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211.
2009年8月8日莫拉克台风重创南台湾,嘉义阿里山区72 h的累积雨量高达2 500 mm以上,百年历史的阿里山森林铁道因沿线路基严重流失而停驶。其中两处大崩塌路段的复建工程以顺应自然为原则,采取迂回隧道方式避开崩塌区,需克服沿线地质变化及地下水问题,评估结果是以凿岩机工法及钻爆工法进行开挖。两座隧道的西口段崩积层分别长达109.8、99 m,是隧道开挖阶段的关键地段。隧道开挖支撑设计系依据台湾岩体分类与支撑系统(PCCR系统)及新奥工法的理念,沿线采用先进支撑材料包括超前管棚钢管、桁型钢支护、钢纤维喷射混凝土及自钻式锚杆等,除了可确保施工安全外,亦可提高施工进度。目前两隧道均已贯通且变形量控制均符合安全,说明隧道采用先进支撑方式穿越破碎崩积层段的成效良好,其研究结果可为相关工程设计提供参考。 相似文献
212.
The temporal and spatial variability of the Yellow Sea Cold Water Mass in the southeastern Yellow Sea, 2009-2011 总被引:1,自引:1,他引:0
The Yellow Sea Cold Water Mass(YSCWM) is one of the important water mass in the Yellow Sea(YS).It is distributed in the lower layer in the Yellow Sea central trough with the temperature less than 10 C and the salinity lower than 33.0.To understand the variability of the YSCWM,the hydrographic data obtained in April and August during 2009–2011 are analyzed in the southeastern Yellow Sea.In August 2011,relatively warm and saline water compared with that in 2009 and 2010 was detected in the lower layer in the Yellow Sea central area.Although the typhoon passed before the cruise,the salinity in the Yellow Sea central trough is much higher than the previous season.It means that the saline event cannot be explained by the typhoon but only by the intrusion of saline water during the previous winter.In April 2011,actually,warm and saline water(T >10 C,S >34) was observed in the deepest water depth of the southeastern area of the Yellow Sea.The wind data show that the northerly wind in 2011 winter is stronger than in 2009 and 2010 winter season.The strong northerly wind can trigger the intrusion of warm and saline Yellow Sea Warm Current.Therefore,it is proposed that the strong northerly wind in winter season leads to the intrusion of the Yellow Sea Warm Current into the Yellow Sea central trough and influenced a variability of the YSCWM in summer. 相似文献
213.
土壤和白菜中低分子量有机酸的气相色谱分析 总被引:4,自引:0,他引:4
利用甲醇-硫酸混合液(体积比10∶7)对土壤和白菜中低分子量有机酸同时进行提取和甲酯化衍生,然后利用二氯甲烷液-液萃取,气相色谱法分析。土壤中7种低分子量有机酸(草酸、丙二酸、反丁烯二酸、琥珀酸、马来酸、L-苹果酸、柠檬酸)的添加回收率为81.93%~95.58%,白菜中的添加回收率为84.78%~106.99%,方法的检出限为0.72~4.14 mg/kg。方法用于测定根际、非根际土壤和白菜根系、茎叶中的低分子量有机酸,结果准确可靠。 相似文献
214.
曾文水库保护带泰山滑坡之调查与治理 总被引:1,自引:0,他引:1
崩塌与滑坡灾害之治理,首重破坏诱因了了解与破坏机制之调查。再根据调查观测所得之资料与参数,着手进行设计适当之防治对策,方能得到良好的治理成效。泰山滑坡位于台湾南部极重要之曾文水库的保护带。其边坡由陆陆续续的崩陷而逐渐演变为坍滑,甚至造成交通中断受阻。调查发现本区为属浅层滑动,滑动区平面类似酒瓶状,主要原因为长期受到雨水之漫流与渗透软化的影响,加上蚀沟之切割淘刷作用,使得边坡容易失去支撑而滑动。经施以经济有效的蚀沟控制工程兴建多座潜坝,跌水与排水设施后,发现确定提高了边坡之稳定性,地区产业因而可以持续动作,是一次相当成功的治理案例模式,但由于施工便道之开 当,遂再度诱发部份边坡的坍滑,故尔后之维护管理工作极为重要。 相似文献
215.
Storm-influenced siliciclastic and carbonate ramp deposits, the Lower Ordovician Dumugol Formation, South Korea 总被引:4,自引:0,他引:4
The Dumugol Formation (Lower Ordovician) in the southern part of the Baegunsan syncline, South Korea, contains mixed siliciclastic and carbonate ramp deposits. The ramp sediments were frequently influenced by storm events resulting in tempestites of sandstone-mudstone couplets, bioclastic grainstones to packstones, flat-pebble conglomerates, a skeletal lag layer and laminated calcisiltites. All tempestites are characterized by an erosive to sharp base, poor grading and a transitional upper boundary. The difference in lithology of tempestites appears to have been controlled by the nature of substrates and by proximality. For example, laminated calcisiltites have developed on the shallow carbonate ramp, flat-pebble conglomerates are closely associated with nodular limestones on shallow and deep ramps, and thin skeletal lag layers from fossiliferous argillaceous sediments formed in a basinal setting. The stratigraphic succession of the Dumugol Formation represents an initial transgression followed by a regression. The vertical facies change records the transition from a shallow siliciclastic ramp to a deep carbonate ramp, to a basin, shallowing to a deep carbonate ramp, and to a shallow carbonate ramp. Storm effects are mostly well preserved in shallow to deep ramp deposits. 相似文献
216.
Meitien is one of the largest villages in Ichanghsien, Hunan, and is situated about 20 km. west-southwest of the Ichang City. The well-known Chitienling (騎田嶺), one of the "Five Ranges" of the Nanling, stands on the north side of Meitien, at a distance of 相似文献
217.
T. LEE 《Geophysical Prospecting》1975,23(4):653-662
The transient electromagnetic fields observed by the MPPO-1 equipment in practice over geological structures cannot always be adequately explained by Maxwell's equation when the imaginary part of the conductivity of the rocks is neglected. If, for any reason, the conductivity of the rocks is a complex function of frequency such that the imaginary part is appreciable the model calculations must include this. This explains why some observed transient electromagnetic decay curves change sign with time. 相似文献
218.
为便于在大陆上研究板块构造,作者提出了几项原则,作为参考:1.板块接触带时常表现为一条大断层或断裂带,延伸至少数百公里,经常超过一千公里;2.在两个相邻的板块上,沉积岩相和古生物群有显著的划分;3.有混杂堆积的出现;4.有蛇绿岩带的出现;5.有蓝片岩的出现;6.侵入岩与喷出岩具有规律性的分布;7.地震震中的分布;8.两个相邻板块所指极向的不同移动轨迹. 根据上述原则,结合中国地质情况进行分析,作者认为我国有几条山脉和地区可能是板块构造接触带.这些是:1.秦岭东西构造带,2.台湾省东岸,3.西藏的雅鲁藏布江,4.金沙江上游,5.龙门山及“康滇地轴”,6.祁连山北部边缘. 在工作中也遇到了以下几个有待进一步研究的问题:1.大陆板块对大陆板块互相碰撞的说法,似应作一定的修改.因为几乎所有大陆上的俯冲带都是沿着地槽的一边或两边发生的,而不是两个大陆板块直接相互接触.它和大陆边缘的海洋板块对大陆板块的移动,极为相似。2.超基性岩是否能侵入到大陆地壳,还是只能生成于地幔?3.如果说超基性岩只出现于地槽,则古老地块中有超基性岩出现时,是否可以说,这是以前地槽沉积的变质岩,而不是古老的岩浆岩体,例如秦岭的大华群和大别山的淮阳地盾等。 相似文献
219.
Petrogenesis of Mesozoic, Peraluminous Granites in the Lamoille Canyon Area, Ruby Mountains, Nevada, USA 总被引:5,自引:0,他引:5
LEE SANG-YUN; BARNES CALVIN G.; SNOKE ARTHUR W.; HOWARD KEITH A.; FROST CAROL D. 《Journal of Petrology》2003,44(4):713-732
Two groups of closely associated, peraluminous, two-mica graniticgneiss were identified in the area. The older, sparsely distributedunit is equigranular (EG) with initial 相似文献
220.
NUTRIENT LOAD ESTIMATION METHODS FOR RIVERS 总被引:2,自引:0,他引:2
Huai-en LI. Joseph Hun-Wei LEE Ming CM Professor Environmental Science Institute Xi''''an University of Technology. Xi''''an . Shaanxi P.R. China.Professor Department of Civil Engineering The University of Hong Kong Pokfulam Road Hong Kong.P.R. China Ph.D. student in Hydrology Water Resources. Environmental Science Institute Xi''''an University ofTechnology Xi''''an Shaanxi P.R. China 《国际泥沙研究》2003,18(4)
Pollutant load estimation is essential for watershed management and water pollution control. For most watersheds, only sparse water quality measurements (e.g. monthly data) are available. The influence of input data on the accuracy of non-point source pollution load estimation is studied using the water quality and stream flow data from a small watershed in Hong Kong. Comparison and analysis of the results using 8 different methods show that the accuracy of stream-flow runoff is the single most important factor for the calculation of pollutant load. Based on the results, the stream flow correction coefficient is advanced to provide a more reliable load estimation. The improved method of pollutant load estimation can be easily applied in practice since the stream-flow runoff can be measured by hydrological station or estimated with various hydrological methods. 相似文献