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1.
水敏现象在石油、岩土和环境工程等领域广泛存在。有效地控制水敏现象的发生，不仅具有科学意义，还有一定的经济价值。本文在广泛查阅国内外研究成果的基础上，总结了水敏性在石油、岩土和环境工程方面应用的研究进展，并在此基础上提出了水敏性研究的发展方向。 相似文献
2.
《Applied Geochemistry》2003,18(5):675-691
The small karstic watershed of Lanmuchang, in a Hg–Tl mineralized area in SW Guizhou Province, China, exhibits an enrichment of toxic Tl in groundwater and related stream water. This affords an excellent demonstration of the natural processes of Tl dispersion, and the resultant impact on the local ecosystem. The distribution of Tl in the water system follows a decreasing concentration pattern from deep groundwater to stream water to shallow groundwater. Tl shows high levels (13–1100 μg/L) in deep groundwater within the Tl-mineralized area, decreasing with distance away from the mineralized area to background levels (0.005 μg/L). The distribution of Tl in the water system is constrained by Tl mineralization, water–rock interactions and hydrogeological conditions. Tl concentrations in waters generally correlate with concentrations of total dissolved solids, sulphate, Ca and pH values, suggesting the contribution of water-rock interactions to water geochemistry. Water–rock interactions are driven by weathering of Tl-bearing sulfides which decreases pH values in groundwater, and by dissolution of limestone enhanced by acid fluids. Tl in stream water in both the base-flow and flood-flow regimes shows higher concentrations than it does in shallow groundwater that serves as the stream's source (mainly springs, dug-well flows and karstic cave waters). Concentrations of Tl in stream water in the flood-flow regime are generally lower than in the base-flow regime due to dilution effects, but those in the waters of mid-stream are almost the same as in the base-flow regime, probably due to contribution from Tl-rich soil water seepage or from acid mine drainage (AMD). Unexpectedly, Tl concentrations in stream water in both regimes are remarkably higher (2–30 fold) downstream than up- and mid-stream. These pronounced increases of Tl concentration are likely caused by unidentified discharges of deep groundwater through fractured zones to the downstream trace. The groundwater-related Tl transfer processes affect the ecosystem through contamination of water supply and arable soil and ultimately the food chain with undoubted risks to human health. Therefore, the results of this study are important for environmental planning and regulations, and will also serve as baseline data for future research on Tl natural dispersion processes. 相似文献
3.
复杂环境下浅埋暗挖隧道穿越薄富含水层冻结温度场研究 总被引：1，自引：0，他引：1
提出了南京地铁2号线新街口－上海路隧道穿越薄富含水层冻结法止水加固方案,利用ADINA有限元软件对该浅埋暗挖隧道涌水段建立冻结温度场数值模型,分析了冻结管间距、冻结盐水温度、冻结管直径对冻结壁发展速率、冻结壁厚度、平均温度的影响,以此为基础对冻结参数开展优化设计,并获得成功应用。研究结果表明：利用人工冻结技术能够有效解决这一特殊岩土工程难题。为了在支护段获得有效地止水冻土帷幕,冻结管间距应小于等于1 m;冻结工程中采取-30℃的盐水温度既能满足需冷量,又能符合经济性要求;采取大直径的冻结管对增加冻土墙厚度与降低冻土壁平均温度的影响并不显著。 相似文献
4.
福州轨道交通建设中的岩土工程问题 总被引：1，自引：0，他引：1
由于福州盆地工程地质条件的复杂性以及隧道工程的特殊性,在福州轨道交通建设过程中将遇到大量环境岩土工程问题。主要的环境岩土工程问题有:(1)隧道掘进范围内的承压含水层。承压含水层富水性、透水性强,由于开挖深度大,必须考虑下部承压水的影响,避免产生基坑突涌问题。砂砾卵石层直接覆盖于基岩裂隙热水上,受热水构造带高温热水的直接补给以及热传导,地下轨道交通建设对地热场是否存在影响以及地热对轨道交通的影响需要深入研究。(2)软土的大变形与低强度。导致地基失稳与土体结构强度破坏。(3)深大基坑开挖施工引发的可能灾变。基坑开挖易产生滑塌、流泥、突水(涌)、地表沉陷等问题,必须采取有效的支护措施,避免基坑失稳而影响工程安全及周边环境。对这些环境岩土工程问题,应加强勘察新技术的应用,查明建设场地岩土工程地质条件;采用人工地层冻结法、桩基托换技术进行施工;开发和利用适合本地区岩土条件的新技术、新工艺,如新型桩、新的止水、降水措施等基坑支护新技术,以及采用信息化施工新技术。 相似文献
5.
The construction of one of the high-speed railway tunnels between Malaga and Córdoba (South Spain) beneath the Abdalajís mountains
occasioned a series of hydrogeological problems with geotechnical and environmental impacts. The double tunnel, 7,300 m in
length, runs south to north across several lines of small, calcareous mountains that have a highly complex structure. Beneath
the Jurassic limestones lie Triassic clays and evaporites. Overlying the limestones is an essentially marly and limestone-marl
Cretaceous series, which culminates with Miocene marls containing some organic matter. These mountains have generated springs
that are used for urban water supply and irrigation, as well as drinking fountains in the surrounding villages. The initial
water level in the aquifer series varied from 400 to 650 m above sea level. After drilling approximately 2,900 m, and intercepting
a fracture zone within the carbonate rocks, a sudden water eruption occurred that reached a peak flow of 800 L/s. After a
short while, spring discharges dried up, leading to a public protest. In this paper, we describe the geological and hydrogeological
settings, the development of the aquifer as the drilling operation proceeded, the measures adopted and the responses subsequent
to completion of the tunnel, including the effect of rainfall on the recovery of water levels. Lastly, a generalized estimate
is made of how the system functions, and a forecast is made for recovery of its equilibrium. 相似文献
6.
Past disposal of oil-field brine at the surface has caused substantial contamination of water resources in Kansas. Natural saline water occurs in and discharges from Permian bedrock in parts of the state, and other anthropogenic sources of saline water exist, requiring clear identification of different sources. Time-series analysis of Cl− concentration and streamflow relative to pre-contamination contents, and end-member mixing plots, especially for Br− and Cl−, are practical methods for source differentiation and quantification. Although regulations preventing escape of saltwater from oil wells were first passed in Kansas in 1935, much oil and gas brine was disposed on the surface through the 1940s. Hydrogeologic characteristics of the areas with past surface disposal of oil brine differ appreciably and result in large differences in the ratio of saltwater transported in streams or ground water. Much of the brine disposed during the 1910s to 1940s in an area of silty clay soils overlying shale and limestone bedrock in south-central Kansas soon ran off or was flushed from the surface by rain into streams. Chloride concentration in the rivers draining this area often exceeded 1000 mg/L after the start of oil production up to the 1950s. Chloride content in the rivers then generally declined to about 100 mg/L or less in recent low flows. Oil brine was also disposed in surface ponds overlying the unconsolidated High Plains aquifer in south-central Kansas from the latter 1920s into the 1940s. Most of the surface-disposed brine infiltrated to the underlying aquifer. Where the High Plains aquifer is thin, saltwater has migrated along the top of clay layers or the underlying shaly bedrock and either discharged into small streams or flowed into thicker parts of the aquifer. Where the aquifer is thick, surface-disposed oil brine moved downward until reaching clay lenses, migrated latterly to the edge of the clay, and again moved downward if still dense enough. Water-level declines from pumping have increased the lateral migration rate of the saltwater contamination in the aquifer towards water-supply wells. The period of flushing most of the surface-disposed saltwater from the area of shale and limestone bedrock is on the order of many decades but is at least many centuries for the deeper parts of the High Plains aquifer. 相似文献
7.
分析了城市环保信息系统建设的现状,基于SuperMap对城市环保信息系统进行系统设计,分析系统的体系结构,设计环保系统的主要功能,在Supermap平台上实现了大气污染扩散、水污染扩散分析等高级功能,为环境保护工程提供了技术支持。 相似文献
8.
9.
Gaza central seawater desalination plant is a promising solution to alleviate the problem of water crisis in the Gaza Strip. The plant in the short term, phase (I), will desalinate seawater for potable uses with a capacity of 55 million cubic meters per year, while in the long term, phase (II), the plant capacity will be doubled to 110 million cubic meters per year of freshwater. As a product from the reverse osmosis process, a huge amount of brine with salinity reaches to 75,000 mg/L will be redirected to seawater; nearly 12,200 m3/h of brine will be rejected from phase (I) while in the long term, a brine flow rate of 24,400 m3/h will be disposed from phase (II). In order to minimize the negative impacts of the rejected brine on the marine environment, it is urgent to modeling numerically the impact of the discharged brine through various disposal systems to define the most environmental system. Various scenarios were defined and simulated using CORMIX model to study the efficiencies of onshore surface open channel, offshore submerged single port as well as offshore submerged multiport outfalls taking salinity variations as an indicator. Sensitivity analysis was conducted to identify the most influencing input parameters on the simulation results as well as to evaluate the optimal environmental disposal system which can mitigate the adverse impacts of brine on the marine ecosystem as much as possible in the worst seawater conditions. The simulation results showed that the discharge via surface open channel is not environmentally feasible where the seawater salinity rose by more than 2000 mg/L at RMZ. The single-port scenario can meet the regulations at RMZ but the standard at GMZ was not met, where the rejected brine from phase (I) through single port at 1500 m offshore raises the seawater salinity at GMZ by more than 600 mg/L. The staged multiport outfall, capped by 24 ports, achieves acceptable brine dilution at seawater depth of about 7.5 m, and in the worst ambient conditions in the case of phase (II) in operation, the brine’s excess salinity was 536, 497, and 379 mg/L above the salinity of seawater at RMZ, GMZ, and ROI, respectively. 相似文献
10.
关于岩土样本统计分析的几点讨论 总被引：1，自引：0，他引：1
结合岩土单元体的天然成因及人为设定的基本特性,阐述了岩土样本离散的必然性及其离散程度与岩土单元体分划范围的相关性,通过对变异系数的适用性及岩土样本概况性的分析,提出采用均同指数评价样本分布的离散程度和按相对容量标准控制岩土样本数量等观点,建议切实针对岩土母体的分布形态推断标准值,同时对小样本条件下标准值的确定方式进行了分析和建议。 相似文献
11.
《Computers and Geotechnics》2006,33(6-7):330-340
Artificial ground freezing is an effective ground improvement technique to deal with diverse geotechnical construction problems as it serves to cut off the water and also improves the ground soil strength. However, ground freezing may produce frost heave and thaw settlement at the ground surface. Predicting and controlling the frost heave is a challenge to engineering construction in a heavily populated city. This paper proposes an analysis model that couples the water freezing, temperature and stress fields. This model is first applied to an underground excavation problem of a corridor where ground freezing is used. The numerical predictions are compared with field measurements. It is then applied for a model tunnel problem to study the effect of the overlying soil thickness, frozen soil wall thickness, excavation radius and brine temperature on the frost heave. It is found that the vertical component of the frost heave follows a normal distribution with a maximum at the tunnel axis, while the horizontal component reaches a maximum at a distance from the tunnel axis. This distance is directly proportional to the thickness of the overlying soil. A critical brine temperature is also found at which the frost heave at the ground surface reaches a maximum. 相似文献
12.
陆相盐湖盐源复杂多样,主要有陆源、海源和地壳深部三大类。前两类主要通过蒸发成盐,气候起着关键作用,形成的陆相盐湖低水位和高水位体系域中盐岩发育,湖侵体系域中盐岩相对不发育;第三类主要通过兑卤成盐,作为深层卤水通道的深大断裂的活动期次控制了盐岩的发育,盐岩主要发育在湖侵体系域,高水位体系域次之,低水位体系域中盐岩一般不发育。 相似文献
13.
城市地下工程中的环境岩土工程问题 总被引：8，自引：0，他引：8
近年来, 随着城市人口的急剧增长, 交通与住房拥挤状况日趋突出, 在我国一些大中城市中, 道路交通隧道、地铁工程、地下商城等地下工程建设项目在逐年增多。由于城市工程环境特殊性和地下工程的特点, 在其施工过程中经常出现基坑失稳 (明挖 )、地面沉降、岩溶塌陷、洞室失稳、巷道突水等多种环境岩土工程问题, 不仅严重影响地下工程建设和周围建筑物环境安全, 而且给国家造成重大经济损失。这一问题已引起岩土工程领域很许多专家的关注, 并成为该领域的研究热点。本文结合南京市区地下工程建设的实际情况, 探讨城市地下工程环境岩土工程问题的特点和形成机理, 并提出解决地下工程环境岩土工程问题的方法和建议。 相似文献
14.
Study of shallow groundwater quality evolution under saline intrusion with environmental isotopes and geochemistry 总被引：2，自引：0，他引：2
Evolution of the shallow groundwater quality under saline intrusion in porous aquifer system has been studied with environmental
isotopes and geochemistry in the Laizhou Bay area, China. Two campaigns of water sampling from various sources were carried
out in spring and winter for environmental isotopic and chemical analyses. The origin of groundwater salinity from intrusion
of both modern seawater and deep brine water was identified by analysing the correlations between 18O, D, T, Cl−, SO42− and electrical conductivity. The results indicate that the brine is originated from evaporating and concentrating of intruded
seawater and its δD and δ18O are different from modern seawater but similar to those of mixture of seawater with fresh groundwater. It is hard to distinguish
the salinity origin in this area by the δD–δ18O relationship alone. The relations between δ18O and conductivity, Cl− and SO42− have been used to identify the salinity origin due to the distinct difference in salinity between the brine and seawater,
conjunctively with use of T. A threshold of T = 12 TU was adopted to identify the origin of saline groundwater. 相似文献
15.
通过对湘西上洞街煤矿区毛家寨段水文地质测绘、地质钻探及邻近生产矿井资料收集，综合分析研究认为：勘查区煤矿床主要充水主要为其顶、底板岩溶裂隙水，目前岩土工程地质条件比较简单，环境地质现状良好。煤矿开采后，因大量疏排岩溶地下水而导致的水、工、环不良地质问题将是今后矿区防治丁作的重点。 相似文献
16.
Anis Chekirbane Maki Tsujimura Atsushi Kawachi Fethi Lachaal Hiroko Isoda Jamila Tarhouni 《Hydrogeology Journal》2014,22(8):1777-1794
The study area is a small coastal plain in north-eastern Tunisia. It is drained by an ephemeral stream network and is subject to several pollutant discharges such as oilfield brine coming from a neighboring oil company and wastewater from Somâa city, located in the upstream of the plain. Furthermore, a hydraulic head near the coastal part of the aquifer is below sea level, suggesting that seawater intrusion may occur. A time-domain electromagnetic (TDEM) survey, based on 28 soundings, was conducted in Wadi Al Ayn and Daroufa plains to delineate the saline groundwater. Based on longitudinal and transversal resistivity two-dimensional pseudosections calibrated with boring data, the extent of saline water was identified. Geochemical tracers were combined with the resistivity dataset to differentiate the origin of groundwater salinization. In the upstream part of the plain, the infiltration of oilfield brine through the sandy bed of Wadi Al Ayn seems to have a considerable effect on groundwater salinization. However, in the coastal part of the aquifer, groundwater salinization is due to seawater intrusion and the saltwater is reaching an inland extent around 1.3 km from the shoreline. The contribution ratios of saline water bodies derived from the inverted chloride data vary for the oilfield brine from 1 to 13 % and for the seawater from 2 to 21 %. 相似文献
17.
环境岩土工程是近年来发展起来的一门新兴学科。随着城市化的进展,环境岩土工程问题已成为制约徐州市国民经济发展的重要因素。本文根据已有资料和工程实践,阐述了徐州市存在的地面塌陷、固体废弃物、矿坑突水、崩塌滑坡、深基坑开挖等城市环境岩土工程问题,并提出了相应的防治对策。 相似文献
18.
油泉子凹地位于柴达木盆地西部,凹地中蒸发岩的晶间孔隙发育,包含了大量的高浓度卤水,KCl品位高,富水性中等,水化学类型有氯化物型、硫酸镁亚型、硫酸钠亚型。研究表明,周边山区岩石中钾、硼、锂、钠、镁等元素物理风化后经流水搬运,形成了研究区丰富的钾盐矿物质;相关元素比值反映了矿区卤水陆相来源、溶滤水的成因特点。研究显示,研究区内地下水的密度、矿化度均有由西向东逐渐变淡的趋势;水文地质条件表明,季节性洪水、大汽降水是卤水重要的补给源。研究区地势低洼,地下水的排泄方式主要为蒸发排泄,形成了具有典型内陆蒸发型的水文地球化学特征,因此富集了大量高矿化度、且含多种金属离子的咸卤水。 相似文献
19.
矿山开发给矿区环境带来了负面影响,对矿山环境质量进行评价是实现矿业可持续发展的必要手段。笔者建立了矿山岩土工程环境质量多目标评价指标体系,运用层次分析法确定出各个评价指标的权重; 规定了分级规则,并对各个评价指标进行了分级; 建立了矿山岩土工程体系环境质量多目标综合评价模型,并将该模型应用于矿山实际,得出该矿山环境质量较差,需及时采取措施进行治理。 相似文献
20.
城市环境岩土工程的地下水灾害问题 总被引：5，自引：2，他引：5
随着城市建设的发展，人类在域市的岩土工程活动越来越频繁，由此产生一系列环境岩土工程问题。其中，由人类的工程活动引发的地下水灾害问题日趋显著，已经引起国内外专家的高度重视。地面沉降范围不断扩展，地下水永喷逐年下降，是当前城市环境岩土工程中日益突出的地下水灾害中最广泛、最严重的两大问题。它们已严重威胁着域市的可持续发展及居民的正常生活。文章概述了地面沉降及地下水水质污染现状，对抽汲地下水引起的地面沉降、建设工程性地面沉降的机理以及城市建设中可能引起的地下水点污染问题等进行了分析，针对地面沉降和地下水污染提出了相应的预防与治理措施，以实现地下水资源的可持续利用，保证城市经济及社会的可持续发展。 相似文献