三峡库区望霞危岩体孕灾地质环境条件分析

危岩体是一种典型的灾害地质体,其形成、变形与破坏受控于地质环境条件,地质基础要素在孕灾的过程中起着决定性作用,各基本地质要素与灾害形成的关系是研究危岩体变形规律和破坏机理的关键性问题。通过对三峡库区望霞危岩体区域地质构造作用分析,横石溪背斜构造解析,各类地质结构面发育特征统计和危岩体岩性组合方式及工程地质条件剖析,结合危岩体两次变形破坏过程,分析各因素对危岩体的形成及变形的关系。研究认为:孕育望霞危岩体的横石溪背斜雏形形成于印支期的隆升阶段,至燕山主期形成褶皱主体,后期则以继承性改造为主,危岩体的形成及孕育主要集中在背斜核部区域,枢纽位置尤为发育。控制危岩体变形的5条关键裂缝与顶部发育的"V"字形裂缝关系密切,其是在纵弯褶皱作用下背斜顶部脆性岩层受到强烈的拉裂影响,叠加台阶式层间滑动作用,形成与轴面近于平行的拉张裂缝。在望霞危岩体中发育多组地质结构面,其中原生结构面对各条关键裂缝及关键块体提供基础背景值,控制其规模、范围及变形强度。控制着变形关键部位特别是前缘软弱层变形位置、牵引区段及强烈程度。构造结构面主要控制关键裂缝的延伸方向、距离及样式,控制关键块体的变形方向,裂解范围及规模,掉块及崩裂位置,控制危岩体底部关键部位即压张裂缝的形成位置、张开度及位移方向。次生结构面主要控制后缘变形区,对各条关键裂缝控制其继承性变形,控制关键块体扩张,对岩体裂解破坏至关重要。同时,望霞危岩体在地层岩性上构成了典型的硬—软—硬岩性组合,为危岩体的变形提供了地质结构组合条件,其底部大面积的采空区控制着危岩体整体滑塌变形。     

坡底饱和型黄土滑坡离心模拟试验

黄土极具结构性和水敏性,人类活动及自然因素作用下的水致地质灾害备受关注,其中坡底饱和型黄土边坡极易失稳破坏并造成危害。基于离心模拟手段,采用未扰动原状黄土制作模型,自主设计模型后缘渗水装置,模拟坡底饱和型黄土边坡的失稳过程;通过模型顶部视频监测、侧面粒子图像测速（particle image velocimetry,简称PIV）分析、底部孔隙水压力及土压的联合监测手段,分析其失稳破坏特征,并结合现场滑坡演化特征进行验证对比。主要得出以下结论：加速度达80g时,模型底部饱和,前缘出现滑移、后缘发生塌陷及内部湿陷,呈多元破坏形式;模型侧面位移表现为滑移前的表层张拉变形、底部湿陷变形及后缘塌陷前的顶部沉降变形;模型底部高孔隙水压力区分布于大面积滑移和塌陷区域下方,表征了坡底高水位对破坏的影响及底部水渗流的不均匀性;模型滑移破坏与现场滑坡具相同演化进程：坡底饱和-张拉裂缝-后退式小型滑移-水位抬升-后退式大型滑移。研究成果可为原状黄土的模型试验研究思路及原位滑坡的多元破坏机制研究提供借鉴。     

基于无人机倾斜摄影三维建模技术的赤马山铜矿地质环境调查及评价

赤马山铜矿位于湖北省东南部长江南岸,因资源枯竭已闭坑。近年来赤马山铜矿区出现严重采空区塌陷、山体裂缝、危岩体等地质灾害问题。基于此,本文通过无人机倾斜摄影测量技术与三维实景建模,结合现场采空塌陷区的调查测绘、工程地质调查等方法,研究湖北省赤马山铜矿采空塌陷造成的一系列次生地质灾害,查明其现状及分布规律,探讨塌陷区-山体裂缝-危岩体与采空区之间的耦合关系。结果表明：地面塌陷由1#、2#、3#、4#四个塌陷坑组成,走向114°～127°;山体裂缝与塌陷长轴平行展布,裂缝宽0.2～3.0 m;塌陷区-山体裂缝-危岩体主要是采用崩落顶底柱及间柱方式处理采空区所导致。同时进行矿山地质环境的预测建模和预测评估,提出合理的采空塌陷区安全对策和治理建议,为矿区生态环境修复提供可靠依据。     

竖井变形破坏机制与继续使用可行性探究

依据程潮铁矿地表变形、岩体变形和井筒裂缝监测资料,分析东主井井筒变形破坏的成因,总结井筒裂缝分布规律及其与采空区的关系,通过数值分析探讨井筒继续使用的可行性。结合后期对地表与深部岩体较为详细的监测资料,建立了倾倒破坏力学模型,探讨井筒裂缝扩展与井区岩体水平位移之间的关系以及井区岩体分区与井筒裂缝分布之间的关系。研究结果表明,东主井变形破坏是由地下采矿引起的,岩体水平位移对井筒变形破坏起重要作用;井筒的裂缝分布在空间上与采空区的位置有关,井筒的东面和西面裂缝发育,南面和北面基本无裂缝。由数值计算结果可知,井区地表与岩体变形将继续加大,但不会发生整体失稳破坏。对比岩体分区与裂缝分布发现,井筒的裂缝分布在深度方向上与井区岩体分区有很好的对应关系。     

三峡库区望霞危岩体变形破坏过程的综合监测与险情预报

三峡库区巫山县望霞危岩体于2010年及2011年两次发生大面积变形破坏,采用全站仪、裂缝位移、GPS等方法对危岩体进行了长期的变形监测,并通过地质基础的调查、监测方案的设计、监测数据的处理、宏观现象的分析,两次成功地对危岩体的垮塌变形实现了预警预报,避免了重大伤亡。研究结果显示,危岩体具有渐变和突变两种类型,在不同的变形阶段应采用相应的监测方法和监测频率,应以地质调查为基础,以监测危岩体关键部位为原则,监测数据的分析要密切结合宏观现象,从后缘、崖壁、崖底全面把握危岩体变形趋势。提出危岩体的监测应做到"详调查、细部署、观现象、握趋势、准预报"5原则,即"望霞经验"。"望霞经验"可以为危岩体的监测工作提供参考。     

金沙江乌东德水电站坝区高陡边坡地质灾害监测预警研究

文章以金沙江下游乌东德水电站坝区右岸水垫塘高陡边坡为例,系统探索了高度超过500 m的高陡边坡地质灾害调查识别与监测预警技术。针对常规方法难以准确捕捉高陡边坡危岩体变形破坏特征这一问题,创新采用了"登山攀岩速降技术与地质调查、工程地质测绘相结合"的方法,在乌东德水电站坝区水垫塘高陡边坡共调查识别了178个危岩体。在此基础上,通过构建分布式光纤应变实时监测系统和具有明显裂缝的危岩体布设拉绳位移传感器,实现了高陡边坡危岩体形变的实时监测,监测结果与实际危岩体变形一致。此外,在高程580~1600 m的坡体上还布设了6个地震动监测台站,捕捉到了包括2016年12月8日乌东德地震和2017年3月12日的鲁甸地震在内的大量地震加速度数据,并以此分析了乌东德地震波作用下的岩体动力响应特征,结果显示该边坡处于基本稳定状态。上述研究思路和方法对西南水电站高陡边坡稳定性监测预警和风险评估具有借鉴意义。      

链子崖煤层采空区治理工程及质量控制

文章介绍了长江三峡链子崖危岩体煤层采空区的治理情况.针对危岩体地质条件及变形特征,结合煤层采空区的实际情况,工程采用承重阻滑键置换煤层采空区内松软的煤渣层,形成一定规格的键槽.在采空区顶底扳打上锚筋,再进行C25混凝土回填浇筑,最后形成混凝土承重阻滑键.所有的键体连结起来,在危岩体底部构成完整的混凝土支撑结构体系,实现了承重阻滑目的.     

四川深溪沟水电站苏姑坪危岩体变形特征及其机理研究

苏姑坪危岩体位于四川大渡河深溪沟水电站库区,破坏失稳后很可能堵塞大渡河,给该水电站、成昆铁路以及上游瀑布沟水电站的安全构成威胁.本文在现场调查测绘资料的基础上,利用岩土工程地质力学分析原理,对该危岩体的变形特征、变形机制及其破坏模式进行了分析,建立了危岩体流变滑移力学模型并以此预测其变形破裂失稳时间.研究结果表明该危岩体变形破裂模式为卸荷-拉裂-蠕滑型,即岸坡岩体随着大渡河下切卸荷变形,在后缘形成近垂直拉裂缝,同时在自重和外部偶然荷载作用下沿缓倾坡外的层面发生剪切蠕滑变形.最后基于流变模型并根据前期蠕滑速率推测出失稳时间.     

济南燕翅山危岩体稳定性评价及防治对策

本文通过对燕翅山危岩体地质特征的分析,建立稳定性评价模型,进行了危岩体稳定性评价,评价结果表明燕翅山危岩体不存在整体倾覆和滑动破坏的可能。由于地下存在铁矿采空区,还存在继续沉陷变形的危险。因此,危岩体防治应以清除陡崖顶部浮石、松动块石为主,从保护山体完整地貌的角度需进一步查清采空区的空间特征,进行充填和支护治理。     

G 109国道拉萨—羊八井段喀努纳危岩体变形破坏模式及稳定性分析

喀努纳危岩体发育于青藏铁路、G109国道和京藏高速公路的交汇路段,对交通工程施工建设和安全运营造成极大威胁。为了评价喀努纳危岩体的稳定程度,同时查明潜在崩塌的失稳条件和主控因素,深入系统地分析了危岩体的地质背景、发育特征及潜在变形破坏机理。利用块体理论和离散元方法,分别研究了自重条件和地震荷载作用下危岩体的稳定性及动力响应。研究表明,危岩体纵向上可以分为上部坡顶整体崩塌源、中部基岩裂隙带和下部块石堆积区,出露有4组优势结构面。通过计算得出,在自重条件下,危岩块体处于基本稳定状态;在地震荷载作用下,危岩体将会以剪切滑动、断裂坠落方式失稳;短时强震加剧了喀努纳危岩体内部损伤的累积。最后,文章给出了针对性防治和监测预警的建议。     

Unity of the national and the international in the socio-cultural development of the peoples of the USSR

International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.     

Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth

It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T ₃ = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″.     

Global repeating events in the history of the Earth and the motion of the Sun in the Galaxy

Chronological analyses of correlations between certain global repeating events (mass extinctions of marine organisms, meteorite impacts, and flashes in the frequency of geomagnetic reversals) during the Phanerozoic Eon and the motion of the solar system in the Galaxy are presented for five rotationally symmetrical models for the regular Galactic gravitational field. Thirteen of sixteen mass-extinction events can be described by a repetition interval of 183±3 million years. This is in agreement with the anomalistic period (interval between two subsequent passages of the Sun through the apocenter of its Galactic orbit) in the model of Allen and Martos. The positions of the minima and maxima in Gaussian functions approximating the frequency distribution for geomagnetic reversals also agree with the times of passage of the Sun through the apocenter and pericenter, respectively, of its Galactic orbit in this model. The maximum in the distribution of the deviations of the dates of mass extinctions from the nearest dates of impacts of large, crater-forming bodies is close to zero, providing evidence that many such events are correlated. As a rule, extinctions follow impact events. The impacts of large bodies have occurred most often when the solar system passes through the Galactic plane, while mass extinctions occur more often at some distance from the Galactic plane (about 40 pc). As a rule, intervals of increases in the frequency of geomagnetic reversals coincide with dates of impacts of large bodies. At the same time, these intervals do not show a clear correlation with the dates of mass extinctions. The intensity of mass extinctions, like the energy released by impacts, is consistently higher in periods when the Sun is moving from the apocenter toward the pericenter of its orbit, than when it is moving from the pericenter toward the apocenter. Thus, there is evidence for a variety of relationships between repeating global events in the Phanerozoic and the motion of the Sun in the Galaxy. Long-period variations in the frequency of geomagnetic reversals are correlated with the orbital motion of the Sun, and increases in the frequency of geomagnetic reversals are correlated with impacts. Mass extinctions are correlated with the impacts of large bodies, whose motions may have been perturbed by clouds of interstellar material concentrated toward the Galactic plane and by the shock front associated with the Perseus spiral arm, through which the solar system passes. The velocity of the Sun relative to the spiral pattern is estimated.     

摩擦桩基桩土间极限摩阻力取值问题探讨

通过对广珠东线高速公路横沥大桥的试桩及土体的工程地质条件分析,总结出影响摩擦桩基桩土间极限摩阻力取值的一般问题以及解决问题的方法和措施。     

从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返

位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压，而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩，榴辉岩及其他直接围岩皆呈包体存在于其中，并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体，表明新元古代花岗岩的组成物质也经受过超高压变质作用，且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次（或阶段）却少于榴辉岩。椐上述可得如下推断：超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部（俯冲板块前部）形成的；榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的，其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升，遭受剥蚀。     

某高速公路下伏煤矿采空区稳定性分析

在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。      

On the consistency of proposed models for the Pyrenees with the structure of the eastern parts of the belt

The structure of the eastern Pyrenees consists mainly of south-directed thrusts involving basement and cover rocks. An antiformal stack developed by the piling up of basement thrust sheets which outcrop in the Axial zone. These structures account for a thin-skinned thrust model rather than a vertical fault model in which the Axial zone would be essentially autochthonous, and the North-Pyrenean fault the axial plane of a fan thrust system. New data from the Eastern Pyrenees and the thin-skinned model suggest that(1) the structure east of the Pedraforca nappe is similar to that of the Central Pyrenees; (2) the cover rocks of the South-Pyrenean units and of the Axial zone-after restoration—built up a northwards-thickening prism consistent with the existence of a unique Pyrenean sedimentary basin during Mesozoic time; (3) the Axial zone is only a complex antiformal stack developed as a part of South-Pyrenean system related to the Paleogene thrusting-tectonics. The Axial zone palaeogeographic area had no special meaning during Mesozoic time.     

Paleomagnetic implications on the evolution of the tethys belt from the atlantic ocean to the pamirs since the triassic

We first re-examined the apparent polar wander curves for stable Eurasia and Africa since the Triassic. These curves were then combined together with curves of North and South America according to the kinematics of the Atlantic ocean and a synthetic polar wander curve was given. Then, most of the paleomagnetic results from the Tethys mobile belt, from the Atlantic to the Pamirs, were analysed.Several groups of plates, microplates and blocks can be seen. First, relatively stable regions like Maghreb and Sicily, which have not moved much. Then we have a group formed by Iberia, Sardinia, Italy and, to a lesser extent, Corsica and the Western and Central Alps. For these blocks, movements are anticlockwise rotations chiefly driven by the anticlockwise rotation of Africa, but they are sometimes stronger.To the east, a major change takes place. The north of the Aegean Sea and the Ionian zone are clockwise rotated and these rotations are recent: Oligocene-Miocene for the first part, Pliocene to the present for the second part.A major problem arises in Turkey, Caucasus and Iran. Paleomagnetic results indicate a position far to the south of Eurasia, and, at the same time, geological evidence is in favour of a position close to Eurasia. We discuss these discrepancies.