钻孔雷达反射成像在岩溶发育场地探测中的应用

我国岩溶区分布广泛,且复杂的岩溶现象对建筑安全、地基稳定以及场地勘察有较大影响。钻孔雷达作为一种井中地球物理方法,可以利用地下介质的物性差异查明岩溶发育的情况,弥补常规勘察手段在探测岩溶发育场地中存在的不足。依据钻孔雷达单孔反射信号的同相轴特征、反射波首波走时和反射波的衰减等特征,可判断钻孔周边未揭露溶洞和裂隙的分布,确定钻探揭露溶洞的水平方向直径以及岩石完整性,从而达到查明各种岩溶形态的规模、空间密度及其分布规律的目的,为工民建各项工程建设的设计和施工提供准确详尽的地质资料,确保工程的稳定性。      

山岭隧道工程综合地质勘察方法探讨

山岭隧道工程具有隐蔽性、施工复杂性、地层条件和周围环境不确定性等特点,采用科学的勘察方法,是查明隧道岩土体工程地质条件的有效手段。本文以海淀区西山隧道为依托,针对隧道工程勘察中的关键地质问题,运用工程地质测绘、钻探、工程物探、水文地质勘查等综合勘察方法,有效地查明隧址区的地质构造、岩土体结构和地下水分布特征,全面、客观地评价隧道进出口段边坡及仰坡稳定性、隧道围岩质量与稳定性、隧道涌水量、地应力及有害气体等工程地质问题,并针对不良地质现象提出防治对策,以期为工期紧张、地形困难且日趋增多的山岭隧道工程地质勘察,提供可以借鉴的模式和方法。     

基于井中超声波成像的岩溶特征高精度探测和评价

复杂的岩溶作用经常制约着人类工程建设.为了避让岩溶不良地质体,如何对岩溶发育特征更准确地探测和评价,是岩溶工程地质勘察面临的难题之一.通过利用钻孔超声波成像技术,高精度刻画钻孔揭露的岩溶现象,并在钻孔线岩溶率的基础上提出"孔壁岩溶率"的概念,将岩溶率的一维空间表达扩展到二维空间,为岩溶区工程建设提供更精细化的基础数据....     

六沾复线梅花山至天生桥线路方案地质选线

贵昆铁路六沾复线梅花山至天生桥段穿越梅花山主脉,地形、地质条件极其复杂,地质构造、不良地质及特殊岩土极其发育,为铁路选线、设计及施工带来极大困难。通过综合地质勘察方法与手段,基本查明了区域内的工程地质特征及各线路方案的工程地质条件,为线路方案的比选提供了可靠的基础地质资料。影响选线的关键地质因素主要为沿观音河、树舍沟成群分布的滑坡、岩堆及危岩落石、深埋长隧的岩溶与岩溶水危害、煤窑(矿)采空区。通过对梅花山至天生桥段长隧方案、短隧方案、观音河出露方案工程地质条件综合定性分析、工程数量及投资比较,比选推荐了观音河出露方案以乌蒙山一号、二号隧道穿越梅花山主脉,地质条件较好,施工安全性较高,施工、运营后效果良好。     

基于地下水流系统理论的岩溶隧道涌突水来源及路径分析

双龙洞是国家重点风景名胜区,拟建金华山隧道位于浙江省金华市双龙洞景区北东向约12 km处,金华山隧道的开挖将可能导致双龙洞景区岩溶水的疏干,同时隧道也可能遭受岩溶涌突水的安全隐患.基于地下水流系统理论,结合研究区水文地质条件调查成果,岩溶地下水流系统的划分,隧道出口段关键岩溶分布区地质结构的分析,以及水文地球化学测试分...     

综合物探方法在广州市金沙洲岩溶地面塌陷、地面沉降地质灾害调查中的应用

综合运用跨孔地震CT、探地雷达、高密度电阻率法、浅层地震反射波、土壤氡浓度和波速测试6种物探方法,对广州市白云区金沙洲岩溶地面塌陷、地面沉降地质灾害进行探测,查明了该区的溶洞、土洞及构造破碎带的分布。介绍了各种方法技术,对综合物探成果进行总结,结合实例说明综合物探方法在该区的应用取得了显著效果,为地质灾害防治提供了基础地质资料。在广花盆地岩溶发育区,首次应用跨孔地震CT探测建筑物地下岩溶分布,为评价受岩溶地质灾害影响的建筑物安全提供依据。     

探地雷达在隧道岩溶普查中的应用

通过在广西岩溶地区实测的岩溶地区典型雷达剖面,介绍了探地雷达在查明隧道岩溶性质及空间发育形态上所取得的实际效果,提出了在实际应用中需要注意施工环境和旁侧影响的问题.     

京珠线湖北省南段岩溶地质问题与勘察对策

岩溶问题是京珠国道湖北南段主要的工程地质问题.通过对京珠国道南段岩溶的地质背景、发育因素、发育程度的分析与研究, 采用工程地质测绘、物探和钻探相结合的综合勘察方法, 有效地查明了岩溶的空间分布特征、发育规律和溶洞间的相互关系, 为工程设计提供了准确可靠的依据.      

电法三维成像技术在隧道岩溶探测中的应用

南石壁高速公路隧道在雨季出现渗水现象,严重影响公路的畅通,存在安全隐患。为查明其渗水路径和水源,采用不同高密度电法测量装置进行实地测量,运用三维电阻率成像技术,结合当地地质条件和现场调查资料,分析隧道围岩的渗水情况,结果表明:高密度电法野外工作采用不同的测量装置,利用各自跑极方式的不同,在成果解释中能达到相互补充的效果;南石壁隧道围岩中内部岩溶裂隙强烈发育;岩溶水主要来自梅岭水库渗漏和雨水补给,并探明了几条主要的渗水路径。该案例说明高密度电法三维电成像技术揭示的地下地质结构,对岩溶灾害的探测、处治具有十分重要的意义。      

西南某山区高速公路岩溶隧道的涌水灾害危险性研究

西南某山区高速公路越岭岩溶隧道所处区域地质环境条件复杂,全段不仅存在通过岩溶进行地下水近、远程补给而发生涌水突泥的风险,而且勘察发现进口段存在岩溶管道与临近龙湖存在水力联系,存在湖水倒灌的风险。因此,本文以隧道近场区地质建造和构造改造格架为分析物质基础,以地质作用过程机制为分析方法,通过调查、物探及钻探等手段基本查明隧址区环境地质条件,在此基础上建立水文地质原型,对地下水、地表水的补径排关系和渗流场特征,及岩溶空间展布特征展开分析研究,定性到半定量地进行了隧道涌水危险性预测评估,并以评价成果为依据对原隧道平纵布置进行了调整,以进一步降低建设和运营期间的涌水突泥危险性。     

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.     

Report of the restudy of the defined global stratotype of the base of the Silurian System

The Global Stratotype Section and Point （GSSP） for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy （SSS） proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy （ICS）. The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob＇s Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs.     

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″.     

The Tendencies of the Development of the Mineral-Resources Sector at the Turn of the Century

Important tendencies in development of the world mineral-resources sector at the beginning of the 21st century were an increase in production and consumption of mineral materials differentiated by types of metals and nonmetallic mineral raw materials, by countries and regions, as well as the concentration of the production of mineral raw materials in a small number of countries, and a reduction in industrial reserves of minerals in the world economy, even at the current stage of their extraction. These tendencies should be taken into account in working out a strategy for development of the Russian mineral raw-material base.     

Causes of the famine among the rural population of the Sahelian zone of the Sudan

Taking the example of W Sudan, an analysis of the climatic incidents leading to the two recent famine disasters is made. On this natural background, the human side is investigated. Focus is directed towards the fragile economic structure of the famine-prone population groups. An early-warning system for famine in the Sahelian Zone is proposed taking grain production and storage, livestock development and the relationship between the prices of livestock and grain as major indicators.     

东濮凹陷北部沙河街组三段中亚段沉积环境分析

东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。     

郯庐断裂南段研究进展与断裂性质讨论

据1：5万区域地质调查和专题研究资料，就郯庐断裂带是否南延与消失的原因，其与大别—苏鲁造山带交截形成的假位错效应，以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上，讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。     

The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads

In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning.