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
Citations
More filters
31 Oct 2019
TL;DR: In this paper, a testing system that can simulate both external water-soil pressures and inner water pressure was designed, based on which both single-ring and three-ring full-scale loading tests were conducted, and some interesting observations were made: increasing inner water head decreased the axial force, which thereby increased the lining deformation; the bending moment transferring mechanism was evident in the three ring tests due to staggered fabrication.
Abstract: A sophisticated and flexible testing system that can simulate both external water-soil pressures and inner water pressure was designed, based on which both single-ring and three-ring full-scale loading tests were conducted, and some interesting observations were made: increasing inner water head decreased the axial force, which thereby increased the lining deformation; the bending moment transferring mechanism was evident in the three-ring tests due to staggered fabrication, which significantly reduced the structural deformation comparing with the single-ring tests; the structural deformation accumulated slightly during the water inflow and drainage cycles, and the structural deformations remained stable after nine loading cycles; the internal forces increased and convergence deformations decreased as hoop effect was caused by the uniformly distributed grouting pressures; increasing longitudinal thrust made the 3D effects more obvious but the influence of increasing longitudinal thrust was limited as the structural deformation became approximately saturated when the longitudinal thrust exceeded a certain threshold value; compared with the increasing of the buried depth, the sensitivity of the lining deformation to the coefficients of subgrade reaction was more obvious during the increasing of the inner water head, and the deformation values at the UST state decreased linearly with the coefficients; both the cracking process captured by DIC technique and measured overall deformations showed that the lining structure failed when the inner water head exceeded 65m (ultimate limit states) .
Cites methods from "Foundation analysis and design"
...Unlike the conventional full-scale loading tests and that prescribed in the design code which consider the lateral soil resistance as a constant, the lateral soil resistance varied with respect to the lining deformation based on Winkler model (Bowles, 1988) determined by Eq....
[...]
07 Jun 2016
21 Feb 2006
TL;DR: In this article, an axi-symmetric model is considered for a square footing which is approximated as an axisymmetric circular footing of the same contact area, and the effect of geotextile as a soil reinforcement is more pronounced in weaker soils.
Abstract: The use of geosynthetics as reinforcement started growing up five decades ago, but faced with many challenges and needed more research. Sometimes it is not always possible to perform experiments on geosynthetics in laboratory as it need specialized equipments and great care during preparing samples and the equipments. For these reasons, an alternative solution is presented in this paper utilizing numerical modeling and comparing its results with experiments data. In numerical analysis, an axi-symmetric model is considered for a square footing which is approximated as an axi-symmetric circular footing of the same contact area. Geo-material is modeled as 15-nodes axi-symmetric elements. Geotextile reinforcement is simulated as elastic membrane. Mohr-Coulomb failure criterion is used to model the nonlinear soil behavior. A series of direct shear box tests were preformed on sand of different relative densities at the sand-geotextile interface to determine the shear properties of the geo-composite at the interface in terms of friction angle and apparent cohesion. These parameters are used in the numerical model and series of trials were preformed to get the value of the initial modulus of elasticity which leads to a match between the numerical and experimental load-displacement response. Numerical model is also used to find equivalent un-reinforced geomaterial with shear strength parameters that give a load-displacement relation matching the laboratory results for reinforced geo-composite. Results of experimental work show that the most effective depth to width ratio (depth of reinforcement over footing width) of geotextile is found to be 0.30 and the most effective length ratio (length of reinforcement over footing width) is 3.00. The work also confirms the fact that the effect of geotextile as a soil reinforcement is more pronounced in weaker soils. The numerical results offer equivalent un-reinforced geo-material with shear parameters which represent the reinforced geo-composite material. The equivalent parameters can be used in numerical analysis to give ultimate load with difference from laboratory values in the range of 10%.
11 Mar 2011
TL;DR: In this article, the authors used CPT profiles (obtained at the same location during different time frames) that are analyzed through signal processing techniques incorporated in the code and also incorporated a series of curve fitting techniques to evaluate the profiles as a function of depth.
Abstract: Cone penetration tests (CPTs) have been performed on very soft marsh and foundation soils in support of the dike design of two containment areas for a liquefied natural gas (LNG) terminal in Georgia. Due to the inherent variability in layer thickness and soil classification within a CPT sounding profile, an algorithm has been written to automate the CPT sounding analysis. The algorithm was initially written to automate the data interpretation process (i.e. soil classification and strength evaluation) and was later expanded to (i) evaluate strength gain and (ii) estimate settlement using CPT profiles. The algorithm uses CPT profiles (obtained at the same location during different time frames) that are analyzed through signal processing techniques incorporated in the code. The signal processing techniques used include high frequency filters and a series of cross-correlation techniques. The algorithm also incorporates a series of curve fitting techniques to evaluate the profiles as a function of depth. This paper provides an overview of the techniques used in the algorithm along with strength gain plots.Comparison between settlements estimated using the CPT soundings through signal processing and settlements calculated using conventional theories are also presented. The comparison shows favorable agreement between the two techniques.
01 Jan 2008
TL;DR: In this article, the authors present a site investigation program that includes literature survey, site visit, subsurface investigation program and sampling, and laboratory test program to identify soil types existing in the site.
Abstract: The geotechnical engineer needs to develop an appropriate game plan to conduct a piling engineering project. Investigation of the site is a very important step in any geotechnical engineering project. In a site investigation program, some major steps are involved, that are, literature survey, site visit, subsurface investigation program and sampling, and laboratory test program. The very first step in a site investigation program is to obtain published information relevant to the project. Subsurface information can be obtained from the sources, namely—national geological surveys, adjacent property owners, published literature, and aerial photographs. After conducting a literature survey, it is a good idea to pay a site visit that is helpful in determining the surface soil characteristics. Surface soil may indicate the existence of underlying fill material or loose organic soil. A comprehensive boring program should be conducted to identify soil types existing in the site. Local codes should be consulted before developing the boring program.