Book•
Foundation analysis and design
01 Jan 1968-
TL;DR: In this paper, Fondation de soutenagement et al. presented a reference record for Dimensionnement Reference Record created on 2004-09-07, modified on 2016-08-08.
Abstract: Keywords: Fondation ; Mur de soutenement ; Pieux ; Capacite portante ; Ancrage ; Dimensionnement Reference Record created on 2004-09-07, modified on 2016-08-08
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TL;DR: The numerical simulation efforts of an 18.1-m span SSCB pertaining to its ongoing preparations for a full-scale field test are presented and it is found that the failure load is reduced when the structure is loaded in an asymmetrical manner.
Abstract: The limit state design of large-span soil–steel composite bridges (SSCB) entails that understanding their structural behaviour in the ultimate state is as much needed as their performance under service conditions. Apart from box culverts, the largest loading-to-failure test was done on a 6.3-m span culvert. More tests on larger spans are believed essentially valuable for the development of the design methods. This paper presents the numerical simulation efforts of an 18.1-m span SSCB pertaining to its ongoing preparations for a full-scale field test. The effect of the different loading positions on the ultimate capacity is investigated. Comparisons are made between three-dimensional (3D) and two-dimensional (2D) models. The results enabled to realise the important role of the soil load effects on the ultimate capacity. It is found that the failure load is reduced when the structure is loaded in an asymmetrical manner. A local effect is more pronounced for the live load when the tandem load is placed closer to the crown. The study also illustrates the complex correlation between 3D and 2D models, especially if one attempts to simultaneously associate sectional forces and displacements.
9 citations
01 Jan 2008
TL;DR: In this paper, a new method for the construction of p-y curves is proposed and the ultimate lateral load is computed from the log-log plot of ground line displacement and applied load and the effect of number of load cycles on the ultimate load resistance is investigated for various pile diameters and load eccentricities.
Abstract: ABSTRACT: In this paper, the ultimate lateral resistance of a long, flexible, unrestrained vertical pile in soft clay is computed under cyclic loading condition using p-y curves. A new method for the construction of p-y curves is proposed. The comparison of calculated results of the proposed method with the field test results reported by Matlock (1970) shows a good agreement. An iterative analysis is employed with secant modulus approach using a matrix method known as moment area method developed by Sawant and Dewaikar (1994). The load-ground line displacement relationship is obtained for different load eccentricities, number of cycles and pile diameters using the proposed p-y curves. Ultimate lateral load is computed from the log-log plot of ground line displacement and applied load and the effect of number of load cycles on the ultimate lateral load resistance is investigated for various pile diameters and load eccentricities.
8 citations
Journal Article•
TL;DR: In this article, the authors have presented the laboratory measurements of the properties of soft clays and their settlements at different applied stresses, at 27% water content and 9 kPa undrained shear strength, to examine their behaviors under loading.
Abstract: Soft clays are widely spread in Iraq particularly in its southern Mesopotamian plain. As many sites within these regions may be used for vital projects; an adequate solution has been found out to improve such clays using stone column and dynamic compaction methods. For this purpose, the present paper has presented the laboratory measurements of the properties of such clays and their settlements at different applied stresses. Thirteen soil model tests have been made, at 27% water content and 9 kPa undrained shear strength, to examine their behaviors under loading .The tested models include : (1) model for untreated soil ; (3) models for soil treated with stone columns (1,2 and 3 columns) with 30mm in diameter and 180mm length ; (9) models for soil treated with dynamic compaction using drop weights 2 , 3 and 5kg at three different drop heights ( 500 , 750 , and 1000mm ) . For dynamic compaction, the behavior of soil stress - settlement reflects two stages for 2 and 3 kg drop weights with slow and rapid settlements respectively. Whereas , three stages were identified using 5kg drop weight with slow, medium and quick settlements. No considerable effect of drop height and no noticeable improvements have been indicated with soil model treated by dynamic compaction except for weight drop of 5kg but with less improvement ratio compared with stone columns model test. Whereas, the behavior of stress- settlement using stone columns reflects three stages with slow, rapid and slow (again) settlements . In comparison with untreated soil, the maximum cumulative settlement improvement ratios were 69% and 178% at applied stress of 30 kN/m 2 for soil models treated with dynamic compaction ( 5kg drop weight ) and 3 stone columns respectively .
8 citations
Cites background from "Foundation analysis and design"
...The imposed energy is dissipated through the ground and rapid excessive pore water pressure is developed and immediate loss of shear strength occurs [7]....
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TL;DR: In this article, the failure mechanism and real causes of failure in the Gangweigou floodway were explored, based on the conditions of hydrology and hydraulics, failure processes and the results of stability analyses, which concluded that ignoring a possible bed incision or bank erosion was likely the primary problem with the improper design.
8 citations
Journal Article•
TL;DR: The results indicate that the proposed method could provide solutions of high quality, accuracy and efficiency for optimum design of foundation.
Abstract: In this study an effective method for nonlinear constrained optimization of shallow foundation is presented. A newly developed heuristic global optimization algorithm called Gravitational Search Algorithm (GSA) is introduced and applied for the optimization of foundation. The algorithm is classified as random search algorithm and does not require initial values and uses a random search instead of a gradient search, so derivative information is unnecessary. The optimization procedure controls all geotechnical and structural design constraints while reducing the overall cost of the foundation. To verify the efficiency of the proposed method, two design examples of spread footing are illustrated. To further validate the effectiveness and robustness of the GSA, these examples are solved using genetic algorithm. The results indicate that the proposed method could provide solutions of high quality, accuracy and efficiency for optimum design of foundation.
8 citations