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Two primary challenges in simulating hydraulic fracturing are the hydro–mechanical coupling and fracture propagation. The material point method (MPM) has advantages over conventional numerical methods by combining the advantages of particle- and mesh-based approaches in handling highly non-linear hydraulic fracturing problems. However, as MPM is primarily utilized for continuous solid simulations, therefore, to realize hydraulic fracturing simulation, a new MPM is proposed considering the discontinuous fields and seepage fields. The two-phase double-point MPM is used to simulate hydro–mechanical coupling within porous medium and fractures. Additionally, it employs the phantom-node method in conjunction with classical fracture mechanics to simulate fracture propagation, with the effect of fracture propagation on the seepage field considered by introducing an transition function. Subsequently, a comprehensive calculation process is presented. The accuracy of the proposed MPM is validated through comparison with finite element method results in two instances involving hydro–mechanical coupling and fracture propagation. Lastly, the MPM algorithm is deployed for simulating hydraulic fracturing within single and multiple fractures, followed by a detailed analysis of the hydraulic fracturing process. [ABSTRACT FROM AUTHOR]

Adsorption plays a vital role in contaminant transport in groundwater. Generally, a local equilibrium assumption is used in which the retardation factor is derived from aquifer material and contaminant type. However, for problems involving faster seepage velocities, this assumption becomes invalid and the mass transfer between mobile and immobile or, sorbed phases of contaminant becomes rate-limited. Traditionally, finite difference method (FDM) models are employed for contaminant transport simulation with rate-limited adsorption (RLA). Nonetheless, due to the presence of a grid, these models show instabilities, especially for advection dominant problems. In the present study, a meshless Radial Point Collocation Method (RPCM-RLA) is proposed for contaminant transport simulation with rate-limited adsorption. The proposed model is verified with semi-analytical solutions and its efficacy is assessed with the popularly used FDM-based Reactive Transport in 3 Dimensions (RT3D) model. The RPCM-RLA model is observed to provide stable and accurate solutions even for advection dominant problems whereas RT3D model simulations show excessive numerical dispersion. Furthermore, the effectiveness of RPCM-RLA model is demonstrated in two case studies concerning heterogeneous unconfined aquifers by comparing it with RT3D. Both model simulations agree consistently with maximum values of normalized mean absolute error (NMAE) being 0.0055 and 0.031 for case studies 1 and 2 respectively, with better performance of RPCM-RLA model. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to form a numerical simulation method for permeability coefficient that can consider the characteristics of gravel gradation and further explore the effects of indoor test factors and gradation characteristics on the permeability coefficient of gravel. Design/methodology/approach: The random point method is used to establish the polyhedral gravel particle model, the discrete element method (DEM) is used to construct the gravel permeability test sample with gradation characteristics and the finite element method is used to calculate the permeability coefficient to form a DEM-computational fluid dynamics combined method to simulate the gravel seepage characteristics. Then, verified by the indoor test results. Based on this method, the influence of sample size, treatment method of oversize particles and the content of fine particles on the permeability coefficient of gravel is studied. Findings: For the gravel containing large particles, the larger size permeameter should be used as far as possible. When the permeameter size is limited, the equal weight substitution method is recommended for the treatment method of oversized particles. Compared with the porosity, the pore connectivity has a higher correlation with the permeability coefficient of the sample. Research limitations/implications: Insufficient consideration of the movement of gravel particles in the seepage process is also an issue for further study. Originality/value: The simulation method described in this paper is helpful for qualitative analysis, quantitative expression of pore size and makes up for the defect that the seepage characteristics in pores cannot be observed in laboratory tests. [ABSTRACT FROM AUTHOR]

The NMM (numerical manifold method) was widely adopted to deal with many types of engineering problems involving moving boundaries, such as multiple crack propagation in rock masses. With regular triangular mathematical meshes, the NMM is further developed for two typical steady seepage problems, such as the confined seepage analysis and the unconfined seepage analysis. For unconfined seepage analysis, procedures to determine free surface location are introduced, and incorporated into the NMM code. Several classic numerical examples with analytical or reference solutions, and two challenge examples including a soil-rock-mixture (SRM) dam and a SRM slope are adopted to confirm capability and accuracy of the proposed numerical model for steady seepage problems. The results show that the exit gradient and free surface for steady seepage problems can be accurately calculated with the proposed numerical model. In addition, the existence of rock blocks have an impact to the distribution pattern of predicted contours of water head. More importantly, the proposed numerical model is able to calculate locations of free surface in SRM dam and SRM slope, which is very important in stability analysis of SRM dam and slope. [ABSTRACT FROM AUTHOR]

• We develop space-time mesh-free numerical techniques to solve the Richards equation. • The proposed numerical method is efficient in terms of computational cost. • The method is able to predict the dynamics of flows through unsaturated porous media. • Various numerical examples confirm the efficiency and robustness of our method. In this study, we focus on space-time mesh-free numerical techniques for efficiently solving the Richards equation which is often used to model unsaturated flow through porous media. We propose an efficient approach which combines the use of local multiquadric (MQ) radial basis function (RBF) methods and space-time techniques. The localized MQ-RBFs meshless methods allow to avoid mesh generation and ill-conditioning problem where a sparse matrix is obtained for the global system which has the advantage of using reduced memory and computational time. To further reduce the computational cost, we use the space-time techniques having the advantages of solving the resulting algebraic system only once and removing the time-integration procedure. The proposed method has the benefit of considering collocation points on the boundaries of computational domains which makes it more flexible in dealing with complex geometries. We implement the proposed numerical model of infiltration and we perform a series of numerical tests, encompassing various nontrivial solutions, to confirm the performance of the proposed techniques. The numerical simulations show the accuracy, efficiency in terms of computational cost, and capability of the proposed numerical techniques in solving the Richards equation in two-, three- and four-dimensional space-time domains with complex boundaries. [ABSTRACT FROM AUTHOR]

The article describes how medical DNA fingerprinting can de-risk hydrocarbon exploration and production. Considered a novel technique, geomicrobial exploration uses the same base principle of signal detection at the surface. Also described are some techniques for detecting micro-seepage, which refers to the causal relationship between anomalies and DNA fingerprints above oil and gas fields.

The purpose of hydraulic fracturing or acid fracturing is to use artificial fractures to connect the caves and establish high-conductivity oil and gas flow channels between the caves and the wellbore, the essence of the process is the interaction of a hydraulic fracture with a hole in poroelasticity medium. While the interaction mechanism between hydraulic fracture and hole in the poroelasticity medium remains unclear. In order to clarify the process, a seepage-free flow-mechanical coupling extended finite element method (XFEM) model was established. In the numerical study, the curved beam fracture propagation path with holes and initial preset fracture was calculated, and fracture connecting holes under triaxial stress was simulated. The results showed that the fracture path deflection degree was reduced by fluid pressure in the holes. Under triaxial stress, hydraulic fractures tend to extend toward the direction of the maximum horizontal principal stress. When the angle between the perforation direction and the maximum horizontal principal stress was 30°, the hydraulic fracture was deflected quickly in the direction of the maximum horizontal principal stress. As the angle was increased, the hydraulic fracture took more time to deflect toward the direction of the maximum horizontal principal stress. [ABSTRACT FROM AUTHOR]

The effects of YO 1.5 doping in yttria-zirconia based thermal barrier coatings (TBCs) against CMAS interaction/infiltration are discussed. The TBCs with an YO 1.5 content ranging from 43–67 mol.% (balance ZrO 2) were produced by electron beam physical vapor deposition (EB-PVD) techniques. The results reveal a trend of higher apatite formation probability with the higher free YO 1.5 available in the yttria-zirconia system. Additionally, the infiltration resistance and amount of consumed coating appears to be strongly dependent on the YO 1.5 content in the coating. The thinnest reaction layer and lowest infiltration was found for the highest produced 67YO 1.5 coating. Complementary XRD experiments with volcanic ash/YO 1.5 powder mixtures with higher yttria contents than in the coatings (80YO 1.5 and pure YO 1.5) also showed higher apatite formation with respect to increasing yttria content. The threshold composition to promote apatite-based reaction products was found to be around 50YO 1.5 in zirconia which was proved in the coatings and XRD powder experiments. An YO 1.5 -ZrO 2 -FeO-TiO 2 bearing zirconolite-type phase was formed as a reaction product for all the coating compositions which implicates that TiO 2 in the melt acts as a trigger for zirconolite formation. This phase could be detrimental for CMAS/volcanic ash infiltration resistance since it can be formed alongside with apatite which controls or limits the amount of Y3+ available for glass crystallization. The Fe rich garnet phase containing all the possible elements exhibited a slower nucleation compared to apatite and its growth was enhanced with slow cooling rates. The implications of phase stability and heat treatment effects on the reaction products are discussed for tests performed at 1250 °C. [ABSTRACT FROM AUTHOR]

The article informs that TPC Harding Park is a city-owned course maintained by city employees working for city golfers and the facility hosts annually on the Harding Park course and year on the Fleming nine. It mentions that Tiger Woods, Brooks Koepka and Rory McIlroy were scheduled to play in the 2020 PGA Championship at the course next month.

With rare exceptions, metallic conduit can only connect to metallic boxes; nonmetallic conduit can be used with either metallic or nonmetallic boxes. This provides GFCI protection to the entire circuit, and can be a good option when all of the receptacles on that circuit require GFCI protection, such as a circuit dedicated to an outdoor deck or patio. The nice thing about GFCI receptacles is they can be reset individually, and they can be wired to provide GFCI protection to all devices connected downstream on the same circuit, including regular receptacles. A single GFCI receptacle installed first in line on the circuit can provide the same whole-circuit protection as a GFCI breaker at a fraction of the cost. [Extracted from the article]

But when my customers' 30-year-old cedar roof started leaking, they were resolute about using cedar again. When most people think of roofs, they think of shingles, but that's not the case when it comes to cedar roofs. Cedar shingles are regularly used on walls, but cedar shakes are more common on roofs. Flashing pipes and penetrations on a cedar-shake roof is similar to flashing asphalt and slate roofs - layers are lapped from the bottom up. [Extracted from the article]

Made of 3 mm environmentally friendly nonpetroleum neoprene, the HydroFlex is a high-quality wetsuit designed for warm-water diving. The wetsuit includes high-stretch neoprene on the arms and calves, and preshaped legs for enhanced flexibility and easy donning and doffing. The 3.5 mm W5 has the same comfort and durability features as Waterproof's heavier suits, including a zipper at the neck and zippered openings at wrists and ankles. [Extracted from the article]

For this vehicle, we opted to install a Bestop sailcloth Replace-A-Top for 1997 to 2002 Wranglers that uses the factory steel half-doors. The sailcloth version is an upgrade to Bestop's traditional replacement top, and it uses a heavier multi-ply fabric to add a bit more isolation from the noise and weather outside. Bestop's installation instructions guide you through a sequence of assembly where plastic strips sewn onto the edges of the fabric top are tucked into metal retainer channels on the body. [Extracted from the article]

Thick, highly-insulated walls are great for lowering energy bills and creating a more comfortable interior environment for occupants, but they present some unique challenges for builders when it comes to installing windows and doors. A standard door installed to the exterior makes for simple trim details, but it requires interior extension jambs, which means the door can only open a bit more than 90°. Door sills or thresholds can be a problem in thick walls when you locate the door at the interior side of the wall. Seal the joint between the factory sill and the sill extension with a high-quality sealant, and be sure to use a self-adhered-membrane sill pan so you don't get the thermal bridging and condensation at the interior that you would get with a metal pan. [Extracted from the article]

Recently, fruitful results of geotechnical problems solved by the NMM (abbreviated form for the numerical manifold method) have been gained. In the present work, a free surface updating strategy is implemented into the NMM to simulate unconfined seepage flow in the soil-rock mixtures (SRMs). Several examples are employed to validate the effectiveness and correctness of the proposed numerical model. Results from the numerical examples indicate that the proposed model can predict the location of free surface with high accuracy, as well as capture the main feature of the unconfined seepage flow. In addition, the influence of rock blocks on the seepage flow in the SRMs can be captured. [ABSTRACT FROM AUTHOR]

The article focuses on Tennessee Valley Authority (TVA's) Boone Dam Internal Erosion Remediation Project. Topics include reduction of dam safety risks; restoration of a regionally important reservoir to full operation; and mitigation of seepage and internal erosion barriers; and use of concrete diaphragm wall.

This work focuses on the study of ink seepage and spreading into paper to ease the deciphering of digitized ancient documents and therefore make them legible and researchable. A three-dimensional model is proposed for the simulation of ink seepage into paper at the fiber level. The model takes into account a finite volume of ink and describes the system state through gravity, cohesion and adhesion force interactions. At the mesoscopic scale, the writing paper is modeled using a discretized fiber structure generated using a numerical deposition procedure. A modified Monte Carlo method is introduced for the simulation of the ink dynamics. Finally a multiphase lattice Boltzmann method is suggested to fine-tune the mesoscopic variational model parameters and it is shown that the ink seepage behaviors predicted by the proposed model can resemble those predicted by a method relying on first principles. [ABSTRACT FROM AUTHOR]

The article reports that Denver Water's Antero Dam has experienced seepage problems, forcing the utility to limit the storage capacity of the associated reservoir which thereby needs rehabilitation. It mentions that focus of the rehabilitation involved dam safety improvements to correct overly steep slopes; seepage through alluvium, the embankment, and shallow bedrock; inadequate slope protection; a lack of a foundation seepage cutoff; and unfiltered seepage at the downstream.

Dike failure includes a complex fluid–solid interaction process, which is one of the challenges in investigating dike failure problem. Given the characteristics of dike failure, a GPU-based coupled discrete element method (DEM)-smoothed particle hydrodynamics (SPH) model is proposed and adopted to simulate dike failure problems in this study. GPU parallel computing is involved in the proposed model and solid and fluid phases are modeled by DEM and SPH respectively. Overtopping-induced dike failure is numerically tested to validate the proposed model, and the computed motion of sediments and water and the dike surface profiles are in good agreement with experimental results. Then the proposed model is adopted to simulate seepage-induced dike failures, which have relatively covert behaviors compared with the overtopping-induced dike failure. The evolution of dike saturated zone and sediment displacement during this process is studied, and a sensitivity analysis of sediment diameter indicates that it has a great impact on the dike deformation. Finally, the effect of bottom drainage length on the development of seepage inside dike is investigated. • GPU parallel computing is involved to increase the model's particle capacity. • Overtopping-induced dike failure is studied using a coupled DEM–SPH model. • Seepage-induced dike failure is studied using a coupled DEM–SPH model. [ABSTRACT FROM AUTHOR]

The article offers information on designing of ventilated milking rooms, as per Pasteurized Milk Ordinance (PMO). Topics discussed include consideration of the direction that the air flows between rooms and through open doors; use of positive pressure ventilation to reduce infiltration to keep room cleaner; and need for exhaust fan to be tied with the toilet light switch to provide ventilation.

In the present study, a fractional seepage model (FSM) is proposed for non-Newtonian fluid via spatial fractional derivative to characterize the non-local characteristics of the non-Newtonian fluid in space and the fractal attributes of the porous medium. The analytical expressions of the permeability and the resistance are derived, in which each parameter contains clear physical meaning. The comparison between the empirical equations and our model with respect to available experimental data verifies the predictive capability of the proposed model. In addition, this study makes the first attempt to bridge the relation between the fractional derivative order and the fractal dimension of tortuosity, and may reveal the correlation between the memory of the complex fluid and characteristic pattern of the microstructure. [ABSTRACT FROM AUTHOR]

Highlighs • The IGA-SBFEM is applied to treat seepage problems in unbounded domain. • It can represent the arbitrary complex geometry exactly. • It gives better results than the conventional SBFEM. • The formulation allows to model seepage problems through the multilayered soils. • The method is applicable for seepage problems in multi-connected domains with inclusions. Abstract According to the infinite representation of the scaled boundary finite element method (SBFEM), an isogeometric scaled boundary finite element method (IGA-SBFEM) using the non-uniform rational B-splines (NURBS) is presented for the numerical solution of seepage problems in the unbounded domain. Further, the proposed method is extended to the modeling of seepage problems considering the parallel semi-infinite side-faces in the multilayered media. The proposed formulation is based on the SBFEM that only requires boundary discretization of the analyzed domain. And it advances the SBFEM by using the NURBS basis functions to exactly represent the geometry of the boundary and to approximate the solutions fields at the boundary. Thus, the proposed method fits neatly with the Boundary Representations (B-Reps) technique provided completely by CAD. The rigid tensor product structure can be reduced by one, since only the boundary information of the analyzed domain is required in the proposed approach. The method enhances the flexibility for describing complex geometry and offers many key improvements in comparison to the conventional SBFEM. Finally, the results from numerical examples are compared with the analytical solutions or reference solutions, illustrating the superiority of the proposed formulation. [ABSTRACT FROM AUTHOR]

This paper presents a practical approach for reliability analysis of steady-state seepage by modeling spatial variability of the soil permeability. The traditional semi-analytical method; named Scaled Boundary Finite-Element Method (SBFEM) is extended by a coded program to develop a stochastic SBFEM coupled with random field theory. The domain is discretized into several non-uniform SBFEM sub-domains. The flow quantities such as exit gradient, flow rate, and the reliability index of piping safety factor are estimated. The precision of the outputs and the accuracy of the method are verified with the Finite-Element Method (FEM). A set of stochastic analysis is performed in three illustrative examples to illuminate the applicability of the proposed method. In these examples, the effect of the variations in the position of the sub-domain discretization center, the cutoff location, and the cutoff length are investigated stochastically. Further, the influence of the permeability's Coefficient of Variation ( COV k ) and the correlation length is evaluated. The results are shown acceptable agreement with those obtained by the conventional Stochastic Finite-Element Method (SFEM). The proposed approach has potential to model the complex geometries and cutoffs in different locations without additional efforts to deal with the spatial variability of the permeability. [ABSTRACT FROM AUTHOR]

The article focuses on the design and construction of the roadways in Texas, U.S. According to the author the management and designing includes pavement structure analysis, mapping, and Hydroplaning. The author suggests that hydroplaning drainage areas are maintained which include water infiltration.

This paper presents the numerical solutions of free surface seepage flow in layered soil using the method of fundamental solutions (MFS). The numerical solutions are approximated by a set of fundamental solutions of the two-dimensional Laplace equation which are expressed in terms of sources located outside the domain of the problem. The unknown coefficients in the linear combination of the fundamental solutions which are accomplished by collocation imposing the boundary condition at a finite number of points can then be solved. To deal with the seepage problems of layered soil profiles, the domain decomposition method was adopted so that flux conservation and the continuity of pressure potential at the interface between two consecutive layers can be considered in the numerical model. The validity of the model is established for a number of test problems, including seepage problems in a rectangular dam, a trapezoidal dam, and an earth dam, by comparing numerical results with those from other methods. Application examples were also carried out. The results reveal that the proposed method based on the MFS has great numerical stability for solving seepage flow with nonlinear free surface in layered heterogeneous soil even with large contrasts in the hydraulic conductivity. [ABSTRACT FROM AUTHOR]

2D carbon fiber reinforced AZ91D matrix composites (2D-C f /AZ91D composites) were fabricated by liquid–solid extrusion and vacuum pressure infiltration technique (LSEVI). In order to modify the interface between fibers and matrix and protect the fiber, pyrolytic carbon (PyC) coating was deposited on the surface of T700 carbon fiber by chemical vapor deposition (CVD). Microstructure observation of the composites revealed that the composites were well fabricated by LSEVI. The segregation of aluminum at fiber surface led to the formation of Mg 17 Al 12 precipitates at the interface. The aluminum improved the infiltration of the alloy and PyC coating protected the fibers effectively. The ultimate tensile strength of 2D-C f /AZ91D composites was about 400 MPa. The fracture process of 2D-C f /AZ91D composites was transverse fiber interface cracking–matrix transferring load–longitudinal fibers bearing load–longitudinal fibers breaking. [ABSTRACT FROM AUTHOR]

According to the author, the most effective method for stabilizing neighborhoods and removing the tensions caused by the competition for dwellings is to provide minorities with the living space they need. The prominent part the fear of infiltration plays in forcing a change in the composition of a neighborhood is confirmed by its absence in certain fixed patterns. In many of the U.S. northern sections, there have always been Negro belts, many of them adjoining the more fashionable sections. The presence of Negroes disturbed neither property values nor social stains.

The article discusses the Indian government's project Namami Gange (National Mission for Clean Ganga). Particular focus is given to the flow of sewage into the Ganga river, disposal of fecal sludge without treatment into the river, and provides details of the report on pollution load given by the statutory organization of India Central Pollution Control Board. Other topics addressed include the need for seepage management and development of sewerage systems.

Seepage is characterized as an inefficient irrigation method with regard to water and nutrient use. There is a need for an economically viable irrigation alternative to seepage, which increases crop productivity and profitability in Florida. The use of plastic mulch and drip irrigation for cabbage (Brassica oleracea var. capitata) production increases plant population per area and reduces the irrigation water requirement. However, plasticulture has a high capital investment and operating cost. The objectives of this study were to compare the profitability of plasticulture cabbage production and traditional seepage bare ground irrigation systems for Florida cabbage production, and to determine the breakeven point for cabbage grown Linder plasticulture given a range of market prices. The preharvest cost per acre for the plasticulture system was significandy higher than the cost for the seepage system ($4726 and $3035 per acre, respectively). However, for all planting dates considered in this study, the plasticulture system resulted in a significant increase in marketable yields when compared with the seepage system. The resulting increase in potential revenue offset the increase in preharvest costs and assured a positive net return on investment over the whole range market prices. It was also observed that low air temperatures combined with reduced solar radiation can prevent optimum plant development for cabbage transplanted between November and mid-December. Therefore, the return on investment may be reduced during less favorable climatic conditions for cabbage growth, making the plasticulture system less economically desirable for certain planting dates. [ABSTRACT FROM AUTHOR]

For the Barenblatt–Zheltov–Kochina model representation of seepage of a fluid in a fractured-porous rock, an explicit form of the solution of the mixed problem in a fractured-porous spatial layer with predominantly horizontal permeability is found by reducing the problem to solution of the abstract mixed problem in a Banach space. [ABSTRACT FROM AUTHOR]

The article offers tips for tree plantings. It mentions the very tree pit should be greened, as the root area of ​​the trees is cooled and kept moist by the plant cover, when planting in clusters and in rows, care should be taken to ensure that the trees can come into contact at least underground, so create large root spaces and connect them with each other, and if necessary, grid stones or stones with green joints can be used on the surface to prevent seepage.

The article focuses on a study which explores the use of seepage-stress analysis and shear tests for Liushagang shale formation in China. Among the topics discussed include hydrocarbon capacity of Liushagang, rock matrices and bedding planes of shale, and the importance of porosity tests for Liushagang shale.

The article discusses wellbore stability by comparing them with a conventional model that does not take fluid seepage into consideration. It is said that a new model is created by combining circumferential stresses with additional stresses which can be combined with the traditional model to fully describe in-situ stress regimes' influence on wellbore stability.

WOLF CREEK DAM is located on the Cumberland river in Kentucky, US. It is operated and maintained by the Nashville District of the US Army Corps of Engineers, providing flood [...]

The article discusses the use of the Solvita Volumetric Aggregate Stability Test (VAST) to measure soil aggregates and improve tilth and water infiltration in planting fields. Topics covered include the possible yearly testing of soil aggregation, steps on starting an evaluation of current aggregate levels, and Solvita VAST's low-cost evaluation. Also noted is the latter's addition to the available tests of several soil labs.

Kinematic boundary condition is usually used when dealing with transient free-surface flow problems in isotropic media. When dealing with anisotropic problems, a transformation can transform the anisotropic media to an equivalent isotropic media for seepage analysis, but the kinematic boundary condition cannot be used directly in the transformed media. A generalization of the kinematic boundary condition along any arbitrary direction is derived for use in the transformed domain for general three-dimensional anisotropic problems. A boundary element method for solving transient free-surface seepage problems is developed and the treatment of the proposed kinematic boundary condition in the boundary element method is given. Three examples have been solved to show the reliability and flexibility of the model. Examples are verified with some available experimental and numerical cases to show the accuracy of the model for predicting the phreatic surface and it is shown that anisotropy has a very important and non-neglecting effect in the behavior and the shape of phreatic surface. [ABSTRACT FROM AUTHOR]

A solution of the Cauchy problem in an isotropic medium and in an anisotropic medium with clearly expressed vertical or horizontal permeability is constructed for the Barenblatt–Zheltov–Kochina model representation of the seepage of a fluid in fissured porous rock by reducing the seepage problems under consideration to solving an abstract Cauchy problem in a Banach space. [ABSTRACT FROM AUTHOR]

The effect of the strain-strength and seepage properties of rock and the compressibility of the percolating fluid on the dimensions of the rock fracture zones, which occur in oil and gas boreholes when the bottom hole pressure is reduced, is investigated. The seepage is considered basing on the stationary formulation of the problem, which enables the general case to be investigated. It is shown that in the case of unsteady flow, the stresses on the boundary of the rock fracture zone and, as a consequence, on its dimensions, are independent of the nature of the pressure distribution in the stratum, and are determined solely by the pressure of the percolating fluid on the boundary of this zone. It is established that an increase in the compressibility of the percolating fluid leads to an increase in the dimensions of the rock fracture zone. [ABSTRACT FROM AUTHOR]

Abstract: A three-dimensional boundary element solution for the seepage analysis in multi-domain general anisotropic media has been developed based on the transformation approach. Using analytical eigenvalues and eigenvectors of the hydraulic conductivity tensor, a closed-form coordinate transformation matrix has been provided to transform the quadratic form of governing equation of seepage for the general anisotropic media to the Laplace equation. This transformation allows the analysis to be carried out using any standard BEM codes for the potential theory on the transformed space by adding small pre- and post-processing routines. With this transformation, any physical quantity like the total head remains unchanged at corresponding nodes on the physical and transformed space, and the normal gradient across the domain boundaries should also be transformed. In multi-domain problems, compatibility equations (equality of the potential on corresponding nodes on the interface) and equilibrium equations (conservation of the flux across the interface boundaries of adjacent domains) on the corresponding nodes of interface between two neighbor domains are needed for boundary element method. In the transformed space, the compatibility equation remains unchanged. However, due to the distortion of boundaries in the mapped space and therefore misalignment of the unit outward normal vectors along the inter-domain boundaries, the equilibrium of the normal fluxes have to be transformed accordingly. Based on the proposed transformation, the normal to boundary flux boundary conditions in the mapped space and the transformed equilibrium equation for interface of adjacent zones have been given in this paper. Examples have been solved with the proposed scheme and the results were verified with the finite element method. Excellent agreement of the results shows the veracity of the proposed transformation and the formulas given for transformation of equilibrium equation for multi-domain general anisotropic media. [Copyright &y& Elsevier]

Abstract: As one kind of meshless methods, the natural element method (NEM) constructs shape functions based on the Voronoi diagrams, and it has advantages of both the conventional meshless method and the finite element method. Since the nodes are independent of the integral mesh, it is more suitable for the analysis of seepage with a free surface than the finite element method. In addition, its shape functions satisfy the Kronecker δ conditions, therefore, its boundary conditions can be dealt with much easily than those of such meshless method as element-free Galerkin method (EFGM). In this paper, the NEM was used in the seepage analysis of dams. The initial free surface was assumed first in the calculations, and the location of the free surface was adjusted according to the calculation results. The examples showed that the natural element method lead to satisfactory results. [Copyright &y& Elsevier]

The article focuses on the distinct separation between the exterior and the interior conditions of the school buildings constructed in the U.S. with respect to the tight building enclosures. The high-performance building enclosures ensure the restriction of the passage heat and water vapor through the walls and the roof of the building. Information on the objectives of the enclosures towards energy conservation and the protection of the buildings from water infiltration is also presented.

The article discusses building envelope commissioning to provide high performance assurance and help avoid costly repairs in the future. It states that it is a multidisciplinary process that can prevent any air leaks or water seepage in buildings that later may be hard to pinpoint and costly to fix. While the process may entail additional costs and time, it can be off-set by avoiding expensive repairs in the future and ensure peace of mind for the owner and the occupants.

Abstract: Coupling the adjacent zones for seepage analysis in porous media needs compatibility and equilibrium equations (equality of potential on coinciding nodes and conservation of flowing mass between zones, respectively). When stretched coordinate transformation is applied to the anisotropic zones, the Dirichlet boundary conditions remain unchanged, but the Neumann boundary condition should also be transformed. Similarly in a zoned problem, for the interface between zones, compatibility equations remain unchanged during the transformation while the equilibrium equations should be transformed. In this paper, transformed Neumann boundary conditions and equilibrium equations for the interface of neighbor anisotropic zones for seepage problems have been developed in three dimensions. A computer program for seepage analysis of zoned anisotropic media based on the Boundary Element Method is developed. The code is used to solve several examples with isotropic and anisotropic zones. Some examples are also solved by finite element method for verification. Illustrated results show the ability and accuracy of the mathematical and the numerical model for solving different types of applied three-dimensional seepage problems that arise in engineering practice. [Copyright &y& Elsevier]

Abstract: A mathematical model of non-isothermal multicomponent flows in a porous medium is investigated. A general case is considered when the model can be used to describe processes with an arbitrary number of components and phases. A general form of the system of mixed-type equations describing the flow, which is similar to the Godunov form for hyperbolic systems is proposed. The equations obtained are applicable to flows with gas, liquid and solid phases. The thermodynamic properties of the medium are determined solely by a single multivalued function, by changing which one can obtain models of different flows in a porous medium. A clear geometrical interpretation of the solutions of the equations is proposed. An equation for the entropy is obtained, and it is shown that in order that the model should not contradict the second law of thermodynamics, it is necessary to take into account, in the energy equation, the work of the gravity force, which is often neglected when investigating seepage. [Copyright &y& Elsevier]

The article discusses the use of electrical methods in the detection of seepage phenomena through the stratigraphic column. These methods which include the Long Offset Time Domain Electromagnetics (LOTEM) became popular and widely used in the gas industry since 1994. It states that LOTEM can be used for assessing deep noncontact electromagnetic induction and resistivity of hydrocarbons to near surface soil salinity.