Karst Geohazards Research Articles

Detecting hypogenic karst features in the northeastern Delaware Basin, west Texas: Applications of Full Tensor Gradient (FTG) gravity data

Extensive karst development in carbonate and evaporate strata often occur in the Upper Permian formations of the Delaware Basin, west Texas. Subsurface karst feature detection is essential since they may cause severe drilling geohazards. In order to detect subsurface karst features, we present an interpretation approach that integrates high-resolution, high-precision airborne full tensor gradiometry (FTG) gravity data, structural interpretations, density and lithological variations derived from well logs, and published seismic refraction data, with regional cross sections to produce a geologically plausible 3D FTG model in the northeastern Delaware Basin. Both traditional gravity (Tz) and FTG (Tzz) density inversions were carried out on three shallow sedimentary layers of the Ochoan-lower Permian section, demonstrating the subtle density distribution in these strata. Detailed low-density karst boundaries were then interpretated by making use of the intrinsic properties of the gradient components, Txz and Tyz, which are: 1) edge detectors, because anomaly maxima and minima are located directly over source boundaries, and 2) indicators of the direction of density change across these boundaries. Source boundaries, or faults, mapped from these components were integrated and combined with regional geology and measured densities to verify existing faults, infer new faults, and predict probable locations and shapes of karst cavities in the southwestern and northeastern parts of the study area. Our results show that the central and southwestern parts of the study area may represent higher drilling risks due to an increase in shallow karst geohazards. This interpretation approach may be used to detect fault systems and geometries of low-density or high-density source geobodies worldwide.

Numerical Evaluation for Roads Considering the Addition of Geogrids in Karst Geohazards Zones

Design of road infrastructure in karst terrain is a challenge for any geotechnical condition caused by the weathering of the subsoil. Previous investigations pointed out the efficiency of the roads with geogrids, however there are few studies analyzing road reinforced under karst geohazards. This paper presents a numerical study of the geogrid additions in a typical Mexican road and considering 19 cavities in the subsoil due to failures of the roads in these terrains. The rocks and the soil were simulated by Hoek–Brown and Mohr–Coulomb constitutive models, considering specific characteristics of karstic materials. Hence, it was carried out in different two-dimension finite element models to analyze the geogrid behavior and its benefits. First, the geogrid position was varied inside of the road structure and applying a heavy truck load in its surface and finally, underground cavities were sequentially opened in the numerical model. It was established the best combination of the road-geogrid structure construction and the influence when cavities are developed underground analyzing the stress paths in the medium. From this study, it is found, that when the geogrid layer is embedded between bedrock and subgrade, the failure is mitigated, observing an increase in the factor of safety even with 19 voids presence in the model. Concluding that the geogrid is an adequate solution of reinforcement of roads.

Detection method of karst features around tunnel construction by multi-resistivity data-fusion pseudo-3D-imaging based on the PCA approach

Abstract During tunnel construction, large groundwater influx poses serious safety hazards. To ensure construction safety, effective measures such as early warning, grouting, and framework support are needed to counteract potential water hazards. It is also critical to clarify the spatial location and size of the water-bearing geological structures before construction to avoid catastrophe. Electrical resistivity tomography (ERT) operates at a high resolution and is sensitive to low-resistivity targets such as water. Thus, it has strong application potential for the detection of karst geomorphology around tunnel construction. However, the use of a single-ERT method may not be sufficient to accurately locate the spatial distribution of karst features. Therefore, it is necessary to carry out multiple-ERT data fusion to generate a comprehensive interpretation of karst geohazards. According to the spatial distribution of different karst caves, we established four geoelectric models for numerical simulation based on the method of principal component analysis. Studies have shown that data fusion is superior to conventional comparative analysis of geophysical data results and creates a more accurate comprehensive description of the same target. For example, inversion data fusion improves poor imaging of the cross-hole ERT near the borehole and reduces the distribution of pseudo-anomalies near the electrode. In this study, the vertical resolution of the surface ERT, and the horizontal resolution of the cross-hole ERT were both improved, while the imaging ability of the borehole-surface ERT in the peripheral low-sensitivity area was enhanced. Moreover, a three-dimensional (3D) conversion method of two-dimensional (2D) detection data in the tunnel environment was employed. An interpolation 3D-imaging of the 2D detection data was carried out, rendering the interpretation of the results more intuitive and comprehensive. Finally, we applied this method in the Daba Tunnel Water Governance Project in Hunan Province, China, and demonstrated that it could overcome the limitations of the single-ERT survey. We were able to accurately delineate the distribution range of the main water-rich bodies around the tunnel. Our findings provide key guidance for the successful implementation of tunnel water-inrush treatment.

Characterization and Delineation of Gypsum Karst Geohazards Using 2D Electrical Resistivity Tomography in Culberson County, Texas, USA

The Delaware Basin of W Texas and SE New Mexico is the western subdivision of the Permian Basin and a northern extension of the Chihuahuan Desert. The major evaporite unit within the Delaware Basin is the Castile Formation, which consists of gypsum/anhydrite and is highly susceptible to dissolution and karstification. Manifestations of karst within the Castile outcrop are abundant and include sinkholes, subsidence features and caves, both epigene and hypogene in origin. Land reconnaissance surveys conducted during 2015 and 2016 documented abundant karst landforms near major thoroughfares in Culberson County, Texas. Two dimensional (2D) electrical resistivity surveys were conducted at four sites to characterize and delineate karst related hazards, both laterally and vertically, associated with the road. The electrical resistivity data were collected with a multi-electrode earth resistivity meter using a dipole-dipole array configuration. The resistivity data were then processed using EarthImager2D to produce inverted profile sections of each site. Two-dimensional electrical resistivity tomography was shown to be an effective non-invasive method in detecting solution conduits, soil filled voids, and fractured bedrock in the shallow subsurface in addition to those directly observed on the surface.

Evaporite karst geohazards in the Delaware Basin, Texas: review of traditional karst studies coupled with geophysical and remote sensing characterization

Evaporite karst throughout the Gypsum Plain of west Texas is complex and extensive, including manifestations ranging from intrastratal brecciation and hypogene caves to epigene features and suffosion caves. Recent advances in hydrocarbon exploration and extraction has resulted in increased infrastructure development and utilization in the area; as a result, delineation and characterization of potential karst geohazards throughout the region have become a greater concern. While traditional karst surveys are essential for delineating the subsurface extent and morphology of individual caves for speleogenetic interpretation, these methods tend to underestimate the total extent of karst development and require surficial manifestation of karst phenomena. Therefore, this study utilizes a composite suite of remote sensing and traditional field studies for improved karst delineation and detection of potential karst geohazards within gypsum karst. Color InfraRed (CIR) imagery were utilized for delineation of lineaments associated with fractures, while Normalized Density Vegetation Index (NDVI) analyses were used to delineate regions of increased moisture flux and probable zones of shallow karst development. Digital Elevation Models (DEM) constructed from high-resolution LiDAR (Light Detection and Ranging) data were used to spatially interpret sinkholes, while analyses of LiDAR intensity data were used in a novel way to categorize local variations in surface geology. Resistivity data, including both direct current (DC) and capacitively coupled (CC) resistivity analyses, were acquired and interpreted throughout the study area to delineate potential shallow karst geohazards specifically associated with roadways of geohazard concern; however, detailed knowledge of the surrounding geology and local karst development proved essential for proper interpretation of resistivity inversions. The composite suite of traditional field investigations and remotely sensed karst delineations used in this study illustrate how complex gypsum karst terrains can be characterized with greater detail through the utilization of rapidly advancing technologies, especially in arid environments with low vegetation densities.

Model ordinance for development on karst terrain: Kentucky, USA

Until the recent economic slowdown, development in rural areas was increasing at a rapid rate in Kentucky and resulting in development pressure on less desirable lands, including large areas of karst land. Most damage caused by karst geologic hazards is from groundwater pollution, cover-collapse sinkholes, and sinkhole flooding. The economic costs of karst-related geologic hazards have been estimated to be $20 million annually in Kentucky. The Kentucky Geological Survey drafted a model ordinance to guide development in karst for the purpose of reducing economic and environmental losses from karst geohazards. The text of the ordinance provides a wide range of ideas for planning and zoning agencies to adopt as needed. The final draft of the model ordinance was completed in the fall of 2008 and went through a thorough technical and editorial review, both internally at KGS and among other karst researchers. An effort was made to find an attorney to volunteer time to review the document, but we were not successful. The decision was made to move forward and send copies to 70 fiscal courts or planning and zoning boards. It was reasoned that any adopted ordinance derived from this document would be reviewed by their attorneys, regardless of previous reviews. To date the response has been poor. Only two agencies have contacted KGS for further information.

Karst geohazards in the UK: the use of digital data for hazard management

An essential prerequisite for any engineering or hydrogeological investigation of soluble rocks is the identification and description of their characteristic, observable and detectable dissolution features, such as stream sinks, springs, sinkholes and caves. The British Geological Survey (BGS) is creating a National Karst Database (NKD) that records such features across the country. The database currently covers much of the region underlain by Carboniferous Limestone, the Chalk, and particularly the Permo-Triassic gypsum and halite where rapid, active dissolution has caused significant subsidence and building damage. In addition to, and separate from, the identification of specific karst features, the BGS has created a National Karst Geohazard geographical information system (GIS). This has been created to identify areas that may potentially contain karst geohazards. Initially, all the soluble rock units identified from the BGS 1:50 000 scale digital geological map are extracted. Each soluble unit has been given an objective score, interpreted, as based on factors including lithology, topography, geomorphological position and characteristic superficial cover deposits. This national zonation of these soluble rocks can then be used to identify areas where the occurrence potential for karstic features is significant, and where dissolution features might affect the stability of buildings and infrastructure, or where karstic groundwater flow might occur. Both datasets are seen as invaluable scientific tools that have already been widely used to support site investigation, groundwater investigations, planning, construction and the insurance underwriting businesses.

Halite karst geohazards (natural and man-made) in the United Kingdom

In the United Kingdom, Permian and Triassic halite (rock salt) deposits have been affected by natural and artificial dissolution producing karstic landforms and subsidence. Brine springs from the Triassic salt have been exploited since Roman times or possibly earlier, indicating prolonged natural dissolution. Medieval salt extraction in England is indicated by the names of places ending in wich, indicating brine spring exploitation at Northwich, Middlewich, Nantwich and Droitwich. Later, Victorian brine extraction in these areas accentuated salt karst development, causing severe subsidence problems which remain a legacy. The salt was also mined, but the mines flooded and consequent brine extraction caused the workings to collapse, resulting in catastrophic surface subsidence. Legislation was enacted to pay for the damage and a levy is still charged for salt extraction. Some salt mines are still collapsing, and the re-establishment of the post-brine extraction hydrogeological regimes means that salt springs may again flow, causing further dissolution and potential collapse.

Karst Geohazards: Engineering and Environmental Problems in Karst Terrane

Karst Geohazards: Engineering and Environmental Problems in Karst Terrane

The problems of constructions on karst — the examples from Sloveni : S. Sebela & A. Mihevc, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 475–479

The problems of constructions on karst — the examples from Sloveni : S. Sebela & A. Mihevc, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 475–479

A spacial-correlation model for assessment of large-areal sinkhole and water quality dat : J. Chen, G. Thomas & S. Upchurch, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 111–116

A spacial-correlation model for assessment of large-areal sinkhole and water quality dat : J. Chen, G. Thomas & S. Upchurch, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 111–116

Conceptual model of groundwater flow in a mantled karst aquifer and effects of the epikarst zone : H. E. Julian & S. C. Young, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 131–139

Conceptual model of groundwater flow in a mantled karst aquifer and effects of the epikarst zone : H. E. Julian & S. C. Young, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 131–139

Modification of highway runoff quality by sinkhole drainage structures, highway 37 improvement project Lawrence County, Indian : J. H. Keith, J. L. Bassett & J. A. Duwelius, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed. B.F. Beck, Balkema, 1995, pp 273–284

Modification of highway runoff quality by sinkhole drainage structures, highway 37 improvement project Lawrence County, Indian : J. H. Keith, J. L. Bassett & J. A. Duwelius, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed. B.F. Beck, Balkema, 1995, pp 273–284

Karst geohazards: engineering and environmental problems in karst terrane. Proceedings of the 5th multidisciplinary conference, Gatlinburg, April 1995 : ed B. F. Beck, (A.A. Balkema), ISBN (hardback) 90 5410 535 6, price Dfl 165, 1995, 579 pp

Karst geohazards: engineering and environmental problems in karst terrane. Proceedings of the 5th multidisciplinary conference, Gatlinburg, April 1995 : ed B. F. Beck, (A.A. Balkema), ISBN (hardback) 90 5410 535 6, price Dfl 165, 1995, 579 pp

Paleokarstic features in the Belgian carboniferous limestones — implications to engineering : A. V. Y. Quinif & J. M. Charlet, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, B.F. Beck, (Balkema), 1995, pp 487–486

Paleokarstic features in the Belgian carboniferous limestones — implications to engineering : A. V. Y. Quinif & J. M. Charlet, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, B.F. Beck, (Balkema), 1995, pp 487–486

Carbonate rock investigation guidance policy for siting landfills in karst areas in Tennessee : J. K. House, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B. F. Beck, (Balkema), 1995, pp 511–515

Carbonate rock investigation guidance policy for siting landfills in karst areas in Tennessee : J. K. House, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B. F. Beck, (Balkema), 1995, pp 511–515

Contaminant transport mechanisms in karst terrains and implications on remediation : W. Barner & K. Uhlman, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 207–212

Contaminant transport mechanisms in karst terrains and implications on remediation : W. Barner & K. Uhlman, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 207–212

Application of fluorescent dye tracing techniques for delineating sinkhole drainage routes, highway 37 improvement project Lawrence County, Indian : J. A. Duwelius, J. L. Bassett & J. H. Keith, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 227–233

Application of fluorescent dye tracing techniques for delineating sinkhole drainage routes, highway 37 improvement project Lawrence County, Indian : J. A. Duwelius, J. L. Bassett & J. H. Keith, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 227–233

Engineering experience with limestone : M. A. Iqbal, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, 3d B.F. Beck, (Balkema), 1995, pp 463–468

Engineering experience with limestone : M. A. Iqbal, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, 3d B.F. Beck, (Balkema), 1995, pp 463–468

The application of thermal infrared thermography in the identification of submerged springs in Chickamaug Reservoir, Hamilton County, Tennessee : F. R. Bogle & K. Loy, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 415–424

The application of thermal infrared thermography in the identification of submerged springs in Chickamaug Reservoir, Hamilton County, Tennessee : F. R. Bogle & K. Loy, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 415–424