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Geology of Urban Watersheds
Published in Daniel T. Rogers, Urban Watersheds, 2020
Groundwater erosion can eventually lead to a type of landform called karst topography. Karst topography is a landscape created by groundwater slowly dissolving sedimentary rock such as limestone (Davies and Legrand 2015). The resulting landforms from this type of erosion include sinkholes and caves. A sinkhole is a rounded depression of the ground and typically forms when a cave in the subsurface collapses. A cave is a natural feature beneath the surface formed by groundwater dissolving away the rock. At many locations throughout the United States, extensive cave systems have formed. Figure 2.21 shows the most common features of a karst area, and Figure 2.22 shows areas of the United States with sedimentary type deposits prone to karst feature formation.
Precast segmental bridge construction in seismic zones
Published in Fabio Biondini, Dan M. Frangopol, Bridge Maintenance, Safety, Management, Resilience and Sustainability, 2012
Fabio Biondini, Dan M. Frangopol
A sinkhole, also known as a sink, shake hole, swallow hole, is a natural depression or hole in the Earth's surface caused by karsts processes, the chemical dissolution of carbonate rocks or suffusion processes for example in sandstone. Sinkholes may vary in size from 1 to 600 meters both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms, Figure 16. Sinkholes may be formed gradually or suddenly, and are found worldwide. It is clear that such phenomena represent a risk for ground stability and a non-negligible safety risk for surface infrastructure in the surrounding areas. In such applications where critical area localizations and the use of the discrete sensors is practically impossible because of the installation complexity and costs, the DiTeSt distributed system and the SMARTGeoTex FOS result to be particularly suitable (Belli, R. et al. 2009).
Management of the discharge quality of highway runoff in karst areas to control impacts to ground water - A review of relevant literature
Published in Barry F. Beck, Felicity M. Pearson, Karst Geohazards, 2018
J. Brad Stephenson, Barry F. Beck
In karst areas, significant ground water recharge occurs through features such as sinkholes and sinking streams. Sinkholes are enclosed depressions (basins) in the land surface generally formed by the dissolution of underlying bedrock. They function as funnels, directing surface water runoff into karst aquifers. Soils in sinkhole bottoms may be thin or nonexistent. Sinking streams range in size from small ditches with ephemeral flows to relatively large perennial rivers. They may sink through a segment of the stream bed or through a discrete opening (swallet), such as a fracture or cave entrance. Flow of surface water into sinkholes and swallets provides rapid, direct recharge of underlying karst aquifers with little or no attenuation of any transported contaminants. In such an environment, the potential for ground water contamination is analogous to that reported by Yousef and others (1984) for surface streams receiving runoff directly from bridges. A significant component of karst ground water migrates through fractures and conduits (including cave passages) which may contain sensitive subterranean ecosystems. Ground water movement through a granular (diffuse-flow) aquifer is commonly measured in meters per year. However, the turbulent flow of karst ground water through conduits and fractures may be measured in kilometers per day, especially during high flow conditions. Discharge of karst ground water occurs through springs and resurgent cave streams with discharge values comparable to those of surface streams (Mull and others, 1988a and 1988b). In addition to contributing flow to surface streams, springs and cave streams often serve as water supplies for individual households or municipalities.
Integration of satellite-based A-DInSAR and geological modeling supporting the prevention from anthropogenic sinkholes: a case study in the urban area of Rome
Published in Geomatics, Natural Hazards and Risk, 2021
Carlo Esposito, Niccolò Belcecchi, Francesca Bozzano, Alessandro Brunetti, Gian Marco Marmoni, Paolo Mazzanti, Saverio Romeo, Flavio Cammillozzi, Giancarlo Cecchini, Massimo Spizzirri
There are several documented cases of populated areas that, in relation to the geological characteristics of the subsoil and/or anthropic actions, suffer damage due to the sudden formation of sinkholes (e.g. Kersten et al. 2017; Malinowska et al. 2019). Sinkhole is a term widely used in the recent literature to refer to surface depressions, sometimes evolving as sudden collapses, originated by a variety of underground phenomena of either natural origin, such as karstic and deep piping processes (Waltham 2008), or anthropic genesis, as in the case of excessive groundwater withdrawal (e.g. Orhan et al. 2021) or deformation/collapse of man-made underground cavities (e.g. Malinowska et al. 2019). The latter can in fact suffer instabilities that may propagate upwards and reach the surface in the form of ‘anthropogenic sinkholes’ with related hazard and risk implications, such as those of interest in this study. When underground cavities form dense and extended networks, as in the case of anthropogenic cavities widespread in the subsoil of Rome (Nisio et al. 2017), the problem may require large-scale zoning approaches, such as hazard analyses, already tested and applied in diverse contexts and according to a variety of approaches (e.g. Galve et al. 2009, 2011; Pradhan et al. 2014; Ciotoli et al. 2015, Parise et al. 2015; Intrieri et al. 2015; Orhan et al. 2020).
Subsidence of sinkholes in Wink, Texas from 2007 to 2011 detected by time-series InSAR analysis
Published in Geomatics, Natural Hazards and Risk, 2019
Yun Shi, Yaming Tang, Zhong Lu, Jin-Woo Kim, Junhuan Peng
A sinkhole is a depression or a hole caused by the collapse of land surface (Gutiérrez et al. 2014). Such phenomenon is generally found in geological formations known as karst topography where soluble rocks (evaporites, carbonate rocks) dissolve as a consequence of chemical process and collapse (e.g. Beck and Pearson 1995; Johnson and Neal 2003; Waltham et al. 2005). Karst is often prone to the ground subsidence induced by the contact with freshwater from aquifer systems. Sinkhole formation can be related to dissolution of the water-soluble rocks, the development and expansion of underground cavities, consecutive roof failures, and crop-out on the surface. According to Gutiérrez et al. (2014), natural sinkholes can be classified into two types: “solution sinkhole” and “subsidence sinkhole”. A solution sinkhole is attributed to the surface dissolution, which creates shafts or conduits and can lead to ground instability. In this case, karst rock is exposed with almost no mantle soil. On the other hand, a subsidence sinkhole is created by ground surface subsidence, which may be attributed, for example, to chemical dissolution of caprock and bedrock underground, internal erosion of rock, subsurface dissolution and downward gravitational movement of the overlying material. It commonly shows one of the phenomena: collapse, sagging and/or suffusion (Gutiérrez et al. 2014).
GPR analysis to detect subsidence: a case study on a loaded reinforced concrete pavement
Published in International Journal of Pavement Engineering, 2022
Mercedes Solla, Norberto Fernández
With the GPR data processed as input, different methods were used to assist with the analysis and interpretation of the GPR signals received. To understand how subsidence occurrence could be detectable in GPR imaging, the expected GPR outputs are listed: - Subsidence within rigid pavement due to poor soil or inadequate drainage, as well as heavy traffic, can cause concrete slab sagging, or floor sinking, resulting in superficial cracking and settlement of the reinforcement. This occurrence can be detectable in the GPR data in terms of (i) higher amplitude values in the damage region because of the larger dielectric contrast at the interfaces between concrete and free-space, (ii) the phase of the reflected waveform is reversed (in form) when a void exists inside concrete (Rhee et al. 2021), (iii) shorter travel-time distances at the slab thickness due to the higher propagation velocity of the GPR signal in free-space and (iv) complex reflections patterns from rebar in slab instead of the typical pattern in form of consecutive hyperbolic reflections.- Superficial cracking favours water infiltration that can cause washing of filling, especially in sand and gravel-based soils, as in this case study. The presence of uncompacted soils or small voids can be detectable in the GPR data in terms of (i) higher amplitude values in the uncompacted soils due to the presence of air filling the loose zones and the superposition of the wavelets reflected from the top and bottom, (ii) scattering of the GPR signals from air voids in soils and (iii) ‘bright-spot’ reflections (Nobes 2016).- In the worst case, hidden sinkholes could be produced, that are usually caused by removal of soil material or gradual subsidence of the surface into a hidden cavity/void. Surface depressions are signs of hidden sinkholes. This event can be detectable in the GPR data in terms of (i) higher amplitude values in the damage region and (ii) identifying the boundaries of the sinkhole.