首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
段青龙 《冰川冻土》2003,25(8):20-23
通过对青藏铁路那曲丘陵区路堑地下水特征及影响因素的分析,研究了地下水对工程的危害,并就防治地下水对路堑的危害提出了工程处理措施。  相似文献   

2.
地下水对岩土工程的危害及预防   总被引:1,自引:0,他引:1  
王道炀 《吉林地质》2009,28(2):71-73,78
地下水问题在工程勘察设计和施工过程中,始终是一个极为重要而又易于被忽视的问题。本文提出了地下水的危害及其解决措施,为工程设计和施工提供必要的水文地质资料,以消除或减少地下水对岩土工程的危害。  相似文献   

3.
路堑边坡工程的动态仿真分析   总被引:5,自引:2,他引:5  
晏鄂川  唐辉明  何淼 《岩土力学》2004,25(2):246-250
高速公路建设中不可避免地会遇到各种结构类型的斜坡,其稳定性状况在很大程度上决定了工程的投资和工期。因此,研究其工程适宜性具有较大现实意义。从影响路堑边坡稳定性的各种因素出发,应用岩体力学理论和数值模拟技术研究边坡开挖过程中的变形破坏特征,分析地下水、时效特性和工程措施优化等对边坡稳定性的影响,对边坡信息化设计和施工具有一定指导意义。研究表明,路堑边坡岩体的变形破坏特征符合卸荷岩体力学行为,在最优坡度设计基础上,应当及时进行加固。  相似文献   

4.
地下水对建筑物基础腐蚀是发育广泛、速率缓慢的地质灾害,它对红层区城市基础工程危害尤显突出。以天水市的红层区为例,利用长期积累的大量地下水化学资料,探讨了腐蚀性地下水的成因,提出了防治地下水对建筑物基础腐蚀的对策。  相似文献   

5.
工程地质勘查是施工的前提和基础,水文地质问题是地质勘查的重要内容,水文地质的稳定性直接影响到岩土工程的稳定性。本文在阐述分析地下水位下降、地下水位上升对岩土工程的危害的基础上,提出建立健全管理制度、加强地下水监测、引进新技术新设备、合理开采地下水等水文地质灾害的防治措施,避免水文地质灾害对工程的危害。  相似文献   

6.
为解决天津某地铁出入段线地下水位较高、或受场地限制及某些特殊原因所不允许的降低地下水的路堑工程问题,地下隧道与地上路基连接段采用U型结构通过。针对场地工程地质条件和水文地质特征,同时结合国内多项工程实例,确定该工程U型结构横断面形式,边墙及底板的计算模型,对结构受力、配筋进行分析和计算; 对裂缝宽度、抗浮稳定性进行验算; 选取基坑围护及地下水控制措施。计算模型边墙按悬臂梁、底板按弹性地基梁选取,结构按最不利荷载组合进行配筋计算; 同时采用管井降水+止水帷幕对地下水进行控制。计算及验算结果均满足设计要求,工程措施选择合理,可为同类工程设计提供借鉴和参考。  相似文献   

7.
依托元江至蔓耗高速公路(红河段)项目,对红河县境内具有代表性的深挖路堑高边坡病害产生的原因进行分析,通过对路堑高边坡工点现场调研及理论分析,得出了路堑高边坡破坏的原因及影响因素,并对路堑高边坡病害进行有效的防护措施,且取得了很好的防护效果。其工程经验可对类似路堑高边坡破坏分析及防护提供参考价值。  相似文献   

8.
《地下水》2017,(5)
地下水对边坡工程的稳定性和施工安全性有着重要影响,针对《高速公路路堑高边坡工程施工安全风险评估指南》中地下水指标的取值范围展开讨论,分析地下水影响机制并采用Geo-Slope数值模拟三类边坡类型的地下水位线对边坡稳定性的影响,得出结论,(1)《指南》中对地下水指标的定义是模糊的;(2)地下水位位于边坡中部及其以下时,地下水位的上升对边坡稳定性影响不大,施工安全风险较低;水位高于边坡中部后,其对边坡稳定性的影响显著增强,施工安全风险亦然。(3)建议将地下水水位作为分级取值依据,并将边坡中部及其以下划为一级,边坡中部以上根据线性插值进行分级。  相似文献   

9.
顺层岩质路堑边坡稳定性的敏感性因素分析   总被引:3,自引:0,他引:3  
龚文惠  王平  陈峰 《岩土力学》2007,28(4):812-816
运用弹塑性理论和有限元法,建立了顺层岩质路堑边坡稳定性的模拟分析模型。结合沪蓉国道主干线湖北宜昌至恩施高速公路的顺层岩质路堑高边坡工程,分析了结构面强度、岩层厚度、岩层倾角等各项因素对顺层岩质路堑边坡稳定性的影响,探讨了顺层岩质路堑边坡稳定性的规律。结果表明:软弱结构面的强度参数对顺层岩质路堑边坡稳定性起主要控制作用,岩层倾角对顺层岩质路堑边坡的稳定性也有明显的影响。在该工程的地质条件下,当岩层倾角为38°左右时,顺层路堑边坡的稳定性最差。  相似文献   

10.
地下水硝酸盐污染与治理研究进展综述   总被引:20,自引:0,他引:20  
毕晶晶  彭昌盛  胥慧真 《地下水》2010,32(1):97-102
地下水的硝酸盐污染是全球所面临的一个日益严重的问题,对硝酸盐污染的地下水修复技术的研究也自然成为近年来国内外学者研究的热点。就地下水硝酸盐污染的机理和途径、对人体及其它生物的危害以及修复技术等方面作了详细介绍,另外,就地下水硝酸盐污染的治理引用了工程实际加以说明。最后指出了未来地下水硝酸盐污染治理研究的方向。  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.
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.  相似文献   

13.
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   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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。  相似文献   

17.
18.
19.
郯庐断裂南段研究进展与断裂性质讨论   总被引:13,自引:3,他引:13  
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。  相似文献   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号