Author
Arnold Verruijt
Bio: Arnold Verruijt is an academic researcher from Delft University of Technology. The author has contributed to research in topics: Groundwater flow & Porous medium. The author has an hindex of 21, co-authored 54 publications receiving 3157 citations.
Papers published on a yearly basis
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Book•
01 Jan 1987
TL;DR: The reference record was created on 2004-09-07, modified on 2016-08-08 as discussed by the authors, using the reference record of the Ecoulement souterrain reference record.
Abstract: Keywords: Ecoulement souterrain Reference Record created on 2004-09-07, modified on 2016-08-08
826 citations
01 Jan 1995
TL;DR: In this paper, a numerical method for the solution of the problem of a beam on an elastic foundation is presented, which can be used as a basis for a sheet pile wall program, and for a laterally loaded pile in a layered soil.
Abstract: In this chapter a numerical method for the solution of the problem of a beam on an elastic foundation is presented. Special care will be taken that the program can be used for beams consisting of sections of unequal length, as the program is to be used as a basis for a sheet pile wall program, and for a program for a laterally loaded pile in a layered soil.
522 citations
420 citations
TL;DR: In this paper, a lower limit for the time steps is derived, in terms of the mesh size and the coefficient of consolidation near the draining boundary, for finite element solutions of consolidation problems.
Abstract: Finite element solutions of consolidation problems often exhibit oscillating pore pressures, which tend to increase when the time steps are reduced. This phenomenon is investigated and a lower limit for the time steps is derived, in terms of the mesh size and the coefficient of consolidation near the draining boundary.
271 citations
TL;DR: In this article, an analytical solution is presented of problems for an elastic half-plane with a circular tunnel, which undergoes acyclic deformation, with a conformal transformation onto a circular ring and in the transformed plane the complex stress functions are represented by their Laurent series expansions.
Abstract: SUMMARY An analytical solution is presented of problems for an elastic half-plane with a circular tunnel, whichundergoesacertaingivendeformation.Thesolutionusescomplexvariables,withaconformalmappingontoa circular ring. The coeƒcients in the Laurent series expansion of the stress functions are determined bya combination of analytical and numerical computations. As an example the case of a uniform radialdisplacement of the tunnel boundary is considered in some detail. It appears that a uniform radial displace-mentisaccompaniedbyadownwarddisplacementofthetunnelasawhole.Thisphenomenonalsomeansthatthedistribution oftheapparentspring constantis strongly non-uniform. ( 1997 by John Wiley & Sons, Ltd. Int. j. numer. methods geomech., vol. 21, 77 — 89 (1997)(No. of Figures: 7 No. of Tables: 1 No. of Refs: 10) Key words: elasticity; tunnel; complex variables INTRODUCTIONIn this paper the stresses and displacements in an elastic half-plane due to the deformation of acircular tunnel are considered. The method used is the complex variable method. 1 The boundaryconditions arethat the upper boundaryof the half-planeisfreeof stress, andthat at theboundaryofthetunnelthedisplacementisprescribed.Thisisusuallycalledthesecondtypeofboundarycondition.In order to solve the problem, a conformal transformation onto a circular ring is used, and in thetransformed plane the complex stress functions are represented by their Laurent series expansions.IntheclassicaltreatisesofMuskhelishvili1andSokoliniko⁄2ontheapplicationofthecomplexvariable method in elasticity, the class of problems studied here, involving a multiply connectedregion and conformal mapping onto a circular ring, is briesy mentioned, but it is stated thatOdiƒcultiesO arise in the solution of these problems, and it is suggested to use another method ofsolution, such as the method using bipolar co-ordinates.3
229 citations
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TL;DR: A review of the state of the art in sea intrusion research can be found in this article, where the authors subdivide SI research into three categories: process, mea- surement, prediction and management.
1,055 citations
Book•
26 Oct 2006
TL;DR: The Porous Medium Equation (PME) as discussed by the authors is one of the classical linear partial differential equations of second order that form the basis of any elementary introduction to the area of PDEs, and only recently has it come to be fairly well understood.
Abstract: The Heat Equation is one of the three classical linear partial differential equations of second order that form the basis of any elementary introduction to the area of PDEs, and only recently has it come to be fairly well understood. In this monograph, aimed at research students and academics in mathematics and engineering, as well as engineering specialists, Professor Vazquez provides a systematic and comprehensive presentation of the mathematical theory of the nonlinear heat equation usually called the Porous Medium Equation (PME). This equation appears in a number of physical applications, such as to describe processes involving fluid flow, heat transfer or diffusion. Other applications have been proposed in mathematical biology, lubrication, boundary layer theory, and other fields. Each chapter contains a detailed introduction and is supplied with a section of notes, providing comments, historical notes or recommended reading, and exercises for the reader.
978 citations
TL;DR: A summary of the current state of seismic analysis and design for underground structures can be found in this paper, where the authors discuss special design issues, including the design of tunnel segment joints and joints between tunnels and portal structures.
939 citations
TL;DR: In this paper, a thermodynamic approach to the definition of capillary pressure provides a theoretically sound alternative to the simple hysteretic function of saturation, and an approach is presented whereby the presence of interfaces and their distribution within a multiphase system are essential to describing the state of the system under study.
Abstract: Important features of multiphase flow in porous media that distinguish it from single-phase flow are the presence of interfaces between the fluid phases and of common lines where three phases come in contact. Despite this fact, mathematical descriptions of these flows have been lacking in rigor, consisting primarily of heuristic extensions of Darcy's law that include a hysteretic relation between capillary pressure and saturation and a relative permeability coefficient. As a result, the standard capillary pressure concept appears to have physically unrealistic properties. The present paper employs microscopic mass and momentum balance equations for phases and interfaces to develop an understanding of capillary pressure at the microscale. Next, the standard theories and approaches that define capillary pressure at the macroscale are described and their shortcomings are discussed. Finally, an approach is presented whereby capillary pressure is shown to be an intrinsic property of the system under study. In particular, the presence of interfaces and their distribution within a multiphase system are shown to be essential to describing the state of the system. A thermodynamic approach to the definition of capillary pressure provides a theoretically sound alternative to the definition of capillary pressure as a simple hysteretic function of saturation.
694 citations
TL;DR: It is suggested that graph theory as applied to conservation biology can provide leverage on applications concerned with landscape connectivity, and the use of graph theory in a metapopulation context, is demonstrated.
574 citations