对广东肇庆河岸滑坡应急治理工程的思考

广东肇庆河岸由于江水上涨浸泡及强降雨冲刷软化边坡土体、坡顶房屋压重等多重不利因素的影响发生推移式滑坡,造成部分房屋倒塌。由于灾害区域较大,实施永久性治理工程量大、工期长,如何快速对灾发范围内的重要建筑物进行保护性应急抢险治理,防止灾情扩大,是一个难题。本文介绍了在未对整个灾发区进行全面系统整治的情况下选定包括保护物在内一个相对较小的特定区域进行应急治理,应用双排钢管微型桩及钢筋砼挡墙进行支挡防护,辅以严密边坡及建筑物变形监测措施,安全高效地对河岸滑坡进行了有效应急治理,保证了一定时期内边坡上重要设施的安全。     

四川广巴高速公路红层滑坡成因分析及防治措施

四川北部山区高速公路红层滑坡灾害广泛存在。根据广巴高速公路木门段滑坡的现场勘查,从地形地貌、地层岩性、地质构造、水文地质及滑坡形态等方面对滑坡形成机制进行分析,指出该滑坡属滑移～牵引型滑坡。通过对滑坡稳定性分析计算,得出其稳定系数K在1．05～1．15,且滑坡前缘在河床中,洪期受河水冲刷,加之匝道路堑和桥梁基坑开挖均对滑坡稳定不利,其稳定系数正逐步降低,处于欠稳定一基本稳定状态,需进行处治。结合工程实际,提出了于二级滑体前部设置抗滑桩、一级滑坡后部设置小直径钢管排桩,并辅以排水、截水设施的防治措施。     

钢花管注浆加固在高速公路边坡挡墙病害防治中的应用研究

高速公路建设期间,挡墙作为边坡加固方式之一得到了普遍应用,但随着高速公路运营时间增长,由于前期设计、施工、养护等原因,边坡挡墙病害不断增多,其安全问题成为了公路运营过程中亟待解决的难题。钢花管注浆加固能够起到加固岩土体、增强抗滑能力,而嵌入地层的钢花管又能起到锚固桩作用,是较好的边坡病害处治方法,但目前在运营高速公路挡墙病害防治中的研究应用相对较少。文章以浙江省某高速公路K298边坡挡墙为例,根据边坡的地质条件及挡墙病害情况采用钢花管注浆加固,并确定了合理的注浆压力、扩散半径及注浆孔间距。工程实践结果表明该方法是一种经济适用、施工简便的挡墙病害处治措施。     

四川西-攀高速公路山神庙隧道进口滑坡综合治理

四川西-攀高速路山神庙1号隧道进口在施工过程中由于连续降雨突发滑坡灾害,滑坡掩埋了左洞口及下方道路,并对右洞造成危害。由于与隧道的干扰、密切相互作用关系,使该滑坡的治理有别于其它一般的滑坡。在整治设计思路上,综合分析得出对其治理原则,即首先采取抢险工程措施使滑坡暂时稳定,不再发展。后期治理不仅要使滑坡彻底稳固,同时要控制变形,避免对隧道的影响。在工序上应先治理滑坡,再对隧道进行整治和恢复。处治方案上,抢险工程以锚索钢管桩为主,同时采取反压护道、截排水等辅助措施,使滑坡得到了控制。再根据地勘资料和计算,设置了锚索抗滑桩,使滑坡得到稳固。最后对仰坡不稳定坡面设置了框架锚索和锚杆并植草,避免对隧道危害。设立了处治各阶段及长期的监测系统,监测处治效果和变形情况。监测结果反映综合处治效果良好。论文介绍了对该滑坡进行动态综合治理的全过程。对设计治理方案按抢险工程、滑坡稳固工程、仰坡治理工程和监测系统进行了系统总结。     

施工诱发边坡失稳变形机制及应急治理对策

通过对香溪大道失稳边坡地质灾害调查,对边坡的地形地貌、地层岩性、岩体结构、原设计方案与施工过程进行研究,在此基础上通过FLAC3D数值模拟,结合工程地质条件分析,对原格构挡墙逆作法施工诱发边坡牵引式滑动过程进行了分析,并对其变形破坏机制进行深入探讨。研究结果表明:边坡变形受工程地质条件控制作用明显,边坡开挖改变了坡体原来的力学平衡条件,为边坡变形失稳创造了客观条件;由于超开挖施工,受格构挡墙自重作用,下部支撑岩体受压破坏,导致格构挡墙失稳下沉,带动其后坡体变形,形成牵引式滑动;随着坡体滑移的发展,边坡将逐渐拉裂破坏并形成贯通的剪切滑动面,从已施工的格构挡墙下部贯通剪出,最终整体失稳破坏;基于破坏机制分析的应急治理措施将重点放在为原格构挡墙下部提供有效支撑和控制潜在滑动面变形上;监测结果表明,应急治理后边坡达到稳定性要求。      

精细化设计理念在边坡防治工程中的应用

基于北京市房山区某不稳定斜坡,通过对保护对象的需求、现场工程地质条件等的精细调查和分析,确定灾害隐患三处,分别为房后边坡欠稳定、公路路基塌空、院前挡墙垮塌。在充分考虑各处地形条件及住户需求的基础上,应用精细化设计理念,针对房后边坡采用重力式挡墙、截水沟进行治理,针对公路路基塌空采用两级重力式挡墙进行治理,针对院前既有挡墙垮塌采用桩板式挡墙进行治理。探讨总结边坡工程的精细化设计理念,提出“工程安全、施工便捷、造价经济、以人为本、环境友好”的边坡工程精细化设计准则。     

单排与三排微型抗滑桩大型模型试验研究

为了得到土质边坡中微型抗滑桩的破坏机制及边坡的破坏模式,通过3组大型物理模型试验对单排与三排微型抗滑桩加固黏性土边坡进行了研究。在加载过程中进行了位移和桩体应变的测量,最后进行开挖观察桩体破坏形态。试验结果表明,三排微型桩具有良好的抗滑效果,其承载力较单排桩提高了51.5%,且允许滑体产生较大位移,有效延缓坡体垮塌,适用于应急抢修工程。边坡会在加桩位置向前产生弧形次生滑面,并与预设滑面贯通;对于三排桩,第3排桩前出现桩土脱空区,坡面产生纵向劈裂缝。桩体变形呈S形,发生弯曲变形引起张拉与压剪破坏,而不是岩质边坡中滑面处的受剪断裂破坏。桩身所受最大弯矩分布于滑面以上,对于三排桩,第1排所受弯矩最大,第3排其次,第2排最小。其研究结果对了解微型桩的抗滑和破坏机制具有参考意义。     

微型桩基础挡墙在边坡治理工程中的应用

浆砌石重力式挡墙广泛应用于边坡治理工程中,但当挡墙基础基槽无法开挖或坡脚地基承载力较低时,浆砌石重力式挡墙的应用就受到限制。本文结合陕西银矿矿山治理工程实例,介绍了采用微型桩基础挡墙在基槽开挖可能导致边坡发生失稳、坡脚承载力低的情况下的应用实例。     

护坡桩+微型钢管桩复合土钉墙联合支护体系研究应用

本文提出了一种新的联合支护体系——护坡桩+微型钢管桩复合土钉墙支护体系,成功解决了基坑周边无放坡空间需垂直开挖、基坑深度大、要求位移小、支护费用高等技术难题,做到了施工便利,对控制边坡位移变形、增强边坡整体稳定性、保证在基坑开挖工程中不发生对周围环境的影响具有良好的作用。采用这种支护方式对北京一工程进行设计施工探讨,经工后监测效果良好,大大地提高了边坡的安全稳定性,从而验证了这一支护形式的可行性,其在深基坑支护中具有常规土钉墙和护坡桩无法相比的技术与经济优势,可供其他类似工程参考,具有较高的适用推广价值。     

深基坑开挖工程PHC桩的保护及边坡稳定性分析

基坑工程主要包括基坑支护体系设计与施工和土方开挖,是一项综合性很强的系统工程。由于各地区的地质条件不同,因此基坑工程具有很强的区域性和很强的个性。本工程用PHC桩代替常用的钢管桩大大地节省了投资,边坡的稳定性也得到了很好的保护。     

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