Calculation of beams on an elastic foundation with a variable modulus of subgrade reaction

1965 ◽  
Vol 2 (5) ◽  
pp. 296-299 ◽  
Author(s):  
S. N. Klepikov
Keyword(s):  
Elastic Foundation ◽  
Subgrade Reaction ◽  
Modulus Of Subgrade Reaction ◽  
Variable Modulus

The Calculation of the Two-Layer Beam Model on an Elastic Basis with Variable Modulus of Subgrade Reaction

2013 ◽  
Vol 351-352 ◽  
pp. 566-569 ◽  
Author(s):  
Vladimir Igorevich Andreev ◽  
Alena Vladimirovna Matveeva ◽  
Elena Vjacheslavovna Barmenkova
Keyword(s):  
Lower Layer ◽  
Single Layer ◽  
Beam Model ◽  
Constant Modulus ◽  
Subgrade Reaction ◽  
Variable Rigidity ◽  
Modulus Of Subgrade Reaction ◽  
Variable Modulus ◽  
Internal Forces ◽  
Elastic Basis

In the present paper is given the calculation of the two-layer and the single-layer beam models on an elastic basis with variable and constant modulus of subgrade reaction. The two-layer beam is the beam of variable rigidity, the lower layer simulates the foundation, and the upper - the structure, at the same time is considered the weight of each layer. In the results of calculations of beams, as the two-layer and the single-layer, the values of the internal forces and stresses are obtained more with variable modulus of subgrade reaction than with constant. With consideration of the two-layer and the single-layer beam models with the same characteristics of the base, the values of internal forces, generated in two-layer beams, are obtained much more.

Effect of FWD Testing Position on Modulus of Subgrade Reaction

2014 ◽  
Vol 518 ◽  
pp. 53-59 ◽  
Author(s):  
S.N. Shoukry ◽  
G.W. William ◽  
M.Y. Riad ◽  
J.C. Prucz
Keyword(s):  
Temperature Gradient ◽  
Early Morning ◽  
Slab Thickness ◽  
Positive Temperature ◽  
Falling Weight Deflectometer ◽  
Subgrade Reaction ◽  
K Value ◽  
Modulus Of Subgrade Reaction ◽  
Late Evening ◽  
Falling Weight

This paper discusses the variation of the Modulus of subgrade reaction (k) backcalculated from slab deflection basins, interactive with the location of the Falling Weight Deflectometer (FWD) load pulse, and curling of slabs due to daily temperature variations. The k-value was calculated following the AASHTO design guides procedures, while deflection basins were recorded at an interval of 3 to 4 hours along the day on an instrumented concrete pavement test section in West Virginia. The state of deformation of the slabs are continuously monitored, through dowel bar bending measurements and records of the temperature gradient profiles through the slab thickness, as well as joint openings every 20 minutes. The results indicated that the backcalculated k-values are greatly affected by the positive temperature gradient, and the least variation in (k) was found in the slab center. In order to minimize errors in back-calculations of k-values, it is recommended to perform the FWD test for recording deflection basins in the interior of the slab during late evening or in the early morning.

EXCEL BASED SETTLEMENT OF BEAMS ON ELASTIC FOUNDATIONS WITH FREE-ENDS AND ARBITRARY LOADING

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Amir W. Al-Khafaji ◽  
Robert Jacobs
Keyword(s):  
Cross Sections ◽  
Engineering Practice ◽  
Subgrade Reaction ◽  
Variable Loading ◽  
Cross Sectional ◽  
Modulus Of Subgrade Reaction ◽  
Elastic Foundations ◽  
Arbitrary Loading ◽  
Finite Differences Method ◽  
Soil Modulus

The deflection of long footings placed on homogeneous and isotropic soils involves soil-structure differential equations models whose solution may not be possible for most practical problems. The analytical solution of beams on elastic foundation problem involves soil modulus of subgrade reaction and simplifying assumptions relative to applied loading. The exact solutions are available in relatively simple cases of loading, uniform cross sectional properties of the footing and constant soil modulus of subgrade reaction. Therefore, the Finite Difference Method (FDM) or Finite Element Method (FEM), are typically used to compute the deformation of beams with variable loading and geometry resting on elastic foundations with variable modulus of subgrade reaction. The finite differences method was used to solve this problem for long beams with arbitrary loading and constant cross-sections using an Excel Workbook to compute beam deflections providing both numerical and graphical output. The foundation is modeled as a long beam with free ends and a constant modulus of subgrade reaction. The proposed solution presents an efficient method involving a complex ordinary differential equation model for beams on elastic foundations encountered in engineering practice.

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.

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