Comparison between various flume tests used for hydraulic-fill studies

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Comparison between various flume tests used for hydraulic-fill studies
                                                                                                                                        ANGELAA. G. KUPPER,~        NORBERT    R. MORGENSTERN,     AND DAVIDC. SEGO
                                                                                                                                    Department of Civil Engineering, University of Alberta, Edmonton, Alta., Canada T6C 2C7
                                                                                                                                                                    Received April 30, 1991
                                                                                                                                                                  Accepted February 22, 1992

                                                                                                                     Several flume deposition tests carried out in different parts of the world to study hydraulic fills are compared and
                                                                                                                   discussed. The results of all test programs are coherent and consistent with field observations of hydraulic fills and
                                                                                                                   natural alluvial deposits, which suggests that, at least qualitatively, flume tests are adequate t o simulate the physical
                                                                                                                   phenomena associated with hydraulic deposition.
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                                                                                                                     Key words: hydraulic fill, flume tests, sand, grain size, profile, slope, density.

                                                                                                                      L'on compare et discute plusieurs essais de dkposition en canal rkalises dans differentes parties du monde. Les risultats
                                                                                                                   de tous les programmes d'essai sont cohkrents et consistants avec les observations sur le terrain de remblais hydrauliques
                                                                                                                   et de dkp6ts alluvionnaires naturels, ce qui indique que les essais en canal simulent adkquatement, du moins qualitative-
                                                                                                                   ment, les phknomttnes physiques associks a la dkposition hydraulique.
                                                                                                                      Mots clPs : remblai hydraulique, essais en canal, sable, granulometrie, profil, pente, densitk.
                                                                                                                                                                                                                     [Traduit par la redaction]

                                                                                                                   Can. Geotech. J. 29, 418-425 (1992)

                                                                                                                                Introduction                                       difference in testing procedure between these tests and
                                                                                                          Flume tests are a convenient tool to study hydraulic fills.              hydraulics-sedimentology aggrading-bed tests is that in the
                                                                                                       Under laboratory conditions it is possible to control and                   first case water and solids are previously mixed and fed to
                                                                                                       isolate variables in a simpler and more economical manner                   the flume as a slurry, whereas in the second case excess sand
                                      For personal use only.

                                                                                                       than would be possible in the field. Flume tests also permit                is dropped onto an already established flow (that is usually
                                                                                                       one to study the hydraulic deposition process of a certain                  much deeper than the flow in slurry deposition tests).
                                                                                                       material at an early stage of the project when information                     In this paper, flume tests performed specifically to study
                                                                                                       is necessary but field data are still not available.                        hydraulic fill are described and their results are summarized
                                                                                                          Owing to these advantages, several flume tests programs                  and compared.
                                                                                                       have been carried out to study hydraulic deposition. In fact,
                                                                                                       there is a large number of flume tests presented in the liter-                   Summary of flume tests presented in the literature
                                                                                                       ature involving the flow of water and sediment. However,
                                                                                                       the majority of these tests study hydraulic deposition from                    A brief description of several flume tests to study hydraulic
                                                                                                       a hydraulics or sedimentology point of view. In these cases,                fills is presented in this section. A summary of the most
                                                                                                       a bed of the selected sediment is usually placed on the flume               important features and parameters utilized in each test pro-
                                                                                                       bottom and water flows over it at specified flow rates and                  gram is presented in Table 1.
                                                                                                       velocities. The water flow may cause the sediment to be                     Porto Primavera Dam, Brazil (UPP)
                                                                                                       transported, defining particular bedforms and stratification.                  The flume tests reported by Ferreira et al. (1980) were con-
                                                                                                       The sediment that is carried out at the downstream end of                   ducted according t o Soviet technology as part of the pre-
                                                                                                       the flume is usually collected and replaced at the upstream                 liminary studies for the design and construction of Porto
                                                                                                       end, so the bed may change shape but it is not aggrading                    Primavera Dam in Brazil, which was planned initially to be
                                                                                                       or degrading. In only a few of these flume tests (Allen 1963;               a hydraulic fill. The Soviets report to have used flume tests
                                                                                                       Bhamidipathy and Shen 1971; Soni et al. 1977; Soni 1981;                    extensively in the past when the hydraulic fill technology
                                                                                                       Garde et al. 1981; Torres and Jain 1984; Yen et al. 1989)                   was being developed in their country. Nowadays the hydro-
                                                                                                       is there net deposition, with additional sediment being placed              mechanization process is standardized in the former U.S.S.R.,
                                                                                                       at the flume head. Typical measurements during these tests                  and laboratory deposition tests are no longer used routinely.
                                                                                                       include water flow rate, velocities, depth, sediment transport                 For the Porto Primavera Dam studies, fine sand from one
                                                                                                       rate, and slope. Bedform and stratigraphy are sometimes                     of the borrow areas was deposited in an 11-m-long flume
                                                                                                       also recorded.                                                              using an independent sand and water feeding system
                                                                                                           Relatively few flume tests found in the literature deal with            (Table 1). Sand was added at a controlled flow rate to a
                                                                                                       hydraulic fill from a geotechnical perspective. The objectives              water flow just before being fed to the flume. Turbulence
                                                                                                       of these tests are, in general, the determination of the beach              ensured the formation of a uniform slurry. The flume was
                                                                                                       slopes and (or) the study of physico-mechanical character-                  provided with piezometers installed along its bottom and
                                                                                                       istics of the deposited material. Flume tests for hydraulic-                sides. The bottom of the flume had a drainage system with
                                                                                                       fill studies obviously have to involve an excess sediment                   valves that allowed drainage of the fill at a rate of 4 cm/h
                                                                                                       being deposited and therefore an aggrading bed. The main                    after the deposition stopped. The slurry was discharged from
                                                                                                                                                                                   a vertical pipe with a series of outlets installed at different
                                                                                                         'present address: HBT AGRA Ltd., 4810-93 Street, Edmonton,                heights. Each outlet was a short piece of pipe pointing
                                                                                                       Alta., Canada T6E 5M4.                                                      upwards (possibly to minimize the flow velocity) and
                                                                                                       Printed in Canada / lrnprirnc au Canada
ET AL.: I1                                                    419

                                                                                                       plugged. As the fill rose, the outlets were successively            disturbed the flow in the flume. After the deposition was
                                                                                                       o~ened.                                                             completed, the deposit was partially drained and Shelby tube
                                                                                                          Three tests were carried out, with slurry concentration          samples were taken at designated distances along the length
                                                                                                       around 10% by weight and specific flow rates (flow rate             of the deposited tailings. The samples were used to deter-
                                                                                                       divided by flume width) varying from 3.3 to 13 cm3/(s ecm).         mine shear strength, permeability, and grain-size distribution.
                                                                                                       The formation of meanders is reported in some cases. Mea-           The average beach slope was also measured for each test.
                                                                                                       surements during the tests included concentration of the
                                                                                                       slurry being discharged and concentration and composition           Delft, The Netherlands (DS, DLI, and DL2)
                                                                                                       of the outflow. After the tests, the final sand profile was            Flume tests were carried out in Delft, The Netherlands,
                                                                                                       recorded and undisturbed samples were taken for determina-          as part of experimental and theoretical studies related to the
                                                                                                                                                                           Deltaworks in the southwestern part of the country, where
                                                                                                       tion of density and grain-size distribution of the sand along
                                                                                                                                                                           various sea arms were closed using hydraulic-fill techniques
                                                                                                       the flume at two depths. Horizontal and vertical undisturbed
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                                                                                                       samples were used to determine permeability, compressibility,       (de Groot et a/. 1988; Winterwerp et al. 1990).
                                                                                                       and shear strength on directions parallel and perpendicular            Two flumes of different sizes were used to deposit three
                                                                                                       to the stratification. The sand deposited in the flume had          gradations of fine to medium sand (Table 1). Slurry concen-
                                                                                                       a relative density in the range of 50-65% and some                  trations between 32 and 68% and flow rates varying from
                                                                                                       anisotropy of the permeability, with Kh/Kv varying                  7 to 35 L/min were utilized for the tests on the small flume
                                                                                                       between 1 and 10. Remolded samples showed lower perme-              (DS). The large-scale flume tests (DL1 and DL2) covered
                                                                                                       ability and less compressibility than the undisturbed flume         a wide range of slurry concentrations (0-64%) and used very
                                                                                                       samples. Shear strength was similar for samples from all            large flow rates (180-2700 L/min), which is out of the range
                                                                                                                                                                           of the values used in other flume tests presented in the
                                                                                                       three tests.
                                                                                                                                                                           literature.
                                                                                                       Lakefield (LK)                                                         The equilibrium slope was defined in these studies as the
                                                                                                          Lakefield Research performed flume tests in 1983 to              slope at which sedimentation and erosion are in balance.
                                                                                                       obtain slope data for the design of East Kemptville tailings        It was determined by decreasing the slope of the tilting flume
                                                                                                       dams in Nova Scotia, Canada (P.C. Lighthall, personal               in small steps of about 0.001 rad until sand bars started
                                                                                                       communication, 1987). A series of tests was conducted with          growing on the bottom of the flume. The previous slope was
                                                                                                       varying flume slopes and slurry concentration. However, the         then defined as the equilibrium slope. Therefore these tests
                                      For personal use only.

                                                                                                       only data available are the grain-size distribution curve of        differ from the others presented in the literature by the fact
                                                                                                       the coarse tailings used for the tests and the profiles of two      that no material was deposited in the flume. It is of relevance
                                                                                                       tests using slurry concentrations of 20 and 45%. The flow           to note that the flumes had sand grains glued to the bottom;
                                                                                                       rate is not known, and there is no information about the            however, for the large-scale tests (DL1 and DL2) the sand
                                                                                                       test procedure, except that there was no water ponding at           glued on the bottom was much coarser than the sand being
                                                                                                       the slope toe. The slopes obtained were reported to be much         tested.
                                                                                                       steeper than the field slopes of the same material.                    Sand concentration, flow rate, slope, flow depth, and
                                                                                                                                                                           slurry temperature were measured in the small-scale flume
                                                                                                       South Africa (B)                                                    tests. In the larger scale tests the following parameters were
                                                                                                          The flume tests conducted by Blight et al. (1985) in South       determined: flow rate, temperature, concentration, slope,
                                                                                                       Africa had the objective of studying tailings beach profiles        flow depth, flow velocity, and sand concentration profiles
                                                                                                       based on the concept of master profile proposed by Melent'ev        at various locations. These tests did not deal with the geo-
                                                                                                       et al. (1973) in which a normalized profile exists independent      technical characteristics of hydraulically deposited materials,
                                                                                                       of the test scale. Three different gradations of silty tailings     but they involved sophisticated hydraulic measurements.
                                                                                                       were deposited at three different slurry concentrations each        More details on these tests can also be found in Mastbergen
                                                                                                       (50, 60, and 70% by weight) in a small flume (Table 1). The         et al. (1988) and Bezuijen and Mastbergen (1988).
                                                                                                       feeding system consisted of a 220-L drum with a bottom
                                                                                                       discharge, but no details are provided on how the slurry was         University of Queenslund, Australia (FB, FN, FFC, and
                                                                                                       kept homogeneous in the drum during the test, nor on the
                                                                                                                                                                                 FCC)
                                                                                                                                                                               The flume tests reported by Fourie (1988) were carried
                                                                                                       testing procedure or flow rates. The only data reported are
                                                                                                       the final normalized profile for each test.                          out using a slurry tank adapted with an electrical agitator
                                                                                                                                                                            to feed a small flume. The discharge device consisted of a
                                                                                                       United States Bureau of Mines (USA and USB)                          horizontal pipe to spread the flow across the flume and an
                                                                                                          Flume tests were also performed at the United States              energy dissipator to minimize the formation of a plunge pool
                                                                                                       Bureau of Mines (USBM) Research Centre in Spokane,                   at the discharge point. A very small flow rate was adopted
                                                                                                       Washington (Boldt 1988). Tailings obtained from two mine             for all tests (Table 1). Three types of tailings were tested:
                                                                                                       sites were deposited in a wooden sloping flume (Table 1).            bauxite from North Queensland (FB), nickel ore slurry from
                                                                                                       Tailings A consisted of a fine mill waste from a copper-             New Caledonia (FN), and two gradations of coal tailings
                                                                                                       silver mine with an average diameter of 0.0135 mm. Tail-             from southeast Queensland, a fine (FFC) and a coarse
                                                                                                       ings B was a slightly coarser tailings (&     = 0.097 mm)            (FCC). These tests will not be compared with the others as
                                                                                                       from a silver-lead-zinc mine. The bulk tailings were diluted         most of them deposited a nonsegregating slurry, thus having
                                                                                                       with water in a 6400-L mixing tank to form the slurry. The           a distinct rheology. In nonsegregating slurries the solids and
                                                                                                       slurry was then pumped into the flume at controlled flow             the carrier fluid do not behave independently but act as a
                                                                                                       rates and concentrations, varying from 58 to 130 L/min and           viscous fluid. Therefore the physical phenomena involved
                                                                                                       from 20 to 57%, respectively. Boldt (1988) reports accen-            are distinct from the cases of segregating slurries, which were
                                                                                                       tuated wall effects with the formation of side eddies that           used in the other experimental programs.
420                                              CAN. GEOTECH. J. VOL 29, 1992

                                                                                                                                                                                        TABLE1. summary of flume tests for hydraulic

                                                                                                                                                       Test   No.    Flume length, Flume width,             Flume depth,     Feeding
                                                                                                                                Ref.                   code of tests     l(m)         w (m)          I/ w      d(m)          system

                                                                                                       Ferreira et al. (1980)                          UPP        3        11.O          0.8          14      >0.8         Independent

                                                                                                       P.C. Lighthall, personal communication (1987)    LK      >2        >1.5           NA"         NA       >0.15            NA

                                                                                                       Blight et al. (1985)                               B     >9          1.8          0.3           6        0.6        220-L drum
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                                                                                                       Boldt (1988)                                    USA       12        12.2          0.6         20         0.6        Mixing tank
                                                                                                                                                       USB

                                                                                                       de Groot et a/. (1988)                           DS     >50          1.5          0.118        13        0.045      Mixing tank

                                                                                                       Winterwerp et al. (1990)                        DL1     >20          9.0          0.3          30        0.3        Recirculation
                                                                                                                                                       DL2

                                                                                                       Fourie (1988)                                    FB        2           2          0.6           3        0.6        Mixing tank
                                                                                                                                                        FN        2
                                                                                                                                                       FFC        4
                                                                                                                                                       FCC        1

                                                                                                       Fan (1989)                                         F       8         4.9          0.3          16        0.5        Independent
                                      For personal use only.

                                                                                                       Kiipper (199 1)                                  SS        5         6.1          0.3         20         1.2        Independent
                                                                                                                                                        TS       37
                                                                                                                                                        KS       19
                                                                                                        NOTE: The b in DSPbstands for bottom.
                                                                                                        ONA, data not available.
                                                                                                       University of Alberta, Department of Chemical Engineering        weight and the flow rate from 50 to 350 cm3/s (3-20 L/min)
                                                                                                            (F)                                                         (see Table 1). Each test was performed on a bed of sand
                                                                                                         The objectives of the flume tests carried out by Fan (1989)    to allow a certain degree of underdrainage and was carried
                                                                                                       were to study the variation of beach profile with time and       out for long enough to develop an equilibrium slope. The
                                                                                                       distance and the effects of slurry concentration and discharge   data obtained during each test consisted of the input param-
                                                                                                       on these profiles.                                               eters, beach profiles at various time intervals during the test,
                                                                                                         These tests were performed using an experimental proce-        and flow description. Remolded and undisturbed samples
                                                                                                       dure common to flume tests for hydraulic or sedimentology        were taken at various locations along the flume for grain-
                                                                                                       studies, where sand is fed independently to a flume where        size distribution analysis, density measurement (Kupper
                                                                                                       a flow of water is already established. However, a very          1991; Kupper et al. 1992), fabric analysis (Kupper 1991; Law
                                                                                                       shallow flow depth was adopted, as occurs in hydraulic fills.    1991), and triaxial tests (Law 1991).
                                                                                                       These tests covered a relatively narrow range of low con-
                                                                                                       centrations and low flow rates. The data produced consisted                          Comparison of results
                                                                                                       of sand profiles at four different times during the tests,          The various flume tests described in the previous section
                                                                                                       which had a duration of 20 min each. The flume dimensions        had the general objective of studying hydraulic fill, however,
                                                                                                       and the sand and flow characteristics utilized are presented     the specific objectives were slightly different in each case.
                                                                                                       in Table 1.                                                      As a result, the variables that were studied and the param-
                                                                                                                                                                        eters that were measured were not necessarily the same for
                                                                                                       University of Alberta, Department of Civil Engineering           all test programs. Moreover, there were differences in exper-
                                                                                                            (SS, TS, and KS)                                            imental procedure, some of which may have influenced the
                                                                                                          Three different sands were tested by Kiipper (1991) to        results obtained. In particular, the experiments carried out
                                                                                                       study the influence of flow rate, slurry concentration, and      by the Delft group (de Groot et al. 1988; Winterwerp et al.
                                                                                                       grain-size distribution on the properties of hydraulic fills.    1990) and by Fan (1989) must be singled out for using very
                                                                                                       These tests used a feeding system where water and sand were      distinct techniques, as described here.
                                                                                                       fed independently in a chute and formed the slurry on the           (1) An equilibrium slope, defined as the slope at which
                                                                                                       way to the flume. The discharge device consisted of a flow       no deposition or erosion occurs, was adopted for the tests
                                                                                                       spreader capable of distributing the flow uniformly across       performed in Delft, since this slope is considered to be
                                                                                                       the flume. An automatic system was designed to keep the          similar to the field slopes (Winterwerp et al. 1990). Conse-
                                                                                                       flow spreader at a constant height from the rising fill. The     quently, no material is deposited in the flume and no data
                                                                                                       slurry concentration was varied between 1.5 and 40.5% by         are available on fill properties. Also, the slurry flows on the
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                                      For personal use only.
CAN. GEOTECH. J. VOL. 29, 1992

                                                                                                                                                                                                             + USB
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                                                                                                                                               0.01                     0.1
                                                                                                                                                                  Grain size (mrn)
                                                                                                                     FIG. 1. Grain-size distribution curves of materials used in various flume-test programs (see Table 1).
                                      For personal use only.

                                                                                                                                                0.01                      0.1
                                                                                                                                                                   Grain size (mm)
                                                                                                       FIG. 2. Grain-size distribution curves of materials used in various flume tests compared with Soviet criteria. Legend as in Fig. 1.

                                                                                                          When comparing tests carried out using different mate-           divided by the distance from the point of maximum height
                                                                                                       rials, it is important to note that grain shape, angularity,        to the end of the beach and expressed as a percentage. Slurry
                                                                                                       and surface features may affect the results and may be              concentration is defined as the weight of solids in the slurry
                                                                                                       responsible for some apparent scatter of the data.                  divided by the total weight.
                                                                                                                                                                              The effect of the mean grain size and the slurry concentra-
                                                                                                       Geometry                                                            tion on the average slope of the fill is shown in Fig. 6. This
                                                                                                          All flume tests that utilized segregating slurries, and for      graph compares results of tests described in Kiipper (1991)
                                                                                                       which profiles were reported, formed fills with a similar con-      and Kiipper et al. (1992) on TS tailings sand with the results
                                                                                                       cave shape as shown in Figs. 3-5. The influence of the input        from Fan (1989) on a commercial sand. All of these tests
                                                                                                       parameters (such as particle size, slurry concentration, and        were carried out using the same flow rate (Q = 250 cm3/s)
                                                                                                       flow rate) on the fill geometry is evident in these figures.        and the same specific flow rate ( q = 8 cm3/(s-cm)) and
                                                                                                          In many cases only overall slopes were presented rather          show that the average slope increases with the mean grain
                                                                                                       than actual profiles. The overall slope is (or is assumed to        size and with slurry concentration.
                                                                                                       be) defined as the maximum height (at the discharge point)             Figure 7 presents the variation of average slope with con-
KUPPER ET AL.: I1
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                                                                                                                                                  0.5
                                                                                                                                                        0                                    2                          4             6             8                 10
                                                                                                                                                                                                            Distance from discharge point (m)
                                                                                                                                          Fro. 3. Profiles of TS, UPP, and F tests for C , = 10% and various specific flow rates.

                                                                                                             1.1

                                                                                                       --
                                                                                                        E
                                                                                                             1 .o
                                                                                                                                                        ........
                                                                                                                                                        aa.nn..a        KS13 - qz4.7 cm3/(s.cm)(DSo=0.466mm)
                                                                                                       +     0.9
                                                                                                        M
                                                                                                       .-
                                                                                                       2              -                                            ..
                                      For personal use only.

                                                                                                             0.8

                                                                                                       2%    0.7      1
                                                                                                                                                                               ......*-..-
                                                                                                                                                                                             -.-..-....... '.."

                                                                                                             0.6      r                                                              .... ........
                                                                                                                                                                                              -'8

                                                                                                                                                                                                          'l.*l,l.,                   0
                                                                                                                                                                                                                                          0          5               10                 15    20
                                                                                                                                                                                                                                                          Slurry Concenwation C, (%)
                                                                                                             0.5          " " " ' " ' " " " " ' " " '
                                                                                                                    0                 1             2                          3                           4                5
                                                                                                                                          Distance from the discharge point (m)
                                                                                                                                                                                                                                  FIG.6. Effect of grain size and concentration on the slope.

                                                                                                            FIG.4. Profiles of TS, KS, and LK tests for C, = 20%.

                                                                                                                                                                                                                                          "
                                                                                                                                                                                                                                              0      20              40                 60    80
                                                                                                                                                                                                                                                          Slurry concentration C, (%)
                                                                                                            0.7                                                                                                                   FIG.7 . Variation of slope with C , for various flume tests (see
                                                                                                                  0               1                 2                          3                           4                5
                                                                                                                                           Distance from discharge point (m)                                                    Table 1).
                                                                                                         FIG. 5. Comparison of profiles of TS (D,, = 0.178 mm) and
                                                                                                       F (D,, = 0.267 mm) tests.
                                                                                                                                                                                                                                 use of materials containing a high percentage of fines (90
                                                                                                                                                                                                                                 and 45% finer than 74 pm, respectively). Limiting this anal-
                                                                                                       centration of the slurry being deposited in various flume                                                                 ysis to sandy fills deposited at flow rates under 2500 cm3/s
                                                                                                       tests. The relatively large scatter in this graph is partially                                                            and specific flow rates less than 40 cm3/(s.cm) to better
                                                                                                       due to the inclusion of points corresponding to a wide range                                                              isolate the effect of the slurry concentration, a much smaller
                                                                                                       of grain sizes and flow rates. The flat slopes of the large-                                                              scatter is observed (Fig. 8), and the increase in average slope
                                                                                                       scale flume tests performed in Delft (DL1 and DL2) can be                                                                 with concentration becomes more evident. The shaded zone
                                                                                                       explained as being caused by the much higher flow rates                                                                   in Fig. 8 includes more than 90% of the experimental points.
                                                                                                       utilized in this case compared with the remainder of the                                                                     An increase in flow rate or specific flow rate causes the
                                                                                                       flume tests. The flat slopes obtained in the tests carried out                                                            slopes to become flatter, and this tendency is shown in
                                                                                                       by Boldt (1988) (USA and USB) can be attributed to the                                                                    Figs. 9 and 10. The small-scale tests carried out in Delft (DS)
CAN. GEOTECH. J. VOL. 29, 1992

                                                                                                            0                                                                               0
                                                                                                                0         20                 40              60            80                   0     50                100              150   200
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                                                                                                                               Sluny concentcation C , (%)                                                  Total flow rate Qt (Urnin)
                                                                                                         FIG. 8. Variation of slope with C, for sandy fills with Q <                 FIG. 9. Variation of slope with flow rate for various flume
                                                                                                       2500 cm3/s.                                                                 tests.
                                      For personal use only.

                                                                                                                                         0
                                                                                                                                             0               10              20                 30         40               50
                                                                                                                                                             Specific flow rate q (cm3/(s. cm))
                                                                                                                                    FIG. 10. Variation of slope with specific flow rate for various flume tests.

                                                                                                       yielded more scattered results featuring relatively steep slopes            adopted for UPP tests in relation to the values used for SS,
                                                                                                       for the correspondent values of flow rate and, especially,                  TS, and KS tests.
                                                                                                       specific flow rate. The results of the companion large-scale                   Results from SS, TS, KS, and UPP tests show the same
                                                                                                       flume tests are not presented, as the much larger flow rates                trend of variation of density with flow rate and slurry con-
                                                                                                       utilized in these tests would have obscured the other results.              centration: density decreases as slurry concentration increases,
                                                                                                       Density                                                                     and density tends to increase as specific or total flow rates
                                                                                                          The only values of density of flume-deposited materials                  increase. This is consistent with the trends reported by Yufin
                                                                                                       which were found in the literature were the results presented               (1965).
                                                                                                       by Ferreira et al. (1980) and Kiipper (1991) (see Table 1).
                                                                                                       Figures 11 and 12 compare the results measured for UPP                                        Summary and conclusions
                                                                                                       (Ferreira et al. 1980) with those obtained for the SS, TS,                     Several flume tests carried out in different parts of the
                                                                                                       and KS series (Kiipper 1991). The scatter of the data is par-               world to study hydraulic fills were compared in this paper.
                                                                                                       tially because the plot of density versus slurry concentration              These tests were performed using slightly different testing
                                                                                                       includes tests using a range of flow rates, and similarly the               procedures and covered a wide range of values of slurry con-
                                                                                                       points in Fig. 12 correspond to different slurry concentra-                 centration and flow rate. Most of the tests deposited sand,
                                                                                                       tions. Also, other factors associated with the data scatter                 but some of them involved very fine tailings materials.
                                                                                                       include difficulties in obtaining accurate density measure-                    The results of all test programs show a consistent trend
                                                                                                       ment of undisturbed samples of relatively clean sands, varia-               of fill slopes becoming steeper as the flow rate decreases and
                                                                                                       tions in grain-size distribution curves, and effects of grain               as the slurry concentration and the mean grain size increase.
                                                                                                       shape, angularity, and surface features.                                    Although more limited, the density data point to an increase
                                                                                                          Compared with SS, TS, and KS values, the densities of                    in fill density as the flow rate increases and a decrease in
                                                                                                       LTPP tests seem a little high for a material with a lower D50.              density for higher values of slurry concentration.
                                                                                                       This fact could have been caused by several factors including                  Generally, these conclusions are consistent with observa-
                                                                                                       (i) a difference in mineralogy and (or) grain shape among                   tions of hydraulic fills and natural alluvial deposits which
                                                                                                       the materials; (ii) the higher coefficient of uniformity (Cu)               suggest that, at least qualitatively, flume tests are adequate
                                                                                                       of UPP material compared with TS and KS sands (voids                        to simulate the physical phenomena associated with hydraulic
                                                                                                       can be better filled); and (iii) the lower discharge velocities             deposition in the field.
KUPPER ET AL.: 11                                                         425
                                                                                                                  1.7                                                                                                      Boldt, C.M.K. 1988. Beach chara'cteristics of mine waste tailings.
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                                                                                                                                                        Sluny concentration (%)                                              pp. 496-516. (In Portuguese.)
                                                                                                                                                                                                                           Fourie, A. 1988. Beaching and permeability properties of tailings.
                                                                                                          FIG. 11. Variation of density of the fill with C, for various                                                      Hydraulic Fill structures, ASCE ceotechnical special publics-
                                                                                                       flume tests.                                                                                                          tion 21. Edited by D.J.A. Van Zyl and S.G. Vick. American
                                                                                                                                                                                                                             Society of Civil Engineers, New York, pp. 142-154.
                                                                                                                  1.7                                                                                                      Garde, R.J., Ranga Raju, K.G., and Mehta, P.J. 1981. Bed level
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                                                                                                                                                                                                                             February 2-7, vol. 2, pp. 247-253.
                                                                                                                            i       "5- g o                                                                                Kupper, A.A.G. 1991. Design of hydraulic fill. Ph.D. thesis,
                                                                                                             .?   1.5
                                                                                                                                            o           .                 8                  e
                                                                                                                                                                                                                             Department of Civil Engineering, University of Alberta,
                                                                                                                                                                                                                             Edmonton, Alta.
                                                                                                                                                                  I
                                                                                                             E ; :
                                                                                                             8 1.4 :
                                                                                                                                    *       L                                              o K S ( D ~ ~ = O W I W-
                                                                                                                                                                                           *TS(D~sa=0.178mm)
                                                                                                                                                                                                                  ~)
                                                                                                                                                                                                                           Kupper, A.A.G., Morgenstern, N.R., and Sego, D.C. 1992. Lab-
                                                                                                                                                                                                                              oratory tests to study hydraulic fill. Canadian Geotechnical Jour-
                                                                                                                                            8                                                                                 nal, 29. This issue.
                                                                                                                                                                                           + SS(Dso=O536mm)
                                                                                                                                    a                                                        UPP(D~=O.~~~)                 Law, D.J. 1991. The effect of fabric on the behaviour of a tail-
                                                                                                                  1.3           '       '       '   '                                  I     .       .   .   .                ings sand. M.Sc. thesis, Department of Civil Engineering, Uni-
                                      For personal use only.

                                                                                                                        o                                5                         10                              15         versity of Alberta, Edmonton, Alta.
                                                                                                                                                    Specificflow rate q (cm3/(s .cm))                                      Mastbergen, D.R., Winterwerp J.C., and Bezuijen, A. 1988. On
                                                                                                         FIG, 12. variation of density of the fill with specific flow rate                                                    the construction of sand fill dams. Part 1: Hydraulic aspects.
                                                                                                       for various flume tests.                                                                                               In Modelling Soil-Water-Structures Interactions, Edited by
                                                                                                                                                                                                                              P.A. Kolkman, J . Lindenberg, and K.W. Pilarczyk.
                                                                                                                                                                                                                              A.A. Balkema, Rotterdam, pp. 353-362.
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                                                                                                                                                                                                                           SN~P-11-53-73 1974. Standard specifications for construction.
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                                                                                                                                                                                                                              Chap. 2. Gosstroi Stroiizdat, Moscow. (In Russian.)
                                                                                                       Research          Of Canada Operating    grants and from an                                                         Soni, J.P. 1981. Laboratory study of aggradation in alluvial chan-
                                                                                                       ESSO university research grant are gratefully acknowledged.                                                            nels. Journal of Hydrology, 49: 87-106.
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