Experimental assessment of the sealing effectiveness of rock fracture grouting

by A. Schaffer

Publisher: Division of Engineering Safety, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission in Washington, DC

Written in English
Published: Pages: 178 Downloads: 606
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Subjects:

  • Grouting.,
  • Grout (Mortar),
  • Permeability.,
  • Sealing (Technology),
  • Sediments (Geology) -- United States -- Permeability.
  • Edition Notes

    Statementprepared by A. Schaffer, J.J.K. Daemen.
    ContributionsDaemen, J. J. K., U.S. Nuclear Regulatory Commission. Office of Nuclear Regulatory Research. Division of Engineering Safety., University of Arizona. Dept. of Mining and Geological Engineering.
    The Physical Object
    Paginationxiii, 178 p. :
    Number of Pages178
    ID Numbers
    Open LibraryOL15351347M

Mechanical (flexural and uniaxial compressive strengths) and physical (thermal conductivity) properties of two new bentonitic grouts doped with 5 and 10% of graphite powder are discussed in this work and evaluated for their potential use in low-enthalpy geothermal applications. The same tests have been also conducted on a pure starting material (bentonitic grout) already present on the market. Consensus Study Report: Consensus Study Reports published by the National Academies of Sciences, Engineering, and Medicine document the evidence-based consensus on the study’s statement of task by an authoring committee of s typically include findings, conclusions, and recommendations based on information gathered by the committee and the committee’s deliberations. especially true in the areas of optimum grouting conditions and preferable grouting pressures to seal fractures around the excavations due to construction to prevent the fractured zone around the excavations from becoming dominant bypass flowpaths around the seals and thereby negating the effectiveness of the seals. Hydraulic Fracture Propagation in Layered Rock: Experimental Studies of Fracture Containment These results suggest that improved fracture treatment designs and an assessment of the potential success of stimulations in low-permeability reservoirs can be made by determining the in-situ stress st ate in the producing interval and bounding.

  The evolution of fracture permeability is crucial as regards the lifespan of the deep fractured geothermal exchanger of an Enhanced Geothermal System site. The objective in developing reactive percolation tests in fractures under thermohydromechanical conditions is to improve our understanding of fluid/rock interactions and their role in the evolution of fracture permeability. Here, focus will be given on the shaft seal experiment. Within the experimental shaft of the HADES URL, the seal was installed. To this end, the bottom part of that shaft was filled with grout and the concrete liner was removed at the location of the seal. The seal consists of a mixture of 50% of powder and 50% of highly compacted pellets of. to the core axis. 3) A copper foil sealing is fitted around the fracture, the fracture is filled with 2 lb/ft² (~ 10 kg/m²) of proppants. During test execution a constant confinement σ 3 of 10 MPa is applied and the specimen is axially loaded (σ 1) to simulate fracture closure. Effective stress is .   Here is a presentation of hydraulic fracture growth in the laboratory setting. An acrylic cylinder is fractured with high pressure epoxy grout injection. During this test, pressure, flow rate.

Groundwater flow in unsaturated, fractured rock is often assumed to be dominated by the porous matrix component. This is frequently the result of reasoning that water flowing in the fractures is rapidly imbibed into the rock matrix by capillary suction forces with negligible resistance to uptake at the fracture. fracture (rock joint) in a relatively large-sized specimen { × mm [8 × 8 in] fracture surface area}. Because of the practical difficulties in measuring shear load effects on permeability in natural rocks, relatively few experimental data are available in the open . Fractured Rock Conference: State of the Science and Measuring Success in Remediation, September , , Portland, Maine. Abstract. In-Situ Chemical Oxidation Huling, Scott G. and Bruce E. Pivetz USEPA, EPA//R/, 60 pp, Rapid Assessment of Remedial Effectiveness and Rebound in Fractured Bedrock. rock fracture spacings, openings, and porosities. the amount of grout to inject into a given volume of fractured foundation rock depends on the fracture porosity and on the spacing and sizes of fracture openings. these properties cannot be measured directly but can be calculated from water-pressure tests if several simplifying assumptions are made.

Experimental assessment of the sealing effectiveness of rock fracture grouting by A. Schaffer Download PDF EPUB FB2

Get this from a library. Experimental assessment of the sealing effectiveness of rock fracture grouting. [A Schaffer; J J K Daemen; U.S. Nuclear Regulatory Commission.

Office of Nuclear Regulatory Research. Division of Engineering Safety.; University of Arizona. Department of. Grout Characterization 74 Fracture Grouting 79 Fracture Compression Behavior 82 EXPERIMENTAL RESULTS 86 Permeability of Intact Tuff 86 Fracture Permeability 91 Fracture Compression Surface Characterization Grout Characterization Grouting Effectiveness Experimental assessment of the sealing effectiveness of rock fracture grouting [microform] / prepared by A.

Schaffer, J.J.K. Daemen Division of Engineering Safety, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission Washington, DC Australian/Harvard Citation. The sealing efficiency is evaluated and graded by the reduction of water drainage through the fracture after grouting.

The experimental results of the orthogonal arrays show that two most influencing factors on sealing efficiency are the initial water flow speed and the aperture width, where the former has a higher impact Experimental assessment of the sealing effectiveness of rock fracture grouting book the by: grout based on Portland cement and showed that it will largely lose its sealing potential in years.

Search for long-lived grout types and techniques for effective injec- tion into rock fractures was initiated and the presently described project shows examples of modern types de- veloped, in particular, for being chemically compatible.

Fracture surfaces are multi-faceted and can become either barriers or conduits to flow. To assess the trans-missibility of a fracture three methods can provide an indication of the sealing capability of the fracture surface: • Clay smear potential (Bouvier et al.

• Shale smear factor (Lindsay et al. A further requirement for sealing fractured rock is that the grain size must be such that a significant fraction of the grout particles can enter the fractures in the rocks with a certain minimum geometric aperture, taken here as micrometers.

The same grout must be suitable also for sealing wider fractures [18]. Components. However, in many subsurface environments, fluid‐rock interactions lead to mineral precipitation, which can significantly reduce fracture permeability.

This fracture sealing process can have the desired effect of enhancing the ability of geologic seals to isolate, for example, overpressurized CO 2 [Huerta et al., ; Matter et al., Grouting is the processes of injecting a cement or similar material into fractures and joints in bedrock to reduce permeability or increase the strength of the rock mass.

The design and imple­ mentation of grouting programs will vary depending on site specific characteristics, but in general, all grouting programs share a few features in common.

The fracture test uses a combination of two plates to simulate a real rock fracture and evaluates the percolation behavior of the slurry in the fracture by studying the grouting pressure and. Supercritical carbon dioxide (SC-CO 2) fracturing is a promising technology for developing shale gas because it can effectively solve problems related to shale swelling and lack of water work conducted simulation experiments on SC-CO 2 fracturing in shale for the first time.

Compared with hydraulic fracturing, using SC-CO 2 as the fracturing fluid reduces the pressure. An understanding of rock fractures is essential for effective exploitation of many of the Earth’s natural resources including ground water, geothermal water, and petroleum. This book combines results from fracture mechanics, materials science, rock mechanics, structural geology, hydrogeology, and fluid mechanics to explore and explain.

grouting, hydro fracture gr outing, jet grouting, rock grouting and compensation grouting and deep mixing method. Figure 1 shows the sketch of gr outing. Sealing of tunnels by grouting demands knowledge concerning the fractured rock and the grout, followed by an appropriate choice of strategy and equipment.

In this thesis, the characterisation of rock is the main issue and, since it addresses the engineering problem of producing a description for grouting, the properties of grout and the grouting procedure need to be considered.

Permeation grouting is used to improve rock conditions under dams and foundations. During recent decades, there has been a substantial increase of understanding of the mechanism behind grout spread in fractured rock.

It is the penetrability of the grout mix and the spread in the joints which will be the governing factors for the quality of the grout curtain. Experimental assessment of the sealing effectiveness of rock fracture grouting Technical Report Schaffer, A ; Daemen, J J.K.

The objective of this investigation is to determine the effectiveness of cement grouts as sealants of fractures in rock. The transmissivity is coupled to the hydraulic aperture of the fracture by the cubic law [4, 5]: where is the viscosity, is the density of water, and is the so-called hydraulic aperture of the hydraulic aperture determined by the cubic law has shown to be a good estimate for the grouting aperture [6, 7].From this it follows that in a borehole to be grouted, only a few fractures.

The grouting of rock used to be a quite empirical constructional technique aimed to improve somewhat the physical properties of the masses, which are actually part of sure, effective stress and closing ratio at point P.

Cement grout Definition of the water-cement ratio Essentially the cement grout, or slurry, is a mixture of cement and.

As an important method for improving dam foundations, curtain grouting is designed to create a hydraulic barrier to decrease permeability, enhance strength, and reduce deformability of rock masses. To evaluate the improvement of rock masses, the Lugeon value (LU), rock quality designation (RQD), and fracture filled rate (FFR) after grouting are key evaluation indicators of grouting efficiency.

Tests of grouting with flowing water in the fracture replica were carried out under different Bardon’s standard roughness profiles.

The interactions between influential factors were considered and an experimental platform for grouting in rough fractures with flowing water was established.

Slurry flow in mining-induced overburden fractures is an important theoretical concept for the grouting design of longwall overburden grout injection engineering. In this study, a visual experimental simulation system of longwall overburden grouting was designed to study the flow, pressure distribution, consolidation, and fill thickness of fly ash slurry in overburden bedding separation.

An investigation was performed to find and describe a rock volume suitable for a grouting field test for tunnels at the Aspo Hard Rock Laboratory, Sweden.

Fixed interval length transmissivities and the corresponding number of fractures from geological mapping of a probe hole were used to calculate a probability of conductive fractures for.

For example, extraction of fluids from a fracture system can lower the fluid pressure, which will increase the effective stress (the stress transmitted directly from particle to particle) in the rock, thereby causing the fractures to close.

2 days ago  The exploitation of deep resources is necessary for human development. At the same time, high-stress environments that are deep underground bring about great challenges vis-à-vis resource exploitation.

A large deep opening is sensitive to high ground stress, and is easily influenced by external interference, which can lead to geologically hazardous occurrences. Self-Sealing of Fractures in Clay Rock Chun-Liang Zhang Gesellschaft für Anlagen- und Reaktorsicherheit (GRS), Repository Safety Research Division, Braunschweig, Germany (@) Excavation of a deep geological repository for disposal of radioactive waste in clay formations generates fractures.

The effectiveness of grouting fractured rock depends on the distance that grout penetrates into individual fractures and spreads into connected fracture networks. Assessing grout spread, and the consequent effect on groundwater flow, requires consideration of the 3-D geometry and hydraulic properties of the natural fracture network.

ASTM's cement and concrete standards are instrumental in the evaluation and testing of concrete, cement, and aggregates. Concrete can have different properties depending upon the mixture that is used in creating it, which contains cement, chemical admixtures, and aggregates.

This is because the rubber particles inside the test block can reduce the elastic modulus, and the test block can withstand large deformation, which reduces the stress concentration in the rock layer with grouting flow and maintain the effective strength of the grouting floor.

Accordingly, the sealing and strengthening effect of the grout. and field permeability testing. Hydraulic fracturing is also a major concern on the effectiveness of soil grouting. Although hydraulic fracturing has been adopted in petroleum industry for decades for oil recovery in rock formations, studies on the fracturing in soils are relatively few and inconclusive.

be used to infer the growth conditions during fracture sealing. See-through experiments The aim of the see-through experiments was the observation and analysis of ongoing fracture sealing, in order to allow conclusions on the boundary conditions of natural veins.

An improved experimental set-up was built and carefully calibrated before. Verification o Grouting Effectiveness. Chapter Numeric Analysis in Grouting (Mike Jefferies and Dawn Shuttle).

About Numerical Analysis. Fractured Rock Grouting. Compaction Grouting. Chapter Specifications and Contracts. Specification Requirements. Contracting Arrangements. Full Scale Trials. Chapter   Book Description. Harmonising Rock Mechanics and the Environment comprises the proceedings (invited and contributed papers) of the 12th ISRM International Congress on Rock Mechanics (Beijing, China, October ).

The contributions cover the entire scope of rock mechanics and rock engineering, with an emphasis on the critical role of both disciplines in .Rock Fracture Mechanics: Principles, Design and Applications (DEVELOPMENTS IN GEOTECHNICAL ENGINEERING) [Whittaker, Barry N., Singh, Raghu N., Sun, Gexin] on *FREE* shipping on qualifying offers.

Rock Fracture Mechanics: Principles, Design and Applications (DEVELOPMENTS IN GEOTECHNICAL ENGINEERING).