scholarly journals Behaviour of a semi-infinite beam in a creeping medium

1992 ◽  
Vol 29 (5) ◽  
pp. 779-788 ◽  
Author(s):  
B. Rajani ◽  
N. Morgenstern
Keyword(s):  
Finite Element ◽  
Lower Bound ◽  
Structural Design ◽  
Three Dimensional ◽  
Approximate Solutions ◽  
Finite Element Analyses ◽  
Laterally Loaded Piles ◽  
Dimensional Solution ◽  
Infinite Beam ◽  
Laterally Loaded

The behaviour of a pipeline embedded in a creeping medium is examined. Approximate solutions for a beam in a creeping foundation are developed, and characteristic nondimensional load–displacement relationships are presented. A comparison of these approximate solutions provides upper and lower bound solutions that are consistent with finite element analyses. Furthermore, the simplified solutions can be readily adapted for analyzing the uplift behaviour of shallow pipelines. These solutions can also be used to analyze the creeping behaviour of laterally loaded piles. The results are presented in the form of nondimensional charts that permit hand calculations and rapid verification of the structural design of the pipelines and piles. An approximate three-dimensional solution that accounts for embedmentis proposed. Key words : creeping behaviour of pipelines, creeping foundation, laterally loaded pile.

Nonlinear solutions for laterally loaded piles

2020 ◽  
Vol 57 (10) ◽  
pp. 1566-1580
Author(s):  
Bipin K. Gupta ◽  
Dipanjan Basu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Differential Equations ◽  
Three Dimensional ◽  
Nonlinear Finite Element Analysis ◽  
Nonlinear Finite Element ◽  
Laterally Loaded Piles ◽  
Element Analysis ◽  
Reduced Modulus ◽  
Laterally Loaded

A nonlinear analysis framework for laterally loaded piles is presented that is as accurate as equivalent three-dimensional nonlinear finite element analysis, but computationally one order of magnitude faster. The nonlinear behavior of sands and clays are account for by using hyperbolic modulus–reduction relationships. These nonlinear–elastic constitutive models are used to calculate the reduced modulus at different points in the soil based on the soil strains induced by lateral pile displacement. The reduced modulus at different points in the soil domain are spatially integrated to calculate the reduced soil resistance parameters associated with the differential equation governing the lateral pile displacement. The differential equations governing the lateral displacements of pile and soil under equilibrium are obtained by applying the principle of virtual work to a continuum-based pile–soil system. These coupled differential equations are solved using the one-dimensional finite difference method following an iterative algorithm. The accuracy of the analysis is verified against equivalent three-dimensional nonlinear finite element analysis, and the validity of the analysis in predicting the field response is checked by comparisons with multiple pile load test results. Parametric studies are performed to gain insights into the lateral pile response.

PROGRESS IN THE APPLICATION OF LOWER BOUND DIRECT METHODS IN STRUCTURAL DESIGN

2010 ◽  
Vol 02 (01) ◽  
pp. 145-160 ◽  
Author(s):  
DIETER WEICHERT ◽  
ABDELKADER HACHEMI
Keyword(s):  
Finite Element ◽  
Lower Bound ◽  
Structural Design ◽  
Numerical Optimization ◽  
Industrial Design ◽  
Direct Methods ◽  
Finite Element Analyses ◽  
Shakedown Analysis

Based on the lower-bound direct methods, namely limit and shakedown analysis, it is shown in this paper how these methods can be used in a constructive manner for structural industrial design. The proposed methods are based on finite element analyses and numerical optimization to determine the admissible loading. Numerical applications are presented and compared with existing results in literatures.

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