The Use of Tracer Techniques to Assess Groundwater Flows in Site Investigations

1986 ◽  
Vol 2 (1) ◽  
pp. 375-384
Author(s):  
H. J. Siddle ◽  
D. B. Jones ◽  
C. D. Warren
Keyword(s):  
Groundwater Flow ◽  
Tracer Tests ◽  
Site Investigation ◽  
Flow Paths ◽  
Site Investigations ◽  
Tracer Techniques ◽  
Standard Procedures ◽  
Hydrogeological Characteristics ◽  
Ground Conditions ◽  
Groundwater Tracers

AbstractProcedures of site investigation included in BS 5930:1981 concentrate on obtaining information on ground conditions near proposed structures. Groundwater flow paths, however, are often influenced by hydrogeological conditions well beyond the area and tracer tests have been found a useful addition to investigations.Different types of groundwater tracers are described and their uses in establishing groundwater flow paths and other hydrogeological characteristics of some regimes are outlined. Precautions are always necessary when using tracers, however, and these are especially stringent with radioactive tracers. The paper shows how groundwater tracers were employed in investigations of landslips, waste disposal studies and other investigations with which the authors have been involved.The paper concludes that the specification of standard procedures for tracer tests is probably not appropriate but reference to the techniques available would be useful in promoting their application.

Groundwater Lowering for Construction of the Kilsby Tunnel – Geological and Geotechnical Interpretation

2021 ◽  
pp. 1-14
Author(s):  
Martin Preene ◽  
Mike Chrimes
Keyword(s):  
Groundwater Flow ◽  
Theoretical Understanding ◽  
Stress Theory ◽  
Glacial Origin ◽  
Buried Channel ◽  
Geological Information ◽  
Ground Conditions ◽  
Glacial Processes ◽  
The Impact ◽  
Groundwater Lowering

The Kilsby Tunnel, constructed in the 1830s, faced severe problems when a section of the tunnel, almost 400 m long, encountered unstable ‘quicksand’ conditions. The engineer for the project, Robert Stephenson, developed an extensive groundwater lowering scheme, unique for the time, using steam engines pumping from multiple shafts, to overcome the quicksand. Modern geological information indicates most of the tunnel was in Middle Lias bedrock, but the ‘quicksand’ section passed through a buried channel of water-bearing sand of glacial origin. In the early 19th century the impact of glacial processes on British geology was not widely accepted and, based on contemporary geological knowledge, Stephenson’s problems appear to be genuine unforeseen ground conditions, not predicted by his experienced advisers. It seems just random chance that trial borings missed the buried channel of sand. The work at Kilsby was two decades before Darcy’s law established the theoretical understanding for groundwater flow, and 90 years before Terzaghi’s effective stress theory described how reducing pore water pressures changed ‘quicksand’ into a stable and workable material. Despite the lack of existing theories, Stephenson used careful observations and interpretation of groundwater flow in the ‘quicksand’ to navigate the tunnel project to a successful conclusion.

Flow pattern and residence time of conduit flow and diffuse flow in calcareous sandstones (Bohemian Cretaceous Basin, Czech Republic)

2021 ◽  
Author(s):  
Iva Kůrková ◽  
Jiří Bruthans
Keyword(s):  
Czech Republic ◽  
Groundwater Flow ◽  
Residence Time ◽  
Dispersion Model ◽  
Tracer Tests ◽  
Water Levels ◽  
Northwestern Part ◽  
Residence Times ◽  
Karst Springs ◽  
Bohemian Cretaceous Basin

<p>Localities containing karst features were studied in the northwestern part of Bohemian Cretaceous Basin. Namely Turnov area in facies transition between coarse-delta sandstones and marlstones (Jizera Formation, Turonian) and Miskovice area in limestones and sandy limestones - sandstones (Peruc-Korycany Formation, Cenomanian). Evolution of karst conduits is discussed elsewhere (Kůrková et al. 2019).</p><p>In both localities, disappearing streams, caves and karst springs with maximum discharge up to 100 L/s were documented. Geology and hydrogeology of this area was studied from many points of view to describe formation of karst conduits and characterize groundwater flow. Tracer tests were performed using NaCl and Na-fluoresceine between sinkholes and springs under various flow rates to evaluate residence times of water in conduits and to describe geometry of conduits. Breatkthrough curves of tracer tests were evaluated by means of Qtracer2 program (Field 2002). Groundwater flow velocity in channels starts at 0.6 km/day during low water levels up to 15 km/day during maximum water levels, the velocity increases logarithmically as a function of discharge. Similar karst conduits probably occur in other parts of Bohemian Cretaceous Basin where lot of large springs can be found.</p><p>Mean residence time of difussed flow based on tritium, CFC and SF<sub>6</sub> sampled at karst springs is 20 years for 75% of water and 100 years for remaining 25%, based on binary mixing dispersion model. This shows that most of the water drained by karst conduits is infiltrated through the soil and fractured environment with relatively high residence time. Residence times in different types of wells and springs were also measured in whole north-western part of Bohemian Cretaceous Basin. Results indicate long residence times in semi-stagnant zones represented by monitoring wells and short residence times in preferential zones represented by springs and water-supply wells.</p><p> </p><p>Research was funded by the Czech Science Foundation (GA CR No. 19-14082S), Czech Geological Survey – internal project 310250</p><p> </p><p>Field M. (2002): The QTRACER2 program for Tracer Breakthrough Curve Analysis for Tracer Tests in Karstic Aquifers and Other hydrologic Systems. – U.S. Environmental protection agency hypertext multimedia publication in the Internet at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=54930.</p><p>Kůrková I., Bruthans J., Balák F., Slavík M., Schweigstillová J., Bruthansová J., Mikuš P., Grundloch J. (2019): Factors controlling evolution of karst conduits in sandy limestone and calcareous sandstone (Turnov area, Czech Republic). Journal of Hydrology: 574: 1062-1073</p>

Route selection for natural gas pipelines in Ireland

1987 ◽  
Vol 4 (1) ◽  
pp. 467-474
Author(s):  
J. H. Redding
Keyword(s):  
Natural Gas ◽  
Rural Areas ◽  
Site Investigation ◽  
Geological Mapping ◽  
Route Selection ◽  
Construction Costs ◽  
Near Surface ◽  
Natural Gas Pipelines ◽  
Potential Difficulty ◽  
Ground Conditions

AbstractBy the end of 1986, over 400 km of high pressure (70 bar) natural gas pipeline will have been constructed in the Irish Republic, much of it laid in sparsely populated rural areas where topography, hydrology, near surface geology and ground conditions can significantly influence construction feasibility and cost. Identifying, quantifying and (where possible) avoiding areas of potential difficulty or hazard are aspects of route selection to which engineering geology can make an important contribution. This contribution is discussed in relation to the Cork-Dublin pipeline completed in 1982, and the Limerick, Waterford and Mallow lines due for completion this year. In particular, the application and merits of stereo aerial photographic interpretation, superficial geological mapping and field study are outlined, together with the use of more traditional methods of site investigation. Attention is focussed on indigenous engineering geological problems associated with shallow rock, limestone karst, peat bog and poorly drained alluvial and morainic soils. Data acquisition and presentation are discussed within the overall context of civil engineering contract preparation and administration. The usefulness of this approach, particularly for predicting and minimising construction costs, forestalling claims and generally facilitating on-site supervision, is emphasised.

Marine Site Investigations and BS 5930

1986 ◽  
Vol 2 (1) ◽  
pp. 163-166 ◽  
Author(s):  
P. G. Carter ◽  
R. M. Pirie ◽  
M. Sneddon
Keyword(s):  
Survey Methods ◽  
Site Investigation ◽  
Land Site ◽  
Site Investigations ◽  
Investigation Methods ◽  
Ground Investigation ◽  
Wide Range ◽  
Marine Site

AbstractMarine site investigations are reviewed briefly, in terms of suitable drilling platforms and craft for various conditions, requirements for permissions and service locations, marine ground investigation methods and marine survey methods including geophysical profiling.The wide range of marine site investigation methods is illustrated and the appreciable differences from land site investigation methods are noted. It is suggested that BS 5930 does not give sufficient guidance on marine site investigations and that this situation should be rectified.

Using hydrogeochemical data to trace groundwater flow paths in a cold alpine catchment

2019 ◽  
Vol 33 (14) ◽  
pp. 1942-1960 ◽  
Author(s):  
Yalu Hu ◽  
Rui Ma ◽  
Yanxin Wang ◽  
Qixin Chang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Flow Paths
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