scholarly journals Modeling of Uplift Resistance of Buried Pipeline by Geogrid and Grid-Anchor System

Author(s):  
S. Reza Maljaei ◽  
Hooshang Katebi ◽  
Majid Mahdi ◽  
Akbar A. Javadi
Author(s):  
Alahyar Koochekali ◽  
Behrouz Gatmiri ◽  
Amirabbas Koochekali

True estimation of soil response during pipeline upheaval buckling is a key parameter in the safe design of subsea buried pipeline. In this paper the effects of sea mean water level over the buried pipeline and the effects of pipe burial depth on the soil response during vertical buckling are investigated. For that purpose a numerical modeling of pipeline upheaval buckling in clayey backfill has been conducted. Different sea mean water levels are considered to simulate the pipeline shore approach. In addition, various pipeline burial depths are considered to predict the soil uplift resistance and the soil failure mechanism. In order to model the large penetration of pipeline into the soft clay, Arbitrary Eulerian Lagrangian (ALE) method is employed. The results reveal that in the shallow water the sea mean water level may have considerable effects on the soil failure mechanism and soil uplift resistance. In addition, as the sea mean water level and pipe burial depth increases, a new transitional failure mechanism can be observed. The mechanism is a combination of vertical sliding block mechanism and the flow-around mechanism.


2021 ◽  
Author(s):  
Junho Lee ◽  
Krishnaveni Balakrishnan ◽  
Charles P. Aubeny ◽  
Sanjay Arwade ◽  
Don DeGroot ◽  
...  

1993 ◽  
Vol 30 (3) ◽  
pp. 441-454 ◽  
Author(s):  
B. Rajani ◽  
N. Morgenstern

The experimental behaviour of model pipelines embedded in polycrystalline ice is studied to improve the understanding of the behaviour of a chilled buried pipeline subjected to frost heave. Two model pipelines with slightly different radius to thickness ratios were subjected to prescribed displacement rates. Their behaviour was monitored until peak strains corresponding to current acceptable strain limits, often referred to as the wrinkling strains, were exceeded. The sizing of the model pipelines and experimental setup are described and detailed procedures on polycrystalline ice sample preparation are given. Representative core samples of polycrystallineice were tested to determine its elastic and creep properties. The observed and predicted responses of strain histories in the pipeline are compared and acceptable agreement between the responses is obtained. Key words : experimental behaviour, embedded model pipelines, polycrystalline ice, frost heave, uplift resistance, critical strain limits.


Measurement ◽  
2015 ◽  
Vol 64 ◽  
pp. 57-63 ◽  
Author(s):  
Danial Jahed Armaghani ◽  
Koohyar Faizi ◽  
Mohsen Hajihassani ◽  
Edy Tonnizam Mohamad ◽  
Ramli Nazir

Author(s):  
Prigiarto Hokkal Yonatan ◽  
Filip Van den Abeele ◽  
Jean-Christophe Ballard

Designing the cover height of buried pipelines to prevent them from buckling requires a method that can thoroughly and realistically model the phenomenon. This paper introduces a new technique to assess the risk of upheaval buckling (UHB) by using backfill soil springs (BFSS) to represent the uplift resistance provided by the backfill soil on top of a buried pipeline. This paper investigates the pre-buckling pipeline behavior related to UHB and highlights some of the key parameters governing the analysis. UHB assessment based on a case study was carried out and the results were then compared with those obtained from force-equilibrium methods generally used in the industry. The comparison shows that UHB assessment can be performed more rigorous using BFSS than using force-equilibrium methods. Therefore, using BFSS for UHB assessment improve the reliability in cover height design.


Author(s):  
Ruslan V. Aginey ◽  
◽  
Rustem R. Islamov ◽  
Alexey A. Firstov ◽  
Elmira A. Mamedova ◽  
...  

Existing methods for estimating the bending stresses of buried pipeline section based on the survey data for the depth of the axis of the pipeline from the ground surface are characterized by a large error between the real values of the bending stress and the values of the bending stress obtained from the calculation results based on the survey data. The purpose of this study is to improve the methodology for calculating the bending stresses of buried pipeline section based on the results of determining the depth of the axis of the pipeline from the ground surface, taking into account the design features of the pipeline and the used search equipment. Mathematical models are proposed that allow for the set value of the maximum error in determining bending stresses for a particular pipeline to choose the optimal measurement step before the survey, which will allow to reduce the error. Explanations are given on the choice of the maximum step of the study based on the strength characteristics of the pipeline. A calculation is provided that confirms the adequacy of the developed mathematical models and the possibility of their application in practice.


2014 ◽  
Vol 2 (1) ◽  
pp. 11-29
Author(s):  
Ahmad Jabber Hussain ◽  
Alaa Dawood Salman ◽  
. Nazar Hassan Mohammad

      According to this theoretical study which was about loading of piles under different condition of loading (compression and up-lift forces ) and for deferent pile installation (vertical and inclined pile ) by which it called (positive batter pile ) when the inclination of the load and pile is in the same direction and called (negative batter pile) when the inclination of load is opposite to the pile inclination, and from studying these cases the results of analysis can be summarize in the flowing points: 1-Variation of load inclination on piles effects on the bearing capacity and uplift resistance. It was found that bearing capacity of the piles increase with increasing of load inclination up to the inclination angle (37.5ͦ) which represents the maximum bearing capacity and then the bearing capacity decrease with increasing of load inclination. 2- Variation of batter pile affects the bearing capacity of the pile and up-lift resistance. by which equivalent angle will be used as result between the load and piles inclination and this angle will be used in calculation of piles resistance . 3- It was noticed the shape of soil failure is highly affected by the inclination of pile. The shape of failure for the soil which is in contact with pile and this include (vertical and batter piles) is highly affected by the angle of inclination.


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