山东省海岸带城市建设面临的地质环境因素浅析

通过对山东省海岸带城市地质环境条件的调查与研究,归纳总结出山东省海岸带城市建设新近面临的影响城市发展的地质环境因素,即城市应急水源地建设、城市地下空间的开发、城市边缘区生态规划建设、湿地资源开发与保护,均是制约城市发展的主要因素,并提出了保护措施和建议,供有关部门在城市规划建设过程中参考。     

Quantitative hazard and risk assessment for slow-moving landslides from Persistent Scatterer Interferometry

Preparation of reliable landslide hazard and risk maps is crucial for hazard mitigation and risk management. In recent years, various approaches have been developed for quantitative assessment of landslide hazard and risk. However, possibly due to the lack of new data, very few of these hazard and risk maps were updated after their first generation. In this study, aiming at an ongoing assessment, a novel approach for updating landslide hazard and risk maps based on Persistent Scatterer Interferometry (PSI) is introduced. The study was performed in the Arno River basin (central Italy) where most mass movements are slow-moving landslides which are properly within the detection precision of PSI point targets. In the Arno River basin, the preliminary hazard and risk assessment was performed by Catani et al. (Landslides 2:329–342, 2005) using datasets prior to 2002. In this study, the previous hazard and risk maps were updated using PSI point targets processed from 4 years (2003–2006) of RADARSAT images. Landslide hazard and risk maps for five temporal predictions of 2, 5, 10, 20 and 30 years were updated with the exposure of losses estimated in Euro (€). In particular, the result shows that in 30 years a potential loss of approximate €3.22 billion is expected due to these slow-moving landslides detected by PSI point targets.     

Field experiments and numerical simulations of whirlpool foundation pit dewatering

A whirlpool foundation pit is a small-diameter, deep circular pit. Because of its depth and small diameter, a large drawdown is required, and a limited number of wells can be installed inside the pit. During excavation, partially penetrating wells inside and outside the foundation pit have to be installed to lower the water level when the aquifer is too thick. However, partially penetrating wells near partially penetrating curtains cannot be treated by analytical methods. Therefore, it is necessary to use numerical methods to predict dewatering during excavation. Field experiments were performed on whirlpool foundation pit 1880 of Baosteel Group, Shanghai, China, to obtain pumping rates and drawdown, pumping with a single well and two wells in the confined aquifer. The results indicate that the drawdown inside the pit induced by pumping wells outside the foundation pit was small, whereas it was large for pumping wells inside the pit. The pumping wells inside and outside the pit had to be combined to lower the water level. A three-dimensional numerical model was developed to simulate the dewatering process. The hydraulic conductivities of the confined aquifers were inversed by using the pumping tests. Operation schedules were simulated with the corrected model for different combinations of wells inside and outside the pit. The results suggest that different schedules and operation conditions affect drawdown. The monitored results during dewatering indicate that the simulation and field measurements were in agreement. The results can be applied to similar situations.     

Experimental investigation on shear strength and permeability of a deeply dewatered sewage sludge for use in landfill covers

This paper presents an experimental study on a deeply dewatered sewage sludge produced by using a new technique of membrane filter press. The experiments involve measurements of sludge composition, basic physical properties, shear strength, water permeability, and leaching toxicity. The measurements of shear strength and permeability were also performed on the sludge specimens soaked in a low acid leachate or distilled water for 1 and 2 months. This is to investigate the influence of chemical change in pore fluid as a result of rainfall infiltration or leachate seepage at landfills. Comparison tests were also carried out on silty clay that is commonly used for landfill cover material. The experimental results show that the deeply dewatered sludge contains 66 % organic content and 85 % water content (dry mass basis). The undrained shear strength of the sludge is >25 kPa even after 2-month soaking in the leachate and distilled water, meeting the requirement of the Chinese standard [CJ/T249-2007, Disposal of sludge from municipal wastewater treatment plant: sludge quality for co-landfilling. Ministry of Building and Construction, P.R. China (in Chinese), 2007]. The measured cohesion and friction angle for the sludge are >20 kPa and 22.3°, respectively. The soaking of sludge specimens in either leachate or distilled water resulted in an increase in frictional angle by several degrees. The water permeability for the sludge ranges from 0.68 × 10^?8 to 1.3 × 10^?8 cm/s, and permeability after 2-month soaking is less than the minimum requirement for the barrier layer of landfill covers (i.e., 1.0 × 10^?7 cm/s). The concentrations of heavy metals leaching from the dewatered sludge are lower than the limit values of leaching toxicity for the wastewater discharge standard of China. The experimental results indicate that deeply dewatered sludge can be used as an alternative material for the barrier layer of landfill covers.     

中国地热研究的进展与展望(1995～2014)

地热是主要地球物理场之一,地热能是地球的本土能源。李四光在20世纪60年代开创了我国地热科学。到90年代,学科体系基本建立。在过去20年里,我国地热研究得到了进一步深化和拓展。本文从大地热流、岩石圈热结构、地热系统、油气盆地地热、矿山地热、天然气水合物以及气候变化等方面回顾地热研究代表性的创新进展,并对深层地热、海洋地热、环境地热等研究方向作了展望。本文认为,过去20年我国地热研究成果丰硕,国际影响力得到提高,未来发展势头强劲。在经历了由浅入深,从今到古的成长之后,地热研究还将不断拓展领域,为我国地球科学,特别是能源与环境安全做出更大贡献。     

Hazardous geology zoning and influence factors in the near-shore shallow strata and seabed surface of the modern Yellow River Delta,China

In this study, on the basis of 3,200 km shallow stratigraphic section and side-scan sonar data of the coastal area of the Yellow River Delta, we delineated and interpreted a total of seven types of typical hazardous geologies, including the hazardous geology in the shallow strata (buried ancient channel and strata disturbance) and hazardous geology in the seabed surface strata (pit, erosive residual body, sand patch, sand wave and scour channel). We selected eight parameters representing the development scale of the hazardous geology as the zoning indexes, including the number of hazardous geology types, pit depth, height of erosive residual body, length of scour channel, area of sand patch, length of sand wave, width of the buried ancient channel and depth of strata disturbance, and implemented the grid processing of the research area to calculate the arithmetic sum of the zoning indexes of each unit grid one by one. We then adopted the clustering analysis method to divide the near-shore waters of the Yellow River Delta into five hazardous geology areas, namely the serious erosion disaster area controlled by Diaokou lobe waves, hazardous geology area of multi-disasters under the combined action of the Shenxiangou lobe river wave flow, accumulation type hazardous geology area controlled by the current estuary river, hazardous geology area of single disaster in the deep water area and potential hazardous geology area of the Chengdao Oilfield. All four of the main factors affecting the development of hazardous geology, namely the diffusion and movement of sediment flux of the Yellow River water entering the sea, seabed stability, bottom sediment type and distribution, as well as the marine hydrodynamic characteristics, show significant regional differentiation characteristics and laws. These characteristics and laws are consistent with the above-mentioned zoning results, in which the distribution, scale and genetic mechanism of hazardous geology are considered comprehensively. This indicates that the hazardous geology zoning based on the cluster analysis is a new attempt in research regarding the hazardous geology zoning of the near-shore waters of the modern Yellow River Delta and that this type of zoning has a high level of reasonability.     

Geo-stress Fields Simulated with 3D FEM and Their Qualitative Influence on Coal and Gas Outburst

Coal and gas outbursts took place about thirty times at one coal mine in China, which not only caused safety problems but also hindered the regular production in different degree. In-situ geo-stresses of two points are successfully measured near coal and gas outburst locations, and the measured maximum principal stress is approximately at the horizontal direction, while the minimum principal stress is at the vertical direction. A three-dimensional model is built with FEM software of ANSYS, the measured geo-stress are taken as boundary pressures to be applied on the FEM model, and the geo-stress fields in the coal seam are calculated. In the end, the qualitative influence of the maximum principal geo-stress on coal and gas outburst is analyzed based on the relationship between geo-stress and number of coal and gas outburst.     

麻江古油藏油源识别与油气运聚分析：来自油气地球化学的证据

充分考虑热演化过程中烃源岩干酪根、族组分、固体沥青及正构烷烃碳同位素相互关系及变化规律,通过地球化学分析并结合前人碳同位素及芳烃标志物研究进行综合分析,结果表明古油藏各区域储层早期均存在下寒武统黑色泥岩来源,后期来源有较大差别,麻江古背斜以南各地沥青均不同程度与中寒武统都柳江组有关,北凯里液态原油及油苗为五峰组及龙马溪组印支期成藏产物,其保存环境为储层早期成岩过程中形成的独立封闭系统。在油源识别的基础上,结合构造地质背景、油气成藏条件及流体活动规律分析,认为黔南坳陷及邻区下寒武统、都柳江组、五峰组及龙马溪组烃源岩的分布控制了该区油气富集规律,黔南海西期断裂系统与加里东运动形成的不整合面构成不同期次油气运聚的输导系统,海西期形成的一系列正断裂是麻江古油藏成藏的关键。     

宁南弧形构造带甘肃大沟—内蒙古乱井中上地壳电性结构

利用大地电磁探测方法在宁南弧形构造带内蒙古乱井—甘肃大沟段进行了中上地壳电性结构特征研究,通过二维反演获得了研究区的电性结构模型,模型清楚揭示出了该区典型的电性结构特征:(1)中上地壳电性结构整体表现为"碎块状"的构造特征,其中走廊构造带总体表现为相对低阻,北祁连碰撞造山带总体表现为相对高阻;(2)海原地震震源区的震源断裂所反映的低阻带构造样式既不像走滑断裂那样陡峭,也不像逆冲断裂那样平缓,而是兼具走滑与逆冲断裂带的双重特征;(3)研究区壳内低阻层呈现不连续分布,总体表现为南深北浅的构造样式,一般都终止于高阻地块边缘或与逆冲推覆构造的滑脱面相交汇处;(4)清水河裂褶带内发育的高阻地块可能为晚古生代或早中生代发育在元古宙基底上的古隆起,为该区燕山期构造运动提供了深部大地电磁资料证据。     

黔中—渝南沉积型铝土矿区域成矿模式及找矿模型

黔中—渝南沉积型铝土矿的区域成矿模式概括如下:志留纪末的广西运动和泥盆纪末的紫云运动等,可能都是在峨眉地幔柱演化的壳幔相互作用阶段,因地幔柱向地壳大量输送物质和辐射能量,从而引发的地壳升降运动,在此期间,全区大面积抬升,形成长期隆起区;泥盆纪末准平原化;早石炭世岩关期气候湿热,暴露地表的早古生代岩石全面红土化、钙红土化,形成的含三水铝石红土风化壳物质,为沉积型铝土矿提供了物源。修文及息烽—遵义沉积区,于早石炭世大塘期早—中期沉积了铝土矿含矿岩系—九架炉组。绥阳—正安—道真沉积区,在晚石炭世的黄龙组石灰岩沉积并钙红土化之后,于马平期沉积了铝土矿含矿岩系的大竹园组。3个沉积区的铝土矿含矿岩系,都是在以陆相为主的环境中沉积形成的。在成岩阶段,铝土矿中的三水铝石逐渐变质为硬水铝石。由于各沉积区形成含三水铝石红土风化壳的母岩不同,由此沉积而成的铝土矿及其含矿岩系,在化学成分和矿物成分上也就有所差异。