Characteristics of the modulus of passive resistance of soil

Watkins, Reynold King

doi:10.31274/rtd-180813-4240

Cited by 14 publications

(19 citation statements)

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“…The Spangler stress formula can be extended to include the beneficial effects of lateral soil restraint based on Watkins work 21 . This first-principles approach can be applied to a variety of equipment loads and are not limited to particular ranges of physical variables.…”

Section: A Proposed Modification To the Spangler Stress Equationmentioning

confidence: 99%

Development of a Pipeline Surface Loading Screening Process

Warman¹,

Chorney²,

Reed

et al. 2006

Volume 1: Project Management; Design and Construction; Environmental Issues; GIS/Database Development; Innovative Projects and

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Pipeline Operators receive numerous requests annually to cross their pipelines. In many of these cases detailed analysis using a number of different methods are performed since no simplified approach is available. The Canadian Energy Pipeline Association (CEPA) with Kiefner and Associates, Inc. undertook the development of a screening methodology for vehicle loading. The hope is a standard approach to these analyses might be established to assist pipeline operating companies. This paper describes an approach detailing the development and implementation of a simplified screening process to assess the effects of surface loads on buried pipelines. A design basis was established based on a literature review to identify theoretical models, standards, codes, and recommended practices that are currently used to assess the surface loading effects on buried pipelines. This design basis was incorporated into a methodology utilized to develop a screening tool which provides a simple “pass/no pass” determination and is based on attributes which are generally easy to obtain (e.g., wheel or axle load, ground surface loading pressure, depth of cover, maximum allowable operating pressure and design factor). Situations which pass the initial screening would require no additional analysis while situations that do not pass the initial screening may need to be evaluated on a more detailed basis. Simplified graphs have been developed to assist in additional screening prior to performing a more detailed evaluation.

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Section: A Proposed Modification To the Spangler Stress Equationmentioning

confidence: 99%

Development of a Pipeline Surface Loading Screening Process

Warman¹,

Chorney²,

Reed

et al. 2006

Volume 1: Project Management; Design and Construction; Environmental Issues; GIS/Database Development; Innovative Projects and

View full text Add to dashboard Cite

show abstract

“…Various methods like simplified equations to predict deflections of buried pipes have been developed for recent years. M. G. Spangler proposed the Iowa formula or Spangler's equation to predict deflections of buried pipes in 1941 [4], and the Modified Iowa formula, with the modulus of soil reaction (E ) a semi-empirica1 soil parameter, was proposed in 1958 [5]. Burns and Richard published their solution at the symposium at the University of Arizona in 1964 [6].…”

Section: Introductionmentioning

confidence: 99%

Three‐dimensional responses of buried corrugated pipes and ANN‐based method for predicting pipe deflections

Kim

Cho

Yun

et al. 2010

Num Anal Meth Geomechanics

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SUMMARYThis study investigated localized responses, such as circumferential stresses, on corrugation and pipe deflections. Also, this study examined the effect of corrugation geometry on the overall and localized response of corrugated pipes with refined three-dimensional modeling of the entire soil-pipe interaction system, including corrugation. To investigate the availability of the traditional two-dimensional method, the results from the three-dimensional finite element method (FEM) were compared with those from the twodimensional FEM. The soil-pipe modeling techniques of this study were verified by comparing the FEM results by Utah State University and analytical results. An artificial neural network (ANN)-based model to predict vertical deflections of buried corrugated pipes was developed to overcome the shortcomings of existing methods and obtain results that are close to the level of accuracy of FEM results. In order to train an ANN, analyses on a large amount of data were executed with various standardized pipe geometries and burial depths regulated by the Korea Highway Corporation using the two-dimensional FEM verified in this study. The widely used back propagation algorithm was adopted. The ANN-based model developed in this study was shown to be an effective tool by comparing the results with test data and sensitivity analyses were executed based on the data from the developed ANN.

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“…The modulus of passive resistance (e) was investigated by Watkins and Spangler (1958). They noticed that it does not have the dimension of a modulus and thus could not represent a soil property.…”

Section: _ P~wbmentioning

confidence: 99%

“…Soil stiffness is the ability of the soil to assist the pipe to withstand the applied loads, to retain the pipe's structural integrity, and to redistribute the stress around the pipe. Watkins and Spangler (1958) introduced the empirical modulus of soil reaction, E', to account for the restraint developed by the soil at the sides of the pipe. Hartley and Duncan (1988) mentioned that because of the empirical nature of the modulus of soil reaction (E'), it may introduce a large uncertainty in deflections calculated using the modified Iowa formula.…”

Section: Pipe Performance Parametersmentioning

confidence: 99%

The structural performance of flexible pipes

Suleiman

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High density polyethylene pipes have been used for over a decade but little information is available on the in-service behavior of these pipes. At the request of the Minnesota Concrete Pipe Association, an investigation to evaluate the field performance of HDPE was undertaken. The objective of the first part of this dissertation was to investigate the field performance of in-service HDPE pipes using visual information obtained from a remote, motorized video camera. Ten projects with a total length of 12,006 feet were investigated in Minnesota. The performance characteristics considered in this evaluation were cross sectional deformations, wall buckling, wall crushing, wall cracking, joint separation, and sediments. Few major structural problems were noticed due to the effect of granular material used as a backfill. CANDE is one of the commonly used programs for buried pipe analysis; however, the limitations of CANDE include application only to small deflections, and neglect the time effects. The recent tendency of using thermoplastic pipes for deep applications, which increased the need for investigating the effect of large deflections, and the dependency of the properties of such pipes on strain rate and time led to the use of ANSYS. The main advantage of CANDE relative to ANSYS is the use of the nonlinear soil models while ANSYS has the advantage of modeling large deflections. A computer code using ANSYS programming language was written to model the soil behavior using hyperbolic tangent modulus with both power and hyperbolic bulk modulus models. CANDE and the small and large deflection theories of ANSYS were compared with Moser's (1994) results. This comparison showed that CANDE over-predicts the pipe deflections as the soil approaches the shear failure and that ANSYS better describes the pipe behavior. CANDE can be used as long as the shear

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Characteristics of the modulus of passive resistance of soil

Cited by 14 publications

References 0 publications

Development of a Pipeline Surface Loading Screening Process

Development of a Pipeline Surface Loading Screening Process

Three‐dimensional responses of buried corrugated pipes and ANN‐based method for predicting pipe deflections

The structural performance of flexible pipes

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