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1.
小金县是四川"5·12"汶川特大地震和"4·20"芦山地震的重灾区。两次地震中,该县诱发了大量地质灾害,造成严重的人员伤亡和财产损失。通过小金县地质灾害的发育类型,空间、时间、地形地貌以及地质特征的分析研究,评述了金县地质灾害发育的控制因素,对该县做好"预防、避让以及治理"等地质灾害防治工作将起到积极作用。  相似文献   

2.
四川5.12地震次生地质灾害的基本特征初析   总被引:32,自引:11,他引:21  
2008年5月12日14时28分, 四川汶川发生里氏8.0级地震给灾区人民带来了巨大的灾难和损失, 特别是山区地震次生地质灾害所带来的严重后果是人们始料未及的.本文主要报道了四川境内震中附近几个重灾山区的地震次生地质灾害的初步调查成果, 简要论述了地震诱发的滑坡、崩塌、泥石流、地裂缝和沙土液化等次生地质灾害发育特征及其危害, 提出了地震次生地质灾害某些发育规律方面一些认识和今后需要进一步研究的问题, 对于灾后重建和高烈度区城镇规划具有一定的指导意义.   相似文献   

3.
我国是世界上地质灾害最严重的国家之一。为了全面查清我国地质灾害的发育分布规律,国土资源部从1999年开始,在地质灾害严重的县(市),陆续部署开展了县市地质灾害调查与区划工作。论文在290个县、市地质灾害调查成果的基础上,分析统计了我国主要地质灾害的规模、诱发因素、发育分布等特征,并以县、市为基本单元,利用地质灾害点密度、体积密度和面密度3个指标,对已调查县、市进行了地质灾害发育程度的评价。评价结果分为4个等级,其中地质灾害高发育县市30个,集中分布在重庆、贵州、湖北、甘肃、四川和云南等省;地质灾害较高发育县市107个,集中分布在湖南、江西、陕西、四川、贵州、湖北、云南和重庆等省市;地质灾害中等发育县市90个,集中分布在河北、四川、浙江和福建等省;地质灾害轻微发育县市62个,集中分布在河北、广西、新疆和山西等省。  相似文献   

4.
系统论述了四川什邡马槽滩河西磷矿区的主要地质灾害问题,分析了其产生的原因及危害,对其稳定性进行了评估,在此基础上提出了矿区地质环境恢复治理思路,对当前影响最严重的崩塌落石灾害提出了箱型明洞的治理方案.  相似文献   

5.
安宁河流域地处川西南山区,安宁河平原是四川的第二大粮仓.区内地质构造复杂,岩体破碎,生态环境脆弱;加之,人类工程活动日趋强烈,流域内地质灾害成为地方经济发展的重要制约因素.本文通过对449个地质灾害点的分析,讨论了安宁河流域地质灾害的主控因素及发育、分布规律,为科学合理地评价预测地质灾害的发展趋势与可能造成的危害提供了科学依据.  相似文献   

6.
管道地质灾害具有独特的发育类型和危害特征。论文结合忠武管道和川气东送管道沿线地质灾害调查结果,总结了山区管道地质灾害的主要发育类型,探讨了不同地质灾害对管道的危害特征及灾害作用下管道的变形破坏行为,同时结合各类管道地质灾害的危害特性综述了基于不同地质灾害作用的主要管道保护措施。  相似文献   

7.
延安市宝塔区崩滑地质灾害发育特征与分布规律初探   总被引:9,自引:0,他引:9  
宝塔区地质灾害发育特征是数量多、密度高、变形模数大,规模以中小型为主.滑坡平面形态典型、剪出口高,基本力学模式简单;崩塌规模小、危害大、变形模式多样;不稳定斜坡坡度跨度大、坡形以直线型为主,潜在危害严重;诱发因素清楚、宏观前兆相对明显、可预防性较强.地质灾害在空间上集中分布在四区和三带内,在时间上集中在雨季.  相似文献   

8.
徐州城区是岩溶塌陷地质灾害危害严重的区域,已发生的塌陷均展布在废黄河断裂带内,有明显的规律性,为断裂带地下水富集区过量抽水所造成。研究表明,废黄河断裂带内岩溶发育,发育有向上开口的溶洞和裂隙,断裂带沟通了不同时代的含水层,形成了地下水强径流带或富集带;地堑式断裂带构成的负地形形成了晚更新世和全新世古河道,古河道区域形成"单一透水型盖层"和"透-阻型盖层",使黄河泛滥沉积的砂性土直接覆盖在岩溶含水层上,为过量抽水发生岩溶塌陷提供了重要水动力条件。因此,废黄河断裂带及其伴生断裂控制了岩溶塌陷的形成条件,特别是岩溶发育强度、岩溶水文地质结构和地下水富集规律。  相似文献   

9.
本文主要以G580线阿热勒至和田公路地质灾害为研究对象,对研究区内地质灾害的发育类型、危险性现状和预测进行了评估。研究结果表明:区内崩塌、滑坡、泥石流、采空塌陷、地裂缝、地面沉降等地质灾害不发育,其他地质灾害主要以风蚀沙埋和土壤盐渍化;现状研究区内地质灾害均发育程度弱,危害程度小,危险性小;预测评估工程建设引发或加剧地质灾害的可能性小,危害程度小,发育程度弱,危险性等级小。  相似文献   

10.
陇南市地质灾害发育规律及其影响因素   总被引:1,自引:0,他引:1       下载免费PDF全文
陇南市地质灾害的发育与危害全国闻名,研究程度也较高,本文在总结和分析前人对该区地质灾害研究资料的基础上,结合1999年以来国土资源部开展的县(市)地质灾害调查与区划成果,分析该区地质灾害的空间与时间上的发育规律,从地质条件、降水条件及人为因素等诸多条件对其成因进行了总结。  相似文献   

11.
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.  相似文献   

12.
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″.  相似文献   

13.
14.
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.  相似文献   

15.
16.
摩擦桩基桩土间极限摩阻力取值问题探讨   总被引:1,自引:0,他引:1  
陈银生 《世界地质》1999,18(1):54-59
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。  相似文献   

17.
从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返   总被引:4,自引:1,他引:4       下载免费PDF全文
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。  相似文献   

18.
某高速公路下伏煤矿采空区稳定性分析   总被引:10,自引:0,他引:10  
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。   相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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