层次分析法在致密油有利区优选中的应用——以川中侏罗系大安寨段为例

层次分析法常用于解决复杂系统分析与决策中目标优选、排序等问题,也适用于油气勘探领域。在前人致密油地质特征研究的基础上,总结了致密油有利区优选指标。使用层次分析法优选有利区的核心内容是建立层次结构模型和构建2类矩阵。以四川盆地中部侏罗系大安寨段为例,介绍了使用层次分析法优选有利区5个主要步骤:1根据研究区地质特征,确定目标及方案,构建目标层和方案层;2根据影响致密油富集的要素,确定准则层;3构建准则层中各要素的成对比较矩阵,确定各准则要素的相对权重;4构建各准则要素对不同方案的判断矩阵,确定不同方案中各准则要素的权重;5将不同方案各准则要素的权重矩阵与准则要素的相对权重矩阵相乘,得到各方案的层次排序,进而选出最佳方案。优选的川中侏罗系大安寨段致密油最有利勘探区为金华—莲池区。操作简单、不需考虑下限值、适用范围广是层次分析法优选有利区的优点,但由于层次分析中的标度根据人为经验赋值,不同评价人员给出的评价结果有所不同。将层次分析法与GIS、特尔菲法、模糊数学法相结合,可以提高准则要素的优选合理性及赋值准确性。     

基于信息熵的水文站网优化准则的应用与评价

将基于信息熵的四类水文站网优化准则,即熵-互信息(H-T)准则、联合熵-总相关(H-C)准则、联合熵-互信息-总相关(H-T1-C/H-T2-C)准则以及信息传递指数(TI)准则,应用于太湖西南山丘区雨量站网,对四类准则进行对比和评价。以2007—2016年日降水序列为样本,根据各优化准则,分别采用3种数值离散化方法计算站点秩次,分析秩次相关性、对多目标准则中指标权重的敏感性以及秩次年际变化。结果表明,H-C准则对应秩次的代表性最好,对指标权重的敏感度最低,秩次年际变化小;H-T2-C准则对指标权重最敏感,秩次年际变化显著。H-C准则有利于反映基于信息熵的基本优化原则(增大信息量和降低冗余度),而H-T2-C准则有利于体现决策偏好。     

基于信息熵的水文站网优化准则的应用与评价

将基于信息熵的四类水文站网优化准则,即熵-互信息(H-T)准则、联合熵-总相关(H-C)准则、联合熵-互信息-总相关(H-T1-C/H-T2-C)准则以及信息传递指数(TI)准则,应用于太湖西南山丘区雨量站网,对四类准则进行对比和评价。以2007—2016年日降水序列为样本,根据各优化准则,分别采用3种数值离散化方法计算站点秩次,分析秩次相关性、对多目标准则中指标权重的敏感性以及秩次年际变化。结果表明,H-C准则对应秩次的代表性最好,对指标权重的敏感度最低,秩次年际变化小;H-T2-C准则对指标权重最敏感,秩次年际变化显著。H-C准则有利于反映基于信息熵的基本优化原则(增大信息量和降低冗余度),而H-T2-C准则有利于体现决策偏好。     

层次分析法结合MAPGIS在地质灾害易发性评价的应用

地质灾害易发程度评价是在区域地质灾害危险性评价中一项主要任务,其表征某一区域地质灾害发生的可能性概率的一个主要指标。利用层次分析法可以定量或半定量的评价区域地质灾害的易发程度．效果比较理想。以成县为例确定地质灾害评价目标层、准则层、指标层,将影响地质灾害的各类因子进行分级,权重分配,利用mapgis平台对工作区进行矢量网格化、空间属性叠加分析、生成等值线图,实现地质灾害易发程度分区的目的。     

层次分析法在四川盆地页岩气勘探区评价中的应用

为了对四川盆地页岩气勘探区进行优选分析,研究了影响页岩气有利区带勘探开发的关键因素,采用层次分析法的原理,通过建立层次结构模型、构造判断矩阵、层次单排序及一致性检验、层次总排序及一致性检验4个基本步骤,建立了页岩气勘探区评价优选层次结构模型:目标层,准则层,子准则层和方案层,并且计算了各个评价指标的权重大小。研究结果表明,影响页岩气勘探区勘探开发的因素主要分为地质条件、开发条件和支持条件三大类(准则层),其中地质条件是页岩气有利区带优选的首要因素,权重高达0.637 0。子准则层主要由富有机质页岩厚度、w(TOC)、Ro、有利面积、埋深、天然裂缝发育程度、市场需求等12个评价指标组成,其中含气量、天然裂缝发育程度、压力系数以及市场需求是页岩气有利区带优选的关键指标。通过评价指标赋值和加权求和法计算了四川盆地页岩气勘探区的综合得分,其中焦石坝和长宁页岩气区块得分最高,是页岩气最有利地区。最后建议在页岩气勘探区运用"分层次,分重点,分先后"的评价方法来优选"甜点"区,以规避不必要的损失。     

多层次模糊综合决策优选软基处理方案

针对吹填土路基处理方法的理论研究发展相对落后,远远不能满足现场施工实践的要求,将系统工程理论中的模糊决策理论和层次分析法相结合,提出了一种较合理而且相对简单的吹填土路基处理方案的决策方法,结合厦门市环东海域综合整治建设项目对影响软基处理方案优选的各因素进行了分析,确定了评判模型和影响因素.其中,各影响因素的权重值采用层...     

基于灰色关联分析的综合评价模型在爆破方案选定中的应用

针对爆破方案选择的复杂性,在灰色关联分析的基础上,利用层次分析法,结合判断矩阵对各指标进行权值分配,将指标的关联系数与其权值相结合,提出了爆破方案综合评价模型,该模型以权重的形式体现各个评价指标对整体的影响程度,利用判断矩阵进行权值分配克服了以往权重赋值主观性较强的局限,最终以关联度为定量指标来对爆破方案进行比较分析,并以回坡底矿爆破方案评价为实例,具体说明了该模型的科学合理性。     

对比加权评分法在边坡治理方案优选中的应用

通过对量化指标和定性指标的评分,用对比法确定各因素权值,用加权评分法对各方案进行优选,得出最优方案。以实例分析了该方法的应用,计算结果表明：该方法简易可行,减少了目标的客观权重与实际情况之间的误差。     

铁层柱蒙脱石催化剂微波诱导催化处理垃圾渗滤液

常规生化处理很难使垃圾渗滤液达到市政污水纳管排放标准,或无法稳定排放,必须进行深度处理。本文探索了微波诱导催化用于渗滤液的深度处理,以铁层柱蒙脱石作催化剂,微波辐照下深度处理垃圾渗滤液。结果表明,对初始COD浓度为1100~1300 mg/L的垃圾渗滤液,以铁层柱蒙脱石作为催化剂,在微波功率600 W,辐照时间30 s条件下,经微波诱导催化处理后,COD去除率达到39%。铁层柱蒙脱石催化剂以"卡房"型介孔结构为主,均匀的介孔结构有利于微波诱导催化。     

地下水污染防治区划研究

以某地区地下水污染调查成果为基础,基于地下水资源的自然属性和社会属性,建立了由1个目标层、2个属性层、3个准则层、6个约束层和12项指标构成的地下水污染防治区划指标体系。利用层次分析法确定指标权重,采用加权平均综合指数模型计算区划指数,并借助MapGIS技术进行相关数据处理和区划结果可视化表达。区划结果符合地下水污染预防为主与分区防治的原则。     

城市固体垃圾应力-应变-时间关系试验研究

通过室内蠕变试验,研究了城市固体垃圾（MSW）的蠕变变形规律。采用分级加载方式对初始孔隙比为2~4和初始有机物含量在15%~75%的MSW试样进行压缩降解试验。研究发现,应力-应变-时间曲线斜率随着初始孔隙比和初始有机物含量的增加逐渐减小,即材料压缩模量逐渐减小。采用指数模型拟合城市固体垃圾的应力-应变等时曲线,并取得了很好的拟合效果,模型参数简单易求,可反映城市固体垃圾压缩性的大小及其压缩机制。通过对指数模型求导,得到城市固体垃圾的切线压缩模量,切线压缩模量随初始孔隙比和易降解有机物含量的增加呈指数型衰减,初始孔隙比在2~3之间时,初始压缩模量衰减较快,也就是说,在该范围内,初始孔隙比对城市固体垃圾变形影响较大。     

万州近水平地层区堆积层滑坡成因与变形破坏特征

近水平地层区堆积层滑坡作为一类典型的滑坡,有其特殊的成因与变形破坏特征。文章在研究万州近水平地层区堆积层滑坡的基础上,详细分析了其物质来源、结构成因、形成模式以及变形破坏特征。通过总结万州堆积层滑坡的滑体和滑床特征,得出了近水平地区堆积层滑坡的物质来源和结构成因为:崩塌堆积为主,冲、洪积为辅;形成模式为:后部陡壁形成,滑床形成,滑体底部物质形成,滑体土石混合体形成,滑体表层物质形成,滑动解体等6个阶段。变形破坏特征为:滑动多沿堆积层和基岩接触面滑动,同时也会沿软弱夹层发生滑动;滑体存在多层剪切带,并在不同位置的剪切带其变形速率和累计变形量差别较大,滑体存在着差异变形,对此文章结合实例进行了分析。     

Geological and environmental implications in the reclamation of limestone quarries in Sierra de Callosa (Alicante,Spain)

Sierra de Callosa have an area of 8 km² and a maximum altitude of 566 masl. Geologically, it is found to be primarily comprised of carbonated rocks. Mine spoils coming from limestone quarries extraction are often used in the working reclamation process. These materials could be actually employed profitably once conveniently amended with organic matter. A study on the temporary evolution of nutrients and several physical–chemical parameters in a mineral waste amended with municipal solid waste (MSW) compost has been carried out. The effect of incorporating such waste to mine spoils in an arid gravel quarry has been studied, quantifying the temporal evolution of nutrients and several physical–chemical parameters in the mixture. Three plots have been prepared with mine spoils proceeding from a limestone quarry located in the south of the province of Alicante (municipality of Redován). These plots have been amended with 3 kg/m² of MSW compost. Texture, pH, electrical conductivity, oxidizable organic matter, N-Kjeldahl, available P, Na, K, Ca, Mg, Fe, Mn, Cu and Zn were analysed. The results reflected the contribution of nutrients to the substrate after the MSW addition. The variability of the information indicated the heterogeneity of the MSW composition, as well as the difficulty of obtaining a homogeneous MSW mixture–mineral waste.     

济南富水孔隙黏性土地层渗透性试验研究

以济南市轨道交通R1线大杨庄站主体基坑降水工程为例,研究表明发育于济南区域孔隙黏性土地层黏性土内具有独特的空间网状孔隙、孔洞结构。通过4种渗透性试验成果对比分析,室内试验、声纳渗流试验测定的渗透系数均较小,与实际地层渗透能力相差很大;抽水试验与回灌试验测定的渗透系数相近,远远大于一般黏性土的渗透性,渗透系数随着回灌压力的增加而呈线性提高,回灌引起周边地下水位上升较小,影响范围有限,符合济南孔隙黏性土地层的富水性强和渗透性好特性,具有独特性和鲜明的区域特点。相关试验成果可以为相关区域基坑降水与回灌设计、施工和泉水环境保护提供参考。     

Mobility of potentially harmful metals in latosols impacted by the municipal solid waste deposit of Londrina,Brazil

The contamination of soils by metals issuing from municipal solid waste (MSW) disposal in tropical environments has hardly been studied with regard to the particular problems associated with them, i.e., generally a high permeability of soils despite the abundance of clay, and the role of reactive Fe compounds. From a previous geotechnical and chemical survey, three latosol profiles differently affected by MSW leachates in the region of Londrina (Paraná, Brazil) were selected. The aims were to evaluate the extent of their contamination, to better understand the fate of potentially harmful metals in tropical soils and rank the determining factors. Samples between 0.5 and 7 m depth were analyzed for their physical, mineralogical and chemical properties, and their micro-morphology was described by optical and transmission electron microscopy. Two steps of a sequential extraction procedure helped to assess the mobility of elements and to better discriminate between metals originating from pedogenesis and issued from MSW. These combined approaches showed that exposed soil profiles have been impacted at various depths, down to 7 m, through increased metal content, especially enhanced mobility of Zn, Co, Mn, Cu and Fe, and through increased salinity and organic matter. The mobility of potentially harmful metals should decrease with pH, which significantly increased in some impacted horizons, but other factors can reverse this trend.     

地铁隧道下穿小河和桥梁的施工方案研究

综合工程经验,对北京地铁5号线过河过桥隧道施工可能采用的4种超前支护方案即水平旋喷桩、全断面深孔注浆、长管棚、加密小导管注浆并辅以临时仰拱进行初步分析,认为加密小导管方案在施工造价、掘进速度和施工影响方面具有优势。采用三维数值模拟方法对长管棚方案和加密小导管方案进行进一步评价并择优。数值模拟结果显示,在不计管棚施工对地层提前扰动的情况下,长管棚方案与加密小导管方案对桥台、桥墩以及小月河河底的影响是相当的,可以认为,加密小导管方案将优于长管棚方案;长管棚、小导管和锁脚小导管承受弯矩较小,锁脚小导管以及隧道拱部的小导管承受轴压力,边墙的小导管既承受轴压力又承受轴拉力,长管棚主要承受轴拉力。     

中高龄期模型固体废弃物三轴试验与强度特性分析

为揭示中、高龄期城市固体废弃物（MSW）的力学特性,通过向石英砂、高岭土混合物中加入不同质量比的草炭人工配制模型固废试样,开展了三轴固结排水剪切和固结不排水剪切试验研究。试验结果表明,中高龄期模型固废均表现出持续硬化的应力应变特性,固结排水试验中中龄期模型固废的体变略大于高龄期,固结不排水试验中高龄期模型固废的孔压略高于中龄期。采用15%轴向应变对应的剪应力描述其抗剪强度,并根据Skempton有效应力原理,通过对比固结排水试验和固结不排水试验结果,得出了固废的孔隙水压力折减系数和抗剪强度参数,孔隙水压力折减系数随龄期增加而增大,高龄期模型固废得到的黏聚力低于中龄期,高龄期固废得到的内摩擦角则高于中龄期。     

Non-segregated municipal solid waste in an open dumping ground: a potential contaminant in relation to environmental health

The present article discusses an overview on the contamination of non-segregated open municipal solid waste (MSW) in and around a dumping site at Garchuk in Guwahati city, Assam, India. Analysis showed depth-wise variations in the concentrations of selected heavy metals in MSW and their subsequent accumulations with increasing depths. Zinc was the most abundant heavy metal in MSW. Six-step selective sequential extractions revealed that most of the heavy metals in MSW were in the residual phase except zinc. Analysis of the leachate from MSW showed high concentrations of fluoride, chloride, ammonium–nitrogen and the ratio of biological oxygen demand/chemical oxygen demand. Concentrations of all the heavy metals in the leachates were higher than the Indian national effluent standards. High amounts of biological oxygen demand, heavy metals, total and fecal coliforms in water samples from the adjoining water body (Deepor Beel, a Ramsar site) of the MSW dumping site indicated its unsuitability for domestic use. Principle component analysis showed that influence of MSW leachate was the major source of water contamination in Deepor Beel. Though accumulation of heavy metals in different vegetables growing in MSW dumping site did not exceed the recommended maximum intake, it was a significant additional source of heavy metals in cooked human diet.     

城市固体废弃物的剪切强度机理及本构关系

根据城市固体废弃物（简称MSW）的大三轴固结排水剪试验结果,延伸岩土工程中研究土体的概念和方法,研究MSW的剪切强度机制。MSW与大变形相关的强度特性主要是由于含有大量的纤维状成分所致,在剪切过程中试样总的抗剪能力由剪切面上的摩擦力和纤维状加筋相的拉力所产生。MSW的摩擦强度主要由3部分构成：纤维状成分与土颗粒之间的摩擦,纤维状成分之间的摩擦,和土颗粒之间的摩擦。基于MSW的剪切强度特性,采用邓肯-张本构模型来描述MSW的应力-应变关系。     

Permeability of Municipal Solid Waste in Bioreactor Landfill with Degradation

Bioreactor landfills are operated for rapid stabilization of waste, increased landfill gas generation for cost-effective energy recovery, gain in landfill space, enhanced leachate treatment, and reduced post closure maintenance period. The fundamental process of waste stabilization in bioreactor landfill is recirculation of generated leachate back into the landfills. This creates a favorable environment for rapid microbial decomposition of the biodegradable solid waste. In order to better estimate the generated leachate and design of leachate recirculation system, clear understanding of the permeability of the Municipal Solid Waste (MSW) with degradation and the factors influencing the permeability is necessary. The objective of the paper is to determine the changes in hydraulic properties of MSW in bioreactor landfill with time and decomposition. Four small-scale bioreactor landfills were built in laboratory and samples were prepared to represent each phase of decomposition. Then, the changes in hydraulic properties of MSW in bioreactor landfill with time and decomposition were determined. A series of constant head permeability tests were performed on the samples generated in laboratory scale bioreactor landfills to determine variation of permeability of MSW with degradation. The test results indicated that the permeability of MSW in bioreactor landfills decreases with decomposition. Based on the test results, the permeability of MSW at the first phase of degradation was estimated as 0.0088 cm/s at density 700 kg/m³. However, with degradation, permeability decreased to 0.0013 cm/s at the same density, for MSW at Phase IV.