海积软土前期固结压力与结构强度的关系及成因分析

通过对不同地区海积软土的大量试验，对原状土样和重塑土样的压缩曲线确定了海积软土前期固结压力和结构强度，并研究了海积软土前期固结压力及结构强度的关系。由于考虑了土的结构强度，对结构性土根据超固结比(OCR)对土的压密状态的判断与实际结果更加相符。为了定量地反映海积软土的结构强弱，首次引入反映海积软土结构性及其对扰动敏感程度的结构稳定系数，反映了海积软土结构性的稳定程度。初步分析了海积软土结构强度的成因。     

唐-曹高速公路软土的微结构特征研究

对软土地基处理技术研究己成为改善投资环境、加快环渤海地区建设、科学合理利用土地资源的重要研究课题。软土地基处理方法的科学合理与否,关键是从软土本身的结构特征揭示出影响软土变形和强度的本质因素。以唐-曹（唐山市至曹妃甸）高速公路通过地区的沉积软土为研究对象,综合海积软土的基本物理力学性质和微结构特征建立软土微结构量化参数。通过室内综合实验和理论分析,对海积软土微结构与宏观力学性质关系进行系统地研究,对海积软土的结构强度与工程效应进行论证,提出以建立在分维分形理论基础上的孔隙结构因子作为衡量海积软土结构强度和破坏趋势的综合性参数,且可以在求解先期固结压力的同时定量地确定土的结构强度,值得同行借鉴。     

天津地区海积软土结构强度及其对力学特征的影响

海积软土是一种结构性土，具有结构连结强度。其压缩曲线呈现出超固结土的压缩的曲线形式。强度曲线为二段折线，在应力小于σ'k时表现出超固结土的力学特征。而当应力水平高于这一临界值时，表现出正常固结土的力学特性。对其结构连结的成因进行了简单探讨。     

海积软土的固结蠕变性状

实验室软土多级固结蠕变试验成果表明,海积软土具有非线性、不可逆的、与时间相关的固结变形特性。在此基础上,提出了时间效应系数的概念,并构造了反映海积软土一维固结蠕变的本构关系。     

海积软土固结变形的结构性模型研究

土结构性模型是 2 1世纪土力学学科的核心问题。基于海积软土一维固结蠕变的宏观力学性状与微观结构定量分析相结合的方法 ,提出了软土在外荷作用下微观结构的演变模式 ,由此建议了一个含结构参数的固结变形本构关系。用试验资料和工程实例进行了初步验证 ,表明所建模型可以预测多级加载条件下海积软土的变形规律。     

结构性海积软土的弹塑性研究

通过对天津市欠固结海积软土进行的大量试验,研究了土的结构性和弹塑性变形本构关系两个方面的问题。首次引入结构强度系数,建立了微结构定量参数与力学参数之间的关系,并提出一种综合考虑结构性影响的应力应变关系模型,为海积软土的结构性模型研究及实际应用提供了一条新的途径。     

天津海积软土Singh-Mitchell蠕变模型及灰色预测

通过三轴不固结不排水蠕变试验,建立了天津海积软土Singh-Mitchen蠕变模型,同时利用实测数据进行了灰色预测。试验结果表明:Singh-Mitchell经验模型适合于天津海积软土蠕变预测,利用实测数据亦可对蠕变进行短期灰色预测,效果较好,工程实践中可作为参考。     

天津地区海积软土结构强度及其对力学特性的影响

海积软土是一种结构性土,具有结构连结强度.其压缩曲线呈现出超固结土的压缩曲线形式.强度曲线为二段折线,在应力小于σ＇k时表现出超固结土的力学特性.而当应力水平高于这一临界值时.表现出正常固结土的力学特性.对其结构连结的成因进行了简单探讨.     

河口滨海区浅层海积软土工程特性研究

永定新河河口地区覆盖了厚约18 m的海积软土.通过对上百组试验数据的统计和回归分析,研究了永定新河河口地区海积软土的工程参数特性及其随深度的变化规律,建立了相应的回归方程.研究结果认为,研究区海积软土具有高含水量、高孔隙比、高压缩性、低强度、弱渗透性和高盐度等特性.天然含水量是软土的基本参数,其与其它工程参数的相关分析结果表明利用天然含水量可粗略评估其它工程参数特性.软土的工程参数随深度变化存在一定的规律性,其变化规律不仅受软土类型制约,而且与埋设深度密切相关.     

天津海积软土结合水固结分析

当前近代海积软土工程沉降分析仍以传统的太沙基单向渗透固结理论为基础。而海积软土有其特殊工程地质性质 ,如 :高孔隙比、高含水量、高压缩性、低渗透性 ,计算结果很难与实际情况相符合。本文从微观角度入手 ,根据压汞和SEM资料分析影响软土固结的本质因素 ;最后借助单向压缩实验 ,对比理论固结曲线与试验压缩曲线 ,分析产生偏差的原因 ,阐述了海积软土固结机制 ,提出结合水固结新概念。     

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.     

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     

OCEANOGRAPHY & MARINE GEOLOGY

正20140582 Fang Xisheng(Key Lab.of Marine Sedimentology and Environmental Geology,First Institute of Oceanography,State Oceanic Administration,Qingdao 266061,China);Shi Xuefa Mineralogy of Surface Sediment in the Eastern Area off the Ryukyu Islands and Its Geological Significance(Marine Geology Quaternary Geology,ISSN0256-1492,CN37     

ENVIRONMENTAL GEOLOGY

正20141810 Bian Yumei(Geological Environmental Monitoring Center of Liaoning Province,Shenyang 110032,China);Zhang Jing Zoning Haicheng,Liaoning Province,by GeoHazard Risk and Geo-Hazard Assessment(Journal of Geological Hazards and Environment Preservation,ISSN1006-4362,CN51-1467/P,24(3),2013,p.5-9,2 illus.,tables,refs.)