城市地面沉降对给排水管道变形的影响—以天津市塘沽区响螺湾地区为例

受地面沉降的影响,敷设在不同位置的给排水管道差异沉降明显。运用GEO-SLOPE软件中的SIGMA/W模块,对天津市塘沽区响螺湾地区敷设给排水管道的地面沉降特征进行数值模拟,分析给排水管道沉降破坏的机理,总结给排水管道的变形规律,指出响螺湾地区给排水管道的规划要点。通过层次分析法确定给排水管道的工程地质要素权重,综合评价给排水管道分布,为给排水管道规划提供合理的工程地质依据,减少地面沉降引发的环境工程地质问题,指导响螺湾地区的总体规划。     

南通通州湾工程地质条件分析

依托海陆域钻孔岩芯资料,结合南通通州湾区域地质、工程勘察资料,分析了南通通州湾基础地质条件、各土层工程地质结构特征、岩土物理力学参数与不良地质体分布情况,讨论了地面沉降、潮流通道稳定性等因素对工程建设的影响,在此基础上对南通通州湾工程地质适宜性进行评价。指出通州湾工程建设需要考虑地面沉降影响,并注意软土及易液化砂土造成的不均匀沉降和局部砂土液化;潮流通道基本保持稳定,但围堤、引桥建设可能改变局部冲淤平衡,建议加强冲淤监测。     

地面沉降预测预警系统

由人类工程经济活动引起的地面沉降，是主要的环境工程地质问题之一，本文运用系统分析的方法，建立了地面沉降预测预警系统（ＤＴＬＡＳ），实现了地面沉降的计算机管理，运用ＤＴＬＡＳ可以预测未来最终地面沉降量，为市政规划和地下水资源管理提供决策依据。     

德州市地面沉降成因及防治对策浅析

通过对德州市地面沉降现状及成因综合分析,得出德州市地面沉降的主要原因是长期超采深层地下水,造成承压水位降低,含水层本身及其上、下相对隔水层中孔隙水压力减小,地层压缩导致地面发生沉降;构造因素、工程地质因素是地面沉降的次要原因。德州市已经制定规划,控制深层地下水的开采,还应利用封停的深水井进行深层地下水人工回灌工作,才能控制地面沉降的进一步发展。     

华北平原鲁北地区地下水超采导致地面沉降区域特征及演化趋势预测

鲁北地区作为华北平原地面沉降的重要组成部分,其地面沉降问题日趋严重。以滨州博兴县为工程背景,基于研究区详细水文地质与工程地质资料以及历年地面沉降监测数据,系统分析该地区地下水动态分布及地面沉降分布演化特征。以Biot多孔介质固结理论为基础,建立博兴县地面沉降三维流 固耦合数值模型,还原地面沉降发展过程并预测分析不同地下水开采方案下的沉降演化规律。研究结果表明：博兴县浅层地下水位降幅呈现南大北小特点,深层地下水形成了以县城区为中心的椭圆形地下水区域降落漏斗;地面逐渐形成了分别以博兴县城区、湖滨镇和店子镇为沉降中心的三个小型沉降区,且有相互关联扩展的趋势;地面沉降三维流固耦合模型较为理想还原了研究区地面沉降发展过程,预测在现状地下水开采方案下未来10年内地面沉降仍以较大速率继续发展,累计沉降量超500mm的区域面积不断扩大,当减小20%现状地下水开采量时是较为合理有效的开采方案。     

徐州大屯中心区地面沉降机理分析与危险性评价

地面沉降已经成为世界主要的环境地质灾害,过量抽取地下水是地面沉降主要的诱发因素.徐州大屯中心区从1976年开始观测地面沉降,1988年建立了地面沉降观测系统,观测数据显示2006年累积沉降量达到873mm.本文以该地区20多年的地下水位观测、地面沉降观测资料为基础,在地理信息系统软件ArcGIS支持下,分析了该地区地面沉降发展演化及沉降机理,并根据累积沉降量进行了危险性评价.     

基于时序InSAR技术的常州市地面沉降监测与分析

城市地面沉降不仅会对居民生命安全造成影响,而且也会给当地的社会经济造成损失。常州市位于长江三角洲地面 沉降区,也是我国经济最发达的地区之一。因此地面沉降监测是常州市掌握地面沉降的动态,为防灾减灾提供决策依据的 重要举措。本文采用SBAS InSAR 方法对2012-2013 年23 景TerraSAR-X 高分辨率雷达影像数据进行了地表形变的反演,获 取了该时间段常州地区年均沉降速率和时序地表累积形变图。结果表明,在整个观测期间,常州市呈现出“全区基本保持 稳定,武进区局部沉降严重”的特点。为此,我们利用PS-InSAR 技术对武进区的地面沉降进行了重点监测,发现该区多条 重要交通线路存在不同程度的地面沉降。最后我们结合历史监测结果和水文地质背景,揭示了常州地区近50 年地面沉降的 时空变化特征和规律。综合分析表明,地下水全面禁采后研究区地面沉降的确得到了有效控制,沉降速率减缓,甚至出现 了回弹。而武进地区的地面沉降虽然也在减缓,但仍然存在明显的地面沉降,一些重要交通线路的周边沉降已超过安全阈 值,有必要在常规监测的同时,对这些沉降严重的区域进行重点监测,并建立预警预报机制,在城市基础设施选址和规划 时提供决策依据。     

城市规划中地面沉降灾害的风险评估方法研究

合理评估城市地面沉降灾害的风险,在城市的规划与建设过程中进行合理规避与应对是当前地面沉降研究中的热点与难点问题。现有地面沉降灾害危险性评估方法在分析地面沉降对城市规划与基础设施建设影响方面存在着不足。本文在系统分析和比较当前地面沉降灾害危险性评估方法的基础上,提出了在规划阶段针对不同基础设施的地面沉降灾害风险评估方法。该方法基于基础设施对沉降的敏感性及重要性分类与平均沉降速率两类指标,给出了各类基础风险分级评价标准。最后采用该方法对北京东部地区某规划地铁线的地面沉降灾害风险进行了分析。     

应用短基线集技术监测河南北部平原区地面沉降

为研究河南北部平原区地面沉降特征和成因,应用短基线集技术获取地表形变数据,总结地面沉降空间分布特征,分析地面沉降与地质环境因素关系.结果显示:2014—2016年研究区均是沉降区,大部分属于地面沉降严重程度较低的地区,局部沉降较严重.最大沉降速率114.85 mm/a,划分出8个重点沉降区.研究区地面沉降最主要原因是地...     

珠江三角洲平原区地面沉降影响因素分析

珠三角平原区地面沉降的成因机理较为复杂,本次研究范围为珠三角平原区中南部珠江口西部沿岸,亦是珠三角平原地面沉降重点区。本文从研究区水文地质、工程地质特征以及地面沉降分布状况、沉降类型、主要控制因素和发展规律入手,综合分析区内地面沉降调查监测资料,研究了地面沉降与各影响因子的关系,总结了产生沉降的主要因素有三个:一是软土厚度大,总厚度一般10～30 m,最厚达63. 8 m;二是局部开采地下水,主要分布于广州市南沙区万顷沙镇和中山市大鳌镇、板芙镇、坦洲镇及珠海市金湾区红旗镇、斗门区白蕉镇、乾务镇等大面积水产养殖区,开发利用强度高区域约123. 21 km2,开发利用强度中等区域约111. 97 km2,开发利用强度低区域约73. 70 km2;三是上部荷载的影响,这类作用类型主要由上部建筑物荷载、大面积人工填土荷载及机械动荷载组成,主要位于城镇、工业园、乡村等建筑区和公路、桥梁、堤坝等线性工程周边,人工填土厚度最大达8. 6 m。该项研究成果可为全面开展珠江三角洲地区地面沉降调查、监测和防治工作提供技术支持,也为地方经济建设规划决策、有效控制地面沉降和保护地质环境等提供地质科学依据。     

Isotopic systematics of He,Ar, S,Cu, Ni,Re, Os,Pb, U,Sm, Nd,Rb, Sr,Lu, and Hf in the rocks and ores of the Norilsk deposits

This paper reports the first results of a study of 11 isotope systems (³He/⁴He, ⁴⁰Ar/³⁶Ar, ³⁴S/³²S, ⁶⁵Cu/⁶³Cu, ⁶²Ni/⁶⁰Ni, ⁸⁷Sr/⁸⁶Sr, ¹⁴³Nd/¹⁴⁴Nd, ^206–208Pb/²⁰⁴Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.     

高压微波消解法测定醋酸纤维过滤器采集的微尘粒子中的砷镉钴铬铜铁锰镍铅钒锌

最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提     

Wavelength-dispersive X-ray fluorescence spectrometric determination of Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites

Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.     

Regional distribution of Al,B, Ba,Ca, K,La, Mg,Mn, Na,P, Rb,Si, Sr,Th, U and Y in terrestrial moss within a 188,000 km2 area of the central Barents region: influence of geology,seaspray and human activity

Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km² area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population).     

Petrographic, mineralogy, and geochemistry of coals of Pabedana, Kerman Province, Central Iran

This paper discusses the result of the detailed investigations carried out on the coal characteristics, including coal petrography and its geochemistry of the Pabedana region. A total of 16 samples were collected from four coal seams d2, d4, d5, and d6 of the Pabedana underground mine which is located in the central part of the Central-East Iranian Microcontinent. These samples were reduced to four samples through composite sampling of each seam and were analyzed for their petrographic, mineralogical, and geochemical compositions. Proximate analysis data of the Pabedana coals indicate no major variations in the moisture, ash, volatile matter, and fixed carbon contents in the coals of different seams. Based on sulfur content, the Pabedana coals may be classified as low-sulfur coals. The low-sulfur contents in the Pabedana coal and relatively low proportion of pyritic sulfur suggest a possible fresh water environment during the deposition of the peat of the Pabedana coal. X-ray diffraction and petrographic analyses indicate the presence of pyrite in coal samples. The Pabedana coals have been classified as a high volatile, bituminous coal in accordance with the vitrinite reflectance values (58.75–74.32 %) and other rank parameters (carbon, calorific value, and volatile matter content). The maceral analysis and reflectance study suggest that the coals in all the four seams are of good quality with low maceral matter association. Mineralogical investigations indicate that the inorganic fraction in the Pabedana coal samples is dominated by carbonates; thus, constituting the major inorganic fraction of the coal samples. Illite, kaolinite, muscovite, quartz, feldspar, apatite, and hematite occur as minor or trace phases. The variation in major elements content is relatively narrow between different coal seams. Elements Sc,, Zr, Ga, Ge, La, As, W, Ce, Sb, Nb, Th, Pb, Se, Tl, Bi, Hg, Re, Li, Zn, Mo, and Ba show varying negative correlation with ash yield. These elements possibly have an organic affinity and may be present as primary biological concentrations either with tissues in living condition and/or through sorption and formation of organometallic compounds.     

Mercury,arsenic, antimony,and selenium contents of sediment from the Kuskokwim River,Bethel, Alaska,USA

The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources.     

Coprecipitation of Ti,Mo, Sn and Sb with fluorides and application to determination of B,Ti, Zr,Nb, Mo,Sn, Sb,Hf and Ta by ICP-MS

We examined the coprecipitation behavior of Ti, Mo, Sn and Sb in Ca–Al–Mg fluorides under two different fluoride forming conditions: at < 70 °C in an ultrasonic bath (denoted as the ultrasonic method) and at 245 °C using a Teflon bomb (denoted as the bomb method). In the ultrasonic method, small amounts of Ti, Mo and Sn coprecipitation were observed with 100% Ca and 100% Mg fluorides. No coprecipitation of Ti, Mo, Sn and Sb in Ca–Al–Mg fluorides occurred when the sample was decomposed by the bomb method except for 100% Ca fluoride. Based on our coprecipitation observations, we have developed a simultaneous determination method for B, Ti, Zr, Nb, Mo, Sn, Sb, Hf and Ta by Q-pole type ICP-MS (ICP-QMS) and sector field type ICP-MS (ICP-SFMS). 9–50 mg of samples with Zr–Mo–Sn–Sb–Hf spikes were decomposed by HF using the bomb method and the ultrasonic method with B spike. The sample was then evaporated and re-dissolved into 0.5 mol l^− 1 HF, followed by the removal of fluorides by centrifuging. B, Zr, Mo, Sn, Sb and Hf were measured by ID method. Nb and Ta were measured by the ID-internal standardization method, based on Nb/Mo and Ta/Mo ratios using ICP-QMS, for which pseudo-FI was developed and applied. When 100% recovery yields of Zr and Hf are expected, Nb/Zr and Ta/Hf ratios may also be used. Ti was determined by the ID-internal standardization method, based on the Ti/Nb ratio from ICP-SFMS. Only 0.053 ml sample solution was required for measurement of all 9 elements. Dilution factors of ≤ 340 were aspirated without matrix effects. To demonstrate the applicability of our method, 4 carbonaceous chondrites (Ivuna, Orgueil, Cold Bokkeveld and Allende) as well as GSJ and USGS silicate reference materials of basalts, andesites and peridotites were analyzed. Our analytical results are consistent with previous studies, and the mean reproducibility of each element is 1.0–4.6% for basalts and andesites, and 6.7–11% for peridotites except for TiO₂.