the U.S. Army engineering Research and Development Center is investigating methods to construct a contingency airfield for C-17 aircraft loadings within a 72-hour construction period. the proposed method to satisfy th...
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ISBN:
(纸本)9780784409381
the U.S. Army engineering Research and Development Center is investigating methods to construct a contingency airfield for C-17 aircraft loadings within a 72-hour construction period. the proposed method to satisfy these stringent design requirements is to use a chemically stabilized in-situ top soil layer as a runway surface. A suite of soil-chemical mixture combinations was examined to optimize the stabilized soil mixture behavior. A numerical approach is developed in this study to supplement limited C-17 full-scale testing data. three stabilized soil mixture types are investigated using as stabilizing agents: 6% cement, 4% cement, and 4% cement + 1.5-in. (38-mm) long polypropylene fibers. Unconfined compression tests under monotonic loading and unconfined compression tests using repeated load tests were conducted to evaluate the stabilized soil mixture for strength and durability. Results have shown that the stabilized soil mixture exhibits damage and plastic behavior. In this study, the Army Corps' finite element code STUBBS is enhanced by including material damage to predict stabilized soil behavior when subjected to repetitive loadings. Damage behavior in the Valanis numerical model is calibrated using only two material properties and two damage parameters. Preliminary work on incorporating plastic behavior to supplement damage is discussed. In earlier work, forces induced by a C-17 aircraft on a runway were limited to a vertical force. However, C-17 aircraft braking forces induced during landing are substantial. therefore, in this work, in addition to the vertical pressure exerted by the aircraft wheels, preliminary work is presented which considers an aircraft braking force. Copyright ASCE 2007.
the Socorridos pumping station is located in Madeira Island, Portugal, and is part of a system conceived to reutilize the water flow from a hydroelectric plant. this underground structure is 26 m high, 12 m wide and t...
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this article focuses on the simulation of soil-structure interactions during a sinkhole by the use of a coupled numerical approach. the 2D model uses a Finite Difference computer code coupled with a Distinct Elements ...
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A benchmark example addressing ultimate limit state (ULS) design of an embedded retaining wall has been specified by the ERTC7 on the occasion of the 6theuropeanconference on numericalmethods in geotechnical Engine...
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ISBN:
(纸本)0415408229
A benchmark example addressing ultimate limit state (ULS) design of an embedded retaining wall has been specified by the ERTC7 on the occasion of the 6th european conference on numerical methods in geotechnical engineering. the main goal of the exercise was to highlight possibilities and limitations of numericalmethods for ULS design with particular reference to Eurocode7 (EC7), where three design approaches (DA1, DA2 and DA3) have been specified. these design approaches differ in the way partial factors of safety are introduced in the analysis. However, the exercise was not restricted to the use of EC7 and thus a wide spectrum of results, which are summarized in this paper, could be expected. Some of the 13 submissions did not actually present design values as requested but provided parametric studies showing the influence of various design assumptions or did an analysis using characteristic values, some introduced factors without given explicit reference to a particular code or standard.
In this paper, the features of S-CLAY1 model are explored through identification of the so-called response envelopes, which is very useful way of studying the incremental behaviour of a constitutive model. To highligh...
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Soil vibrations induced by high-speed trains may often cause malfunctioning of sensitive equipments and discomfort to population in proximity to train lines. In this paper the propagation of ground-borne vibrations ca...
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An elastic-perfect plastic model associated withthe Mohr-Coulomb failure criterion is applied to describe the behavior of soil material in the framework of smoothed particle hydrodynamics (SPH). numerical tests of dr...
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When modelling vertical drains in a real boundary value problem the radial flow around a drain needs to be mapped into equivalent plane strain conditions. this can be done by using either permeability, geometry or com...
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Based on the classical limit theorems of upper and lower bounds, the numerical procedures developed at Newcastle utilise finite elements and non-linear programming and has proven to be both effective and efficient in ...
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ISBN:
(纸本)0415408229
Based on the classical limit theorems of upper and lower bounds, the numerical procedures developed at Newcastle utilise finite elements and non-linear programming and has proven to be both effective and efficient in solving many geotechnical stability problems. the bounding techniques have yet to be applied to the seismic stability of geotechnical structures. In this paper, both seismic bearing capacity of footings located near slopes and seismic earth pressures on retaining walls will be examined.
the structure of most natural soft soils is anisotropic and apparently bonded. the apparent bonding gives the soil additional resistance to yielding, resulting in an increased value of undrained shear strength. It is ...
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