浅析公路边坡防护与加固   总被引：1，自引：0，他引：1  

樊占平 《中国勘察设计》2009,(6):66-68

介绍了公路边坡防护与加固的类型,对各类防护与加固方法的优缺点进行了分析,并结合隆昔公路的工程实践提出意见和建议。  相似文献   

岭澳核电三期强风化角岩边坡岩体直剪试验研究     

鲁祖德  陈从新  陈建胜  童志怡  左保成  戴旭明 《岩土力学》2009,30(12):3783-3787

采用堆载法进行天然状态与饱和状态下强风化角岩边坡岩体的现场直接剪切试验,获得不同正应力水平下剪切应力-剪切变形关系曲线和剪切强度参数,对其剪切应力-剪切变形关系曲线特征和不同正应力作用下剪应力随正应力的变化规律以及水-力耦合作用对剪切强度与变形特性影响进行了分析。试验结果表明：岩体峰值剪切强度和屈服剪切强度均随正应力的增大而增大;天然状态和饱水状态下剪应力随不同正应力的变化趋势基本相同;岩体剪切强度随含水率的增大而减小,在低法向应力下尤其敏感;水对岩体强度参数中黏聚力c的弱化作用更加明显,同时加大了岩体变形量,延长了岩体变形过程;通过现场直剪试验测得的法向变形可以估算岩体的压缩模量,为边坡稳定性分析提供参数。  相似文献   

黄土高边坡稳定性影响因素分析 ——以宝鸡峡引水工程为例   总被引：3，自引：1，他引：2  

王俊卿  李靖  李琦  陈立 《岩土力学》2009,30(7):2114-2118

黄土高边坡稳定性受多种因素影响,对高边坡稳定性影响因素进行敏感性分析非常必要。通过建立合理的计算模型,采用灰色关联度法,对影响宝鸡峡引水工程黄土高边坡稳定性的主要因素进行了分析。结果表明,土体的内摩擦角和黏聚力对其稳定性影响最大;采用正交实验分析可知,除土体的内摩擦角、黏聚力和坡高外,地震作用对黄土高边坡稳定性的影响也较大。以上分析表明,抗剪强度指标是影响黄土高边坡稳定的主要敏感性因素,提出了在黄土高边坡稳定性分析时应尽量使抗剪强度指标的选取准确、合理,同时也应考虑边坡高度和地震的影响,进而为黄土高边坡类的工程设计和运行管理提供重要参考。  相似文献   

热处理天然金红石的微结构研究   总被引：1，自引：0，他引：1  

庄伟  罗泽敏  刘迎新  吴婧  秦善  鲁安怀 《岩石矿物学杂志》2009,28(6):629-636

利用粉晶X射线衍射(XRD)、透射电镜(TEM)等分析手段对在氩气气氛中加热、退火的天然金红石样品的微结构进行了研究.研究表明样品在热处理后,晶格发生膨胀,并且在900 ℃和1000 ℃的样品中出现了钛铁矿物相.钛铁矿也是一种天然半导体矿物,沿与金红石(010)面网成大约31°夹角的方向生长,与金红石形成了二元复合半导体.紫外漫反射实验结果表明热处理后,金红石中出现的钛铁矿相有效地促进了光催化效果.  相似文献   

Overpressure within upper continental slope sediments from CPTU data,Gulf of Lion,NW Mediterranean Sea     

S. Lafuerza  N. Sultan  M. Canals  J. Frigola  S. Berné  G. Jouet  M. Galavazi  F. J. Sierro 《International Journal of Earth Sciences》2009,98(4):751-768

Data from in situ piezocone tests (CPTU) and laboratory analyses are utilized for the interpretation of the stress history of Quaternary sedimentary sequences in the upper continental slope of the Gulf of Lion, northwestern Mediterranean Sea. A CPTU based preconsolidation pressure profile referenced to the current effective stress indicates that the deposit is underconsolidated from 12 meters below the seafloor (mbsf) down to at least 150 mbsf. Excess pore pressure below 12 mbsf is further supported by results from oedometer and dissipation tests. Subseafloor pockmarks and indications of free gas in seismic reflection profiles reveal four main overpressure sources (SI–SIV) with overpressure ratios >0.3 at subseafloor depths coinciding with levels where the dominantly silty-clayey sediment contains increased proportions of sand. We relate the excess pore pressure related to free gas due to gas exsolution processes and sea level variations driven by Pleistocene sea level changes.  相似文献   

Sustainability Through an Alternative Property‐Rights Regime for Bangladesh's Mangrove Forest     

Anjan Kumer Dev Roy  Khorshed Alam  Jeff Gow 《Geographical review》2013,103(3):372-389

This study examines the challenges of achieving sustainable management of the world's largest mangrove forest, the Sundarbans, in Bangladesh. The Sundarbans is currently managed by the Bangladesh Department of Forest, under a state property‐rights regime, while our study explores an alternative property‐rights regime. We employed a mixed‐method approach to examine the prospects of alternative management and livelihood strategies to achieve sustainability. Both focus groups and household surveying were used to assess the opportunities for, and barriers to, achieving sustainability. It was found that two conflicting groups—forest‐dependent communities and foresters—are responsible for policy failures due to the absence of power‐sharing arrangements, nor is it likely a common property‐rights regime will be enough to cap degradation and achieve sustainability, while supply‐and‐demand policy interventions may well could help achieve sustainable management of the Sundarbans.  相似文献   

帕默尔干旱指数在天山北坡典型绿洲干旱特征分析中的适用性   总被引：2，自引：0，他引：2  

刘卫国  王曼  丁俊祥  吕光辉 《中国沙漠》2013,33(1):249-257

以天山北坡为实验区,采用2002-2008年精河、乌苏、石河子、蔡家湖4个气象站的气象数据,进行月的水分平衡及其各分量的多年平均值计算,然后计算各气候常数;基于气候常数计算气候适宜蒸散量、气候适宜补水、气候适宜径流量、气候适宜失水量,确定月正常气候所需的水量,即气候适宜降水量;进而计算水分距平,最终确定研究区的帕默尔干旱指数.对帕默尔干旱指数与本地的历史文献记录的实际干旱情况进行对比,验证了帕默尔干旱指数模式的可应用性,并得出了研究区内4站点的帕默尔干旱指数计算公式,根据该指数计算的结果与实际的旱情记录相符合.  相似文献   

Dangerous deformations of subgrade and methods of their calculation     

Alexander Isakov 《寒旱区科学》2013,5(4):0353-0362

The main reasons for a breach of trouble-free operation of the subgrade are the different kinds of deformation, such as train load impact on subgrade surface, loss of stability to subgrade slope, weight of embankment on the base, and partial or complete failure of the railway track due to frost heaving. This paper gives a summary of deformation analysis methods being developed in Russia to estimate the operating conditions of the railway subgrade.  相似文献   

A large landslide event in a post‐glacial landscape: rethinking glacial legacy     

Timothy R. H. Davies  Jeff Warburton  Stuart A. Dunning  Alodie A. P. Bubeck 《地球表面变化过程与地形》2013,38(11):1261-1268

Threlkeld Knotts (c. 500 m above sea level) in the English Lake District has hitherto been considered to be a glacially‐modified intrusion of microgranite. However, its surface features are incompatible with glacial modification; neither can these nor the subsurface structures revealed by ground‐penetrating radar (GPR) be explained by post‐glacial subaerial processes acting on a glacially‐modified microgranite intrusion. Here we re‐interpret Threlkeld Knotts as a very large post‐glacial landslide involving the microgranite, with an estimated volume of about 4 × 10⁷ m³. This interpretation is tested against published and recent information on the geology of the site, the glacial geomorphic history of the area and newly‐acquired GPR data. More than 60 large post‐Last Glacial Maximum (LGM) rock–slope failures have significantly modified the glaciated landscape of the Lake District; this is one of the largest. Recognition of this major landslide deposit in such a well‐studied environment highlights the need to continuously re‐examine landscapes in the light of increasing knowledge of geomorphic processes and with available technology in currently active or de‐glaciating environments. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Effects of terrain attributes on snow-cover dynamics in parts of Chenab basin,western Himalayas     

Retinder Kour  Akhouri Pramod Krishna 《水文科学杂志》2013,58(10):1861-1876

ABSTRACT

Terrain variables are the main factors affecting the spatial distribution of snow cover. This paper aims to find a relationship between snow-cover area (SCA) and topographic variables (elevation, slope and aspect), using MODIS Terra data (MOD09A1) in parts of the Chenab basin, western Himalayas. The inter-annual variability of SCA% for each month has been analysed for the years 2000 to 2011. The analysis reveals that mean annual SCA value was maximum (37.89%) in 2005 and minimum (32.07%) in 2001. The slope classes with maximum and minimum SCA% are 5°–10° and 30°–35°, respectively. Among the 16 aspect classes, the ESE-facing slope evinces maximum SCA%. During the snow accumulation period, the expanse at 3600–4300 m elevation, and in the depletion period, 4300–5000 m elevation are found to have maximum rate of change in SCA% per 100 m rise in elevation, i.e. 3.37% and 3.67%, respectively.