粉质粘土中的桩承载性能分析     

陈安  彭振斌  杜长学  张玉池  刘靓 《矿产与地质》2006,20(2):187-190

应用桩静载荷试验和数学分析的方法,对粉质粘土层中的桩的承载性能进行分析研究。结果显示,粉质粘土层中的桩的侧摩阻力标准值为37.6kPa,桩的端阻力标准值可达3.34M Pa,位于粉质粘土层中的桩端阻力占桩承载力的50%±,桩为端承摩擦桩,而非纯摩擦桩,且桩的承载力较高,沉降变形小,可以满足一般建筑物的荷载需求,设计时应充分挖掘该土层的潜力。  相似文献   

Management of karst water resources in mining area: dewatering in mines and demand for water supply in the Dongshan Mine of Taiyuan, Shanxi Province, North China   总被引：6，自引：0，他引：6  

Qiang Wu  Wanfang Zhou  Duo Li  Zhiqiang Di  Ying Miao 《Environmental Geology》2006,50(8):1107-1117

Coalfields in North China contain six to seven coal seams in the Permo-Carboniferous strata. The coal seams are underlain by the Ordovician limestone. Large-scale dewatering or depressurizing of the karst aquifer was considered essential to avoid water inrushes and keep the mines safely operational. This practice, however, has caused water supply shortage in the mining areas. The most effective solution to this conflict is to use the uncontaminated karst water from the mines for water supply. This paper explores a management model to maximize the utilization of the karst water while maintaining the safe operation of the mines. The model can provide essential information on water resource distribution for decision makers. The model was applied to the Dongshan Coal Mine in Taiyuan City, China.  相似文献   

Groundwater quality monitoring in Italy for the implementation of the EU water framework directive   总被引：1，自引：0，他引：1  

G. Onorati  T. Di Meo  C. Fabiani  A. Fava  F. Mion  A. Martinelli 《Physics and Chemistry of the Earth》2006,31(17):1004-1014

In 1999 the Italian Parliament approved a law encompassing all the themes of the water cycle, including monitoring of groundwater. The new regulation takes into account the EU Directives, and charges the Regions to create monitoring networks, according to Art. 8 of the Water Framework Directive (WFD). The approach of the Italian regulation is, on the whole, coherent with the technical guidelines listed in annexes II and V of the WFD. On basis of the new law, the national environment agency (APAT) gathers data and produces assessment reports on the contamination of groundwater in Italy.  相似文献   

Using Rock‐Eval 6 pyrolysis for tracking fossil organic carbon in modern environments: implications for the roles of erosion and weathering     

Yoann Copard  Christian Di‐Giovanni  Thomas Martaud  Patrick Albric  Jean‐Emmanuel Olivier 《地球表面变化过程与地形》2006,31(2):135-153

This work relates to the debate on the fossil organic carbon (FOC) input in modern environments and its possible implication for the carbon cycle, and suggests the use of Rock‐Eval 6 pyrolysis as a relevant tool for tracking FOC in such environments. Considering that such a delivery is mainly due to supergene processes affecting the continental surface, we studied organic matter in different reservoirs such as bedrocks, alterites, soils and rivers in two experimental catchments at Draix (Alpes de Haute Provence, France). Samples were subjected to geochemical (Rock‐Eval 6 pyrolysis) investigations and artificial bacterial degradations. After comparing the geochemical fingerprint of samples, geochemical markers of FOC were defined and tracked in the different reservoirs. Our results confirm the contribution of FOC in modern soils and rivers and display the various influences of weathering and erosional processes on the fate of FOC during its exchange between these pools. In addition, the contrasting behaviour of these markers upon the supergene processes has also highlighted the refractory or labile characters of the fossil organic matter (FOM). Bedrock to river fluxes, controlled by gully erosion, are characterized by a qualitative and quantitative preservation of FOM. Bedrock to alterite fluxes, governed by chemical weathering, are characterized by FOC mineralization without qualitative changes in deeper alterites. Alterite to soils fluxes, controlled by (bio)chemical weathering, are characterized by strong FOC mineralization and qualitative changes of FOM. Thus weathering and erosional processes induce different FOM evolution and affect the fate of FOC towards the global carbon cycle. In this study, gully erosion would involve maintenance of an ancient sink for the global carbon cycle, while (bio)chemical processes provide a source of CO₂. Finally, this study suggests that Rock‐Eval 6 pyrolysis can be considered as a relevant tool for tracking FOC in modern environments. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Major-ion bulk deposition around an active volcano (Mt. Etna, Italy)     

A. Aiuppa  S. Bellomo  L. Brusca  W. D'Alessandro  R. Di Paola  M. Longo 《Bulletin of Volcanology》2006,68(3):255-265

Bulk atmospheric deposition of major cations (Na, K, Ca, Mg) and anions (Cl, F, SO₄) were measured at 15 sites around an active volcano, Mount Etna, from 2001 to 2003. Their composition indicates several natural sources, among which deposition of plume-derived volcanogenic gas compounds is prevalent for F, Cl and S. Plume-derived acidic compounds are also responsible for the prevailing acidic composition of the samples collected on the summit of the volcano (pH in the 2.45–5.57 range). Cation species have complex origin, including deposition of plume volcanogenic ash and aerosols and soil-dust wind re-suspension of either volcanic or carbonate sedimentary rocks. Variation of the deposition rates during the March 2001–March 2003 period, coupled with previous measurements from 1997 to 2000 (Appl Geochem 16:985–1000, 2001), were compared with the variation of SO₂ flux, volcanic activity and rainfall. The deposition rate was mainly controlled by rainfall. Commonly, about 0.1–0.9% of HF, HCl and SO₂ emitted by the summit crater's plume were deposited around the volcano. We estimate that ∼2 Gg of volcanogenic sulphur were deposited over the Etnean area during the 2002–2003 flank eruption, at an average rate of ∼24 Mg day⁻¹ which is two orders of magnitude higher than that typical of quiescent degassing phases.  相似文献   

随机方法模拟地震动的应用研究          下载免费PDF全文

董娣  刘锐  桑向国 《地震工程学报》2006,28(4):298-302

对随机方法模拟地震动的实际应用进行了研究。通过实际模拟验证,此方法简单有效,可为结构抗震设计提供验算依据,同时为设计反应谱的拟合提供参照数据,有一定的实用性,但仍存在一定的不足。  相似文献   

用爆破事件检验区域数字地震台网常规地震定位方法的定位精度     

王平  狄秀玲  李少睿  张春芳  李媛媛 《地震地磁观测与研究》2006,27(3):25-28

选取陕西省数字地震台网记录的2005年5月西安活断层探测爆破资料和2005年6月28日柞水铁矿爆破资料,运用数字地震台网地震速报及地震编目使用的3种常规地震定位软件,对12次爆破事件进行分析,将其定位结果与GPS测定的爆破位置进行对比,以此对地震定位系统的定位精度进行检验。  相似文献   

一种强雷雨天气预报因子的选取方法     

胡迪 《河南气象》2006,(2):29-30

利用极值剔除法,选取了预报武汉天河机场夏季强雷雨天气的5个因子。经检验发现,采用这些预报因子进行预报,可减少强雷雨天气的漏报率。  相似文献   

太旧高速公路周缘地区地震灾害损失预测与防震减灾对策     

兰青龙  安卫平 《华北地震科学》1998,16(2):37-44

概述了太旧高速公路周缘地区（１９个县市）的地震灾害。在寻建筑物的类型进行划分的基础上,用地震安全性评定的综合概率法计算每个单元遭遇烈度的概率,得到了各类建筑物的易损性矩阵,最后计算得出１９个计算单元所有建筑物的破坏数量和预期经济损失,并对计算结果进行了分析和比较,最后提出防震减灾对策。  相似文献   

根据IGRF计算1995～2000年中国及邻区地磁长期变化   总被引：2，自引：0，他引：2  

安振昌 《地球物理学进展》1998,13(3):79-82

根据最新的第七代国际地磁参考场,计算并绘制１９９５～２０００年中国及邻区地磁长期变化图,分析了长期变化的空间变化。  相似文献