽  
Seismic Fragility ◽  
Ground Shaking ◽  
Permanent Ground Deformation

Seismic fragility relations of buried segmented pipelines are currently defined in terms of pipe repairs per unit length as a function of some measure of ground shaking or ground movement. In some current relations, both wave propagation (WP) and permanent ground deformation (PGD) damage are addressed by combining the hazard into a measure of ground strain. One troubling aspect of these fragility relations is that each new event seems to provide new data that in some cases, are significantly different from existing relations. Herein, we investigate the robustness of these expressions by using new data from the 1999 M = 7.4 Turkey earthquake. A methodology is presented to calculate ground strains, by considering relative PGD along the axis of the pipeline. Results indicate that, for the strain/damage range of interest, a linear function (on a log-log scale) provides a relatively robust fragility relation for buried segmented pipes.

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.

scholarly journals A Large-Scale Model of Lateral Pressure on a Buried Pipeline in Medium Dense Sand

2021 ◽  
Vol 11 (12) ◽  
pp. 5554
Author(s):  
Hamzh Alarifi ◽  
Hisham Mohamad ◽  
Nor Faridah Nordin ◽  
Muhammad Yusoff ◽  
Aminu Darda’u Rafindadi ◽  
...  
Keyword(s):  
Large Scale ◽  
Ground Deformation ◽  
Earth Pressure ◽  
Scale Model ◽  
Buried Pipeline ◽  
Buried Pipelines ◽  
Buried Pipe ◽  
Long Distance ◽  
Soil Movement ◽  
Lateral Soil Movement

Modern countries utilise buried pipelines for the long-distance transportation of water, oil, and gas due to their efficiency and continuity of delivery to receiving locations. Due to soil movements such as landslides, excessive earth pressure imposed on buried pipelines causes damage and, consequently, leaking of liquids, gases or other harmful effluents into the soil, groundwater, and atmosphere. By using a large-scale physical model, the lateral pipeline–soil interaction in sandy soil was researched. This study investigated the stress distribution on a buried pipe induced by lateral soil displacement. The external forces on the buried pipe caused by the surrounding soil motion were measured using earth pressure cells installed in the active zone along the pipeline. Additionally, visual inspection of ground deformation patterns on the surface, including tensile cracks, above a shallow-buried pipeline subjected to lateral soil movement was reported. The results revealed that lateral soil movement has a potency effect on buried pipelines. The findings also indicated that the highest stresses occur at the unstable soil boundaries prior to reaching the soil’s peak strength. After observing the soil surface’s rupture, most of the stress increments were concentrated in the middle section of the pipe.

Seismic Damage to Segmented Buried Pipe

2004 ◽  
Vol 20 (4) ◽  
pp. 1167-1183 ◽  
Author(s):  
Michael O'Rourke ◽  
Erik Deyoe
Keyword(s):  
Wave Propagation ◽  
Ground Deformation ◽  
Empirical Relation ◽  
Seismic Damage ◽  
Reliable Data ◽  
Ground Movement ◽  
Buried Pipe ◽  
The Past ◽  
Using Data ◽  
Permanent Ground Deformation

A fragility relation for buried segmented pipe subject to either the wave propagation or permanent ground deformation (PGD) hazard is presented. In the past, relations to estimate wave propagation damage to buried segmented pipe frequently use peak particle velocity (Vmax) to characterize the seismic hazard. For example, in 1993, O'Rourke and Ayala developed an empirical relation between damage (quantified by repairs per kilometer of pipe) and Vmax using data from four U.S. and two Mexican events. Existing fragility relations for PGD typically characterize the hazard by the amount of permanent ground movement. It is shown herein that for statistically reliable data, differences in estimated wave propagation repair rates become much smaller when the seismic shaking is characterized by ground strain as opposed to Vmax. Furthermore, damage rates for PGD are shown to be consistent with those for wave propagation when the PGD hazard is similarly characterized by ground strain. The combined wave propagation and PGD relation is quite consistent for four orders of magnitude of ground strain.

scholarly journals Jointed pipeline response to tunneling-induced ground deformation

2016 ◽  
Vol 53 (11) ◽  
pp. 1794-1806 ◽  
Author(s):  
Brad P. Wham ◽  
Christina Argyrou ◽  
Thomas D. O’Rourke
Keyword(s):  
Cast Iron ◽  
Ductile Iron ◽  
Large Scale ◽  
Ground Deformation ◽  
Joint Rotation ◽  
Soil Movement ◽  
Assessment Design ◽  
Geometric Conditions ◽  
Dimensional Finite Element ◽  
Lateral Soil Movement

This paper focuses on the effect of tunneling-induced ground deformation on the response of jointed cast iron and ductile iron pipelines that (i) cross the settlement profile perpendicular to the tunnel centerline and (ii) connect through 90° tees with a pipeline parallel to the tunnel centerline. The modeling involves two-dimensional finite element analyses that account for coupled forces both parallel and perpendicular to the pipeline, and incorporates the results of large-scale laboratory tests to characterize the joints. Pipeline response is quantified with respect to joint rotation and pullout at various leakage levels as well as the allowable tensile strain. The paper describes soil displacements induced by a 6.1 m (20 ft.) diameter tunnel in clay and sand. Joint rotations and maximum tensile strains for pipelines in sand exceed those in clay by up to three for the same geometric conditions. Cast iron pipelines crossing the tunnel centerline are most vulnerable to leakage from joint rotation; ductile iron pipelines have sufficient capacity against joint leakage in all cases studied. Cast iron pipelines that connect with 90° tees are highly vulnerable to leakage from pullout due to lateral soil movement. Guidance is provided for risk assessment, design, and utility operations.

Preliminary Monitoring of Ground Slumping Across a Natural Gas Distribution Network With Satellite Radar

2016 ◽  
Author(s):  
Michael D. Henschel ◽  
Benjamin Deschamps ◽  
Gillian Robert ◽  
Dan Zulkoski
Keyword(s):  
Natural Gas ◽  
Satellite Imagery ◽  
Large Scale ◽  
Ground Deformation ◽  
Deformation Monitoring ◽  
Ground Movement ◽  
Satellite Monitoring ◽  
Gas Distribution ◽  
Pipeline Network ◽  
Integrity Management

Ground deformation from natural or anthropogenic processes is a significant factor in the integrity management plan for natural gas distribution networks. Rapid or large scale deformation can pose an immediate rupture threat. Smaller, more gradual or repeated ground deformations may lead to material stresses, damage and strain accumulation, posing a longer-term threat. Satellite monitoring can play a key role in pipeline integrity management programs by measuring ground deformation over an entire pipeline network, at high spatial and temporal resolutions with the ability to capture both rapid large scale and subtle, repeated ground movement over a longer period of time. Millimeter accuracy ground deformation estimates are derived from radar satellite imagery using InSAR, a well-established and validated remote sensing technique. InSAR is an effective tool for rapidly identifying new regions requiring ground geotechnical surveys, deriving estimates of deformation rate, extents, and evolution of deformation patterns, for validating or extending traditional ground-based measurements, and for forward-looking operational monitoring. We present the results of InSAR ground deformation monitoring over a natural gas distribution pipeline network in Saskatchewan, Canada. At the case study site, small diameter pipelines (up to 40 years old) have been subjected to ground slumping from a retrogressive landslide affecting multiple lakeshore communities and compounded in recent years by a high water table. Some locations have recently experienced slumping at rates greater than 50 cm/yr leading to important structural issues with roads, buildings, water mains, and gas pipelines. The ground movement analysis is based on RADARSAT-2 satellite imagery acquired at 24-day intervals over a short period in 2015. Thousands of suitable measurement points were identified over two communities on opposite shores of the lake. The measured InSAR deformation time series showed deformation toward the lake. The extents of the deformation are clearly delineated by the InSAR measurements.

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