Vehicle Load Distribution Under Timber Mats and Flexible Slab

2020 ◽  
Author(s):  
Benjamin B. Zand
Keyword(s):  
Elastic Foundation ◽  
Load Distribution ◽  
Ground Surface ◽  
Point Load ◽  
Buried Pipeline ◽  
Surface Loading ◽  
Element Analysis ◽  
Continuous Contact ◽  
Conventional Vehicle ◽  
Beam On Elastic Foundation

Abstract Pipeline operators commonly use means of temporary crossing such as timber-mat, airbridge, and slab to reduce surface loading induced stresses in a buried pipeline at locations where a heavy vehicle crosses the buried pipeline. When a temporary crossing has a continuous contact with soil, (e.g. timber mat, flexible slab) load distribution over the ground surface is not immediately known. Load distribution under a timber-mat or flexible slab is a function of the slab to soil stiffness ratio. The load distribution tends to become more uniform with increasing timber-mat or slab stiffness. In this work an analytical model using beam-on-elastic-foundation has been developed and Laplace transform has been utilized to find the solution and apply free-end boundary conditions. The analytical solution can be used for any arbitrary load distribution over a beam-on-elastic foundation. In this work the solution for a point load and a partially distributed uniform load were employed as these scenarios can accurately represent conventional vehicle foot-prints, while being computationally efficient. The analytical solutions are compared to finite element analysis to validate the model. This model can be used in conjunction with the Canadian Energy Pipeline Association (CEPA) surface loading calculator (or similar tools) to analyze pipeline encroachment problems when means of temporary crossing is installed. This model can help the operators determine dimensions and bending stiffness of timber-mat or flexible slab to assure a desirable load distribution will be achieved. The model can also be used for structural analysis of a timber-mat or flexible slab under vehicular load.

scholarly journals A comparative study of soil-structure interaction in the case of frame structures with raft foundation

2016 ◽  
Vol 63 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Balázs Móczár ◽  
Zsuzsanna Polgár ◽  
András Mahler
Keyword(s):  
Elastic Foundation ◽  
Soil Structure ◽  
Structural Engineering ◽  
Soil Structure Interaction ◽  
Engineering Practice ◽  
Subgrade Reaction ◽  
Element Analysis ◽  
Structure Interaction ◽  
Beam On Elastic Foundation ◽  
Raft Foundations

AbstractDesign and modelling of raft foundations and selecting the value of coefficient of vertical subgrade reaction are still actively discussed topics in geotechnical and structural engineering. In everyday practice, soil–structure interaction is mostly taken into account by using the theory of ‘beam on elastic foundation’, in which the soil is substituted by a certain set of coefficients of subgrade reaction. In this study, finite element analysis of a building was performed using a geotechnical software (Plaxis 3D), which is capable of modelling the subsoil as a continuum, and a structural software (Axis VM), which uses the concept of ‘beam on elastic foundation’. The evaluation of the results and recommendations for everyday engineering practice are introduced in this paper.

Influence of Shield Tunneling on a Nearby Buried Pipeline

2011 ◽  
Vol 90-93 ◽  
pp. 1840-1845
Author(s):  
Da Yong Li ◽  
Li Xue Cao ◽  
De Wei Fan
Keyword(s):  
Elastic Foundation ◽  
Analytical Method ◽  
Bending Moment ◽  
Bending Moments ◽  
Buried Pipeline ◽  
Shearing Force ◽  
Shield Tunneling ◽  
Maximum Settlement ◽  
Beam On Elastic Foundation ◽  
Set Up

The influence of shield tunneling on a nearby buried pipeline is studied by using the analytical method. Equations of displacements, rotations, bending moments, and shearing forces of a buried pipeline are set up respectively on the base of the theory of Winkler’s beam on elastic foundation. It shows the maximum settlement of the buried pipeline occurs in its middle span. Both the maximum bending moment and the shearing force of a buried pipeline take place at its two ends. The diffusion angle of the subgrade and the buried depth of the buried pipeline play an important role in the behavior of the buried pipeline.

Study on Buried Pipeline Floatation Response Induced by Soil Liquefaction

2014 ◽  
Vol 608-609 ◽  
pp. 820-824
Author(s):  
Su Nan Deng ◽  
Wen Tao Peng ◽  
Jun Qi Lin
Keyword(s):  
Elastic Foundation ◽  
Axial Force ◽  
Virtual Work ◽  
Soil Liquefaction ◽  
Initial Deformation ◽  
Beam Model ◽  
Buried Pipeline ◽  
Beam On Elastic Foundation ◽  
Model Based ◽  
Element Method

On the basis of Virtual Work, in this paper, the formulae are deduced for the floatation response of buried pipeline duo to the soil liquefaction. A beam model based on the theory of beam on elastic foundation is used for the pipeline buried in non-liquefied and liquefied area, considering the effects of nonlinear soil constraint and the initial deformation, the length of liquefied area, and the axial force acting on the pipeline. The study of floatation response of buried pipeline are conducted using the nonlinear increment element method, some results are given.

Development of the mathematical model for assessing the optimal measurement step when surveying the depth of the underground pipeline from the ground

2020 ◽  
Vol 10 (4) ◽  
pp. 364-371
Author(s):  
Ruslan V. Aginey ◽  
◽  
Rustem R. Islamov ◽  
Alexey A. Firstov ◽  
Elmira A. Mamedova ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Survey Data ◽  
Ground Surface ◽  
Maximum Error ◽  
Large Error ◽  
Bending Stress ◽  
Buried Pipeline ◽  
Optimal Measurement ◽  
Pipeline Section ◽  
Bending Stresses

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.

The Compliance of Solid, Wide-Faced Spur Gears

1990 ◽  
Vol 112 (4) ◽  
pp. 590-595 ◽  
Author(s):  
J. H. Steward
Keyword(s):  
Experimental Data ◽  
Contact Line ◽  
Load Distribution ◽  
3D Model ◽  
Spur Gear ◽  
Point Load ◽  
Spur Gears ◽  
Line Load ◽  
Gear Teeth ◽  
Theoretical Results

In this paper, the requirements for an accurate 3D model of the tooth contact-line load distribution in real spur gears are summarized. The theoretical results (obtained by F.E.M.) for the point load compliance of wide-faced spur gear teeth are set out. These values compare well with experimental data obtained from tests on a large spur gear (18 mm module, 18 teeth).

Comparison of Buried Pipeline Crossing Assessments Using API RP 1102, Analytical Method and Finite Element Approach

2020 ◽  
Author(s):  
Nikhil Joshi ◽  
Pritha Ghosh ◽  
Jonathan Brewer ◽  
Lawrence Matta
Keyword(s):  
Finite Element ◽  
Analytical Method ◽  
Rapid Assessment ◽  
Buried Pipeline ◽  
The Finite Element Method ◽  
Buried Pipelines ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Element Approach ◽  
Multiple Loading

Abstract API RP 1102 provides a method to calculate stresses in buried pipelines due to surface loads resulting from the encroachment of roads and railroads. The API RP 1102 approach is commonly used in the industry, and widely available software allows for quick and easy implementation. However, the approach has several limitations on when it can be used, one of which is that it is limited to pipelines crossing as near to 90° (perpendicular crossing) as practicable. In no case can the crossing be less than 30° . In this paper, the stresses in the buried pipeline under standard highway vehicular loading calculated using the API RP 1102 method are compared with the results of two other methods; an analytical method that accounts for longitudinal and circumferential through wall bending effects, and the finite element method. The benefit of the alternate analytical method is that it is not subject to the limitations of API RP 1102 on crossing alignment or depth. However, this method is still subject to the limitation that the pipeline is straight and at a uniform depth. The fact that it is analytical in nature allows for rapid assessment of a number of pipes and load configurations. The finite element analysis using a 3D soil box approach offers the greatest flexibility in that pipes with bends or appurtenances can be assessed. However, this approach is time consuming and difficult to apply to multiple loading scenarios. Pipeline crossings between 0° (parallel) and 90° (perpendicular) are evaluated in the assessment reported here, even though these are beyond the scope of API RP 1102. A comparison across the three methods will provide a means to evaluate the level of conservatism, if any, in the API RP 1102 calculation for crossing between 30° and 90° . It also provides a rationale to evaluate whether the API RP 1102 calculation can potentially be extended for 0° (parallel) crossings.

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