Simulation of carrier-facilitated transport of phenanthrene in a layered soil profile

2002 ◽  
Vol 56 (3-4) ◽  
pp. 209-225 ◽  
Author(s):  
Alexander Prechtel ◽  
Peter Knabner ◽  
Eckhard Schneid ◽  
Kai Uwe Totsche
2006 ◽  
Author(s):  
P. Jeanjean ◽  
D. Znidarcic ◽  
R. Phillips ◽  
H. -Y. Ko ◽  
S. Pfister ◽  
...  

2018 ◽  
Vol 12 (01) ◽  
pp. 1850005 ◽  
Author(s):  
Haizhong Zhang ◽  
Yan-Gang Zhao

The first resonance peak, Gs1, represents the amplification ratio of seismic motion when resonance between input motion and the local site occurs. The Gs1 is important for understanding amplification characteristics of local site, thus it has been adopted for evaluating site effects in the Japanese Seismic Code. Herein, a simple method for estimating the Gs1 of layered soil profiles is proposed. By replacing a multi-layer soil profile on bedrock with an equivalent one-layer soil profile, the Gs1 and fundamental period are easily obtained. To realize the one-layer profile, we develop a procedure to replace a two-layer soil profile on bedrock with an equivalent single-layer profile. This procedure is then applied successively to a multi-layer soil profile to obtain an equivalent single-layer soil profile. The validity of the proposed method is demonstrated by evaluating 67 representative sites. The results obtained using the proposed procedure agree well with those produced by the wave propagation method.


1999 ◽  
Vol 1 (2) ◽  
pp. 127-138 ◽  
Author(s):  
Karsten Schulz ◽  
Bernd Huwe

A methodology based on fuzzy set theory is presented to express imprecision of input data in a non-probabilitic sense. Imprecision may originate from indirect measurements, estimation routines, subjective interpretation, and expert judgement of available information. A numerical finite difference solution scheme was chosen to solve one-dimensional steady-state water flow in the unsaturated zone of a layered soil profile. To extend the solution algorithm to operate with fuzzy soil-hydraulic properties and boundary conditions, it is necessary to incorporate the scheme into a nonlinear optimisation routine from where resulting membership functions of soil water pressures with depths can be calculated. By subsequently considering the different imprecise parameters in the calculations and analysing their impact, it is concluded that resulting imprecision not only depends on the degree of imprecision and the number of uncertain parameters but also very much on the system context (e.g. boundary conditions and spatial distribution). The comparison with a closed form solution to solve the fuzzy water flow problem show the potential of that method to be extended towards transient, two- and three-dimensional process descriptions.


Author(s):  
Guillermo M. Álamo ◽  
Luis A. Padrón ◽  
Juan J. Aznárez ◽  
Orlando Maeso

AbstractThis paper presents a three–dimensional linear numerical model for the dynamic and seismic analysis of pile-supported structures that allows to represent simultaneously the structures, pile foundations, soil profile and incident seismic waves and that, therefore, takes directly into account structure–pile–soil interaction. The use of advanced Green’s functions to model the dynamic behaviour of layered soils, not only leads to a very compact representation of the problem and a simplification in the preparation of the data files (no meshes are needed for the soil), but also allows to take into account arbitrarily complex soil profiles and problems with large numbers of elements. The seismic excitation is implemented as incident planar body waves (P or S) propagating through the layered soil from an infinitely–distant source and impinging on the site with any generic angle of incidence. The response of the system is evaluated in the frequency domain, and seismic results in time domain are then obtained using the frequency–domain method through the use of the Fast Fourier Transform. An application example using a pile-supported structure is presented in order to illustrate the capabilities of the model. Piles and columns are modelled through Timoshenko beam elements, and slabs, pile caps and shear walls are modelled using shell finite elements, so that the real flexibility of all elements can be rigorously taken into account. This example is also used to explore the influence of soil profile and angle of incidence on different variables of interest in earthquake engineering.


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