The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform

M. El Sawwaf - One of the best experts on this subject based on the ideXlab platform.

  • Experimental and Numerical Study of Strip Footing Supported on Stabilized Sand Slope
    Geotechnical and Geological Engineering, 2010
    Co-Authors: M. El Sawwaf
    Abstract:

    The paper presents the results of laboratory model tests and theoretical analysis on the behavior of a strip footing supported on sheet Pile Wall-stabilized sandy slope and loaded vertically to failure. The parameters varied in the study include the height, stiffness and location of the sheet Pile Wall, the location of the footing relative to the slope crest and the relative density of sand. Two-dimensional plane strain finite element analyses was used to analyze a prototype strip footing on sandy slope with same conditions. The results indicate that the inclusion of sheet Pile Wall has significant effect in improving the response of the strip footing and the slope itself. The theoretical results confirm the experimental results of the model footing tests and show reasonable agreement. Based on the numerical and experimental results, critical values of the sheet Pile Wall parameters for maximum stabilizing effect are established.

Ahmed M A Nasr - One of the best experts on this subject based on the ideXlab platform.

  • behavior of strip footing on fiber reinforced cemented sand adjacent to sheet Pile Wall
    Geotextiles and Geomembranes, 2014
    Co-Authors: Ahmed M A Nasr
    Abstract:

    Abstract In urban areas, shallow foundations are often placed along the ground surface above a sheet Pile Wall. In this research, the potential benefits of reinforcing the active zone behind a model sheet Pile Wall by using polypropylene fiber and cement kiln dust have been investigated experimentally and numerically. Tests were conducted by varying parameters including fiber ratio (RF), cement kiln dust (CKD) ratio, thickness of reinforced layer, footing location relative to the sheet Pile Wall and curing time of reinforced layer. Finite element computer code PLAXIS 2D foundation was used for numerical modeling. Close agreement between the experimental and numerical results was observed (maximum difference 14%). Experimental and numerical results clearly show that fiber insertion into the cemented soil causes an increase in ultimate bearing capacity of footing and significant reduction in the lateral deflection of the sheet Pile Wall. At higher fiber ratios (RF ≥ 0.75%), the bearing capacity ratio (BCR) increased by about 42% and the effect of CKD ratio on BCR is more pronounced. The addition of fibers changed the brittle behavior of cemented sand to a more ductile one. Critical values of reinforcing parameters for maximum reinforcing effects are established.

  • effect of geosynthetic reinforcement in active zone on the behavior of sheet Pile Walls
    Geotechnical Testing Journal, 2013
    Co-Authors: Ahmed M A Nasr, Ashraf K Nazir
    Abstract:

    The potential benefits of reinforcing the active zone behind a model sheet Pile Wall were studied. A series of plane strain laboratory model tests were performed on both unreinforced and reinforced active zones loaded with a rigid strip footing. Parameters including the sand relative density, reinforcement embedment depth, type of reinforcement, footing location relative to the sheet Pile Wall, length of reinforcement, and number of reinforcing layers were varied. The sheet Pile Wall deflection during loading was measured. Finite element (FE) analyses were performed on a prototype sheet Pile Wall to supplement the results of the model tests. A two-dimensional plane strain FE model using the computer code PLAXIS was used. Close agreement between the experimental and numerical results was observed (about 4 % to 11 %). The results indicate that the inclusion of reinforcement in the active zone leads to a reduction by about 48 % to 75 % in the lateral deflection. The effectiveness of the reinforcement in decreasing the lateral deflection of the sheet Pile Wall is attributed to its tensile strength and type. Based on the results of the laboratory model and the numerical analyses, critical values of reinforcement parameters for maximum reinforcing effects are suggested. The results are used to development linear regression equations relating the ultimate lateral capacity of the sheet Pile Wall to the aforementioned parameters.

Roger Wisen - One of the best experts on this subject based on the ideXlab platform.

  • time lapse surface waves to detect the stiffness of a grouted Pile Wall
    First Break, 2015
    Co-Authors: Stefano Stocco, Paolo Bergamo, Roger Wisen
    Abstract:

    We adopt the surface waves method to assess the stiffness of a grouted Pile Wall in the ground. The acquisition is performed in time-lapse mode, col¬lecting data soon after the grouting and a few months later and comparing the results. We use a 48-geophone single array, shooting in different positions along the array, in order to extract several dispersion curves to compare, provid¬ing a set of curves referring to different subsurface portions. We applied a spatial windowing based on a set of Gaussian windows with different shapes, optimising lateral and wave¬number resolutions. The comparison between the time-lapse dispersion curves shows an increase of the phase-velocity on the portion of the ground interested by the grouted Pile Wall. Surface waves data was collected also on a transect close to the grouted Wall but not influenced by it, to obtain a reference line. The results demonstrate the reliability of time-lapse sur¬face wave data analysis to assess the changing of the mechani¬cal properties of the ground after consolidating works. The reliability and performance of surface waves have been tested to assess the stiffness of a grouted Pile Wall. The grouting injection in a urban area interested a depth ranging from 2 m up to 15 m, in a geological environment of a calcareous bedrock 15 m deep, with alluvium overburden. The project is based on the collaboration between Ramboll Denmark and Gamut srl, which is part of the Politecnico di Torino. Seismic data have been collected at two different periods to evaluate the changes of the stiffness of the consolidating ground; the approach is cost-effective because it is non-invasive and is capable of operating in urban areas. As the ambient noise limits the use of methods based on the travel¬time analysis (detection and picking of first time arrivals), surface waves, more energetic than P or S-waves, ensure a high data quality. The challenge is to obtain different surface waves of data along a Wall, using a single seismic array.

Rasmus Müller - One of the best experts on this subject based on the ideXlab platform.

  • Multivariate approach in reliability-based design of a sheet Pile Wall
    Transportation Geotechnics, 2016
    Co-Authors: Anders Prästings, Stefan Larsson, Rasmus Müller
    Abstract:

    In light of a restricted budget, there is a need to stress on the potential savings in conducting qualitative geotechnical investigations. This paper presents a case study on how site investigation efforts can be linked to potential savings in designing a sheet Pile Wall in central Sweden. The uncertainty in the undrained shear strength is a measure of investigation effort and have been evaluated from multivariate information, several investigation methods. A multivariate analysis (MVA) procedure based on Bayesian statistics was used to cross-validate information obtained by different investigation methods, thus allowing the uncertainty or effort to be updated (reduced) when additional investigations are included in the analysis. The uncertainty was evaluated for two sets of investigations, one of which included additional measurements and hence less uncertainty. A reliability-based design method, FOSM, was then used to study how the additional investigations affected the evaluated uncertainty and one design constraint of the sheet Pile Wall, namely the depth of penetration. The results show that the depth of penetration can potentially be reduced by approximately 11% of the total Wall area.

Van De Kuilen, J.w.g. - One of the best experts on this subject based on the ideXlab platform.

  • Biodynamic timber sheet Pile Walls: vegetation retaining structure
    'Springer Science and Business Media LLC', 2020
    Co-Authors: Kamath A.c., Gard W.f., Van De Kuilen, J.w.g.
    Abstract:

    Timber sheet Pile Walls are widely used for the protection of stream banks in different parts of the world. However, there is a tendency to create more sustainable types of stream banks not only because exploitable wood is more difficult to obtain, but also because of disturbance to the natural habitat of plants and animals due to hard embankments. In the Netherlands alone, about 2500 km of engineered timber sheet Pile Wall embankments exist, primarily made with tropical hardwood, besides an even much larger amount of ‘non-engineered’ small-size timber-based embankments. As an alternative, the authors propose to use a mixed timber sheet Pile-vegetation system, where locally available timber can be applied in combination with natural vegetation. Unlike the usual bioengineering scheme, vegetation is not seen as an element, which could replace the timber sheet Piles. Instead, a new perspective is tested, where the vegetation is included as a ‘structural’ element which can even counteract the consequences of time-dependent biological degradation of the timber sheet Pile. By doing so, both long-term durability as well as reliability of the stream bank is improved. A comprehensive design strategy was developed based on well-established sub-models from the literature on plant growth, root reinforcement as well as timber damage accumulation. The timber sheet Pile Wall-vegetation system is illustrated in an example case study. Preliminary analysis including only the mechanical reinforcement of vegetation shows that there is a decrease in moment and shear acting on the timber sheet Pile with growth of the vegetation. Consequently, the damage accumulation due to load duration effects on the timber decreases and the service life of the system increases. Thus, using vegetation in combination with highly degradable timber could possibly negate the need for using hardwood timber, or more generally, save resources that are currently used for these structures.Bio-based Structures & Material