Search results for "Geotechnical engineering"
showing 10 items of 489 documents
On the Multipeakon Dissipative Behavior of the Modified Coupled Camassa-Holm Model for Shallow Water System
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/107450 Open Access This paper investigates the multipeakon dissipative behavior of the modified coupled two-component Camassa-Holm system arisen from shallow water waves moving. To tackle this problem, we convert the original partial differential equations into a set of new differential equations by using skillfully defined characteristic and variables. Such treatment allows for the construction of the multipeakon solutions for the system. The peakon-antipeakon collisions as well as the dissipative behavior (energy loss) after wave breaki…
A comparison between simulation and experiment for hysteretic phenomena during two-phase immiscible displacement
2014
[1] The paper compares a theory for immiscible displacement based on distinguishing percolating and nonpercolating fluid parts with experimental observations from multistep outflow experiments. The theory was published in 2006 in Physica A, volume 371, pages 209–225; the experiments were published in 1991 in Water Resources Research, volume 27, pages 2113. The present paper focuses on hysteretic phenomena resulting from repeated cycling between drainage and imbibition processes in multistep pressure experiments. Taking into account, the hydraulic differences between percolating and nonpercolating fluid parts provides a physical basis to predict quantitatively the hysteretic phenomena observ…
Dimensional analysis of pore scale and field scale immiscible displacement
1996
A basic re-examination of the traditional dimensional analysis of microscopic and macroscopic multiphase flow equations in porous media is presented. We introduce a ‘macroscopic capillary number’\(\overline {Ca}\) which differs from the usual microscopic capillary number Ca in that it depends on length scale, type of porous medium and saturation history. The macroscopic capillary number\(\overline {Ca}\) is defined as the ratio between the macroscopic viscous pressure drop and the macroscopic capillary pressure.\(\overline {Ca}\) can be related to the microscopic capillary number Ca and the LeverettJ-function. Previous dimensional analyses contain a tacit assumption which amounts to setting…
Fractional Tajimi–Kanai model for simulating earthquake ground motion
2014
The ground acceleration is usually modeled as a filtered Gaussian process. The most common model is a Tajimi–Kanai (TK) filter that is a viscoelastic Kelvin–Voigt unit (a spring in parallel with a dashpot) carrying a mass excited by a white noise (acceleration at the bedrock). Based upon the observation that every real material exhibits a power law trend in the creep test, in this paper it is proposed the substitution of the purely viscous element in the Kelvin Voigt element with the so called springpot that is an element having an intermediate behavior between purely elastic (spring) and purely viscous (dashpot) behavior ruled by fractional operator. With this choice two main goals are rea…
Non-stationary spectral moments of base excited MDOF systems
1988
The paper deals with the evaluation of non-stationary spectral moments of multi-degree-of-freedom (MDOF) line systems subjected to seismic excitations. The spectral moments of the response are evaluated in incremental form solution by means of an unconditionally stable step-by-step procedure. As an application, the statistics of the largest peak of the response are also evaluated.
Exact Solutions of the Two Dimensional Boussinesq and Dispersive Water Waves Equations
2010
In this paper two-dimensional Boussinesq and dispersive water waves equations are investigated in exact solutions. The Exp-function method is used for seeking exact solutions of the equations through symbolic computation.
Shear strength degradation due to flexural ductility demand in circular RC columns
2014
An analytical model was developed to estimate the shear-strength degradation and the residual capacity of circular reinforced concrete (RC) columns subjected to seismic action. The proposed model is an upgrade of a previously proposed model for axial force $$N$$ , bending moment $$M$$ and shear force $$V$$ ( $$N$$ – $$M$$ – $$V$$ ) interaction domain evaluation for rectangular and circular cross-section RC elements subjected to static loading. The model was extended to the case of circular cross-sections subjected to seismic actions with limitation of the range of variability of the deviation angle between the directions of the stress fields and the crack inclinations, as a function of the …
Experimental investigations of the soil–concrete interface: physical mechanisms, cyclic mobilization, and behaviour at different temperatures
2016
Behaviour of the pile–soil interface is important to correctly predict the response of floating piles in terms of displacement and lateral friction. Regarding energy piles, which couple the structural roles of deep foundations with the principle of shallow geothermal energy, the response of pile–soil interfaces is influenced by seasonal and daily cyclic thermal variations. Accordingly, the goal of this paper is to experimentally investigate the response of the pile–soil interface at different temperatures. This experimental campaign aims to analyse (i) the cyclic mobilization of the shear strength of the soil–pile interface that is induced by thermal deformation of the pile and (ii) the di…
Air Pollution Research Based on Spider Web and Parallel Continuous Particulate Monitoring—A Comparison Study Coupled with Identification of Sources
2021
Air pollution is monitored mainly in urban or industrial areas, even if it is known that in rural ones, low emission can significantly worsen air quality. Hence, cheap and easily accessible methods of monitoring are needed. Recently, spider webs biomonitoring is getting popular, however, there is no information about its comparison with active methods. In this study, PTEs accumulated on spider webs were compared with results from continuous particulate monitor (CPM). Generally, higher potentially toxic elements concentrations were noted in spider web, with exception in the case of Zn. Zn may be present rather in smaller fractions, hence it needs more time for accumulation on spider web whil…
Receiving water body quality assessment: an integrated mathematical approach applied to an Italian case study
2011
This study presents a basin-scale approach to the analysis of receiving water body quality considering both point and non-point pollution sources. In particular, this paper describes an extensive data gathering campaign carried out in the Nocella catchment, which is an agricultural and semi-urbanised basin located in Sicily, Italy. Two sewer systems, two wastewater treatment plants and a river reach were monitored during both dry and wet weather periods. A mathematical model of the entire integrated system was also created. Specifically, a detailed modelling approach was developed by employing three well known models: Storm Water Management Model, GPS-X and Soil and Water Assessment Tool. T…