Simple monitoring method for precaution of landslides watching tilting and water contents on slopes surface

A low-cost and simple monitoring method for early warning of landslides is proposed. To detect abnormal deformation of a slope, this method employs a tilt sensor in place of an extensometer on the slope surface. In order to examine the relevance of measuring rotation angle on a slope surface by tilt sensor, model tests were conducted, and rotation on the slope surface was observed together with slide displacement along the surface. The rotation data responded 30 min before failure in a model test, which could be useful as a signal for early warning. However, the behavior of rotation before failure varies from case to case, and thus, criteria to issue warning should be defined more carefully. For a model slope made of uniform loose sand, measurement of slide displacement along the slope surface is sensitive to failure at the toe, while the measurement of rotation on the slope surface is useful to detect the development of progressive failure upward along the slope. Wireless sensor units with microelectromechanical systems (MEMS) tilt sensor and volumetric water content sensor were also examined on a real slope in Kobe City, and a long-term monitoring was attempted. A simple but possible way to define the criteria of judgment to issue warning can be proposed based on combination of data obtained by the tilt sensors and volumetric water content sensors.     

Runoff of the upper Yellow River above Tangnag: characteristics, evolution and changing trends

1 IntroductionThe basin above Tangnag is the principal area for runoff formation in the upper reaches of the Yellow River. For example, the runoff from the Tangnag Station occupies 95% of the inflow into the Longyangxia Reservoir, the largest reservoir on the upper Yellow River. So variations on runoff in the upper Yellow River above Tangnag have been very important for the utilization of the water resources in the entire Yellow River Basin. However, the runoff in the upper Yellow River…     

312国道蓝小二级汽车专用公路K37+580-K37+654边坡治理工程设计与施工

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。     

自然光辐射各分量卫星遥感图像的计算机生成原理与方法

本文讨论了利用卫星遥感数据和与之匹配的数字地面模型以及它们和光辐射各分量之间的定量关系，使用计算逐点分解遥感数字图像以生成成像瞬间直、散射辐射光照射下相应的卫星遥感图像的原理、方法。最后，阐述了生成的辐射各分量遥感图像特点和应用前景。     

边坡稳定离心模型试验中离心力分布不均匀的影响

边坡稳定离心模型试验中离心力分布不均匀会给试验结果带来误差。本文用圆弧滑动计算法探讨了这种误差的大小、影响因素及变化规律，提出了减少误差的措施。     

浙江省陈蔡群的^40Ar—^39Ar年龄与变质年代

本文对陈蔡群变质岩进行了４０Ａｒ－３９Ａｒ年龄测定。其中在诸暨陈蔡测得的４１５．１Ｍａ的坪年龄代表了主变质晚期的冷却年代。采自义乌尚阳的样品受燕山期火山活动影响有明显的氩丢失，与主变质有关的年龄亦明显降低，仅３１５．３Ｍａ。在龙泉东书获得的年龄谱和当地广泛发育的混合岩化作用有关，２７６．９Ｍａ的坪年龄为这次热事件的冷却年代。根据对现有年代资料的讨论，可以认为不同衰变体系记录了陈蔡群主变质事件的演化。Ｒｂ－Ｓｒ体系在变质早中期实现均匀化，年龄值为５５２．４～６６０．６Ｍａ。锆石、磷灰石在变质高峰期形成的铅丢失年龄为５０８，４～５７８Ｍａ。上述资料表明陈蔡群主变质年代属加里东期。     

定向井侧钻技术

结合我国首例定向井双重套管开窗例钻修井实例，详述了定向井侧钻工艺及其应用效果，介绍了提高定向井侧钻效率、降低成本的方法，指出定向井开窗成败主要取决于导斜器的安装方位。     

黄金珠宝首饰市场状况与四川宝石资源开发

介绍了黄金珠宝首饰的一些基本观念和近年来黄金珠宝市场的发展状况，指出１９９４年纯金饰品消费将会稳定增长，而且仍占主流，珠宝首饰市场会出现消费量增长，竞争日渐激烈，并由大中城市向中小城市扩展的趋势。就四川宝玉石普查找矿和开发利用提出了见解。