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1.
Anthony H. Cooper 《Environmental Geology》2002,42(5):505-512
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. 相似文献
2.
The impact of mining subsidence on the environment can occasionally be very catastrophic, destroying property and even leading
to the loss of life. Usually, however, such subsidence gives rise to varying degrees of structural damage that can range from
slight to very severe. Different types of mineral deposits have been mined in different ways and this determines the nature
of the associated subsidence. Some mining methods result in contemporaneous subsidence whereas, with others, subsidence may
occur long after the mine workings have been abandoned. In the latter instance, it is more or less impossible to predict the
effects or timing of subsidence. A number of different mineral deposits have been chosen to illustrate the different types
of associated subsidence that result and the problems that arise. The examples provided are gold mining in the Johannesburg
area; bord and pillar mining of coal in the Witbank Coalfield, South Africa; longwall mining of coal in the Ruhr district;
mining of chalk and limestone in Suffolk and the West Midlands, respectively; and solution mining of salt in Cheshire. These
mineral deposits have often been worked for more than 100 years and, therefore, a major problem results from abandoned mines,
especially those at shallow depth, the presence of which is unrecorded. Abandoned mines at shallow depth can represent a serious
problem in areas that are being developed or redeveloped. Abstraction of natural brine has given rise to subsidence with its
own particular problems and cannot be predicted. Although such abstraction is now inconsequential in Cheshire, dereliction
associated with past subsidence still remains.
Received: 21 October 1999 · Accepted: 14 February 2000 相似文献
3.
It is suggested that in a localized remnant of Kalahari sand at Dufuya, central Zimbabwe, groundwater flows in an integrated pattern inherited from the paleochannel network of the underlying gneiss. Contact springs occur at discrete localities along the Kalahari sand/gneiss boundary and are associated with spring sapping and land surface subsidence. Subsidence is presumed to be due to preferential solute removal by leaching and dissolution as a result of concentration of groundwater flow within the buried paleochannel network and the location of the springs is presumed to occur where the paleochannel network intersects the Kalahari sand/gneiss boundary. Over time the surficial Kalahari sand is preferentially removed along these buried drainage lines by spring sapping and headwards erosion, exposing the gneiss. Multi-electrode direct current resistivity profiling and radar have been used to map the sub-surface, revealing the topography of the basement and nature of the Kalahari cover. Coincidence of gneiss basement depressions with the spring sites, leached sands and subsidence zones suggests inheritance of the gneiss fluvial paleochannel network pattern by the present day groundwater flow. Washed sand and gravel intersected in shallow boreholes in these areas provides further evidentiary support for the concept of inherited drainage. 相似文献
4.
中国地面沉降及其需要解决的几个问题 总被引：46，自引：2，他引：46
我国地面沉降主要出现在东、中部17个省市,总面积超过5×104km2,同时在17个省市出现成因上与它有关的地裂缝,危害是多方面的。沉降发生在经济高速发展的东部地区,造成的危害和损失也更大。我国地面沉降有下列特点:过量开采地下水是主要原因;各土层变形量既与其压缩性有关,也与它本身的厚度有关;砂土变形基本特征是压缩过程中总的应力与应变关系为非线性,压缩变形以塑性变形为主并包含有蠕变;水位恢复到开采前水平,沉降仍在继续,存在滞后等。从目前研究,特别是模拟研究的现状出发,指出存在8个方面的不足,进而提出需要研究解决的6个科学问题,为提高我国的研究水平献策。 相似文献
5.
Subsurface dissolution (subrosion) of evaporites such as halite and gypsum can lead to extensive land subsidence. Recent land subsidences have been surveyed at six separate locations in northwestern Switzerland. The diameters of the affected surface areas range from 100 to 1,500 m, and corresponding subsidence rates reached more than 100 mm/year. Based on a geometrical model, three sites could be outlined where land subsidence can likely be attributed to salt solution mining. The effects of increased hydrostatic gradient due to both groundwater withdrawal and fluid density contrasts were evaluated in more detail for the remaining sites with a series of 2D density-coupled solute-transport simulations along an approximately 1,000-m-long and 150-m-deep 2D cross section. Simulation results indicate that the upconing process of saline groundwater into the main aquifer occurs under different distributions of subsurface parameters and hydraulic boundary conditions. For the presented setup, the simulations also revealed that the most sensitive factor for the dissolution rate is the structure or dip of the halite formation, which leads to an increase of dissolution rate with increasing dip. Due to the increased density of the brine, an intrinsic flow dynamic develops which follows the direction of the dip. 相似文献
6.
GIS-based assessment of risk due to salt mining activities at Tuzla (Bosnia and Herzegovina) 总被引：1，自引：0，他引：1
Ground subsidence triggered by salt mining from deposits located beneath the city of Tuzla (Bosnia and Herzegovina) is one of the major dangers acting on a very densely urbanized area since 1950, when the salt deposit exploitation by means of boreholes began. As demonstrated in this paper, subsidence induced several hazard factors such as severe ground deformations, the arising of deep and superficial fractures and a very fast water table rise, connected with the brine extraction, now affecting several districts. The above mentioned factors have been quantified by the use of geomatic methodologies, including field surveys and analysis of geographical data. In order to estimate the historical sinking rates, authors processed the large (and never before processed) amount of topographical data collected during two periods; from 1956 to 1991, and from 1992 to 2003, with only poor data collected. Afterward, traditional surveys were completely and definitively stopped. The analysis reveals a cumulative subsidence as high as 12 m during the whole period, causing damage to buildings and infrastructures within an area that includes a large portion of the historical town, at present almost entirely destroyed. Modern sinking rates have been monitored with static GPS whereas the presence of superficial fractures monitored with kinematic GPS. Factors related to the presence of deep fractures and water table rise have been evaluated by curvature analysis techniques and piezometric data respectively. Finally, hazard factors have been combined in a risk map using the GIS (Geographical Information System) map algebra capabilities and a simple multicriteria decision analysis (MDA). In order to do that, a vulnerability map has been derived on the basis of information reported on a couple of recently sensed high resolution satellite imageries. The final risk, arisen from the combination of single hazard factors and vulnerability map, highlights critical scenarios and unsuspected threatening that are under consideration by the local decision makers and urban planners. In particular, as highlighted in the final risk map, the present-day water table rise, triggered by the decrease in brine pumping, is seriously posing a threat to a portion of the city which is not the most involved in ground deformations. 相似文献
7.
本文主要依据重力资料讨论了柴达木盆地中卤水钾矿床的空间展布规律,预测了盆地含钾卤水中的氯化钾总资源量.柴达木盆地的钾盐矿床以卤水钾矿为主,卤水钾矿受第四纪凹陷的严格控制,并与重力负异常相对应,第四纪凹陷的形成和发展又与柴达木地块的基底性质有着密切的联系.根据重、磁异常推断表明:柴达木盆地分为东、西两部分,从西部到东部成盐时间由早变晚,盐层由厚变薄.含钾卤水层厚度与重力负异常强度呈线性正相关.我们以此为基础在上述盆地西部50000km2的范围内进行了钾资源总量预测. 相似文献
8.
The large hydrocarbon basin of South Caspian is filled with sediments reaching a thickness of 20–25 km. The sediments overlie a 10–18 km thick high-velocity basement which is often interpreted as oceanic crust. This interpretation is, however, inconsistent with rapid major subsidence in Pliocene-Pleistocene time and deposition of 10 km of sediments because the subsidence of crust produced in spreading ridges normally occurs at decreasing rates. Furthermore, filling a basin upon a 10–18 km thick oceanic crust would require twice less sediments. Subsidence as in the South Caspian, of ≥20 km, can be provided by phase change of gabbro to dense eclogite in a 25–30 km thick lower crust. Eclogites which are denser than the mantle and have nearly mantle P velocities but a chemistry of continental crust may occur beneath the Moho in the South Caspian where consolidated crust totals a thickness of 40–50 km. The high subsidence rates in the Pliocene-Pleistocene may be attributed to the effect of active fluids infiltrated from the asthenosphere to catalyze the gabbro-eclogite transition. Subsidence of this kind is typical of large petroleum provinces. According to some interpretations, historic seismicity with 30–70 km focal depths in a 100 km wide zone (beneath the Apsheron-Balkhan sill and north of it) has been associated with the initiation of subduction under the Middle Caspian. The consolidated lithosphere of deep continental sedimentary basins being denser than the asthenosphere, can, in principle, subduct into the latter, while the overlying sediments can be delaminated and folded. Yet, subduction in the South Caspian basin is incompatible with the only 5–10 km shortening of sediments in the Apsheron-Balkhan sill and south of it and with the patterns of earthquake foci that show no alignment like in a Benioff zone and have mostly extension mechanisms. 相似文献
9.
R. D. Lokhande V. M. S. R. Murthy K. B. Singh 《Geotechnical and Geological Engineering》2013,31(2):793-799
Subsidence is a gradual or sudden depression of the ground on the surface due to extraction of minerals from underground. It occurs in two forms, namely, trough and pot-hole subsidence. Trough subsidence is a depression covering a large surface area, whereas pot-hole subsidence is a localized phenomenon which occurs due to sudden collapse of overburden into the underground voids. Pot hole is extremely hazardous as it does not give any prior indication before its occurrence. Several pot-holes have occurred in the recent past in the coal mines of South Eastern Coalfield Limited and therefore the study assumes great importance. This paper presents the mechanism, behaviour and critical influencing parameters concerning pot-holes. Field investigations and analysis carried out on pot-holes which occurred in some of the Indian coal mines are presented for highlighting the importance of the same. 相似文献
10.
V. PAUL WRIGHT 《Sedimentology》1986,33(2):221-241
During early Carboniferous times a major sea-level rise led to the development of an extensive carbonate ramp over what is now South Wales. Differential subsidence and sea-level changes resulted in distinctive facies sequences in the ramp succession and a model is offered which recognizes three distinct geomorpho-tectonic settings; inner, mid- and outer ramp. The inner ramp zone occurs in the more landward part of the province and was an area undergoing little or no subsidence. The sequence is dominated by oolitic grainstones and peritidal limestones representing shoal and back shoal environments. The peritidal units are transgressive deposits consisting of stacked asymmetrical shallowing-up cycles. The sequence contains many subaerial breaks and tectonic uplift resulted in base-level changes and fluvial incision. The mid-ramp zone sequence is intermediate in thickness between the inner and outer ramp successions and consists mainly of bioclastic limestones deposited below fairweather wave base. Sedimentation periodically exceeded sea-level rise and subsidence, and regressive (progradational) oolitic sand bodies developed, the thickest of which are stacked units with up to four individual sand bodies. Storm processes were of major importance in this setting. The outer ramp zone is represented by a thick sequence of muddy bioclastic limestones deposited below storm wave base and major Waulsortian reef-mounds also developed. None of the shallowing phases seen in the other ramp zones can be detected in this sequence. Subsidence and eustatic sea-level rise seem to have been the major controls on deposition but the recognition of eustatic sea-level falls is difficult. The detailed facies model for ramp carbonates presented here may be applicable elsewhere in the geological record. 相似文献
11.
柴达木盆地西部卤水水化学特征与找钾研究 总被引：11，自引：0，他引：11
柴达木盆地自中生代末-新生代初以来,四周山体不断抬升,形成"高山深盆"的沉积环境,为盆地带来了大量盐类物质,再加上晚第三纪干旱封闭的气候环境,使其西部沉积了广阔而厚层的盐岩.在对柴达木盆地西部第三系、第四系地层出露盐矿点实地考察的过程中,采集、分析了22件水样品的水化学组成,通过K+含量及一些水化学系数变化特征的研究,查明了卤水的水化学类型主要为氯化物型和硫酸镁亚型,其成因基本属溶滤岩盐卤水、深部循环水以及二者的混合水体,Br-、B3+、Sr2+、Li+等微量离子含量较高,区域差异性较大,出现显著水化学系数异常;相比之下,柴达木盆地西部南翼山坳陷Br-、B3、Sr2+、Li+含量值明显高于昆特依、察汗斯拉图、油砂山、开特米里克、油泉子、油墩子等坳陷区.Br×103/Cl、K×103/Cl等具找钾意义的水化学系数比其他地区高1～2倍,Br-、K+出现相对的富积,推测该坳陷成盐原始卤水曾浓缩达到较高析盐阶段或可能有大量深部富钾水体的补给,可作为寻找钾盐矿(富钾卤水)重点区域之一. 相似文献
12.
唐山沿海地区经济在迅速发展,沿海地区城市化规模在扩大,地下水开采量增大,地面沉降加剧.文中分析了唐山沿海地区的水文地质条件,概化为3个含水层、3个弱透水层,共6个压缩层.建立了三维地下水流和垂向一维压缩完全耦合模型.采用25a的观测资料校正模型,计算值与实测值拟合较好,模型具有较高的仿真性和适用性.预测了10a末的地面沉降;当地下水以现有开采量开采时,沉降中心累计达1192.3mm, 10a沉降352.3mm,沉降速率为35.23mma-1;当地下水的开采量在现有开采量的基础上增加10%时,沉降中心累计达1260.8mm, 10a沉降420.8mm,沉降速率为42.08mma-1; 当地下水的开采量在现有开采量的基础上减小10%时,沉降中心累计达1088.7mm, 10a沉降247.9mm,沉降速率为24.79mma-1.增大10%的地下水开采量, 10a地面沉降量增加68.5mm;减少10%的地下水开采量, 10a地面沉降量减少104.4mm.因此,控制地下水开采量是控制地面沉降的有效方法. 相似文献
13.
牛驼镇凸起是冀中拗陷中一个显著的次级正向构造,其地理位置见图1。1973—1978年进行石油普查和勘探时,在该区相继发现了地下热水,引起了人们的注意,先后对热水的分布有过报道和论述[1,2]。鉴于牛驼镇凸起(包括容城凸起)地热异常在华北平原具有代表性,我们在石油部门的协助下,在本区较系统地开展了地温测量并收集有关资料进行研究。本文试图剖析这个典型地区地温场的特点,作为圈定和预测华北平原地热异常区以及分析地下热水分布规律的基础。 相似文献
14.
Thomas L. Holzer 《Engineering Geology》1989,27(1-4):449-466
Land subsidence caused by man-induced depressuring of underground reservoirs has occurred in at least nine urban areas in the United States. Significant efforts to control it have been made in three areas: Long Beach, California; Houston-Galveston, Texas; and Santa Clara Valley, California. In these areas coastal flooding and its control cost more than $300 million. Institutional changes were required in each area to ameliorate its subsidence problem.
In Long Beach and Houston-Galveston, efforts were made to mitigate subsidence only after significant flood damage had occurred. To arrest subsidence at Long Beach, the city lobbied for a special state law, the California Subsidence Act, that required unitization and repressuring of the Wilmington oil field. In the Houston-Galveston region, the Texas State Legislature authorized formation of the Harris-Galveston Coastal Subsidence District with authority to regulate ground-water pumping by permit. This solution, which was achieved through efforts of entities affected by subsidence, was the product of a series of compromises necessitated by political fragmentation and disjointed water planning in the region. Amelioration of subsidence in the Santa Clara Valley was a collateral benefit from the effort by water users to curtail ground-water overdraft in the valley. Importation of surface water and a tax on ground-water pumpage reduced ground-water use, thereby allowing the recovery of water level and the arresting of subsidence. 相似文献
15.
Land subsidence caused by ground water withdrawal in urban areas 总被引：1，自引：0，他引：1
At least eight urban areas in the world have encountered significant economic impact from land subsidence caused by pumping of ground water from unconsolidated sediment. The areas, most of which are coastal, include Bangkok, Houston, Mexico City, Osaka, San Jose, Shanghai, Tokyo, and Venice. Flooding related to decreased ground elevation is the principal adverse effect of the subsidence. Lesser effects include regional tilting, well-casing failures, rising buildings, and ground failure or rupture. Subsidence of most of these urban areas began before the phenomenon was discovered and understood. Thus, the subsidence problems were unanticipated. Methods to arrest subsidence typically have included control of ground water pumping and development of surface water to offset the reductions of ground water pumping. Ground water recharge has also been practiced. Areas threatened by flooding have been protected by extensive networks of dikes and sea walls, locks, and pumping stations to remove storm runoff. 相似文献
16.
Deep-seated salt dissolution and associated subsidence have occurred in many salt-bearing sedimentary basins. Because of its capacity for brea hing the hydrologic integrity of a thick salt unit, the dissolution-subsidence process is a potential hazard requiring thorough assessment at proposed radioative-waste repository sites in bedded salt. In order to develop a better understanding of this potential hazard, a combination of field studies and theoretical analyses are used to delineate the physical processes that control dissolution and subsidence. This information is used, in turn, to develop strategies for assessing this hazard at any given bedded salt repository site.
A generalized hydrogeological model of dissolution has been developed consisting of a salt unit separated from an underlying aquifer by a low-permeability unit. This model suggests that local salt-removal rates can vary over many orders of magnitude, from microns per year to meters per year, depending on the hydrogeologic conditions beneath the salt unit.
Salt deformation is strongly rate-sensitive, so the rate of salt removal strongly influences the structural form of subsidence. Low salt-removal rates produce predominantly ductile subsidence, which is characterized by the gradual formation of a braod shallow depression that is narrower and deeper in successively lower horizons. On the other hand, high salt-removal rates produce predominantly brittle subsidence, which is characterized by the formation of a steep-walled chimney, filled with down-dropped, brecciated rock. Ductile subsidence depressions and brittle subsidence chimneys most likely represent the endpoints of a continuous range of structural forms.
Assessing potential dissolution-subsidence hazards at a given repository site begins with the identification and characterization of existing dissolution-subsidence features in the site area. Studies of existing features should be complemented by an evaluation of the potential for undetected or future dissolution activity, based on the deep hydrogeologic conditions at the site. Potential salt-removal rates predicted by this analysis are then used as an analysis of the structural character and timing of potential subsidence. 相似文献
17.
徐强 刘宝珺 余光明 G. Einsele W. Frisch 刘光华 J. Wendt A. Wetzel L. Ratschbacher H. P. Luterbacher 《沉积与特提斯地质》1993,(1):58-65
喜马拉雅特提斯中、新生代属印度板块北部被动大陆边缘。对充填这个被动大陆边缘的沉积物用“反剥法”(backstrippiog)进行研究,恢复了从被动大陆边缘到前陆盆地的抓降史。对分离出的盆地构造沉降曲线与McKenzie模式图版进行对比相关性分析,判断认为被动大陆边缘成熟期主要为热耗散沉降,前陆盆地时逆冲推覆动力为主要影响因素。 相似文献
18.
Subsidence involves sinking of the ground surface. The movement generally is localised and may or may not involve some amount of horizontal movement. It may be rapid or take place gradually over a period of time. Subsidence may be brought about by natural causes as, for example, when the roof of a cavern in limestone is weakened to the extent that it is no longer self-supporting and so collapses. Other more exotic examples are associated with volcanism and earthquakes. Perhaps, however, subsidence is more frequently associated with movements caused by mining activities, that is, the removal of mineral deposits, be they in solid, liquid or gaseous form, from within the ground. Mining is one of the earliest activities of man and has taken place in every continent. Subsidence also can result from subsurface excavations such as tunnels, caverns, cellars and sewers. One of the added problems of some forms of subsidence is that it is impossible to predict. This, coupled with the fact that the presence of potentially collapsible voids may be unknown, unrecorded or simply forgotten about further complicates the problem. The objectives of this paper are to document and draw attention to a number of unusual examples of subsidence. These have been generated due to the mining of chalk in southern England, the collapse of slate mines and caverns in Germany, the underground extraction of evaporites in Northern Ireland, fault reactivation in Wales and northern England and the extensive extraction of pumice on the flanks of Galeras volcano in Colombia. 相似文献
19.
Persistent pumping of groundwater is known to cause subsidence of the ground surface. When the soil is composed of alternating layers of sand and clay, subsidence is, in general, a consequence of pressure change in and deformation of all layers. Even with various simplifications, the mathematical task for the mechanics of a layered soil is complex and, in the past, many idealizations have been introduced in the literature. Among the existing approximations, a well-known approximation by Hantush1 for well-hydraulics in leaky aquifers is intuitively attractive. He used the fact known to be strictly true for simple flows in a soil system with horizontal layers, that the flow must be mainly horizontal in a relatively porous aquifer and mainly vertical in a highly impervious aquitard, and invoked the same approximation for transient flows induced by well-pumping. In this paper we shall apply a perturbation analysis to give a mathematical confirmation of the hydrological approximation and to show its degree of accuracy. In particular, we treat a three-layered system, where the middle layer is a relatively soft aquitard, and the well withdraws water from the artesian aquifer at the bottom. The upper aquifer has a phreatic surface. Physically, we examine the often ignored effects of self-weight which is important for thick aquitards. The perturbation theory is worked out for sufficiently weak pumping rates and small soil deformation. Subsidence in the vertical direction due mainly to the deformation of the soft aquitard is studied. Results show that the common assumption of constant total stress with respect to depth is valid only when the storage coefficient is very small. 相似文献
20.
国际地面沉降研究综述 总被引：20，自引：2，他引：18
文章在介绍国际地面沉降会议历史及２０００年第六届国际地面沉隆会议简况的基础上,并根据２０００年第六届国际地面沉降会议论文,对国际地面沉降研究进展情况分成如下六个方面进行了综述。地面沉降地质因素介绍了古代地面沉降、泥炭层沉降、地震砂土液化地面沉降和海平面上升研究状况。地下流体运移地面沉降方面介绍了以地下水开采为主的地面沉降问题及地面塌陷、天然气开采引起的地面沉降、均匀沉降对建筑结构的破坏和欠固结石英 相似文献