scholarly journals Reducing Statistical Uncertainty in Elastic Settlement Analysis of Shallow Foundations Relying on Targeted Field Investigation: A Random Field Approach

Geosciences ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 20 ◽  
Author(s):  
Panagiotis Christodoulou ◽  
Lysandros Pantelidis
Keyword(s):  
Finite Element ◽  
Random Fields ◽  
Soil Property ◽  
Property Values ◽  
Field Investigation ◽  
Shallow Foundations ◽  
Statistical Uncertainty ◽  
Sampling Points ◽  
Elastic Settlement ◽  
Settlement Analysis

The present paper deals with the practical problem of reducing statistical uncertainty in elastic settlement analysis of shallow foundations by relying on targeted field investigation with the aim of an optimal design. In a targeted field investigation, the optimal number and location of sampling points are known a priori. As samples are taken from the material field (i.e., the ground), which simultaneously is a stress field (stresses caused by the footing), the coexistence of these two fields allows for some points in the ground to better characterize the serviceability state of structure. These points are identified herein through an extensive parametric analysis of the factors controlling the magnitude of settlement; the number of different cases considered was 3318. This is done in an advanced probabilistic framework using the Random Finite Element Method (RFEM) properly considering sampling of soil property values. In this respect, the open source RSETL2D program, which combines elastic finite element analysis with the theory of random fields, has been modified as to include the function of sampling of soil property values from the generated random fields and return the failure probability of footing against excessive settlement. Two sampling strategies are examined: (a) sampling from a single point and (b) sampling a domain (the latter refers to e.g., continuous cone penetration test data). As is shown in this work, by adopting the proper sampling strategy (defined by the number and location of sampling points), the statistical error can be significantly reduced. The error is quantified by the difference in the probability of failure comparing different sampling scenarios. Finally, from the present analysis, it is inferred that the benefit from a targeted field investigation is much greater as compared to the benefit from the use of characteristic values in a limit state design framework.

scholarly journals Field Investigation and Rapid Deterioration Analysis of Heavy Haul Corrugation

2021 ◽  
Vol 11 (14) ◽  
pp. 6317
Author(s):  
Feng Jin ◽  
Hong Xiao ◽  
Mahantesh M Nadakatti ◽  
Huiting Yue ◽  
Wanting Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Cracks ◽  
Field Measurements ◽  
Field Investigation ◽  
The Finite Element Method ◽  
Rail Corrugation ◽  
Rapid Deterioration ◽  
Heavy Haul

In this study, the rapid growth of corrugation caused by the bad quality of grinding works and their wavelength, depth, and evolution processes are captured through field measurements. The residual grinding marks left by poor grinding quality lead to further crack accumulation and corrugation deterioration by decreasing plastic resistance in rails. In this case, the average peak-to-peak values of corrugation grow extremely fast, reaching 1.4 μm per day. The finite element method (FEM) and fracture mechanics methodologies were used to analyze the development and trends in rail surface crack deterioration by considering rails with and without grinding marks. Crack propagation trends increase with residual grinding marks, and they are more severe in circular curve lines. To avoid the rapid deterioration of rail corrugation, intersections between grinding marks and fatigue cracks should be avoided.

scholarly journals Elastic Settlement Analysis of Rigid Footings Relying On The “Characteristic Point” Concept

2021 ◽  
Author(s):  
Lysandros Pantelidis
Keyword(s):  
Finite Element Analysis ◽  
Characteristic Point ◽  
Compressible Medium ◽  
Tabular Form ◽  
Element Analysis ◽  
3D Finite Element ◽  
Influence Area ◽  
Elastic Settlement ◽  
Rigid Footing ◽  
Settlement Analysis

Abstract In the present paper, the problem of finding the location of the so-called “characteristic point” of flexible footings is revisited. As known, the settlement at the characteristic point, is equal to the uniform settlement of the respective rigid footing. The cases of infinitely long strips and circular footings are studied fully analytically. For the case of rectangular footings, analytical results (for flexible footings) are compared with the respective numerical results (for rigid footings) obtained from 3D finite element analysis (210 cases were examined). As shown, the location of the characteristic point may greatly deviate from the well-known values reported in the literature, as it strongly depends on the thickness and Poisson’s ratio value of the compressible medium. For rectangular footings this location also depends on their aspect ratio, L/B. The location of the characteristic point with respect to the center of footing for the various cases examined is given in tabular form. Strain influence area values (Aj=ρjEs/qB) are also given for the convenient calculation of the settlement (ρj) of footings, especially the rigid, rectangular ones; q is the uniform surcharge of footing and Es the soil modulus.

Coupled Electromagnetic-Thermal Field Investigation in Induction Heating Device

2009 ◽  
Vol 152-153 ◽  
pp. 407-410
Author(s):  
Ilona Ilieva Iatcheva ◽  
Rumena Stancheva ◽  
Hristofor Tahrilov ◽  
Ilonka Lilianova
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Induction Heating ◽  
Heating System ◽  
Field Investigation ◽  
Field Analysis ◽  
The Finite Element Method ◽  
Nonlinear Transient ◽  
Induction Heating System ◽  
Element Method

The aim of the work is precise coupled –electromagnetic and temperature field analysis of an induction heating system by finite element method. Presented example is referred to real induction heating system. The problem was solved as nonlinear, transient and axisymmetrical. The numerical model of the coupled fields is based on the finite element method and electromagnetic and temperature distributions have been obtained using COMSOL 3.3 software package.

scholarly journals Comparative Analysis of Kazakhstani and European Approaches for the Design of Shallow Foundations

2020 ◽  
Vol 10 (8) ◽  
pp. 2920
Author(s):  
Assel Shaldykova ◽  
Sung-Woo Moon ◽  
Jong Kim ◽  
Deuckhang Lee ◽  
Taeseo Ku ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Summation Method ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Design Procedures ◽  
Geological Conditions ◽  
Elastic Settlement ◽  
Geotechnical Design ◽  
The Difference ◽  
Design Calculations

The design of shallow foundations is performed in accordance with different building regulations depending on geotechnical and geological conditions. This paper involves the design calculations applying Kazakhstani and European approaches. The design of shallow foundations in Nur-Sultan city in Kazakhstan was implemented by the calculation of bearing capacity and elastic settlement in accordance with the design procedures provided in SP RK 5.01-102-2013: Foundations of buildings and structures, and Eurocode 7: Geotechnical design. The calculated results of bearing capacity and elastic settlement for two types of shallow foundations, such as pad foundation and strip foundation, adhering to Kazakhstani and European approaches are relatively comparable. However, the European approach provided higher values of bearing capacity and elastic settlement for the designed shallow foundation compared to the Kazakhstani approach. The difference in the results is explained by the application of different values of partial factors of safety for the determination of bearing capacity and different methods for the calculation of the elastic settlement of shallow foundations (i.e., elasticity theory and layer summation method).

VERIFICATION OF APPLICABILITY OF MACRO-ELEMENT IMPLEMENTATION IN A FINITE ELEMENT CODE FOR SHALLOW FOUNDATIONS

2013 ◽  
Vol 13 (08) ◽  
pp. 1350041 ◽  
Author(s):  
PENGPENG NI
Keyword(s):  
Finite Element ◽  
Shallow Foundations ◽  
Finite Element Code ◽  
Single Author ◽  
Macro Element

It has been found that the above article authored by Pengpeng Ni, includes works of Dr. António A. Correia from LNEC, Portugal, and Dr. Raffaele Figini from Enel Produzione, Ingegneria Civile e Idraulica, Milano, Italy (described in Secs. 2 and 3), and hence, Mr. Ni does not justify the publication with a single author name. This article was therefore, retracted from its publication in IJSSD. A statement of retraction is published in Int. J. Struct. Stab. Dyn., Volume 14, Issue 7 (2014) http://dx.doi.org/10.1142/S0219455414930018.

Sign in / Sign up

Export Citation Format

Share Document