Elastic Settlement Analysis for Various Footing Cases Based on Strain Influence Areas

2020 ◽  
Vol 38 (4) ◽  
pp. 4201-4225 ◽  
Author(s):  
Lysandros Pantelidis
Keyword(s):  
Elastic Settlement ◽  
Settlement Analysis

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.

scholarly journals Analysis of tangential contact boundary value problems using potential functions

2019 ◽  
Vol 6 (3) ◽  
pp. 182106
Author(s):  
Adam G. Taylor ◽  
Jae H. Chung
Keyword(s):  
Boundary Condition ◽  
Boundary Conditions ◽  
Boundary Value Problems ◽  
Boundary Value ◽  
Potential Functions ◽  
Shallow Foundation ◽  
Contact Boundary ◽  
Elastic Settlement ◽  
Tangential Traction ◽  
Settlement Analysis

This paper presents an analysis technique of high-order contact potential problems and its application to an elastic settlement analysis of a shallow foundation system subjected to a combined traction boundary condition. Closed-form solutions of potential functions are derived for an elastic half-space subjected to bilinear tangential traction boundary conditions over rectangular surface regions. Using the principle of superposition, the present solutions provide a means to form an approximate and continuous solution of elastic contact problems with higher-order tangential boundary conditions. As an application example, an elastic settlement analysis of a rigid footing founded on a dense granular soil is performed under a tangential traction boundary condition prescribed in an analogy with the stress equilibrium states of static sandpiles. A generalized solution approach to combined normal and tangential traction boundary value problems is discussed in the context of foundation engineering.

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 Elastic Settlement Analysis of Rigid Rectangular Footings on Sands and Clays

Geosciences ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 491
Author(s):  
Lysandros Pantelidis ◽  
Elias Gravanis
Keyword(s):  
Characteristic Point ◽  
Applied Pressure ◽  
Third Parties ◽  
Elastic Response ◽  
Analysis Method ◽  
Contact Pressure Distribution ◽  
Equal Area ◽  
Elastic Settlement ◽  
Rigid Footing ◽  
Settlement Analysis

In this paper an elastic settlement analysis method for rigid rectangular footings applicable to both clays and sands is proposed. The proposed method is based on the concept of equivalent shape, where any rectangular footing is suitably replaced by a footing of elliptical shape; the conditions of equal area and equal perimeter are satisfied simultaneously. The case of clay is differentiated from the case of sand using different contact pressure distribution, whilst, additionally, for the sands, the modulus of elasticity increases linearly with depth. The method can conveniently be calibrated against any set of settlement data obtained analytically, experimentally, or numerically; in this respect the authors used values which have been derived analytically from third parties. Among the most interesting findings is that sands produce “settlement x soil modulus/applied pressure” values approximately 10% greater than the respective ones corresponding to clays. Moreover, for large Poisson’s ratio (v) values, the settlement of rigid footings is closer to the settlement corresponding to the corner of the respective flexible footings. As v decreases, the derived settlement of the rigid footing approaches the settlement value corresponding to the characteristic point of the respective flexible footing. Finally, corrections for the net applied pressure, footing rigidity, and non-elastic response of soil under loading are also proposed.

scholarly journals Comparative Analysis of Kazakhstani and European Design Specifications: Raft Foundation, Pile Foundation, and Piled Raft Foundation

2021 ◽  
Vol 11 (7) ◽  
pp. 3099
Author(s):  
Assel Zhanabayeva ◽  
Nazerke Sagidullina ◽  
Jong Kim ◽  
Alfrendo Satyanaga ◽  
Deuckhang Lee ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
International Standards ◽  
Piled Raft ◽  
Codes Of Practice ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Eurocode 7 ◽  
Elastic Settlement ◽  
Geotechnical Design ◽  
The Difference

The introduction of Eurocode in Kazakhstan allows for the application of modern technological innovations and the elimination of technical barriers for the realization of international projects. It is significant to study the international standards and design requirements provided in Eurocode. This study presents a comparative analysis of Kazakhstani and European approaches for the geotechnical design of foundations and provides the design methods in the considered codes of practice. Three different types of foundations (i.e., raft, pile, and piled raft foundations) were designed following SP RK 5.01-102-2013—Foundations of buildings and structures, SP RK 5.01-103-2013—Pile foundations, and Eurocode 7: Geotechnical design for the Nur-Sultan soil profile. For all three types of foundations, the calculated results of bearing resistance and elastic settlement showed the conservativeness of Eurocode over SNiP-based Kazakhstani building regulations, as the values of bearing resistance and elastic settlement adhering to Kazakhstani code exceeded the Eurocode values. The difference between the obtained results can be explained by the application of higher values of partial safety factors by Eurocode 7. Sensitivity analysis of the bearing resistance on foundation parameters (i.e., raft foundation width and pile length) for the Kazakhstani and European approaches was performed to support the conclusions of the study.

The Settlement Analysis of the Cement Fly-Ash Gravel Pile Composite Foundation of Baotou

2014 ◽  
Vol 580-583 ◽  
pp. 518-523
Author(s):  
Juan Li ◽  
Yao Xu ◽  
Jun Yin
Keyword(s):  
Fly Ash ◽  
Composite Foundation ◽  
Settlement Calculation ◽  
Practical Engineering ◽  
Cfg Pile Composite Foundation ◽  
Modified Formula ◽  
Gravel Pile ◽  
Final Settlement ◽  
Settlement Analysis ◽  
Cfg Pile

This paper analyzes the causes of larger differences of final settlement calculated value of cement fly-ash gravel pile (CFG pile) composite foundation of Baotou with actual observed result of it. On the basis of analysis on a number of practical engineering data of Baotou, we modify the settlement formula of the CFG pile composite foundation and gain the modified coefficient applied to the settlement calculation of the CFG pile composite foundation of Baotou. The modified formula and coefficient proposed in this paper have a positive effect on the accurate settlement calculation of puting forward a more accurate correction formula and coefficient of the calculation of the CFG pile composite foundation of Baotou.

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