ABSTRACT: In-situ measurement of subsurface temperature (temperature prospecting) has been developed as a method of groundwater-vein surveying. However, the usual method is labour intensive and the temporal resolution is poor, so we could never obtain sequential data of the temperature distribution. Continuous observation of the temperature distribution (i.e. distribution of the preferential flow-path) using fibre-optic temperature sensor is reported in this paper. High temperature regions indicate the groundwater pathway. The intensity of its signature was found to show slight fluctuations. In addition to that, it was found that these high temperature regions also have relatively large vertical temperature gradients. These signatures may be associated with the fluctuations of the preferential flow-path of groundwater, indicate the dynamic state of groundwater flow, and provide new parameters for the temperature prospecting method. INTRODUCTION The existence of preferential flow-paths for groundwater is an important factor which influences form of groundwater flow. It could be not only an ideal place for the water resource, but also a cause of disaster such as road and river bank failure. Therefore, having an accurate grasp of the preferential flow-path, such as distribution, scale and dynamics of preferential flow-path is important to prevent natural hazards and to develop water resources. In-situ measurement of subsurface temperature (temperature prospecting) has already been used in groundwater surveying (e.g., Cartwright, 1968a; Krcmar and Masin, 1970; Takeuchi and Akibayashi, 1977). This method is based on the concept that the subsurface temperature is affected by flux and temperature of the groundwater flowing through the measurement point. This method has been established both empirically (e.g., Cartwright, 1968b; Yamamoto et aI., 1994; Yasuda and Takeuchi, 1998) and theoretically. However, the conventional method is labour intensive, and has poor temporal resolution. Thus, until now, the method only indicates the static distribution (i.e. a snap-shot) of the preferential flow-path.

ABSTRACT: Grouting is normally based on empirical relationships and on the experience of the grouting personnel. To assist grouting projects, a large number of researches using mathematical modeling have been carried out into the clarification of the flow processes during grouting. From this point of view, we constructed a mathematical model to explain the injection process to the rock voids by grouting materials. There are many models of the description of flow paths, clogging of cement suspension in rock voids, flow properties of the grouting materials, and so on. In this analysis, we supposed that the clogging process of the rock voids is occurred by the injection of cement grout. As to the analysis of the voids clogging process, the mass conservation law, in which filtration theory was used, was applied and the analysis was done in one dimension. In this analysis, the concentration and the filter coefficient were considered as parameters to make the injection phenomenon clear. As a result, the voids clogging process by the difference in the cement grout concentration could be explained very well. And the voids clogging process by the difference in the filter coefficient which is in the inside of the mass conservation law, was also explained. INTRODUCTION Controlling water flow through soil or fractured rock mass is important for various reasons. Water leakage into underground openings, with the lowering of the ground water table and consolidation settlements clay layers as a result, can cause surface damage to building. In order to reduce the water flow through soil or fractured rock mass, grouting is a commonly used method. In particular, in dams construction grouting is a very important method to ensure water-tightness and tightness because water seepage under dams causes energy loss and erosion of the damcore.

ABSTRACT: Inclinometers are devices for monitoring movements of natural slopes or man-made slopes such as embankment dams, open cut excavations, etc. The conventional inclinometers measure the lateral deformation by means of a probe passing along a casing installed either in a borehole or in fill. In spite of being widely used, the inclinometers are of limited use for remotely continuous measurements of displacement since the displacement is measured when the sensing probe is manually lowered into the casing. As far as monitoring of slope movement is concerned, continuous measurement will provide the basis for early warning systems and real-time monitoring and forecasting of slope movement behaviour. But also the attributes of inclinometers concerning the damage in case of large displacements need to be improved. An investigation has been performed to develop a new inclinometer device using fibre optic approach. A fibre optic cable was attached to the outer surface of a plastic pipe in two loops. Each half of the loop made up one quadrant of the circular section of the plastic pipe. As the fibre cable was firmly fixed to the pipe, any stress acting on the pipe will be transmitted to the fibre cable. The experiment results reported in this Paper indicated that this technique give the possibility in performing real-time continuous measurement of both direction and displacement of slope movements. INTRODUCTION Inclinometers are the established devices for monitoring lateral deformation normal to the axis of a casing. The conventional inclinometers measure the deformation by means of a probe passing along the casing. When compared with conventional inclinometers, advantages of these devices include remote real-time reading, and the option for connection to a console for triggering alarm. However, the devices still have a major limitation to obtain the all points-measurement along the vertical section.

ABSTRACT: A combined boundary element/Laplace transform solution of time-dependent thermo-elasticity is extended to solve problems in multi-layered media in 2D. The method requires only boundary discretisation and no time stepping. An efficient Laplace inversion scheme is implemented which significantly improves the performance of the method. A library of constant, linear and quadratic elements is created. Equations of thermal conductivity are solved in the Laplace domain and the solution is inverted back to time domain. The effect of transient thermal loads on the boundary integral formulation of elastostatics is represented by an additional boundary integral. The scope of the method is illustrated by analysing a heated repository buried in a three-layer semi-infinite medium. Three factors combine to make the method an attractive option for the solution of transient thermoelasticity: the Laplace transform removes the need for time stepping, predictions are highly accurate as a result of the use of Green's functions, only boundary meshing is needed. It is found that, with the newly implemented Laplace inversion scheme, forty to eighty linear analyses are required to derive the entire stress history of a typical problem at any number of time stations. The application of the method to nonhomogeneous media extends its applicability and improves its ability to solve realistic problems. INTRODUCTION Differential thermal temperatures in layered media may occur in problems of mining excavations, road subgrade construction, extraction of geothermal energy, furnace foundation structures, or deep burial of heatgenerating waste. When temperature changes are moderate, the strata remain in the elastic range. When inertia loads and hydraulic effects are negligible, the problem may be represented by the coupled equations of transient thermo-elasticity. In many cases, the dependence of temperature on volume strain may be neglected and the equations uncoupled (Boley and Weiner, 1960).

ABSTRACT: This paper investigates the possibility to extend the models used frequently in soil mechanics to another materials. The absorption of fuel oil by a man-made sorbent is compared with the absorption of water by the soil, a natural material. A synthetic sorbent with capillary properties allowing to separate water from oil products was investigated. The sorbent is made of a dense network of intertwined fibers. Laboratory absorption tests were performed on a column of this material using fuel oil. The experimental set-up allowed to establish the evolution of the absorption as function of the time. The absorption curve observed at equilibrium had the same characteristics as the water absorption curve observed for a soil. The experimental set-up was modelled using a numerical scheme integrating the equation of the water flow equation in an unsaturated soil. The two constitutive descriptions needed by the model were the absorption curve and the conductivity curve. The absorption curve was represented with the empirical model of van Genuchten whose parameters were calculated on the absorption curve measured at equilibrium. The conductivity curve was calculated by using the model of Mualem whose parameters depend of those needed for van Genuchten's model. The different transient stages observed during the experiment before matching equilibrium were also calculated. A very good accordance between the calculated results and the experiments was observed. The results of this investigation show that models frequently used to represent the water flow in unsaturated soil can be extended to other materials, even if the structure of the materiel is very different. DESCRIPTION OF THE SYNTHETIC SORBENT The sorbent used in this investigation is a synthetic foam that absorbs selectively a large set of pollutants (a.o. products extracted from the petroleum industry, alcohol, solvent, …).

ABSTRACT: The methodology used for the laboratory measurements of the heat capacity and diffusivity of the rocks interesting a mine having an anomalous terrestrial gradient is presented, explicating the necessity to extend the research to some in situ determination both of the diffusivity and of the surface heat transfer coefficient. A comparative analysis of the values obtained in situ and in laboratory, on different scale, and some correlations between thermal characteristics and physical and texture properties of the examined rocks are attempted and conclusions are outlined about the influence of the measurement precision in forecasting the thermal regime of the mine. 1 FOREWORD: Investigation on thermal properties of rocks may have some interest both for geophysical problems and for exploitation of deep and hot mines, as well as for geothermal power production and thermal comminution. As the authors measured these properties in connection with some climatization problems of Campiano mine (Tuscany, Italy - see Ref.1971) where terrestrial temperature gradient is higher than usual and rocks can be studied as deep formations from several point of view- they discuss the met o dology and related experimental values. 2 LABORATORY THERMAL PROPERTIES MEASUREMENTS 2.1 Methods Rocks are typical materials, where often solid, liquid and gaseous phases can be coexist and anisotropy influences physical p a rameters: therefore it is necessary for rock investigation purposesto develop special essays or to modify the existing methods, evaluating moreover the results in a stat i stical way. Two thermal properties are generally con sidered: heat capacity and conductivity (or related diffusivity); in mine climatization problems the surface heat coefficient is a l so required. In this research heat capacity (C) was d e termined with a Regnault calorimeter (the accuracy was 0.01 °C for temperature and 0.01 g for mass measurements); repeatibility was estimated into the second decimal figure. Conductivity depends upon temperature and can be influenced by porosity, fluid content and fissuration; it can be measured by steady or variable state experiments, d i rectly or through the correlated diffusiv i ty (a = λ/C). The former methods are cons i dered more accurate, but less expeditive; accuracy of temperature measurement must be 0.01–0.1 for high precision or technical purpose respectively. The known experimental methods for condu c tivity measurement were analysed in conne c tion with the characteristics of the Campiano rocks: finally we resorted to two procedures, not too complex nor expensive, that might satisfy the operational features of the research. Method (1) is more suitable for poor co n ductors (i.e. gangues): a rock disc R (fig. 1a), 50 mm in diameter and 10 - 20 mm thick, is pressed between a copper plate H, that acts as a heat source (its temperature To is mantained constant by a water flux, circulating from a thermostatic apparatus) and a copper cylinder P that acts as a heat sink. The rock disc and the cylinder are thermically insulated by a cork jacket J. 2.2 Sources of errors in the measurements The error sources of the above described tests derive from the following causes.

ABSTRACT: Geothermal studies commonly assume that heat production is non randomly distributed with depth in the earth crust. The linear relationship between surface heat flow and surface heat production serves in modelizing several types of heat producing elements distribution with depth. Amongst them, a step, a linear or an exponential model are usually assumed though no factual data have yet demonstrated their validity. Intragranitic deep boreholes may be used to validate these assumptions. A comparison is attempted between various data on the heat production content within selected boreholes. Several examples are described for sites from Wyoming (GM-l and DW). Illinois (UPH-3), Ontario (ATK-l), Manitoba (DC) and French Massif Central (AUR-l and ECH-l). This includes only data from boreholes penetrating granites with depths ranging from 900 to 3000 m. All sites present different characteristics from which no definitive model of heat production distribution with depth can be selected. The theoretical heat production at depth computed from the heat flow/heat production relationship is not relevant to the observed heat production at depth. The radio-elements enrichment observed in the uppermost part of boreholes reflects local magmatic differentiation processes. Therefore, the knowledge of the radiogenetic elements distribution in granitic bodies is not sufficient to constrain the total heat production distribution within the upper crust. 1 HEAT FLOW - HEAT PRODUCTION RELATIONSHIP Heat flow measured within various regions show an increase of the average heat flow in the youngest ones provided they are in thermal equilibrium (Sclater et al. 1980, Morgan 1984). Heat flow (Q) is commonly related to heat production (A) by a linear relationship (Roy et al. 1968). The reduced heat flow (Q*) represents the contribution from beneath the enriched zone (Fig. 1). In its original form, the law has been deduced from measurements performed on granitic plutons (Roy et al. 1968). In that case, the heat flow values and their corresponding heat production values fall on a line. Extended to a geothermal province, a regression analysis computed on the data provides constant values of Q* and D (Morgan 1984, Drury 1987). Various heterogeneities within the continental crust contribute to point departure from the linear relationship. Experimental errors include local water circulation affecting the heat flow measurements, non representative estimates of the heat production or variations in either thermal conductivity or in heat production related to crustal heterogeneities (Jaupart 1983, Vasseur and Singh 1986, Nielsen 1987). Some of these can be appreciated and corrected. When data are considered from a region large enough to include crustal variations, the points no more fit a linear relationship, but cluster within an elongated pattern. A regression analysis can still be attempted, provided errors on both variables are taken into account (Vigneresse 1988a). The thermal parameters obtained from such a regression analysis should be considered as a first order approximation to the linear trend. In the simplest one, or step model, the heat producing elements are uniformly distributed within a layer of thickness D (Roy et al. 1968, Lachenbruch 1970).

ABSTRACT: A method for estimating the in situ thermal conductivity at basin scale from various well logs is presented. This method is based on the use of the geometric mean model for estimating the thermal conductivity of the different lithofacies of a given well; the various well logs are interpreted in terms of lithologic content and porosity; a mineralogic composition varying with the stratigraphy is assumed for each lithologic unit and a procedure for computing the in situ thermal conductivity profile is proposed. From there, the variations of the average thermal conductivity in each formation - obtained as an harmonic average over the depth - can be mapped at basin scale. The procedure is applied to a number of wells in the Viking graben (North Sea) and the resulting conductivity structure is compared to the present thermal structure. 1 INTRODUCTION Thermal conductivity of sedimentary rocks is a very important parameter for basin modelling: its value directly controls the vertical distribution of temperature. Unfortunately, in oil exploration boreholes, core samples are seldom and laboratory measurements of conductivity difficult to perform. Therefore, the thermal conductivity has to be estimated from the available, routinely recorded information such as well logs. The possibility of deducing thermal conductivity from well logs has been studied by various authors. A first approach is to define an empirical relationship between thermal conductivity and one or several well logs (Houbolt & Wells, 1980, Vacquier et al, 1988). However such an empirical relation has no physical basis and should be calibrated for each situation (Brigaud et al, 1989). An alternative approach, proposed by Brigaud et al (1989) and developped here, makes use of a composition model - the geometric mean model expressing the thermal conductivity of a multicomponent sedimentary rock as a function of its composition and structure. In this later case, the well logs are first interpreted in terms of lithologic composition and porosity; the available mineralogic information is also used for estimating the conductivity of the various lithologic end-terms. A vertical profile of thermal conductivity can then be computed using the relevant composition law, i.e. the geometric mean model. Although this later method is somewhat more laborious than a direct regression vs. well logs, it has the advantage of taking into account the actual mineralogic composition which is difficult to approach using well logs data alone. The results of this method have been found to yield consistent thermal conductivity estimates when compared with laboratory measurements (Brigaud et al, 1989) or to detailed temperature loggings. The purpose of this paper is to present the various aspects of a method designed for obtaining the detailed in situ thermal conductivity structure at basin scale. Then the procedure for estimating in situ thermal conductivity at the formation scale, using well logs as well as complementary information, is described in details. Finally, this technique is applied to a data set in the Viking graben in the North Sea; the conductive structure is described and compared with the thermal structure.

ABSTRACT: Mud temperature may have a direct influence on the behaviour of deep boreholes. Among other effects, the principle of thermal stresses is presented. It is shown through two case histories how it explains failure phenomena and suggests corrective actions. A pilot test showed that cooling the mud on an hydrocarbon well was possible and easy. The test also pointed out the importance of the drillstring rotation on downhole temperature. During rotation, hydraulic instabilities increase the heat transfer through the pipe, preventing a major cooling at great depth. There are and controllable many reasons to believe that temperature must be considered as an important drilling parameter. 1 INTRODUCTION Nowadays, good drilling performance is achieved by controlling several drilling fluid characteristics, mainly: density, to apply downhole pressure, Viscosity, to ensure good cleaning and, fluid loss and chemistry, to ensure stability and to limit formation damage. Mud temperature is often considered as a second order parameter influencing the downhole values of the previous parameters. Attempts have been made to properly evaluate the temperature distribution in a well while drilling, in order to assess this influence. For instance Galate and Mitchell (1986) used a computer code to evaluate the influence of temperature on the downhole values of density and viscosity of oil-base muds. Besides cases where excessive values of mud temperature made the drilling operation impossible, as in frozen ground or geothermal areas, no attempt to control this parameter has been reported. The objective of this paper is to show that mud temperature may have a direct influence on borehole behaviour and that it can be controlled. In other words, mud temperature may be considered as a first order drilling parameter. 2 MUD TEMPERATURE AND BOREHOLE WALL BEHAVIOUR 2.1 Effect of mud temperature change There are several reasons why a temperature change may affect the behaviour of the rock at the borehole wall: Temperature change will modify the rock properties stiffness, strength, toughness. A temperature gradient generates stiffness changes around the hole in an axisymmetric manner. This will modify the stress distribution around the hole, as does confining stress -dependent stiffness (Santarelli 1987). Cooling the rock can create a stiffer zone at the wall, where in situ stress concentration may lead to higher stress values. On the other hand, this cooling effect will enhance the strength of the material. Cyclic variations of temperature while drilling contribute to the alteration of rock properties (ei g. Timofeev et al 1969). The nonuniform temperature distribution around the hole, i.e. axisymmetric temperature gradient, induces thermal stresses. This effect will be discussed herein. The temperature change and the associated volume change of the porous skeleton, but also of the fluid itself, will have an effect on the pore pressure. This coupled effect is far from being negligible, depending on the rock type, and is now under further investigation (e.g. Coussy, 1989). The swelling behaviour of clayey rocks has been shown to be temperature dependent.

ABSTRACT: With basis on the flow conception model using main discontinuities in fractured rock masses, the influence of the seasonal temperature variations on the increase in the uplift pressures was studied, and their responsibility was defined in the main disasters caused by infiltration. Of them all, the rupture of the Malpasset Dam is the best known. INTRODUCTION With the recent information obtained from the "Teste de Registro Hidraulico" - TRH (Hydraulic Record Test) and "Ensaio de Injecao d'Agua sob Pressoes Decrescentes"- EIPD(Water Injection Test under Decreasing Pressures) (Andrade 1987 a,b) the flow in fractured rock masses may be interpreted as a flow only through continuous main discontinuities which are characterized by their offering least resistance to underground water flow. This model admits that there are blocks of fractured rock between these main discontinuities forming subdomains,inside which the pressures are a result of equalizing the pressures in the discontinuities, since the latter impose the boundary conditions on them (Andrade 1987 c). The application of the EIPD on the site of the future Santa Isabel hydroelectric plant showed that, in one discontinuity of the rock mass foundation, the flow speed was considerable since the conductivity for gradient 10 reached 0.8 cm/s. Given these two important facts, the folowing reflection was made: – If there is high conductivity in the discontinuities responsible for establishing the pressures inside the foundation, then when the underground water is cooled by the seasonal variation in temperature, the rock mass foundation will also be cooled and the conductivity will be considerably increased. To prove this idea, we asked CESP-Companthia Energtēca de São Paulo, among others, obtain piezometric information from a series of dams. From this research we produced the work "Seasonal oscillation of uplift pressures in hydraulic structure foundations due to environmental thermal variations (Guidicini & Andrade 1987). Here it can be clearly seen that, despite being in a temperate tropical region and the dams being gravity models, the phenomenon can still be proved since, in the dams analysed, 107.of the instruments installed in the first 15 metres deep showed considerable seasonal variations in uplift pressure, once more reinforcing our model and the values obtained in the tests. INFLUENCE OF TEMPERATURE The water flowing through the main discontinuities due to the fall in seasonal temperature will be cooling the adjacent blocks of rock, or rather, the adjacent subdomains. Figure 1 shows 3 main discontinuities. Suppose that each one, according to its distance from the intake source, allows for changes in different temperature variations ATl, AT2. and AT3 r, SUBDOMAIN 1 Fig. 1 - Main discontinuities THE SEASONAL TEMPERATURE VARIATION AND DAM DISASTERS If the influence of the temperature on conductivity is as important as we saw, and considering the piezometric variation of the Água Vermelha Dam for piezometer PZ-154 (fig. 2) which rose 28 meters, that is, an increase of 2.8 kg/cm', we feel able to discuss how seasonal variation would influence the dam disasters caused by infiltration in the foundation.

ABSTRACT: Empirical uplift pressure diagrams are still used for stability analyses of concrete structures founded on rock, particularly during preliminary studies. Piezometric measurements on several brazilian dam foundations were collected and analyzed. These measurements were taken at both rock-concrete contact and in descontinuities in the rock foundations, for different types of rocks. To facilitate the analyses the structures were divided in groups with similar characteristics and employing a standard basis of analysis used in other works. The data indicates that the design criterium for normal operating Conditions predicting a 67% efficiency of drainage seems to represent an upper limit for observed uplift pressures, both at rock-concrete contact and in descontinuities. The data also shows that the hypothesis of full reservoir pressure acting under the upstream toe of the structures seems to be satisfactory whereas for descontinuities in the foundation it gives conservative estimates of uplift pressures. The highly beneficial effect of drainage tunnels in the foundations is clearly seen from the measurements. 1 INTRODUCTION Despite the recent advances in different techniques for analysis of flow problems in rock masses as related to concrete dam foun dations, empirical uplift pressure diagrams are still very used in practice. These are taken as an envelope for measured water pressures for different types of rock foundations, dam structures, drainage conditions, etc. They suffer from obvious limitations but still serve a very useful purpose at least in the initial design stages. In Brazil the most commonly used empirical up lift diagrams are those suggested by the Bureau of Reclamation (USBR, 1976) and by Cruz and Barbosa (1981). A complete review of evolution of criteria for uplift pressures in gravity dams, including empirical, analytical and numerical techniques, is presented by Rocha (1987). The USBR empirical criterium considers only one drainage line in the rock founda tion and assumes a value 01: pressure at the drainage line equal to the downstream toe pressure plus one third of the difference between tl1e upstream and downstream toe Pressures. This value is connected by Straight lines to the upstream and downstream toe pressures, assumed to be equal to the reservoir and tailwater level pressures respectively. When the dam foundation is not horizontal, the criterium is considered in terms of total head. The Cruz and Barbosa (1981) empirical criterium for normal operating conditions is shown in figure 1for two drainage lines. In the upstream drainage line the pressure is given by the difference in level between the gallery (under atmospheric pressure) floor and the point of inter section of the slip surface with the drainage line plus one third of the difference between the reservoir water level and the gallery floor. The same consideration is made in relation to the pressure acting in the downstream drainage line, as shown in figure 1. The same authors consider that when a drainage tunnel (under atmospheric pressure) is excavated in the rock foundation and linked to the gallery by drainage holes, zero water pressures should be assumed in the drainage line.

ABSTRACT: The Bath County Pumped Storage project, owned jointly by Virginia Power and Allegheny Generating Company, is located 70 miles (112 km) north of Roanoke, virginia, USA. It is a six unit, pump-generating station rated at 2100 MW, the largest pumped storage project in the world. All six units were declared commercial in December 1985, and the plant has operated continuously since that date. Initial filling of one of the three power tunnels produced unacceptable amounts of leakage from the tunnel. In addition, seepage pressures buckled and ruptured a short Section of one of the steel liners in an unwatered penstock adjacent to one that was filled. The remedial treatment program that followed, included an extensive, high pressure tunnel grouting program, and an expanded drainage and monitoring program. During the second filling, the three power tunnels were filled simultaneously. Piezometer readings and. penstock drainage tunnel flow rates generally increased with the reservoir level. However combined leakage from the three tunnels was significantly less than the leakage from a single tunnel had been during the initial filling; piezometric pressures,.though higher generally, rose in a predictable manner. On two occasions, however, piezometric increases adjacent to the upstream ends of the steel penstocks and Within the surrounding rock mass prompted additional drain hole and relief well drilling. The remedial program consisting of grouting and drainage has been effective in reducing tunnel leakage and the high pressures resulting from it. Pressure migration has been controlled. A maintenance program of flushing and cleaning drainholes has been successful in maintaining the low flows and reduced pressures. PROJECT DESCRIPTION The upper and lower reservoirs are Contained by embankment dams (Figure 1). The upper reservoir dam is approximately 480 feet (145 m) high; the lower dam is approximately 150 feet (47 m) high. Water is conveyed through three, 28.5 foot (8.7 m) diameter, concrete lined power Conduits. Each has an upper and lower horizontal segment approximately 3100 to 3600 feet (966–1122 m) long, connected midway by a 990-foot (302 m) vertical shaft. Each lower tunnel bifurcates into two, reinforced concrete and steel-lined Penstocks, 18 feet (5.5 m) in diameter and 900 to 1260 feet (280–392 m) long. The Penstocks lead to the powerstation located On the west bank of the lower reservoir. Maximum static pressure within the tunnels at the upstream ends of the steel lined Penstocks is about 1320 feet (402 m). PROJECT GEOLOGY The Bath County Project is located at the northwestern margin of the Appalachian Fold Belt of western Virginia. Rock units in the project area are predominately thinly bedded siltstone and shale of the Millboro/Brallier formation, and blocky sandstone and siltstone of the overlying Chemung formation. Both units are Devonian (Figure 2). The structural trend is northeast southwest, paralleling the trend of the Appalachian Mountains. Rock units are buckled in tight chevron folds in the vicinity of the powerstation and penstocks, but strata in the remainder of the tunnel route generally dip at very low angles (5–10 degrees) to the northwest.

SUMMARY: The planned isolation of nuclear waste in mined rock repositories poses unusual requirements for rock mass characterization. This paper describes recently developed block test methods for characterizing and quantifying the thermal, mechanical and hydraulic properties of rock masses. The heated block test, recently conducted in situ on an 8m 3 block of jointed gneiss, provides normal stress and temperature-dependent data such as deformation modulus, joint stiffness, joint permeability, thermal expansion, thermal conductivity and dynamic elastic modulus. Simpler tests conducted on singly jointed blocks or on jointed drill core provide joint roughness data. This is incorporated in recently developed constitutive models which describe the coupling of normal displacement, shear displacement, shear strength, dilation and permeability. ZUSAMMENFASSUNG: Die geplante Isolierung von radioaktivem Abfall in abgebauten Gesteinsabflallen stellt ungewöhnliche Anforderungen an Felsgesteinkennzeichnung. Dieser Bericht beschreibt kuerzlich entwickelte Blocktestmethoden zur Kennzeichnung und quantitativen Bestimmung der Warmeeigenschaften und der mechanischen und hydraulischen Eigenschaften der Felsmasse. Der HeiBblocktest, der kuerzlich "in-situ" auf einem 8m 3 groBen Block von geklueftetem Gneis durchgefiuehrt wurde, gibt normale Spannungs- und Temperaturabhangigkeitswerte wie Verzerrungsmodul, Verbindungssteifigkeit, Verbindungsdurchlassigkeit, Warmeausdehnung, Warmeleitfahigkeit und Dynamik elastizitatsmodul. Einfachere Messungen, die an einzeln gekliuefteten Blcoks oder an gekluefteten Bohrkernen vorgenommen wurden, geben Kluftrauhigkeitswerte an. Diese sind miteingeschlossen in kiuerzlich entwickelte zusammenfassende Modelle, die die Kupplung normaler Verlagerung, Scherverlagerung, Scherfestigkeit, Dehnung und Durchaissigkeit beschreiben. RESUME: L''isolation projetee des dechets nucleaires dans des depôts de roche extraites presente des exigences peu commune pour la caracterisat ion de la masse de roche. Cette etude decrit les methodes, recemment developpees, des essais des blocs pour caracteriser et pour quantifier les proprietes thermiques, mechaniques et hydrauliques des masses de roche. L''essai du bloc chaud, recemment conduit in situ sur un bloc de gneiss jointe (de 8m 3 ) fournit l''indication normale qui depend de la force et de la temperatureˆ par exemple, le coefficient de la deformation, la durete de la jointure, la permeabilite de la jointure, l''expansion thermique, la conductivite thermique et le coefficient dynamique et elastique. Des essais plus simples qu''on a conduits sur des blocs individuellement jointes ou sur le centre jointe d''un trepan ·fournissent les indications de la rugosite des jointures. Tout ça est incorpore dans des modeles de base, recemment developpes, qui decrivent le couplage du deplacement normal, du deplacement du cisaillement, de la force du cisaillement, de la dilation et de la permeabilite. INTRODUCTION Characterization of rock masses is usually associated with construction and excavation projects such as dams, tunnels, mines, etc. In general the parameters of most importance are associated with deformation moduli, shear strength and permeability, each a function of stress and orientation. Civil engineering experience suggests that the natural joint sets have most effect on the magnitude of these parameters. Jointing is also responsible for their directional anisotropy. The planned isolation of nuclear waste in mined rock repositories poses additional problems in rock mass characterization. The extended time scale and the thermal load associated with long-term isolation add to the number of significant parameters that need to be quantified. Numerical modeling of potential groundwater and radionuclide transport through changing stress and temperature regimes demands an advanced level of input data. Particular emphasis falls on accurate joint characterization, in particular on the manner in which the hydraulic, thermal and mechanical properties should be coupled. THE HEATED BLOCK TEST The schematic block diagram shown in Figure 1 represents the 8 m3 in situ test recently completed by Terra Tek for the Office of Nuclear Waste Isolation. The objective was to demonstrate a suitable method for obtaining appropriate hydrothermomechanical data for modeling

SUMMARY: Straightforward approximate formulas are presented for the estimation of flow rates of air (gas) and water (incompressible liquid) from a cavern in a permeable mass; the cavern acting as a source or a sink. The mass may be soil or fractured rock and the cavern may be a drill "vole, a tunnel or a compressed air surge chamber among others. The idealized geometry of the cavern and the distance to a boundary equipotential, which may be the groundwater table, determines the value of a geometry factor appearing in the flow rate formulas. One formula applies to water flow in completely water saturated media and a slightly different formula to air flow in dry media. Special emphasize is given to the application of the formulas in questions regarding design of unlined compressed air surge chambers in jointed rock. ZUSAMMENFASSUNG: Vereinfachte, approximative Formeln sind fuer die Bestimmung der Stömungsgeschwingigkeit von Luft (Gas) and Wasser (unzusammendrueckbarer Fluessigkeit) aus einer Kaverne in durchlassiger Materie prasentiert, wo die Kaverne als eine Quelle oder Senke fungiert. Die Materie könnte Erde oder klueftiger Fels sein, and die Kaverne könnte ein Bohrloch, ein Tunnel oder ein geschlossenes Wasserschloss das mit Druckluftpolster arbeitet sein, u.a. Der in den Strömungsformeln auftretende Geometriefaktor wird durch die ideale Geometrie der Kaverne and durch den Abstand von einem Randàquipotential (z.B. dem Grundwasserspiegel) bestimmt. Die eine Formel ist fuer die Wasserströmung in wassergesattigten Böden anwendbar, and eine àhnliche Formel fuer die Luftstrimung in trockenen Baden. Besondere Betonung wird our die Anwendung der Formeln in den Fragen der Konstruktion unausgekleideter geschlossener Wasserschlösser mit Druckluftpolstern in zerklueftetem Fels gelegt. RESUME: Des formules approximatives et directes pour estimer les vitesses d''ecoulement de l''air (gaz) et de l''eau (liquide incompressible) à partir d''une caverne dans une masse permeable sont presentees; la caverne agissant comme source ou comme drain. La masse peut être un sol ou un roc fracture et la caverne peut être un trou de fourage, un tunnel ou une chambre d''equilibre a air comprime entre autres. La geometrie idealisee de la caverne et la distance à une equipotentielle limite, qui peut être la nappe d''eau souterraine, determine la valeur d''un facteur de geometrie apparaissant dans les formules de vitesse d''ecoulement. Une première formule s''applique à l''ecoulement de l''eau dans un medium complètement sature d''eau et une autre formule, legèrement differente, à l''ecoulement de l''air dans un medium sec. Un accent special est mis sur l''utilisation des formules en question pour le calcul des chambres d''equilibre à air comprime sans recouvrement interieur dans un roc comprenant des joints. Fig. 2. Geometry in an idealized flow problem(figure in the paper). INTRODUCTION The planning of closed air surge chambers in Norway in the early seventies called for methods to predict air loss from caverns located in fractured rock. The work undertaken by the- present authors (1973) was directed towards the development of appropriate formulas for estimating rock mass permeability from borehole tests(Lugeon tests) and measurements of water flow into tunnels and caverns. Furthermore to develop formulas for estimating water and air flow from a cavern knowing the effective permeability of the rock mass. Fig. 1(Figure in the paper). Closed air surge chamber in a fractured rock mass (not in scale). Fig. 1 shows the typical problem; an air surge chamber partially filled with compressed air. Under air pressure higher than, or even slightly below the original water pressure at the chamber location, compressed air will migrate into the rock joints intersecting the chamber. The air loss must be compensated for by compressors. One crucial question is the compressor capacity needed. The analysis of flow problems in fractured rock is difficult for several reasons. The flow taking place in hard rock suitable for the location of air surge chambers is exclusively limited to fissures and joints. The spacing, distribution and openings of such are likely to be most irregular. Considering even a single joint parallel plate theory may not be correct as the flow may take place in channels. In the theory to be presented the medium in which flow takes place is considered homogenous. Thus the theory itself is not developed particularly for flow problems in fissured rock. The flow equations to be presented applies to soils and other permeable media as well. In the present paper emphasize is, however, given to the application of the flow equations to inhomogenous rock. The combined flow of air and water (two fluid system) is hard to analyse. Much easier is the analysis of water (liquid) flow in a completely water saturated porous medium and the analysis of air (gas) flow in a dry porous medium. When able to handle the latter problem at least an upper limit of the air flow in a mixed air-water flow problem is given. The theory to be presented is limited to single fluid flow, but some emphasis is given to the application of the results to the mixed flow problem of an air surge chamber.

INTRODUCTION The purpose of the paper is to bring data on uplift pressures at the base and in discontinuities of preferential flow within the rock foundations of seven brazilian dams, involving 16 concrete gravity structures. Dams were built within the last 20 years and are in operation for 3 to 15 years. All rock foundations are basalts with their typical sequence of flows with sub-horizontal contacts and joints that represent preferential paths of flow. All dams were built in the State of Sao Paulo, Brazil, and belong to the Companhia Energética de São Paulo. The authors are indebited to CESP for the possibility of publishing this data. The paper includes data on uplift, measurements of flow, consideration of the nature of flow, design criteria, and recommendations on foundation treatment.