Chapter 15 Dissolution – carbonates

2020 ◽  
Vol 29 (1) ◽  
pp. 389-401 ◽  
Author(s):  
Clive N. Edmonds
Keyword(s):  
Carbonate Rock ◽  
Land Development ◽  
Slope Instability ◽  
Rock Surface ◽  
Unstable Condition ◽  
Geological Time ◽  
Development Control ◽  
Planning Development ◽  
The Uk ◽  
Rock Strata

AbstractThe dissolution of limestone and chalk (soluble carbonates) through geological time can lead to the creation of naturally formed cavities in the rock. The cavities can be air, water, rock or soil infilled and can occur at shallow levels within the carbonate rock surface or at deeper levels below. Depending upon the geological sequence, as the cavities break down and become unstable they can cause overlying rock strata to settle and tilt and also collapse of non-cemented strata and superficial deposits as voids migrate upwards to the surface. Natural cavities can be present in a stable or potentially unstable condition. The latter may be disturbed and triggered to cause ground instability by the action of percolating water, loading or vibration. The outcrops of various limestones and chalk occur widely across the UK, posing a significant subsidence hazard to existing and new land development and people. In addition to subsidence they can also create a variety of other problems such as slope instability, generate pathways for pollutants and soil gas to travel along and impact all manner of engineering works. Knowledge of natural cavities is essential for planning, development control and the construction of safe development.

scholarly journals About this title - Geological Hazards in the UK: Their Occurrence, Monitoring and Mitigation – Engineering Group Working Party Report

2020 ◽  
Vol 29 (1) ◽  
pp. NP-NP
Author(s):  
D. P. Giles ◽  
J. S. Griffiths
Keyword(s):  
Working Party ◽  
Volcanic Eruptions ◽  
Engineering Geologist ◽  
Geological Hazards ◽  
Geological Time ◽  
Full Spectrum ◽  
The Public ◽  
Wide Range ◽  
The Uk ◽  
Swelling And Shrinking

The UK is perhaps unique globally in that it presents the full spectrum of geological time, stratigraphy and associated lithologies within its boundaries. With this wide range of geological assemblages comes a wide range of geological hazards, whether they be geophysical (earthquakes, effects of volcanic eruptions, tsunami, landslides), geotechnical (collapsible, compressible, liquefiable, shearing, swelling and shrinking soils), geochemical (dissolution, radon and methane gas hazards) or georesource related (coal, chalk and other mineral extraction). An awareness of these hazards and the risks that they pose is a key requirement of the engineering geologist.The Geological Society considered that a Working Party Report would help to put the study and assessment of geohazards into the wider social context, helping the engineering geologist to better communicate the issues concerning geohazards in the UK to the client and the public. This volume sets out to define and explain these geohazards, to detail their detection, monitoring and management and to provide a basis for further research and understanding.

scholarly journals Risk Premium Assessment for the Sustainable Valuation of Urban Development Land: Evidence from Spain

2019 ◽  
Vol 11 (15) ◽  
pp. 4191 ◽  
Author(s):  
Codosero Rodas ◽  
Cabezas Fernández ◽  
Naranjo Gómez ◽  
Castanho
Keyword(s):  
Risk Factors ◽  
Urban Planning ◽  
Risk Premium ◽  
Financial Models ◽  
Land Development ◽  
Investment Project ◽  
Influential Factors ◽  
Investment Risk ◽  
Land Valuation ◽  
Planning Development

One of the most important parameters in sustainable urban land valuation is the risk premium. Correct assessment of the risk premium is essential for sustainable valuation. Generally, it is estimated that traditional financial models or historic rates do not take into account the specific risk factors of an investment project. In this paper, we propose a sustainable model to obtain it. It is based on investment risk factors and the urban planning land development stages. We conducted a study in Badajoz, Spain, on four urban stages: first, land without an execution program; second, land with an execution program; third, land with reparceling; and fourth, fully developed and urbanized land. We calculated one different risk premium value for each urban stage. The results show that with this model, we can obtain the risk premium at any time during urban planning development. The urban stage is one of the most influential factors in the risk premium value. It decreases during urban planning development, and fully developed and urbanized land has a lower risk premium.

A Test for the Wettability of Carbonate Rocks

1970 ◽  
Vol 10 (01) ◽  
pp. 3-4 ◽  
Author(s):  
E.M. Duyvis ◽  
L.J.M. Smits
Keyword(s):  
Crude Oil ◽  
Carbonate Rock ◽  
Cold Water ◽  
Extraction Procedure ◽  
Soxhlet Extraction ◽  
High Viscosity ◽  
Spontaneous Imbibition ◽  
Rock Surface ◽  
Test Plate ◽  
Water Saturated

Direct imbibition experiments to test carbonate-rock wettability are occasionally prevented by high viscosity of the oil or rigid films between oil and water. The oil must then be removed from the rock before the imbibition test. A new extraction procedure was tested on limestones born Middle East reservoirs. Samples were taken from rubber-sleeve cores under nitrogen in a polythene glove bag to avoid formation of surface-active compounds through oxidation of crude oil. Conventional Soxhlet extraction of crude oil made water-wet carbonate rock oil-wet. Obviously the hot, dry solvent removes the water before the oil is completely extracted; the oil then contacts the rock surface, making it oil-wet. The extraction procedure was therefore modified so that cold and water-saturated chloroform reached the sample. To remove the oil effectively, the material was crushed and then stirred vigorously during extraction. Fig. 1 shows the extraction apparatus. The chloroform in the extraction thimble was kept saturated with water by the initial addition of some water to the boiling vessel. The vapor from this vessel is then richer in water than cold, water-saturated chloroform. The alundum thimble was made oil-wet (by dimethyl dichlorosilane allowing the solvent to pass through. Blank tests with water-wet and oil-wet samples showed a 1-week test to be appropriate for the extraction. The samples were dried and the wettability was determined by imbibition. A small amount of the sample was placed as a ridge in a hollow of a test plate and was wetted with toluene. By placing plate and was wetted with toluene. By placing water and toluene on either side of the ridge, we could determine whether water displaces toluene from the sample. This can be detected easily because sample material wetted with water is much lighter than that wetted with toluene. If water was indeed imbibed the sample was water-wet. Those samples in which water was not imbibed were tested as follows:the material was mixed with watera edge was again formed in a hollow; andwater and oil were placed on either side to determine whether or not toluene displaced water. So far, we have never observed this spontaneous imbibition. We therefore mixed the fluids and the sample and observed whether the grains were now wetted by toluene (darkening of the grain surface). If so, the sample was called oil-wet. A sample showing no imbibition in either case was neutral. The reliability of the procedure was verified by subjecting limestone core samples to both dry Soxhlet extraction and our wet extraction. The parts of samples from the dry extraction were parts of samples from the dry extraction were oil-wet, and those from the wet extraction were water-wet. Thus, either the samples were originally water-wet and became oil-wet by dry extraction, or they were originally oil-wet and became water-wet through wet extraction. The oil-wet samples could not be made water-wet by subsequent prolonged wet extraction. Thus the original samples must have been water-wet. Wet extraction does change an oil-wet condition to neutral, but never to water-wet. Therefore, a sample found to be water-wet was water-wet before extraction, and a sample found to be neutral was either oil-wet or neutral before extraction. P. 3

Building a New Village Prepared Regulatory Approaches and Methods under the Background of Suburban Towns - A Case Study in Renhe, Dazhu County of Sichuan

2013 ◽  
Vol 689 ◽  
pp. 500-504
Author(s):  
Bin Shi ◽  
Kang Cai Nie
Keyword(s):  
Land Use ◽  
Land Development ◽  
Small Towns ◽  
Spatial Layout ◽  
Coordination Control ◽  
Development Control ◽  
Regulatory Detailed Planning ◽  
Regulatory Plan ◽  
Planning And Construction

Under the background of the new village rapid planning and construction, the author tries to explore regulatory detailed planning ideas and methods on district from the structure of land use, spatial layout, road system, land development control. It aims at solving township in regulatory plan coordination control and providing reference for small towns and suburbs of regulatory detailed planning village planning and construction.

Slope instability and valley formation in Canadian soft clay deposits

1986 ◽  
Vol 23 (3) ◽  
pp. 261-270 ◽  
Author(s):  
Guy Lefebvre
Keyword(s):  
Slope Stability ◽  
Soft Clay ◽  
Slope Instability ◽  
Coarse Grained ◽  
Stability Conditions ◽  
Geological Time ◽  
Eastern Canada ◽  
Valley Bottom ◽  
Clay Deposits ◽  
Groundwater Regime

The purposes of the paper are to examine the deepening of valleys in clay deposits of Eastern Canada and in particular to look at the changes in the groundwater regime and slope stability conditions during valley formation. Field observations and laboratory testing indicate that the rate of valley deepening in Champlain clay deposits is of the order of only a few millimetres a year, owing to the low erodibility of the intact clay. The clay banks are, however, more erodible, owing to alteration and fissuration.The stratigraphy of Eastern Canadian clay deposits can be simplified by considering it to be a stratum of low permeabilityconfined between two boundary layers of relatively high permeability, which are the till layer at the base and a weathered crust or coarse-grained layer at the top. As the valley bottom get closer to the bottom till layer, the groundwater regime, and consequently the stability conditions, are modified. During the process of valley formation, the groundwater regime passes through astage where the conditions are rather detrimental to slope stability as it evolves toward conditions that enhance bank stability. Those changes in stability conditions happen over geological time more rapidly or less, depending on clay erodibility. Key words: soft clay, valley formation, slope stability, groundwater, erosion, erodibility.

scholarly journals Land, development and the political class: In a translocal ‘Londoni’ village

2020 ◽  
Vol 54 (2) ◽  
pp. 215-235
Author(s):  
Ashraf Hoque
Keyword(s):  
Conflicts Of Interest ◽  
Local Level ◽  
Land Development ◽  
The State ◽  
Political Class ◽  
Anthropology Of The State ◽  
Political Economies ◽  
And Migration ◽  
The Uk ◽  
The Impact

This article expands Akhil Gupta’s (1995, American Ethnologist, 22(2), 375–402) thesis of ‘blurred boundaries’ between ‘the state’ and ‘society’ in South Asia to incorporate the impact of historic labour migrations, which complicate established conceptions of the state in Bangladesh. Based on ethnographic fieldwork in an area of high migration to the UK, the article draws attention to a class of transnational politicians, and their intra-class conflicts of interest, in shaping local-level politics. The article supports Faguet’s (2017, Modern Asian Studies 51(6), 1668–94) contention that the decentralisation of local government has led to the emergence of vernacularised political economies that operate in the shadow of the state, which are also intrinsically facilitated by it. It suggests that state actors appropriate symbols, offices and resources, together with traditional authority and kinship dynamics, to create an idiosyncratic polity. Aspiration towards power that might lead to the occupation of state offices are determined by either the aspirant’s status as a British citizen (Londoni) or through intimate social and economic connections to Britain through kinship (gushti) networks. The article thus makes a broader contribution to the existing literature on the anthropology of the state, transnational politics and the nexus of power, money and migration in postcolonial contexts.

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