- Infiltration Study for Deep Foundations in Ephemeral Streams
- Naresh C. Samtani
- Book Title / Journal: International Journal of Geoengineering Case Histories
- Year: 2019 , Volume: 5
- Deep Excavations ; Groundwater & Seepage
- Keywords: Infiltration ; Ephemeral ; bridge ; deep foundation ; unsaturated ; Pore water pressure ; Flood ; scour
- Abstract
The duration of a flood event in an ephemeral stream is finite, ranging from a few hours to a few days. However, for design of deep foundations, an assumption is typically made by geotechnical specialists that at the time of a flood event all stream bed geomaterials are saturated and fully-buoyant. This assumption leads to larger deep foundations because full-buoyancy can significantly reduce the geomaterial resistances to applied loads. Consequently, a large increase in foundation investigation and construction costs can occur. This paper presents a case study that included an evaluation of the infiltration of transient flood waters into unsaturated geomaterials within an ephemeral stream bed. Considerable cost reductions were realized as a result of this evaluation. The presented approach permits a rational geotechnical evaluation of deep foundations in ephemeral streams. PDF |
- The May 25th 2011 Railroad Embankment Failure in Ann Arbor, Michigan, As a Means for Teaching Geotechnical Engineer
- Dimitrios Zekkos ; Adda Athanasopoulos-Zekkos ; Athena Grizi ; William Greenwood
- Book Title / Journal: International Journal of Geoengineering Case Histories
- Year: 2016 , Volume: 3
- Slope Stability Analysis ; Site Characterization & In-situ Testing (General) ; Seepage ; Railway Geotechnics
- Keywords: Education ; Embankment ; stability ; Seepage ; railroad ; site characterization
- Abstract
A 30-m long railroad embankment failure that occurred on May 25 2011 in the city of Ann Arbor, Michigan, is presented. Emphasis is given on the field observations of the failure, the characterization of the site conditions and the seepage and slope stability analyses, all of which represent important components of the training and practice of a geotechnical engineer. The failure occurred following a record wet season that resulted in ponding water against the embankment and high enough water pressures and exit gradients that resulted in instability of the railroad embankment. Detailed background material and the methodology for using the case history in geotechnical engineering education are presented. PDF |
- Modeling of Landslide Inducing Groundwater Table Surges in Residual Soils due to Rainfall
- T. Dahigamuwa ; M. Gunaratne
- ICGE Colombo 2015
- Year: 2015
- Numerical & Constitutive Modeling ; Landslides ; Residual Soils ; Groundwater & Seepage
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- Seepage and Pore Water Pressure Behavior: A Case Study of Landslide Triggering Mechanism in Uttaradit, Thailand
- A. Jotisankasa ; J. Tepparnich
- ICGE Colombo 2015
- Year: 2015
- Seepage ; Landslides
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- Observations on groundwater leakage through cracks and segment joints in a concrete segmental tunnel lining
- V. Tellioglu ; S. Lerpido
- IS SEOUL '14
- Year: 2014
- Groundwater & Seepage ; Tunneling
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- Mangla Dam Raising: Effectiveness of Seepage Reduction Measures for Sukian Dyke
- Jehan Zeb ; Tahir M. Hayat ; Aziz Akbar ; M. Azam
- Book Title / Journal: International Journal of Geoengineering Case Histories
- Year: 2014 , Volume: 3
- Dam Engineering ; Earth / Rockfill Dams ; Groundwater & Seepage ; Seepage ; Finite Element / Finite Difference
- Keywords: Mangla Dam ; Sukian dyke ; Sandstone ; Seepage ; Upstream Blanket ; FEM analysis
- Abstract
Mangla Dam (Pakistan) is one of the largest Earth Core Rock fill Dam (ECRD) in the world in terms of volume of material used. The Sukian dyke of Mangla Dam Project is 5.33 km (17,500 ft.) in length and is founded on alternate beds of clay and weak (friable) sandstone. Raising of the dam subjected the project area including the dyke to an additional head of about 12.19m (40 ft.) in 2013. Before raising, the maximum seepage in the entire project was observed in the Sukian dyke area. An upstream blanket was selected to control seepage in this area after dam raising. FEM analyses were carried out to determine the efficiency of the upstream blanket in controlling seepage. After raising and impoundment, the FEM results were compared with instrumentation readings and seepage measurements and close agreement was observed. PDF |
- Safety of a protection levee under rapid drawdown conditions. Coupled analysis of transient seepage and stability
- G. Auvinet ; de Fuente ; N.P. López-Acosta
- Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering, Paris, September 2-6 2013
- Year: 2013
- Levees ; Seepage ; Slope Stability
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- The Design of Filter Materials and their Importance in Geotechnical Engineering
- S. Messerklinger ;
- Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering, Paris, September 2-6 2013
- Year: 2013
- Seepage
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- Deformation and water seepage observed in a natural slope during failure process by artificial heavy rainfall
- I. Seko ; S. Nishie ; L. Wang ; G. Gizachew ; T. Uchimura
- Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering, Paris, September 2-6 2013
- Year: 2013
- Seepage ; Slope Stability
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- Modeling of Proppant Permeability and Inertial Factor for Fluid Flow Through Packed Columns
- B.R. Meyer ; L.W. Bazan ; D. Walls
- Book Title / Journal: Effective and Sustainable Hydraulic Fracturing
- Year: 2013 , Series: Chapter 26
- Numerical & Constitutive Modeling ; Groundwater & Seepage
- Keywords: permeability ; fluid flow ; packed columns
- Description
- Standard industry testing procedures provide proppant quality control and methods to
determine long term reference conductivity for proppants under laboratory conditions. However, test methods often lack repeatable results. Additionally, the testing procedures are not designed to account for fundamental parameters (e.g., proppant diameter, porosity, wall effects, multi-phase/non-Darcy effects, proppant and gel damage) that greatly reduce absolute proppant bed conductivity under realistic flowing conditions.
A constitutive model for permeability and inertial factor for flow through packed columns has been formulated from fundamental principles. This work provides a detailed deterministic proppant permeability correlation and defines a methodology to help explain why different proppant types behave differently under stress. The theory also characterizes the origin of inertial, or non-Darcy flow, based on a unique approach formulated from the extended
Bernoulli equation based on minor losses. The physical model provides insight into the dominant parameters affecting the pressure drop in a proppant pack and improves our understanding of fluid flow and transport phenomena in porous media.
The fundamental solution for flow through packed columns can be characterized by the sum
of viscous (Blake-Kozeny) and inertial forces (Burke-Plummer) in Ergun’s equation. Coupling
Ergun's equation with the Forchheimer equation results in a deterministic set of equations that
describe the fracture permeability and inertial factor as functions of the proppant diameter, pack porosity, sphericity, and fracture width. Plotting the dimensionless permeability, (k/dp
2), versus the characteristic proppant porosity parameter, Ω, is a very useful diagnostic tool
that can indicate: 1) sphericity, 2) channeling, 3) crushing, 4) non-uniform sphere size distri‐
bution, 5) embedment and 6) deviation of the friction multiplier λm from Ergun's equation.
The dimensionless experimental proppant permeability data can be plotted as a linear function of dimensionless porosity with large deviations from these equations signifying poor or inconsistent experimental results or inadequate proppant characterization. The formulated permeability and non-Darcy equations provide the foundation for a quantitative (including quality control of the test) and qualitative analyses for determining fracture permeability and the inertial factor based on the physical properties of the proppant pack.
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- A New Approach to Hydraulic Stimulation of Geothermal Reservoirs by Roughness Induced Fracture Opening
- N.G. Doonechaly ; S.S. Rahman ; A. Kotousov
- Book Title / Journal: Effective and Sustainable Hydraulic Fracturing
- Year: 2013 , Series: Chapter 27
- Groundwater & Seepage
- Keywords: fractures ; geothermal reservoirs
- Description
- In this study an innovative analytical approach based on the distributed dislocation technique
is developed to simulate the roughness induced opening of fractures in the presence of compressive and shear stresses as well as fluid pressure inside the fracture. This provides
fundamental basis for computation of aperture distribution for all parts of the fracture which
can then be used in the next step of modeling fluid flow inside the fracture as a function of time. It also allows formulation of change in aperture due to thermal stresses. The stress distribution and the fluid pressure are calculated using the fluid flow modeling inside the fracture in a numerical framework in which thermo-hydro mechanical effects are also considered using finite element methods (FEM). In this study, fractures with their characteristic properties are considered to simulate rock deformation.
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- Pressurization of a PKN Fracture in a Permeable Rock During Injection of a Low Viscocity Fluid
- E. Sarvaramini ; D.I. Garagash
- Book Title / Journal: Effective and Sustainable Hydraulic Fracturing
- Year: 2013 , Series: Chapter 30
- Rock Mechanics ; Groundwater & Seepage
- Keywords: rock mass ; low viscocity fluid ; PKN fracture
- Description
- The aim of the present work is to investigate injection of a low-viscosity fluid into a pre-existing fracture within a linear elastic, permeable rock, as may occur in waterflooding and supercritical CO2 injection. In conventional hydraulic fracturing, high viscosity and cake building properties of injected fluid limit diffusion to a 1-D boundary layer incasing the crack. In the case of injection of low viscosity fluid into a fracture, diffusion will take place over wider range of scales, from 1-D to 2-D, thus, necessitating a new approach. In addition, the dissipation of energy associated with fracturing of the rock dominates the energy expended to flow a low viscosity fluid into the crack channel. As a result, the rock fracture toughness is an important parameter in evaluating the propagation driven by a low-viscosity fluid. We consider a pre-existing, un-propped, stationary Perkins, Kern and Nordgren’s (PKN) fracture into which a low viscosity fluid is injected under a constant flow
rate. The fundamental solution to the auxiliary problem of a step pressure increase in a fracture [1] is used to formulate and solve the convolution integral equation governing the
transient crack pressurization under the assumption of negligible viscous dissipation. The
propagation criterion for a PKN crack [2] is then used to evaluate the onset of propagation.
The obtained solution for transient pressurization of a stationary crack provides initial conditions to the fracture propagation problem.
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- Effects of Freeze-Thaw History on Deformation-Strength Properties and Permeability of Fine-Grained Soil
- T. Ishikawa ; S. Yamasaki ; S. Yamashita ; D. Nakamura ; T. Kawaguchi
- Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering, Paris, September 2-6 2013
- Year: 2013
- Shear Strength of Underground Materials ; Laboratory Testing ; Groundwater & Seepage
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- Experimental Analysis on the Influence of Surcharge Filters on Safety Against Hydraulic Heave
- C. Boley ; P. Schober
- Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering, Paris, September 2-6 2013
- Year: 2013
- Deep Excavations ; Retaining Walls ; Seepage ; Laboratory Testing
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- Accumulated Stress Based Model for Prediction of Residual Pore Pressure
- J.-K. Ahn ; D. Park
- Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering, Paris, September 2-6 2013
- Year: 2013
- Groundwater & Seepage ; Soil Mechanics ; Soil Behavior Modeling
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