scholarly journals Seepage Characteristics of a Single Ascending Relief Well Dewatering an Overlying Aquifer

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 919
Author(s):  
Wenxue Wang ◽  
Boris Faybishenko ◽  
Tong Jiang ◽  
Jinyu Dong ◽  
Yang Li
Keyword(s):  
Numerical Simulations ◽  
Underground Mining ◽  
Ground Surface ◽  
Water Levels ◽  
Type Curves ◽  
Unconfined Aquifers ◽  
Pumping Wells ◽  
Power Law Function ◽  
Seepage Characteristics ◽  
Seepage Face

The application of groundwater relief, i.e., dewatering, ascending wells, drilled upward from the mining tunnel into the overlying aquifer, is common in underground mining engineering. In this study, the seepage characteristics of single ascending partially and fully penetrating relief wells are investigated using a series of laboratory sand-tank experiments and numerical simulations. The seepage characteristics of ascending wells dewatering an overlying aquifer are different from those of conventional pumping wells descending from the ground surface into the underlying aquifer, because of the pronounced influence of the seepage face boundary condition along the seepage boundary of the ascending dewatering well. The seepage face of the ascending well is formed as the well casing remains open and water is discharged under the action of gravity through the well casing. The results of laboratory sand-tank experiments and modeling show that when the degree of penetration of an ascending relief well does not exceed a critical value, the effect of the seepage face cannot be ignored. In particular, the seepage flux increases as the degree of penetration increases following an exponential function, and the relationship between the seepage flux and the well radius can be described using a power law function. The results of numerical simulations are used to develop a series of type curves to evaluate the effects of the critical degree of penetration for different well radii and different aquifer water levels. Modified versions of the Dupuit and Dupuit–Thiem formulae for a single ascending partially well for the degree of penetration less than the critical one for the unconfined, confined, and confined-unconfined aquifers are developed.

Numerical Simulations as a Reliable Alternative for Landmine Explosion Studies: The AUTODYN Approach

2010 ◽  
Author(s):  
Stephanie Follett ◽  
Amer Hameed ◽  
S. Darina ◽  
John G. Hetherington
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Reasonable Agreement ◽  
Specific Impulse ◽  
Numerical Procedure ◽  
Ground Surface ◽  
Time Of Arrival ◽  
Linear Dynamics ◽  
Non Linear

In order to validate the numerical procedure, the explosion of a mine was recreated within the non-linear dynamics software, AUTODYN. Two models were created and analysed for the purposes of this study — buried and flush HE charge in sand. The explosion parameters — time of arrival, maximum overpressure and specific impulse were recorded at two stand-off distances above the ground surface. These parameters are then compared with LS-DYNA models and published experimental data. The results, presented in table format, are in reasonable agreement.

scholarly journals A partially-coupled hydro-mechanical analysis of the Bengal Aquifer System under hydrological loading

2018 ◽  
Author(s):  
Nicholas D. Woodman ◽  
William G. Burgess ◽  
Kazi Matin Ahmed ◽  
Anwar Zahid
Keyword(s):  
Mechanical Load ◽  
Groundwater Resources ◽  
Ground Surface ◽  
Coupled Model ◽  
Hydraulic Head ◽  
Water Levels ◽  
Elastic Model ◽  
Surface Boundary ◽  
Aquifer System ◽  
Terrestrial Water

Abstract. The coupled poro-mechanical behaviour of geologic-fluid systems is fundamental to numerous processes in structural geology, seismology and geotechnics but is frequently overlooked in hydrogeology. Substantial poro-mechanical influences on groundwater head have recently been highlighted in the Bengal Aquifer System, however, driven by terrestrial water loading across the Ganges-Brahmaputra-Meghna floodplains. Groundwater management in this strategically important fluvio-deltaic aquifer, the largest in south Asia, requires a coupled hydro-mechanical approach which acknowledges poro-elasticity. We present a simple partially-coupled, one-dimensional poro-elastic model of the Bengal Aquifer System, and explore the poro-mechanical responses of the aquifer to surface boundary conditions representing hydraulic head and mechanical load under three modes of terrestrial water variation. The characteristic responses, shown as amplitude and phase of hydraulic head in depth profile and of ground surface deflection, demonstrate (i) the limits to using water levels in piezometers to indicate groundwater recharge, as conventionally applied in groundwater resources management; (ii) the conditions under which piezometer water levels respond primarily to changes in the mass of terrestrial water storage, as applied in geological weighing lysimetry; (iii) the relationship of ground surface vertical deflection to changes in groundwater storage; and (iv) errors of attribution that could result from ignoring the poroelastic behaviour of the aquifer. These concepts are illustrated through application of the partially-coupled model to interpret multi-level piezometer data at two sites in southern Bangladesh. There is a need for further research into the coupled responses of the aquifer due to more complex forms of surface loading, particularly from rivers.

scholarly journals Infiltration and Anti-Filtration Recharge-Pumping Well and Laboratory Recharge Tests

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1834
Author(s):  
Yuxi Li ◽  
Wanglin Li ◽  
Jiapeng He ◽  
Xiaojiao Zhang ◽  
Xinyi Li
Keyword(s):  
Steady State ◽  
Flow Pattern ◽  
Theoretical Equation ◽  
Steady State Flow ◽  
Inlet Flow ◽  
State Flow ◽  
Unconfined Aquifers ◽  
Pumping Wells ◽  
Single Well

Infiltration and anti-filtration recharge-pumping wells (hereinafter, referred to as IAF recharge-pumping wells) can enable rain-flood flowing in rivers or channel recharge to aquifers, in flood periods, and pump groundwater to be utilized in non-flood periods. In this study, a round IAF recharge-pumping well and a square IAF recharge-pumping well were developed, the structure and characteristic were introduced, the calculation equations of single-well recharge quantity of IAF recharge-pumping wells, in unconfined aquifers were deduced, and the steady-state flow recharge test was conducted in the laboratory. The conclusions were as follows. The theoretical equation of the single-well recharge quantity was reasonable. Compared to existing anti-filtration recharge wells, the new IAF recharge-pumping well had stronger anti-deposit and anti-scour abilities and the single-well recharge quantity increased by 400%. Compared to the square IAF recharge-pumping well, the round IAF recharge-pumping well had a better inlet flow pattern and a larger single-well recharge quantity. With an increase in the test times, the single-well recharge quantity gradually decreased and tended to be stable. The existence of the pumping pipe had a little influence on the single-well recharge quantity.

scholarly journals Case Studies of Rock Bolt Support Loads and Rock Mass Monitoring for the Room and Pillar Method in the Legnica-Głogów Copper District in Poland

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2998 ◽  
Author(s):  
Krzysztof Skrzypkowski
Keyword(s):  
Underground Mining ◽  
Mechanical Load ◽  
Ground Surface ◽  
Rock Bolt ◽  
Copper Ore ◽  
Essential Condition ◽  
Rock Bolting ◽  
Rock Bolt Support ◽  
The Impact ◽  
Bolt Support

The article presents the impact of geological and mining factors on the stability of room excavations in the Legnica-Głogów Copper District (LGOM) in Poland. In underground mining, the primary task of bolting of mining excavations is to ensure their stability as an essential condition of work safety. Appreciating the role and importance of the rock bolting in Polish ore mining; rock bolt load sensors were designed, manufactured and tested under laboratory conditions. The purpose of the research was to characterize the sensors and determine the elastic range of the bearing plate, which are an integral part of the sensor. The sensors have been verified in industrial conditions. The tests were carried out in the underground copper ore mine in Poland. Three rooms in the exploitation field were selected for testing, where exploitation was carried out at a depth of 809–820 m below the ground surface with the application of room and pillar with roof deflection and maintaining the central part of the field. The exploitation field included 60 rooms and pillars. The effectiveness of the mechanical load sensor of the expansion rock bolt support has been experimentally confirmed. Based on mine research, it was found that the largest increases in the load of the rock bolting, vertical stress and convergence occur in the middle of the mining field.

scholarly journals Study On The Law Of Ground Strata Subsidence And Movement Induced By Caving Mining Of Slowly Inclined Large And Thick Ore Body

2018 ◽  
Vol 53 ◽  
pp. 03062
Author(s):  
Li Teng ◽  
Fu Jianxin ◽  
Song Weidong
Keyword(s):  
Underground Mining ◽  
Ground Surface ◽  
Beam Theory ◽  
Tectonic Stress ◽  
Collapse Mechanism ◽  
Surface Movement ◽  
Strata Movement ◽  
Leading Role ◽  
Metal Mine ◽  
The Law

Taking the Western District of Chengchao Iron Mine as engineering background, based on the GPS monitoring data of nearly 8 years and the record of the ground surface movement, the law of ground strata subsidence and movement is studied. The studies have shown that the surface movement caused by underground mining has the characteristics of time delay and displacement angle development has the law of jumping. The strata movement caused by mining is divided into the stage of overlying strata collapse and the collapse stage of surrounding rock to goaf. In the first stage, the vertical stress plays a leading role and rock failure is shown as a regular barrel collapse. In the second stage, horizontal tectonic stress plays a leading role and the collapse mechanism of rock strata can be explained by the cantilever beam theory. According to the mechanism of strata movement analysis, strata movement of Chengchao Iron is divided into six regions, which respectively included vertical subsidence area, toppling sliding zone, dumping area, deformation zone, cumulative deformation area and undisturbed zone. The results of this paper can provide a theoretical basis for the surface movement prediction of caving mining in similar metal mine.

Hydrology of a Southern Appalachian Hypocrene Spring-Fed Fen

2020 ◽  
Vol 26 (3) ◽  
pp. 359-366
Author(s):  
Jeffrey Wilcox ◽  
Emily Bradshaw Marino ◽  
Adam Warwick ◽  
Megan Sutton
Keyword(s):  
Open Space ◽  
Ground Surface ◽  
Early Spring ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Fractured Bedrock ◽  
Southern Appalachian ◽  
Discharge Rates ◽  
Hydrologic Restoration ◽  
Spring Flow

ABSTRACT Garland Seep is a Southern Appalachian fen that supports a population of federally endangered green pitcher plants (Sarracenia oreophila). The wetland is underlain by clayey stream deposits above fractured bedrock, is located at the base of a mountain slope, and is fed by groundwater that originates as recharge on the adjacent hillslope. Groundwater wells were installed following a hydrologic restoration in the mid-1990s and have been monitored at varying frequencies since that time. The 20+ year record provides evidence that Garland Seep can be classified as a “hypocrene fen,” in which spring flow rarely reaches the ground surface because of low discharge rates and high evapotranspiration (ET). In general, water-level fluctuations followed seasonal ET patterns, with higher water levels in the winter and early spring (when ET is low) and lower levels in the summer and fall. During wetter years, the water table remained near the ground surface for much of the year, with the clay layer underlying the site retaining moisture even after water levels had dropped. The “clay wetting” period was shorter during dryer years and corresponded with a reduction in the number of pitcher plant clumps observed at the site. In addition to the geologic and climatic controls on hydrology, previous landowners used fire to maintain open space for grazing, and The Nature Conservancy has continued the practice to combat woody vegetation and to open the canopy. Prescribed burns reduce ET (at least initially), cause a rise in water levels, and have helped maintain a thriving Sarracenia population.

Numerical Simulations of a Ground Source Heat Pump System With Pile Heat Exchangers

2014 ◽  
Vol 7 (1) ◽  
Author(s):  
Masahito Oguma ◽  
Takeshi Matsumoto ◽  
Takao Kakizaki
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Heat Supply ◽  
Ground Surface ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source

Feasibility of a ground source heat pump (GSHP) system with pile heat exchangers for use in houses is evaluated through a numerical simulation. This GSHP system differs from ordinary borehole-type GSHP systems because short foundation piles installed at close intervals are used as heat exchangers. It is shown that the annual heat supply provided by this GSHP system is able to satisfy the demand of a house due to the air-source exchange at ground surface.

scholarly journals LAND SUBSIDENCE MONITORING USING PS-InSAR TECHNIQUE FOR L-BAND SAR DATA

2016 ◽  
Vol XLI-B7 ◽  
pp. 995-997 ◽  
Author(s):  
S. Thapa ◽  
R. S. Chatterjee ◽  
K. B. Singh ◽  
D. Kumar
Keyword(s):  
Time Series ◽  
Land Subsidence ◽  
Land Surface ◽  
Surface Deformation ◽  
Underground Mining ◽  
Ground Surface ◽  
Sar Interferometry ◽  
Persistent Scatterer Interferometry ◽  
Long Time ◽  
Subsidence Monitoring

Differential SAR-Interferometry (D-InSAR) is one of the potential source to measure land surface motion induced due to underground coal mining. However, this technique has many limitation such as atmospheric in homogeneities, spatial de-correlation, and temporal decorrelation. Persistent Scatterer Interferometry synthetic aperture radar (PS-InSAR) belongs to a family of time series InSAR technique, which utilizes the properties of some of the stable natural and anthropogenic targets which remain coherent over long time period. In this study PS-InSAR technique has been used to monitor land subsidence over selected location of Jharia Coal field which has been correlated with the ground levelling measurement. This time series deformation observed using PS InSAR helped us to understand the nature of the ground surface deformation due to underground mining activity.

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