JP GIROUD Inc.

Ocean Ridge, United States

JP GIROUD Inc.

Ocean Ridge, United States

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Peggs I.D.,I Corporation International | Giroud J.P.,JP GIROUD Inc.
10th International Conference on Geosynthetics, ICG 2014 | Year: 2014

Evaluating the performance of a reservoir liner is a challenge. While zero leakage into the ground is a legitimate goal if the leaking liquid may pollute the ground and the ground water, or the soil integrity can be impaired, zero is unrealistic and impossible to measure. In this paper, it is shown that the concept of action leakage rate, developed for landfills in the United States, can be adapted to reservoir liners. The action leakage rate provides a criterion that makes it possible to evaluate the performance of a reservoir liner and that triggers monitoring and remedial actions to be taken if the performance goal is not met. This paper presents a discussion of the parameters that have an influence on the selection of the action leakage rate for a given reservoir and suggests values of action leakage rates for reservoirs depending on the relevant parameters. It is concluded that it is possible to rationally select action leakage rates for reservoirs. This should contribute to the safety of geomembrane-lined reservoirs.


Cazzuffi D.,Centro Elettrotecnico Sperimentale Italiano | Giroud J.P.,JP GIROUD Inc. | Scuero A.,Carpi Technology | Vaschetti G.,Carpi Technology
9th International Conference on Geosynthetics - Geosynthetics: Advanced Solutions for a Challenging World, ICG 2010 | Year: 2010

In more than 270 dams worldwide, geomembranes are the main waterproofing component. The geomembrane is generally associated with other geosynthetics performing various functions, thereby forming a geosynthetic barrier. In this paper, uses of geosynthetic barriers in the various types of dams are reviewed. The types of dams reviewed include: embankment dams (earthfill and rockfill dams), concrete and masonry dams, and roller compacted concrete (RCC) dams. Design and construction aspects are considered, as well as selection of geosynthetic materials and performance (including seepage control and durability). The paper is illustrated using a number of examples of new dams and rehabilitation of existing dams, including examples of the early dams constructed or rehabilitated using geosynthetic barriers in the 1950s, 1960s and 1970s.


Giroud J.P.,JP GIROUD Inc. | Gourc J.P.,Grenoble University
10th International Conference on Geosynthetics, ICG 2014 | Year: 2014

The first double liner with two geomembranes was constructed in June 1974 and has been in continuous service since then. The lined structure is a 10 m deep, 195 m long and 55 m wide water reservoir, located on top of a 50 m high 33°slope. The geotechnical study concluded that the slope was stable, but could become unstable in case of major leakage of water from the reservoir. Any risk of instability was unacceptable because a large chemical plant was, and still is, located at the toe of the slope. Because safety was essential, a double liner was recommended by the senior author. The primary liner is a 1.5 mm thick butyl rubber geomembrane. The secondary liner is a bituminous geomembrane formed in situ by impregnating a geotextile with hot bitumen. The leakage detection layer between the two liners is made of gravel stabilized with mortar. The reservoir has been monitored by the plant personnel since the end of construction. No leakage was detected until 2004, i.e. 30 years after construction, when atnckle of water appeared at the monitoring building. The leak, a defective seam, was repaired under water. The reservoir described in this paper can be considered a historic landmark of the geosynthetic discipline.


Giroud J.P.,JP GIROUD Inc.
9th International Conference on Geosynthetics - Geosynthetics: Advanced Solutions for a Challenging World, ICG 2010 | Year: 2010

A rational development of criteria for geotextile and granular filters is presented. It is shown that, whereas two criteria are sufficient for granular filters, a permeability criterion and a retention criterion, four criteria are required for geotextile filters. The four criteria are: permeability criterion, retention criterion, porosity criterion and thickness criterion. The analysis shows that the permeability criterion includes two requirements, a pore water pressure requirement and a flow rate requirement. It is shown that, in the case of granular filters, the two requirements generally reduce themselves to the classical Terzaghi's permeability criterion, whereas, in the case of geotextile filters, the hydraulic gradient in the soil next to the filter determines which of the two requirements is the most stringent. Regarding the retention criterion, the analysis shows that, for both geotextile and granular filters, a complete retention criterion should take into account the density of the soil and the coefficient of uniformity of its particle size distribution curve. This analysis explains the limitations of the classical Terzaghi's retention criterion. The retention criterion proposed herein provides a means to overcome these limitations. Then, the need for two additional criteria for geotextile filters is pointed out. These two criteria are a porosity criterion expressed as a minimum porosity of the filter and a thickness criterion expressed as a minimum thickness of the filter. It is shown that these two criteria are always met by granular filters and, therefore, are needed only for geotextile filters.


Botelho K.J.,Geosyntec Consultants | Heynes O.,Insight Numerics LLC | Giroud J.-P.,JP Giroud Inc.
Geotechnical Special Publication | Year: 2014

The accurate calculation of wind uplift forces on an exposed geomembrane is essential for generating design requirements for the anchorage system. These requirements often largely dictate construction costs, so inaccuracies in the uplift calculation may have significant economic repercussions. Inaccuracies may occur when using generic suction factors rather than a site-specific assessment using computational fluid dynamics (CFD) technology. This paper presents preliminary research conducted to determine whether potential cost savings warrant more complex CFD modeling. Preliminary results comparing a two-dimensional case of an exposed geomembrane (which was used to develop generic suction factors commonly used to evaluate wind uplift) indicate the wind uplift forces calculated from a CFD model resulted in tensions that were significantly less than those using generic suction factors. Preliminary research was performed with the intention of employing CFD modeling to refine the simple prescription of generic suction factors on a site-specific basis. © 2014 American Society of Civil Engineers.


Giroud J.P.,JP GIROUD Inc. | Kavazanjian Edward E.,Arizona State University
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2014

Flow in porous media, such as geosynthetic and granular drains, is often nonlaminar. Nonlaminar flow can vary in character from semiturbulent to turbulent, depending upon the flow velocity, which is related to the hydraulic gradient. An exponent on the hydraulic gradient is used in the relationship among the hydraulic gradient, the apparent flow velocity, and the saturated hydraulic conductivity or transmissivity to quantify the degree of turbulence of the flow in porous media. Numerical values of this exponent are established for both granular and geosynthetic drains based on an analysis of published and unpublished experimental data. It appears that for typical hydraulic gradients encountered in practice, the degree of turbulence for flow in granular drains depends essentially on the particle size, with flow through sand drainage layers being laminar and flow through gravel drainage layers being nonlaminar. In geosynthetic drains, the degree of turbulence depends on the applied compressive stress and the material in contact with the drain. © 2014 American Society of Civil Engineers.


Giroud J.P.,JP Giroud Inc | Gourc J.P.,Joseph Fourier University | Kavazanjian E.,Arizona State University
Geosynthetics International | Year: 2012

Hydraulic transmissivity tests on common geosynthetic and granular drainage materials (e.g. geonets and gravel) show that the hydraulic transmissivity of these materials often depends heavily on the hydraulic gradient, which indicates that the flow is non-laminar. Despite the non-laminar nature of flow in these materials, Darcy's equation and equations derived from Darcy's equation are extensively used for the design of geosynthetic and granular drainage systems, even though these equations are strictly valid only for laminar flow. Therefore it is important to identify the drainage materials and flow conditions for which the flow is laminar in order to evaluate the applicability of Darcy's equation. In classical hydrodynamics, the conditions for laminar flow are generally described in terms of a limiting Reynolds number. This paper provides guidance for Reynolds number calculation in geosynthetic and granular drains, and presents a methodology to establish the conditions for laminar flow as a function of the Reynolds number. Numerical applications of the methodology show that, for typical hydraulic gradients used in hydraulic transmissivity tests in the laboratory and encountered in drainage layers in the field, flow is generally laminar in needle-punched nonwoven geotextiles and sand, whereas it is generally non- laminar in geonets and gravel. However, in the case of geonets adjacent to geotextiles (such as in geocomposites), the flow becomes closer to laminar conditions as the geotextile progressively intrudes into the geonet channels under increasing values of the applied normal stresses. Practical recommendations are given for the use of Darcy's equation and equations derived from Darcy's equation to obtain approximate solutions when flow is not laminar. ©2012 Thomas Telford Ltd.


Giroud J.P.,JP Giroud Inc. | Gourc J.P.,Joseph Fourier University | Kavazanjian E.,Arizona State University
Geosynthetics International | Year: 2012

This paper shows that two physical characteristics of geosynthetic drains can be significantly affected by the flow boundaries: the specific surface area and the average flow path diameter. These two physical characteristics are important, because they have a significant influence on the hydraulic characteristics of geosynthetic drains. A theoretical analysis leads to a quantification of the effect of smooth and rigid flow boundaries on the specific surface area and the average flow path diameter. Numerical calculations performed using the equations proposed in this paper show that the effect of these flow boundaries is negligible in cases where the geosynthetic drain consists of a needle-punched nonwoven geotextile. In contrast, the effect of smooth and rigid flow boundaries on geonet drains is usually significant. The fact that even boundaries that are smooth and rigid have a significant influence on the measured hydraulic transmissivity of geonets supports the usual recommendation that, to measure a representative geonet transmissivity in the laboratory, flow boundaries that are representative of the field conditions must be used. For the sake of comparison, the methodology is also applied to granular drains. It is shown that the effect of flow boundaries is generally negligible in the case of granular (sand and gravel) drains. More generally, it is shown that the effect of flow boundaries that are smooth and rigid is negligible when the drain thickness is at least 20 times the size of the solid constituents of the drainage material, such as the diameter of the granular particles, or the diameter of geotextile fibers and geonet ribs. © 2012 Thomas Telford Ltd.


Gourc J.P.,Joseph Fourier University | Giroud J.P.,JP Giroud Inc | Aubert V.,JP Giroud Inc
Geosynthetics International | Year: 2012

This technical note presents a theoretical model for laminar and non-laminar flow through porous media. The relationship between hydraulic conductivity and hydraulic gradient expressed by the model is in good agreement with the results of hydraulic conductivity tests. The model provides a means to rigorously extend (by interpolation and extrapolation) the results of tests giving the hydraulic characteristics of porous media, such as the results of hydraulic transmissivity tests on geonets. A numerical example, based on actual test results, is presented.


Perera L.A.K.,HDR | Giroud J.P.,JP Giroud Inc. | Roberts M.G.,HDR
Geotechnical Special Publication | Year: 2011

There have been several exposed geomembrane cover (EGC) applications permitted as long-term interim cover systems for landfills since 1992. The first EGC as final closure was approved by State of Georgia in 2009. This EGC utilizes a 1.5-mm (60-mil) reinforced polypropylene geomembrane adhered with flexible photovoltaic (PV) cells to generate electricity. This paper presents a simplified design approach used to improve previous EGC designs by incorporating a modified anchor trench configuration to more effectively address wind uplift and ease the installation process. Calculations for the anchor trench pullout due to the modified anchor trench configuration are discussed and the wind suction coefficients, previously published using models tested in wind tunnels, are modified by considering suction forces generated under the EGC and other similar designs that have taken place over the last thirty years. The paper concludes with a case study of a final EGC design which incorporates PV cells to generate revenue during the post closure period. The case study demonstrates the design simplifications, determination of wind uplift forces, design considerations for anchor trench pullout and anchor trench dimensions. © 2011 ASCE.

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