工程岩爆灾害判别的RBF-AR耦合模型

岩爆是深部高地应力区地下岩体工程中的主要工程地质灾害之一,其发生及烈度预测是一个复杂的不确定系统问题。为了有效预测和判别深部工程岩爆灾害,在总体考虑岩爆各影响因素的基础上,选取地下工程中岩体完整性指数、岩石单轴抗压强度、岩石单轴抗拉强度、围岩最大切向应力、围岩抗压强度与其抗拉强度的比值、围岩切向应力与围岩抗压强度比值、弹性能量指数、岩爆倾向性指数作为岩爆预测的评判指标,提出了一种基于非线性参数优化的RBF-AR岩爆预测模型。在终南山隧道竖井岩爆判别中,利用RBF-AR法进行计算,计算结果与实际情况完全一致,表明该模型在岩爆预测中的可行性和有效性。     

基于熵权-正态云模型的岩爆烈度分级预测研究

岩爆是深埋地下工程主要的工程地质灾害之一,其烈度分级预测是必须解决的岩石工程重大问题。针对岩爆烈度分级的不确定性,选取岩石单轴抗压强度与抗拉强度比σ_c/σ_t、切向应力与岩石单轴抗压强度比σ_θ/σ_c、弹性变形能指数Wet和岩石完整性系数K_v等定量化指标建立评价指标体系,应用熵权法确定各评价指标权重,结合云理论建立了岩爆烈度分级预测的熵权-正态云模型。以国内外12组典型岩爆工程实例对所建模型进行检验,并与逼近理想解法、高斯径向基函数法的判别结果及实际情况进行对比。为进一步考察该模型的有效性和实用性,利用该模型对终南山公路隧道工程竖井的岩爆实例进行分析。研究结果显示,基于熵权-正态云模型的岩爆判别预测结果与实际岩爆情况较吻合,表明熵权-正态云模型在研究岩爆烈度分级预测中具有良好的实用性和可靠性,可为深部地下工程岩爆烈度分级预测提供一种新思路。     

基于正态云模型的深埋地下工程岩爆烈度分级预测研究

岩爆是深埋地下工程开挖建设过程中常见的工程地质灾害,对其发生的可能性及其烈度分级预测一直是岩石地下工程的世界性难题。针对岩爆烈度评估过程中存在的模糊性和随机性问题,建立了基于德尔菲法和正态云的综合评判模型。在系统分析影响岩爆发生的相关因素的基础上,选取岩石单轴抗压强度与抗拉强度比σc/σt、切向应力与岩石单轴抗压强度比σθ/σc、岩石脆性指数Is和弹性变形能指数Wet构建评价指标体系,通过德尔菲科学方法确定其权重系数。基于云模型理论计算各评价因子隶属于岩爆级别的云数字特征,生成正态云滴,实现了岩爆烈度与评价指标值之间的不确定映射,保留了评估过程中的随机性。最后,利用国内外典型岩爆工程实例对所建模型进行检验,其判别结果与实际岩爆等级相符,且准确率高于功效系数法和集对分析理论,表明采用云模型对岩爆烈度进行预测是可行的、有效的。该模型具有较高的准确性和可靠性,能满足工程应用需要,在深埋地下工程岩爆预测中具有良好的工程应用前景。     

基于模糊C-均值算法粗糙集理论的云模型在岩爆等级评价中的应用

岩爆等级评价具有模糊性和不确定性,而粗糙集理论的云模型对处理模糊性和不确定性问题具有独特优势,由此提出了基于模糊C均值（简称FCM）算法粗糙集的云模型理论在岩爆等级评价中的新模型。该模型选用岩石单轴抗压强度 、洞室围岩最大的切向应力 、岩石单轴抗拉强度 和岩石弹性能量指数Wet作为岩爆等级评价因子,依据岩爆分级标准计算各评价因子隶属于不同岩爆等级的云数字特征。同时,以国内外40例岩爆工程为研究对象,运用基于FCM算法的粗糙度理论进行因子属性重要性评价,计算各评价因子权重。根据正向正态云发生器,得到待评样本的综合确定度,由最大综合确定度判定岩爆级别。研究表明：该模型的评价结果与实际情况基本一致,具有一定的可行性,为岩爆预测提供了一种新的研究方法与思路。     

基于网格搜索法优化支持向量机的围岩稳定性分类模型

为科学评价围岩稳定性,本次研究借助支持向量机(SVM)处理小样本、非线性问题能力强的特性,对围岩的稳定性进行了分类。选取16组围岩数据作为学习样本,以岩石质量指标、岩石单轴饱和抗压强度、完整性系数、结构面强度系数和地下水渗水量5个指标作为模型输入,围岩稳定程度为模型输出,建立了基于支持向量机的围岩稳定性分类模型。为增强模型的推广性能,提高其预测准确率,运用改进的网格搜索方法(GSM)寻找最优的支持向量机参数,并对8组围岩数据进行预测,并同BP神经网络模型的预测结果进行对比。结果表明,建立的GSM-SVM模型对预测样本的评判结果与实际结果一致,其预测精度较BP神经网络有很大的提升。     

基于功效系数法和地应力场反演的深埋长大隧道岩爆预测研究

岩爆是深埋长大隧道面临的主要地质灾害之一,其“孕育-发生-发展”全过程异常复杂,使其成为地下工程中的世界性难题。准确反映地应力变化规律以及区域内地质构造影响,结合实测资料进行岩爆分级预测,对保障隧道前期勘察设计及后期安全施工具有重要意义。根据隧道工程地质资料,通过COMSOL Multiphysics和Rhino建立三维数值计算模型,反演分析得到整个区域的初始地应力场。在综合分析影响岩爆关键因素的基础上,从“储能性-倾向性-突发性”研究角度,选取岩石单轴抗压强度与围岩洞壁最大主应力比(σ_c/σ_max)、围岩洞壁最大切向应力与岩石单轴抗压强度比(σ_θ/σ_c)、岩石强度脆性系数(σ_c/σ_t)及岩石弹性能指数(W_et)作为评价指标。采用熵权法确定指标权重,运用功效系数法加权计算总功效系数值,构建了一种基于功效系数法和地应力场反演的深埋长大隧道岩爆预测模型,并将其应用于川藏铁路桑珠岭隧道。研究结果表明,该模型具有较高的准确性和可靠性,为类似深埋长大隧道岩爆预测提供了一种新的参考。     

人工神经网络在岩体质量分级中的应用

结合四川省金沙江某水电站工程实例，应用BP人工神经网络方法建立3层BP网络模型，选取岩石单轴抗压强度等6个影响因素为输入变量，对坝基复杂岩体进行质量分级。通过机算机Visual C 语言编程实现神经网络模型，进行网络的学习和运算。以神经网络合理结构分析方法选取合理结构，确定合理隐层单元的数量，提高网络测试的精度。对测试结果的分析发现，经过优化的BP网络模型经多次学习后，测试精度提高，结果可靠，取得较好的实际应用效果。     

岩爆等级判定的距离判别分析方法及应用

将距离判别分析方法应用于岩爆等级判定问题。选用洞室围岩最大的切向应力σθ、岩石单轴抗压强度σc、抗拉强度σt、岩石弹性能量指数Wet作为岩爆等级判定的距离判别分析模型判别因子,以工程中实际岩爆情况及数据作为训练样本,进行分析计算,建立岩爆等级判定的距离判别分析模型。运用该分析模型对国内外工程实际岩爆情况进行判定,判别结果与工程实际完全相符。将该模型应用到诸（暨）永（嘉）高速公路括苍山隧道工程的岩爆情况预测中,判别结果与实际情况相符。研究表明,岩爆等级判定的距离判别分析方法,判别能力强,误判率低,是解决岩爆等级判定的一条有效途径。     

基于P波模量的岩石单轴抗压强度预测

传统获取岩石单轴抗压强度参数需要钻进取样、加工制作等严格的试验步骤,需要建立一种参数易于获取且准确的岩石单轴抗压强度预测公式。基于岩石物理力学参数的内在联系,建立了岩石单轴抗压强度与岩石P波模量的关系式。根据英安斑岩和页岩两种岩石的干密度、P波速度及单轴抗压强度的测试数据,采用线性拟合的方法建立了岩石基于P波模量的单轴抗压强度预测公式,并采用统计检验的方法对上述预测公式与传统基于P波速度的预测公式进行了对比分析。结果表明,所建立的强度预测通式简单、精度高,模量容易获取,具有很强的实用性。     

基于P波模量的岩石单轴抗压强度预测EI北大核心CSCD

传统获取岩石单轴抗压强度参数需要钻进取样、加工制作等严格的试验步骤,需要建立一种参数易于获取且准确的岩石单轴抗压强度预测公式。基于岩石物理力学参数的内在联系,建立了岩石单轴抗压强度与岩石P波模量的关系式。根据英安斑岩和页岩两种岩石的干密度、P波速度及单轴抗压强度的测试数据,采用线性拟合的方法建立了岩石基于P波模量的单轴抗压强度预测公式,并采用统计检验的方法对上述预测公式与传统基于P波速度的预测公式进行了对比分析。结果表明,所建立的强度预测通式简单、精度高,模量容易获取,具有很强的实用性。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.     

PALEONTOLOGY

正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)     

GEOCHEMICAL EXPLORATION

正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)     

MICROPALAEONTOLOGY

正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)     

PETROLOGY

正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,     

ENVIRONMENTAL GEOLOGY

正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an     

PROSPECTING EXPLORATION

正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of