FLOW IN FRACTURED BEDROCK CRACK NETWORK AND ITS ROLE IN PLUCKING

2017 ◽  
Author(s):  
Kameko R Landry ◽  
◽  
David Jorgensen Harbor
Keyword(s):  
Crack Network ◽  
Fractured Bedrock

CHARACTERIZATION OF INDIGENOUS BACTERIA AS A GROUNDWATER TRACER IN FRACTURED BEDROCK

2018 ◽  
Author(s):  
Ryan Ordung ◽  
◽  
Gary A. Robbins ◽  
Kendra Maas ◽  
Mark Higgins
Keyword(s):  
Indigenous Bacteria ◽  
Fractured Bedrock

scholarly journals Three-dimensional hydrostratigraphy and groundwater flow models in complex Quaternary deposits and weathered/fractured bedrock: evaluating increasing model complexity

2021 ◽  
Author(s):  
Susanne Charlotta Åberg ◽  
Annika Katarina Åberg ◽  
Kirsti Korkka-Niemi
Keyword(s):  
Groundwater Flow ◽  
Three Dimensional ◽  
Model Complexity ◽  
Quaternary Sediments ◽  
Fractured Bedrock ◽  
Flow Models ◽  
Flow Modelling ◽  
Crystalline Bedrock ◽  
Discharge Patterns ◽  
Geological Units

AbstractGreater complexity in three-dimensional (3D) model structures yields more plausible groundwater recharge/discharge patterns, especially in groundwater/surface-water interactions. The construction of a 3D hydrostratigraphic model prior to flow modelling is beneficial when the hydraulic conductivity of geological units varies considerably. A workflow for 3D hydrostratigraphic modelling with Leapfrog Geo and flow modelling with MODFLOW-NWT was developed. It was used to evaluate how the modelling results for groundwater flow and recharge/discharge patterns differ when using simple or more complex hydrostratigraphic models. The workflow was applied to a study site consisting of complex Quaternary sediments underlain by fractured and weathered crystalline bedrock. Increasing the hydrostratigraphic detail appeared to improve the fit between the observed and simulated water table, and created more plausible groundwater flow patterns. Interlayered zones of low and high conductivity disperse the recharge/discharge patterns, increasing the vertical flow component. Groundwater flow was predominantly horizontal in models in which Quaternary sediments and bedrock were simplified as one layer per unit. It appears to be important to define the interlayered low-conductivity units, which can limit groundwater infiltration and also affect groundwater discharge patterns. Explicit modelling with Leapfrog Geo was found to be effective but time-consuming in the generation of scattered and thin-layered strata.

High-Efficiency Cut Blasting with Shell Radial Shaped Charge in Laboratory-Scale Blasting

2015 ◽  
Vol 1094 ◽  
pp. 445-450 ◽  
Author(s):  
Wei Chen ◽  
Hong Hao Ma ◽  
Zhao Wu Shen ◽  
De Bao Wang
Keyword(s):  
High Efficiency ◽  
Circular Tube ◽  
Rock Breaking ◽  
Shaped Charge ◽  
Axial Line ◽  
Rock Excavation ◽  
Crack Network ◽  
Utilization Ratio ◽  
The Cost ◽  
The Ideal

Due to the inefficiency problem of the cut blasting in rock excavation and rock breaking, a shell radial shaped charge device was proposed based of the ideal of ‘cutting to slotting’ and it was validated through experiments. For this device, the shell materials are used to be shaped materials and multiple shaped ring is designed on the circular tube. It can not only reduce charge quantity but also raise the utilization ratio of explosive energy. After explosion, multiple radial shaped charge jets can be formed along the axial line in sequence and then the surrounding rock mass would be cracked. The crack network will be formed along with the further extension of the fraction under the action of quasi static loading of detonation gas. The shell radial shaped charge device was tested through the cut blasting model experiment. Experimental results show that the utilization ratio of blasting hole nearly approaches 98% with this device. The blasting efficiency and cyclical footage can be improved effectively and the cost of drifting can also be reduced.

Calibration and Validation of an Elasto-Viscoplastic Material Model for a Hot Work Tool Steel Used in Pressure Casting Dies

2007 ◽  
Vol 345-346 ◽  
pp. 685-688 ◽  
Author(s):  
Werner Ecker ◽  
Thomas Antretter ◽  
R. Ebner
Keyword(s):  
Constitutive Model ◽  
Tool Steel ◽  
Mechanical Response ◽  
Mechanical Load ◽  
Kinematic Hardening ◽  
Ex Situ ◽  
Pressure Casting ◽  
Viscoplastic Material ◽  
Crack Network ◽  
Hot Work Tool Steel

Pressure casting dies are subjected to a large number of thermal as well as mechanical load cycles, which are leading to a characteristic thermally induced crack network on the die surface. As a typical representative for a die material the cyclic thermo-mechanical behavior of the hot work tool steel grade 1.2343 (X38CrMoV5-1) is investigated both experimentally as well as numerically. On the one hand the information from isothermal compression-tension tests is used in a subsequent analysis to calibrate a constitutive model that takes into account the characteristic combined isotropic-kinematic hardening/softening of the material. On the other hand the non-isothermal mechanical response of the material to thermal cycles is characterized by means of a periodic laser pulse applied to a small plate-like specimen which is cooled on the back. The residual stresses developing at the surface of the irradiated region of the specimen are determined ex-situ by means of X-ray diffraction. The obtained values agree well with the results of an accompanying finite-element study. This information is used to verify the calibrated constitutive model. The material law is finally used for the prediction of stresses and strains in a die.

Infiltration pattern in a regolith–fractured bedrock profile: field observation of a dye stain pattern

2006 ◽  
Vol 20 (2) ◽  
pp. 241-250 ◽  
Author(s):  
Jae Gon Kim ◽  
Gyoo Ho Lee ◽  
Jin-Soo Lee ◽  
Chul-Min Chon ◽  
Tack Hyun Kim ◽  
...  
Keyword(s):  
Field Observation ◽  
Fractured Bedrock ◽  
Profile Field

Hydrogeochemical and isotopic evaluation of VOC commingled plumes in a weathered fractured bedrock aquifer treated with thermal and bioremediation

2022 ◽  
pp. 103940
Author(s):  
SashaT. Hart ◽  
Reginaldo A. Bertolo ◽  
Maria S. Agostini ◽  
Roland Feig ◽  
Paulo Lojkasek-Lima ◽  
...  
Keyword(s):  
Fractured Bedrock ◽  
Fractured Bedrock Aquifer ◽  
Bedrock Aquifer

Accounting for frictional contact in an anisotropic damage model based on compliance tensorial variables, illustration on ceramic matrix composites

2018 ◽  
Vol 28 (8) ◽  
pp. 1150-1169 ◽  
Author(s):  
Emmanuel Baranger
Keyword(s):  
Damage Mechanics ◽  
A Priori ◽  
Damage Model ◽  
Ceramic Matrix Composites ◽  
Inelastic Strain ◽  
Ceramic Matrix ◽  
Thermomechanical Properties ◽  
Matrix Composites ◽  
Crack Network ◽  
Evolution Laws

Ceramic matrix composites have good thermomechanical properties at high or very high temperatures. The modeling of the crack networks associated to the degradation of such composites using damage mechanics is not straightforward. The main reason is the presence of a crack network mainly oriented by the loading direction, which is a priori unknown. To model this, compliance tensorial damage variables are used in a thermodynamic potential able to account for crack closure effects (unilateral contact). The damage kinematic is initially completely free and imposed by the evolution laws. The key point of the present paper is to account for friction in such cracks that can result in an apparent activation/deactivation of the shear damage. The initial model is enriched with an inelastic strain and a friction law. The plasticity criterion is expressed only using tensorial variables. The model is identified and illustrated on multiaxial data obtained at ONERA on tubes loaded in tension and torsion.

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