惠安县东港溪综合生态治理工程设计方案探讨

生态河道堤防护岸工程的设计决定了工程施工的质量,河道堤防护岸的生态性、抗冲击性、耐久性和自净能力等性能会受到护岸工程材料和结构的影响。本文以福建惠安县东港溪(东桥段)安全生态水系建设项目为例,针对生态河道堤防护岸存在问题,对常用的砖砌石和混凝土护岸、生态格宾石笼和生态土工织物袋护岸、生态砌块和仿木桩护岸、墙式护岸、坝式护岸、坡式护岸及植物护坡方案进行分析的基础上,根据东港溪河道的实际情况,对该生态河道治理的护岸设计方案进行探讨,从经济、施工和景观等方面进行比较,最终采用复合式结构方案,可实现生态河道堤防护岸的安全性和经济性。     

安康汉滨区防洪工程最优护坡形式比选探讨

月河是汉江左岸较大的一级支流,安康汉滨区处月河下游段,径流量大,防洪压力大,故在城区沿河段采用了多种护坡形式,选择合理护坡形式是保障河段行洪安全的重要措施。通过对汉滨区城区堤防工程建设中多种护坡形式进行比选分析,总结各种护坡的优缺点,最终优先适宜护坡形式。比选结果可知：在防洪工程建设中共采用浆砌石挡墙、浆砌石护坡、干砌石护坡三种传统护坡和新型的生态砼护坡和铰接式护坡;从一个汛期检验效果看,生态砼护坡生态效果最佳,铰接式护坡次之。浆砌石挡墙节约土地效果最佳,干砌石护坡造价最经济。分析结论为远期河道治理提供借鉴和参考。     

现浇透水性生态混凝土在河道边坡工程中的应用

针对传统护坡工程方法在河道边坡工程生态环境保护和修复方面的缺陷,提出了新型现浇透水性生态混凝土护坡技法,优化设计了该技法组成材料,并对生态混凝土的耐久性、植生能力和净水性能进行了综合分析。通过该技法在泰州周山河河道边坡生态治理工程中的实际应用,认为所提出的现浇透水性生态混凝土护坡技法不仅能充分保证护坡工程的安全性,还可维持和改善周边生态环境与生态系统。     

生态河道建设中生态护坡技术的应用分析

护坡形式多种多样,近年来生态护坡越来越受人喜爱,在生态护坡应用和结构设计方面辽宁义县大凌河生态治理工程做了有益尝试。实践表明,该工程考虑试验研究成果、遵循生态护坡设计原则,坚持营造生态环境、以人为本的理念合理设计生态边坡,为其他河流生态整治提供一种新的思路。     

《DIKE ENGINEERING》（堤防工程）

《DIKE ENGINEERING》是我国第一部关于堤防工程专业的外文专著,江河堤防是我国防洪工程体系的重要组成部分。在长江、黄河等七大江河的中下游地区,堤防是防御洪水的最后屏障。目前,我国建有各类堤防达 26 万公里,其中主要堤防 6.57 万公里。我国堤防历史悠久,是逐渐形成的。1998 年,长江、松花江等大江大河发生了百年不遇的特大洪水,期间沿江堤防经受了严峻的考验,发挥了巨大的作用。但也有堤防暴露了严重的质量隐患,甚至发生溃决,给国家和人民的生命财产造成了巨大的损失。因此,近年来堤防设计和施工中形成了许多新理论、新技术和新…     

传统护坡与生态护坡在护岸设计中的组合应用

该文对传统护坡和生态护坡进行了比较分析,并以重庆市江津区大肚子河整治工程为实例,说明2种护坡组合应用可以扬长避短,为今后水利工程建设提供了较好的参考。     

生态防护在高速公路护坡中的应用研究

在系统总结国内外常用护坡方法的基础上,提出了要将工程护坡和植被护坡相结合的思想。文章介绍了一种新的特别适用于膨胀土边坡的生态防护方法锚杆框架梁护坡,并对这种防护的护坡原理、力学机制、施工工艺等做了较为详细的阐述。     

格宾技术在长江三峡三斗坪镇护岸防治工程中的应用

格宾护坡技术因其较以往传统方法具有柔性整体强固、透水性能好、经久耐用、利于植被生长等优点,近些年来逐渐在我国堤防治理、边坡防护等工程中加以应用。本护岸防治工程位于长江南岸三斗坪镇一带,上距三峡大坝4.5 km,该段岸坡全长3 137 m,其中土质岸坡2 917 m,其护坡材料主要为格宾石垫,工程治理后,该段护岸面貌已焕然一新。工程监测结果表明,截止2005年10月,该段岸坡无变形,取得了良好的经济和社会效益,值得在以后护岸工程治理中加以推广。     

彰武县城段堤防加固方案比选探析

辽宁彰武县城区各段堤防由于建设时间久远,均不同程度存在边坡失稳、堤防不均匀沉降和护坡损毁等问题,通过现场查勘和问题分析。进行提防加固很有必要,在坚持不改变原有堤线布局的原则下,从投资、增加占地量、运行寿命、生态效果、施工难易程度以及毁林量大小等方面对拟定的均质土堤加固、浆砌石挡墙加固和混凝土挡墙加固3个方案优缺点进行对比分析,确定采用浆砌石挡墙加固型式作为本次彰武城市段堤防加固方案。     

农村河道护坡治理模式及生态护坡应用探讨

河道护坡在农村河道护理中发挥重要作用,生态护坡的应用不仅改善了农村河道护坡治理,同时对河道周边植被起到重要保护作用,是河道护坡模式的具体应用。本文将传统护坡模式与生态护坡模式进行对比分析,并结合相关文献资料的研究,提出传统护坡模式对生态环境的影响,同时给出生态护坡模式下的护坡功效和生态保护作用。在社会经济迅速发展的背景下,生态护坡会逐渐普及到农村河道护坡治理当中,为生态环境的可持续发展提供重要依据。     

Statistical considerations for grain-size analyses of tills

Relative percentages of sand, silt, and clay from samples of the same till unit are not identical because of different lithologies in the source areas, sorting in transport, random variation, and experimental error. Random variation and experimental error can be isolated from the other two as follows. For each particle-size class of each till unit, a standard population is determined by using a normally distributed, representative group of data. New measurements are compared with the standard population and, if they compare satisfactorily, the experimental error is not significant and random variation is within the expected range for the population. The outcome of the comparison depends on numerical criteria derived from a graphical method rather than on a more commonly used one-way analysis of variance with two treatments. If the number of samples and the standard deviation of the standard population are substituted in at-test equation, a family of hyperbolas is generated, each of which corresponds to a specific number of subsamples taken from each new sample. The axes of the graphs of the hyperbolas are the standard deviation of new measurements (horizontal axis) and the difference between the means of the new measurements and the standard population (vertical axis). The area between the two branches of each hyperbola corresponds to a satisfactory comparison between the new measurements and the standard population. Measurements from a new sample can be tested by plotting their standard deviation vs. difference in means on axes containing a hyperbola corresponding to the specific number of subsamples used. If the point lies between the branches of the hyperbola, the measurements are considered reliable. But if the point lies outside this region, the measurements are repeated. Because the critical segment of the hyperbola is approximately a straight line parallel to the horizontal axis, the test is simplified to a comparison between the means of the standard population and the means of the subsample. The minimum number of subsamples required to prove significant variation between samples caused by different lithologies in the source areas and sorting in transport can be determined directly from the graphical method. The minimum number of subsamples required is the maximum number to be run for economy of effort.     

Stress-strain analysis of geogrid-supported liners over subsurface cavities

Summary Finite element analyses were conducted to investigate the magnitude of tensile strains imposed on landfill liners due to the formation of subsurface cavities. The study incorporated the significance of using geogrids to reduce the magnitude of strains and possibly the potential for collapse of landfill liners. Variations of key parameters included depth of overburden (D) and diameter of the cavity (B). Estimated stress distributions were compared to theoretical values obtained from a model reported in the literature. Results indicated that, contrary to conventional wisdom, the critical area based on the mechanics of arching was above the edge of the cavity where stress concentration occurred. Incorporation of geogrid reinforcement reduced the magnitude of tensile strains. The tensile force in the geogrid was dependent upon the size of the cavity, the depth of the overburden, and the applied pressure.     

Evolution of the European Cenozoic Rift System: interaction of the Alpine and Pyrenean orogens with their foreland lithosphere

The evolution of the European Cenozoic Rift System (ECRIS) and the Alpine orogen is discussed on the base of a set of palaeotectonic maps and two retro-deformed lithospheric transects which extend across the Western and Central Alps and the Massif Central and the Rhenish Massif, respectively.During the Paleocene, compressional stresses exerted on continental Europe by the evolving Alps and Pyrenees caused lithospheric buckling and basin inversion up to 1700 km to the north of the Alpine and Pyrenean deformation fronts. This deformation was accompanied by the injection of melilite dykes, reflecting a plume-related increase in the temperature of the asthenosphere beneath the European foreland. At the Paleocene–Eocene transition, compressional stresses relaxed in the Alpine foreland, whereas collisional interaction of the Pyrenees with their foreland persisted. In the Alps, major Eocene north-directed lithospheric shortening was followed by mid-Eocene slab- and thrust-loaded subsidence of the Dauphinois and Helvetic shelves. During the late Eocene, north-directed compressional intraplate stresses originating in the Alpine and Pyrenean collision zones built up and activated ECRIS.At the Eocene–Oligocene transition, the subducted Central Alpine slab was detached, whereas the West-Alpine slab remained attached to the lithosphere. Subsequently, the Alpine orogenic wedge converged northwestward with its foreland. The Oligocene main rifting phase of ECRIS was controlled by north-directed compressional stresses originating in the Pyrenean and Alpine collision zones.Following early Miocene termination of crustal shortening in the Pyrenees and opening of the oceanic Provençal Basin, the evolution of ECRIS was exclusively controlled by west- and northwest-directed compressional stresses emanating from the Alps during imbrication of their external massifs. Whereas the grabens of the Massif Central and the Rhône Valley became inactive during the early Miocene, the Rhine Rift System remained active until the present. Lithospheric folding controlled mid-Miocene and Pliocene uplift of the Vosges-Black Forest Arch. Progressive uplift of the Rhenish Massif and Massif Central is mainly attributed to plume-related thermal thinning of the mantle-lithosphere.ECRIS evolved by passive rifting in response to the build-up of Pyrenean and Alpine collision-related compressional intraplate stresses. Mantle-plume-type upwelling of the asthenosphere caused thermal weakening of the foreland lithosphere, rendering it prone to deformation.     

Tectonics of the western part of the Polish Outer Carpathians

The western part of the Polish Outer Carpathians is built up from the thrust, imbricated Upper Jurassic-Neogene flysch deposits. The following Outer Carpathian nappes have been distinguished: Magura Nappe, Fore-Magura group of nappes, Silesian, Subsilesian and Skole nappes. Interpretation of seismic and magnetotelluric survey from the region South of Wadowice, allows observation of relationship between basement and flysch nappes in the Outer Carpathians. It also allows identification of dislocation cutting both flysch nappes and their basement. All the Outer Carpathian nappes are thrust over the southern part of the North European Platform. The platform basement is composed of older Precambrian metamorphic rocks belonging to the Bruno-Vistulicum terrane. Sedimentary cover consists of Paleozoic, Mesozoic and Neogene sequences. The characteristic features of this boundary are horsts and troughs of general direction NW-SE, turning W-E. Faults cutting only the consolidated basement and the Paleozoic cover were formed during the Hercynian Orogeny in the Carboniferous and the Early Permian. Most of the older normal faults were covered by allochtonous flysch nappes forming thus the blind faults. During the last stage of the geodynamic development the Carpathians thrust sheets moved towards their present position. Displacement of the Carpathians northwards is related to development of dextral strike-slip faults of N—S direction. The orientation of this strike-slip fault zones zone more or less coincides with the surface position of the major faults perpendicular to the strike of the Outer Carpathian thrustsheets. The huge fault cuts formations from the Paleozoic basement through the flysch allochton between the boreholes in Sucha Beskidzka area. The displacement of nappes of the Carpathian overthrust and diapiric extrusion of plastic formations of the lower flysch units occurred along this fault.     

Lower Carboniferous (Dinantian) stratigraphy and structure of the Walterstown-Kentstown area,Co. Meath,Ireland

Stratigraphic units are defined and described for the Lower Carboniferous succession in the Walterstown-Kentstown area of Co. Meath, Ireland. A complete (unexposed) Courceyan succession from the terrestrial red bed facies of the Baronstown Formation to the Moathill Formation of the Navan Group has been penetrated in several boreholes. Although the lower part of the sequence is comparable with the Courceyan succession at Navan and Slane, the middle part of the sequence differs markedly in the Walterstown-Kentstown area and two new members, the Proudstown and Walterstown Members, are defined in the upper part of the Meath Formation. Syndepositional faulting was initiated during the Courceyan, probably in latest Pseudopolygnathus multistriatus or early Polygnathus mehli latus time. Movement on the ENE trending St. Patrick's Well Fault influenced the deposition of the Walterstown Member and the overlying Moathill Formation and was probably associated with the development of the East Midlands depocentre to the south of the area. A second episode of tectonism in the latest Courceyan or early Chadian resulted in uplift and erosion and the development of ‘block and basin’ sedimentation. Subsequent transgression of the uplifted block led to the establishment of the Kentstown Platform, bounded to the north, west and south by rocks of basinal facies. The Milverton Group (Chadian-Asbian), confined to this platform, unconformably overlies Courceyan or Lower Palaeozoic strata and is subdivided into three formations: Crufty Formation (late Chadian), Holmpatrick Formation (late Chadian-Arundian) and Mullaghfin Formation (late Arundian-Asbian). The Walterstown Fault controlled the western margin of the Kentstown Platform at this time. Contemporaneous basinal sediments of the Fingal Group (Lucan and Naul Formations) accumulated to the west of the Walterstown Fault and are much thicker than age-equivalent platform facies. Platform sedimentation ceased in latest Asbian to early Brigantian time with tectonically induced collapse and drowning of the platform; platform carbonates of the Mullaghfin Formation are onlapped northwards by coarse proximal basinal facies of the Loughshinny Formation. A distinct gravity anomaly in the Kentstown area suggests the presence of a granitoid body within the basement. The Kentstown Platform is therefore considered to have formed on a buoyant, granite-cored, footwall high analogous to the Askrigg and Alston Blocks of northern England.     

Controls on the evolution and demise of Lower Carboniferous carbonate platforms,northern margin of the Dublin Basin,Ireland

Shallow water platform limestones of the Chadian–Asbian Milverton Group are restricted to the north-eastern part of the Lower Carboniferous (Dinantian) Dublin Basin. Here, they are confined to two granite-cored fault blocks, the Kentstown and Balbriggan Blocks, known to have been active during the late Dinantian. Three areas of platform sedimentation are delimited (the Kentstown, Drogheda and Milverton areas), although in reality they probably formed part of a single carbonate platform. Resedimented submarine breccias and calciturbidites (Fingal Group) composed of shallow water allochems and intraclasts sourced from the platform accumulated, along with terrigenous muds, in the surrounding basinal areas. Sedimentological evidence suggests that the Kentstown and Balbriggan Blocks possessed tilt-block geometries and developed during an episode of basin-wide extensional faulting in late Chadian time. Rotation of the blocks during extension resulted in the erosion of previously deposited sequences in footwall areas and concomitant drowning of distal hangingwall sequences. Antithetic faults on the northern part of the Balbriggan Block aided the preferential subsidence of the Drogheda area and accounts for the anomously thick sequence of late Chadian platform sediments present there. Continued subsidence and/or sea-level rise in the late Chadian–early Arundian resulted in transgression of the Kentstown and Balbriggan Blocks; carbonate ramps developed on the hangingwall dip slopes and transgressed southward with time. Subsequent progradation and aggradation of shallow water sediments throughout the Arundian to Asbian led to the development of carbonate shelves. Several coarse conglomeratic intervals within the contemporaneous basinal sequences of the Fingal Group attest to periodic increases of sediment influx associated with the development of the shelves. Sedimentological processes controlled the development of the carbonate platforms on the hangingwall dip slopes of the Kentstown and Balbriggan Blocks, though periodic increases of sediment flux into the basinal areas may have been triggered by eustatic falls in sea level. In contrast, differential subsidence along the bounding faults of these blocks exerted a strong control on the margins of the late Dinantian shelves, maintaining relatively steep slopes and inhibiting the progradation of the shelves into the adjacent basins. Tectonically induced collapse and retreat of the platform margins occurred in the late Asbian–early Brigantian. Platform sediments are overlain by coarse-grained proximal basinal facies which fine upwards before passing into a thick shale sequence, indicating that by the late Brigantian carbonate production had almost stopped as the platforms were drowned.     

Viscous effects on penetrating shafts in clays

The penetration of rigid objects such as piles and penetrometers into soils creates a zone of soil disturbance around them. The extent of this disturbed zone influences the resistance of the moving rigid body. This paper presents a theoretical framework to analyze the resistance in the disturbed zone created by a shaft penetrating a clay soil. The soil is modeled as a viscous material after it reaches failure [critical state (CS)]. The results of this analysis show that the viscous drag stress component on the shaft surface is influenced by the size of disturbed zone that has reached CS around the shaft, the shear viscosity of the soil and the velocity profile (or strain rate) in the CS zone around the shaft. The size of CS zone, the velocity profile and the viscosity of soil are interdependent. Large variation in viscous drag occurs when the size of the CS soil zone is less than four times the shaft’s radius. Limiting drag occurs when the size of the CS soil zone exceeds six times the shaft’s radius. The theoretical velocity distribution of the movement of soil in the CS zone shows that the soil is dragged along with shaft in the near field (close to the shaft surface) and moves upwards in the far field.     

具彩色斑纹颅形贝在广西桂林下石炭统黄金组中的发现:兼论颅形贝属的地质地理分布

文中描述了产自广西桂林地区下石炭统黄金组下部的颅形贝属一新种,桂林颅形贝(Cranaena guilinensis)。新种以平直的前结合缘和背壳上发育中槽为特征。在4枚标本上发现保存有放射状的彩色条带,表明该种当时生活在温暖海域的浅水环境。对该属70个种的地质地理分布和生物多样性变化的初步分析表明,该属可能起源于早泥盆世欧美大陆西北缘的老世界区,之后的地理分布和生物多样性发展以北美地区为中心,经历了中泥盆世—晚泥盆世早期和早石炭世2次比较明显的辐射演化、迁移扩散高峰和晚泥盆世晚期的1次严重衰退。第1次高峰是中泥盆世—晚泥盆世早期,该属的生物多样性达到巅峰,生物地理分布范围扩大到欧美大陆之外的西伯利亚板块、哈萨克斯坦板块和华南板块等;第2次高峰是早石炭世,该属的生物多样性虽不及前一次,但获得了最广泛的地理分布,不仅在北方大陆有分布,而且已进入到冈瓦纳大陆边缘。晚泥盆世晚期该属的1次严重衰退显然与F/F灭绝事件有关。早石炭世之后,该属进入衰退阶段,最终在二叠纪初灭绝。     

Nouvelle interprétation tectonique de la montagne Sainte-Victoire (Provence,France)

The explanation normally given for the tectonics of Sainte-Victoire Mountain, a dozen kilometres east of Aix-en-Provence, to the north of the limestone Provence, is incorrect. To the east, the morphology of the Sainte-Victoire is subdued, whereas to the west, before the mountain breaks savagely, the morphology is that of a young mountain as appears in Alpine landscapes. This unusual aspect in the region and the large subvertical faults with vertically striated surfaces that mark the massif to the south and to the west, induce the idea of strong vertical uplifts and caste doubt on the tectonic interpretation given in 1962 by Corroy et al. According to those authors, the Sainte-Victoire is a unit of Jurassic and Cretaceous formations overthrusting 1800 m to the south conglomerates of the Late Cretaceous or Palaeocene. New observations about the conglomerate transgression over the Jurassic and Cretaceous beds, and about the faults around and on the massif do not give evidence of an overthrusting but, on the contrary, induce the idea of a uplift, perhaps still active, in the form of a ‘piano key’ inclined to the northeast. To cite this article: J. Ricour et al., C. R. Geoscience 337 (2005).     

中国中新元古代重要沉积地质事件及其意义

地球曾经历了3次超大陆演化过程,其中2次超大陆(哥伦比亚(Columbia)和罗迪尼亚(Rodinia))旋回涉及中新元古代,并与一系列区域性事件相联系,形成了多成因的超大陆演化模型。华北中东部新元古代沉积事件、扬子和塔里木新元古代裂谷事件、雪球事件等都被视为Rodinia超大陆的裂解响应,它们对定时三大陆块相互关系及定位其在全球超大陆的位置具有至关重要的作用,也反映了重要沉积地质事件在超大陆研究中不可或缺的作用和意义。此外,在中新元古代的Columbia和Rodinia超大陆演化过程中,还伴随发育具有广泛区域性甚至全球意义的巨厚白云岩与碳酸盐岩微生物(岩)、红层与黑色页岩、全球性臼齿亮晶碳酸盐岩和埃迪卡拉纪盖帽碳酸盐岩等沉积事件群及元素(同位素)漂移等地球化学异常事件,也包括特殊且重要的磷块岩、锰、铁矿等沉积成矿事件。由于不断显示出来在全球古大陆重建和古地理恢复方面的重要作用,它们越来越得到学术界的广泛关注和研究。文中通过系统分析中国中新元古代超大陆旋回演化中发育的部分重要或关键地质事件(群)时空发育与分布特征,并结合作者团队的实际资料和测试数据,以期揭示超大陆演化过程与重要沉积地质事件的内在联系,为超大陆聚散旋回演化和时空定位及原型沉积盆地的发育和评价提供科学证据。