• Title/Summary/Keyword: soil mechanics

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DYNAMIC DESIGN METHODS OF ROCK ENGINEERING

  • Feng, Xia-Ting
    • Proceedings of the Korean Society for Rock Mechanics Conference
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    • 2011.09a
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    • pp.23-33
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    • 2011
  • The key features of an intelligent and dynamic design methodology for rock engineering projects has been introduced and summarized firstly, which include some new functions such as intelligent recognition of mechanical rockmass parameters, strategies to select modeling methods and codes, integrated feedback modeling and information, and technical auditing in rock engineering design process. Then typical examples of applications of the dynamic design methodology in some large slopes, underground powerhouses in China are summarized. The discussions are given for the future of the methodology.

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CHARACTERISTICS OF SOME WET CLAY SOILS AFTER REMOULDING TREATMENTS

  • Ou, Yinggang;Chen, Liancheng
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.1036-1042
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    • 1993
  • In order to derive homogeneous remould soil sample, which is very important for obtaining reliable experimental results in terra-mechanics research, the characteristics of two clay soils at high moisture contents after remoulding treatment were investigated . It was found that with the remoulding process employed the coefficients of variation was less than 1.2% for the soil density and the soil could be treated as fully saturated soil. Therefore, the remoulded and will restore after a period of time. Some suggestiions were given follow the results of the drop cone test.

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Performance-based framework for soil-structure systems using simplified rocking foundation models

  • Smith-Pardo, J. Paul
    • Structural Engineering and Mechanics
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    • v.40 no.6
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    • pp.763-782
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    • 2011
  • Results from nonlinear time-history analyses of wall-frame structural models indicate that the condition of vulnerable foundations -for which uplifting and reaching the bearing capacity of the supporting soil can occur before yielding at the base of the shear walls- may not be necessarily detrimental to the drift response of buildings under strong ground motions. Analyses also show that a soil-foundation system can inherently have deformation capacity well in excess of the demand and thus act as a source of energy dissipation that protects the structural integrity of the shear walls.

Impact of spatial variability of geotechnical properties on uncertain settlement of frozen soil foundation around an oil pipeline

  • Wang, Tao;Zhou, Guoqing;Wang, Jianzhou;Wang, Di
    • Geomechanics and Engineering
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    • v.20 no.1
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    • pp.19-28
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    • 2020
  • The spatial variability of geotechnical properties can lead to the uncertainty of settlement for frozen soil foundation around the oil pipeline, and it can affect the stability of permafrost foundation. In this paper, the elastic modulus, cohesion, angle of internal friction and poisson ratio are taken as four independent random fields. A stochastic analysis model for the uncertain settlement characteristic of frozen soil foundation around an oil pipeline is presented. The accuracy of the stochastic analysis model is verified by measured data. Considering the different combinations for the coefficient of variation and scale of fluctuation, the influences of spatial variability of geotechnical properties on uncertain settlement are estimated. The results show that the stochastic effects between elastic modulus, cohesion, angle of internal friction and poisson ratio are obviously different. The deformation parameters have a greater influence on stochastic settlement than the strength parameters. The overall variability of settlement reduces with the increase of horizontal scale of fluctuation and vertical scale of fluctuation. These results can improve our understanding of the influences of spatial variability of geotechnical properties on uncertain settlement and provide a theoretical basis for the reliability analysis of pipeline engineering in permafrost regions.

Analysis of post-failure response of sands using a critical state micropolar plasticity model

  • Manzari, Majid T.;Yonten, Karma
    • Interaction and multiscale mechanics
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    • v.4 no.3
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    • pp.187-206
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    • 2011
  • Accurate estimations of pre-failure deformations and post-failure responses of geostructures require that the simulation tool possesses at least three main ingredients: 1) a constitutive model that is able to describe the macroscopic stress-strain-strength behavior of soils subjected to complex stress/strain paths over a wide range of confining pressures and densities, 2) an embedded length scale that accounts for the intricate physical phenomena that occur at the grain size scale in the soil, and 3) a computational platform that allows the analysis to be carried out beyond the development of an initially "contained" failure zone in the soil. In this paper, a two-scale micropolar plasticity model will be used to incorporate all these ingredients. The model is implemented in a finite element platform that is based on the mechanics of micropolar continua. Appropriate finite elements are developed to couple displacement, micro-rotations, and pore-water pressure in form of $u_n-{\phi}_m$ and $u_n-p_m-{\phi}_m$ (n > m) elements for analysis of dry and saturated soils. Performance of the model is assessed in a biaxial compression test on a slightly heterogeneous specimen of sand. The role of micropolar component of the model on capturing the post-failure response of the soil is demonstrated.