Till behavior and its relationship to active-layer hydrology, District of Keewatin, Northwest Territories

1988 ◽  
Vol 25 (1) ◽  
pp. 167-172 ◽  
Author(s):  
Larry Dyke ◽  
Paul Egginton

Well-graded tills are a common surficial material over much of the Canadian Arctic from northern Manitoba to Somerset Island. The compactibility and bearing strength of these tills when thawed appear to be controlled by groundwater flow in the active layer. Water seeping from bedrock outcrops flanked by till enters the till active layer and flows via macropores formed as ice lenses thaw. This flow appears to retard consolidation of the till. Slopes having no seepage source consolidate more rapidly. This seepage maintains the till in a state highly susceptible to liquefaction and would yield material with a moisture–density condition unsuitable for construction use. Key words: till, surficial, compactibility, bearing capacity, groundwater, seepage, freeze–thaw, liquefaction.

2018 ◽  
Vol 10 (2) ◽  
pp. 276-284 ◽  
Author(s):  
Gang Chen ◽  
Shiguang Xu ◽  
Chunxue Liu ◽  
Lei Lu ◽  
Liang Guo

Abstract Mine water inrush is one of the important factors threatening safe production in mines. The accurate understanding of the mine groundwater flow field can effectively reduce the hazards of mine water inrush. Numerical simulation is an important method to study the groundwater flow field. This paper numerically simulates the groundwater seepage field in the GaoSong ore field. In order to ensure the accuracy of the numerical model, the research team completed 3,724 field fissure measurements in the study area. The fracture measurement results were analyzed using the GEOFRAC method and the whole-area fracture network data were generated. On this basis, the rock mass permeability coefficient tensor of the aquifer in the study area was calculated. The tensor calculation results are used in the numerical model of groundwater flow. After calculation, the obtained numerical model can better represent the groundwater seepage field in the study area. In addition, we designed three different numerical models for calculation, mainly to explore the influence of the tensor assignment of permeability coefficient on the calculation results of water yield of the mine. The results showed that irrational fathom tensor assignment would cause a significant deviation in calculation results.


2018 ◽  
Vol 114 ◽  
pp. 196-218 ◽  
Author(s):  
Christophe Grenier ◽  
Hauke Anbergen ◽  
Victor Bense ◽  
Quentin Chanzy ◽  
Ethan Coon ◽  
...  

1977 ◽  
Vol 34 (12) ◽  
pp. 2369-2373 ◽  
Author(s):  
Doris Fraser Hiltz ◽  
D. H. North ◽  
Barbara Smith Lall ◽  
R. A. Keith

Refrozen silver hake (Merluccius bilinearis), processed as fillets and minced flesh after thawing of stored round fish that had been frozen within 14 h of capture, underwent rapid deterioration during storage at −18 °C compared with once-frozen control materials from the same lot of fish. The estimated maximum storage life of silver hake refrozen as fillets after 3 and 6 mo storage of the round fish at −25 °C was reduced to about 4.5 and 1 mo, respectively, from 10 mo for once-frozen control fillets. Quality of the refrozen materials immediately after thawing and refreezing was similar to that of the round-frozen fish, except after 6 mo, where some initial deterioration occurred, particularly in minced flesh. Minced flesh was more unstable in frozen storage than fillets. In all once- and twice-frozen materials, formation of dimethylamine occurred concomitantly with decrease in protein extractability. Round-frozen fish underwent no loss in protein extractability during 6 mo storage at −25 °C, but some lipid hydrolysis occurred. These results suggest that the freeze–thaw–refreeze process as applied to silver hake will yield a final product of acceptable quality provided that storage of the round fish does not exceed 3–4 mo and that the refrozen materials are marketed within a month after processing. Key words: silver hake, Merluccius bilinearis, refrozen storage, dimethylamine, minced flesh


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Guozhu Zhang ◽  
Ziming Cao ◽  
Xu Zhao ◽  
Yongli Xie ◽  
Xiaohua Liu ◽  
...  

The insulation layer is usually installed in the tunnel structure, whereas the influence of the insulation layer on the thermal behavior of energy tunnel ground heat exchangers (GHEs) is rarely investigated. The model tests were performed in this study to evaluate the heat transfer potential of the energy tunnel with the insulation layer under ventilation and groundwater seepage. The results can be obtained as follows: first, the fluctuations of air temperature and surrounding rock temperature at different locations are relevant to insulation layer, ventilation, and groundwater seepage. Second, the reduction effect of ventilation on the interface temperature of tunnel lining and surrounding rock is alleviated when using an insulation layer, and the interface temperature at upstream section of groundwater seepage is more easily affected by the energy tunnel GHEs. Third, the variation range of ground temperature is wider at the downstream section of groundwater flow. Moreover, the heat exchange rates of tunnel without the insulation layer improve by 5.82% and 6.45% with increasing wind speed at two groundwater flow velocities of 1 × 10 − 4 and 5 × 10 − 4  m/s, and there are only 2.03% and 0.77% enhancements of heat exchange rates by ventilation for the tunnel with the insulation layer. However, the thermal performance of the energy tunnel improved by groundwater is less relevant to the existence of the insulation layer. The relevant findings can provide an effective guidance for the following research and design of the energy tunnel.


2021 ◽  
Vol 47 (1) ◽  
pp. 164-173
Author(s):  
Mohammad Mehdi Khabiri ◽  
Bahareh Ebrahimialavijeh

Improving the subgrade performance and increasing their efficiency can lead to improving the operation and increasing the life of the pavement. One of the common solutions to improve the resistance and engineering properties of the soils is using the stabilizing materials. Using the waste materials as a stabilizer in the soil can lead to a reduction in project costs and help the protection from the environment. In this study, emulsion bitumen and crushed waste tile are used to stabilize the sand dune which is soil with low bearing capacity and resistance properties. In the present study, the emulsion bitumen and crushed waste tile have been used. The effect of dimensions and percentage of crushed tile with different percentages of emulsion bitumen on the compressive pressure and bearing capacity as well as the compressive strength after applying freeze-thaw cycle. The results indicate that the addition of crushed waste tile increases the compression strength and bearing capacity and the tile with a higher dimension has shown more effectiveness. Applying the freeze-thaw cycle has reduced the compression strength and increasing the number of cycles has increased the resistance drop rate. Soil stabilized with coarse-grained tile has more resistance drop rate which increases by increasing the tile percentage. Then, the 3D graph and the recommended function related to each parameter investigated in the test were provided using the response surface analysis method.


1995 ◽  
Vol 32 (6) ◽  
pp. 957-975 ◽  
Author(s):  
L.D. McKay ◽  
J. Fredericia

In the unconsolidated clay-rich glacial deposits underlying a site in southwestern Ontario, fractures and root casts greatly influence hydraulic conductivity and groundwater flow. The fractures are predominantly vertical and have visible oxidation staining from surface to a depth of 6 m. Root casts commonly occur along fracture surfaces in the upper 3 m, but can also occur as holes in apparently unfractured blocks. The fractures are believed caused mainly by dessication during past periods of low water table. This hypothesis is supported by a decrease in fracture density with depth and the presence of a stiff crust, presumably caused by desiccation-induced consolidation. The random pebble fabric and faint layering indicate deposition in a calm lacustrine environment, which precludes the possibility of the fractures having been caused by overriding ice. Fractures were found below the depth of oxidation staining (6 m) but most of these appear to have been caused by stress-relief due to the excavation and subsequent drying. In the upper 3 m the fractures and root casts are responsible for field-measured hydraulic conductivity values that are up to 3 orders of magnitude greater than measured in the laboratory for samples of the unfractured matrix. High values of field-measured hydraulic conductivity, seasonal head variations greater than 0.5 m, and high tritium content all persist below the depth of root casts, indicating that hydraulically conductive fractures do exist to depths of at least 6 m and possibly as great as 12–15 m, which is well below the depth of oxidation staining. However, there is some uncertainty in this assessment of the extent of hydraulically conductive fractures because of the sensitivity to small leaks in the piezometer installations. Key words : clay, glacial, fractures, desiccation, hydraulic conductivity.


2016 ◽  
Vol 143 ◽  
pp. 828-835 ◽  
Author(s):  
Shinichiro Kawabata ◽  
Tatsuya Ishikawa ◽  
Shuichi Kameyama

1993 ◽  
Vol 30 (3) ◽  
pp. 545-549 ◽  
Author(s):  
M.T. Omar ◽  
B.M. Das ◽  
V.K. Puri ◽  
S.C. Yen

Laboratory model test results for the ultimate bearing capacity of strip and square foundations supported by sand reinforced with geogrid layers have been presented. Based on the model test results, the critical depth of reinforcement and the dimensions of the geogrid layers for mobilizing the maximum bearing-capacity ratio have been determined and compared. Key words : bearing capacity, geogrid, model test, reinforced sand, shallow foundation.


2016 ◽  
Vol 43 (3) ◽  
pp. 380-392 ◽  
Author(s):  
SUSAN HENDRICKS ◽  
ROBERT VANDE KOPPLE ◽  
PETER GOODSPEED ◽  
DAVID WHITE

ABSTRACT Sandy-gravelly deposits are highly permeable and allow groundwater to seep from one lake to another in glacial lake districts such as occur throughout much of Michigan. The springs that form the headwaters of Carp Creek were assumed to have their origins as groundwater seepage from Douglas Lake. A tracer test using a concentrated fluorescein dye solution was conducted during the summer of 2011 to confirm the velocity of groundwater flow from Douglas Lake to a series of springs in Carp Creek. Five springs were monitored from 28 June to 21 September 2011. Dilution of the dye by groundwater was nine orders of magnitude (g−L to ng−L) by the time it reached the springs. The fastest travel times of the dye were ≤ 10 days to all except one spring giving an average observed linear velocity of approximately 100 m d−1 to travel an average distance of 1036 m. Dye was not detectable in the springs after 19 August (day 53 of the experiment). Observed seepage velocities were faster than those predicted from Darcy's Law using hydraulic conductivities for gravel and sand. Douglas Lake and Carp Creek are connected hydrologically through the sand-gravel aquifer and much of the groundwater seepage most likely originates in the deep hole in South Fishtail Bay. This study contributes to our understanding of subsurface connectivity and drainage patterns between glacial lakes of northern Lower Michigan.


Sign in / Sign up

Export Citation Format

Share Document