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981.
In-situ data from cruises in the Pearl River estuary and adjacent marine areas were collected during March to May 2001. The absorption coefficients of the water color components were studied in detail containing total suspended matter (TSM), chlorophyll-a (chl-a), colored dissolved organic matter (CDOM), and de-pigment particles. For absorption coefficient of TSM, ap, and that of de-pigment particles, ad, correlations of ap(440)-TSM, ad(440)-TSM, ap(440)-chl-a and ad-chl-a were done (the italicized term means the concentration). There was a good correlation between ap(440) and chl-a concentration. An empirical relationship model between aph(675) and chl-a was developed showing a strong correlation of 0.93. Based on the two models the chl-a and aph(λ) were correlated. The values of calculated empirical spectral slope for CDOM absorption coefficients and that of de-pigment particles, 0.017 0 and 0.011 6 respectively, both are within a relative standard error of 10.0%. 相似文献
982.
边坡稳定性的神经网络预测研究 总被引:21,自引:0,他引:21
根据神经网络法的基本原理,结合38个实际边坡工程稳定实例,应用VB5.0可视化编程语言,建立了边坡稳定性的神经网络预测模型,并运用该模型对部分边坡工程的稳定性进行预测,预测结果与边坡实际稳定状态相吻合,从而表明了神经网络法在边坡稳定性预测中的有效性。 相似文献
983.
以龙塘山 2号大桥为工程背景 ,在综合考虑桥基岸坡的工程地质条件尤其是岩体结构的基础上 ,建立了数值分析模型 ,采用离散元法对该桥 10 #墩所处岸坡的破坏模式进行了模拟。模拟结果表明 :( 1)龙塘山 2号大桥 10 #墩所处岸坡基本稳定 ;( 2 )施工时 ,应对既有公路上方岸坡坡顶及坡面可能崩滑岩块进行预清除与加固 ;( 3)根据岸坡破坏趋势可得其稳定坡角为 5 0° 相似文献
984.
985.
Milena AMALIKOVA 《《地质学报》英文版》2001,75(3):303-307
The Moravian karst belongs to one of the famous karst regions in Central Europe. It is situated in Moravia in the eastern part of the Czech Republic. According to the geology it is of Devonian age and the main rocks are of different types of limestones. The process of karstification is still active. They are many caves with rich stalagmites and stalactites and the Macocha abyss, the depth of which is 138.5 m. The underground Punkva River flows through the main part of the karst, forming beautiful underground lakes. Typical karst phenomena, such as sinkholes and deep canyons, may be observed on the surface of the terrain. Because of the karstification, water erosion and frost weathering, many steep unstable slopes and walls originated. To solve the stability from a geotechnical point of view is not easy. This requests a special engineering-geological knowledge and experience. 相似文献
986.
Jeongi-Gi Um Pinnaduwa H. S. W. Kulatilake 《Geotechnical and Geological Engineering》2001,19(1):21-42
The granitic rock mass that exists in the shiplock region of the Three Gorges dam site contains a number of major discontinuities and about four sets of minor discontinuities. One hundred and thirty three major discontinuities have been mapped around the shiplock covering an area of 1740×600 m. These major discontinuities were used to perform rock slope kinematic and block theory analyses. Kinematic analyses were performed under the following two cases: (1) assuming all the mapped discontinuities cross the shiplock; (2) using only discontinuities that actually intersect the shiplock. Under case (1) and case (2) the shiplock faces in the proposed permanent shiplock region in fresh rock were found to be stable up to a cut slope of about 45° and 58°, respectively. Block theory was applied to identify different block types that exist on the shiplock faces and to estimate the maximum safe slope angles on the shiplock faces. The orientations of the major discontinuities that actually intersect the shiplocks were considered in this analysis. The total length of the shiplock (1750 m) was divided into 50 m segments. From the stereo-plots, the key blocks (Type I) and/or potential key blocks (Type II) were found for only five segments of the shiplock slopes. It was found that the dip of the cut slope should be less than about 60° to avoid creation of a key block on the proposed shiplock slopes. However, it is important to keep in mind that these conclusions are based on the kinematic analyses performed using only the major discontinuities. Further kinematic as well as kinetic analyses are recommended incorporating minor discontinuities, water forces, earthquake forces etc. before making the final conclusions about the maximum safe slope angle for the shiplock region. 相似文献
987.
李钟 《水文地质工程地质》2001,28(2):《水文地质工程地质》-2001年28卷2期-61-62.7页-《水文地质工程地质》-2001年28卷2期-61-62.7页
本文根据工程实例了软弱地层的基坑边坡支护方法,防止周边建筑物沉降变形的控制措施,邻潮防渗技术及残留 滞水的处理方法。 相似文献
988.
989.
陕西黄陵彬长矿区地质灾害的评价预测 总被引:4,自引:0,他引:4
通过对黄陵彬长矿区地质灾害类型、现状与特点的分析研究,确立了矿区地面塌陷、斜坡变形等各类地质灾害评价预测的原则与模型,依据评价预测的计算与分析结果,将矿区划分为稳定区、次稳定区、危险区和极危险区,确定出12个灾害段。 相似文献
990.
通过312国道蓝小二级汽车专用公路K37+580-K37+654段公路边坡的稳定性进行分析,提出了以预应力锚索支护为主的边坡治理方案,并对工程施工的有关技术要求进行了详细介绍。 相似文献