Experimental study on the dynamic modulus of compacted loess under bidirectional dynamic load

The dynamic characteristics of compacted loess are of great significance to the seismic construction of the Loess Plateau area in Northwest China, where earthquakes frequently occur. To study the change in the dynamic modulus of the foundation soil under the combined action of vertical and horizontal earthquakes, a hollow cylindrical torsion shear instrument capable of vibrating in four directions was used to perform two-way coupling of compression and torsion of Xi'an compacted loess under different dry density and deviator stress ratios. The results show that increasing the dry density can improve the initial dynamic compression modulus and initial dynamic shear modulus of compacted loess. With an increase in the deviator stress ratio, the initial dynamic compression modulus increases, to a certain extent, but the initial dynamic shear modulus decreases slightly. The dynamic modulus gradually decreases with the development of dynamic strain and tends to be stable, and the dynamic modulus that reaches the same strain increases with an increasing dry density. At the initial stage of dynamic loading, the attenuation of the dynamic shear modulus with the strain development is faster than that of the dynamic compression modulus. Compared with previous research results, it is determined that the dynamic modulus of loess under bidirectional dynamic loading is lower and the attenuation rate is faster than that under single-direction dynamic loading. The deviator stress ratio has a more obvious effect on the dynamic compression modulus. The increase in the deviator stress ratio can increase the dynamic compression modulus, to a certain extent. However, the deviator stress ratio has almost no effect on the dynamic shear modulus, and can therefore be ignored.     

油气管道工程中投影长度变形的处理

为了减小投影长度变形对油气管道工程的影响,对影响长度变形的每个因素进行了理论分析,并对不同位置和不同高程的投影长度变形进行了实际统计和数据分析,总结了投影长度变形的规律。针对油气管道工程的特点,分别对线路工程、穿跨越工程和场站工程提出了相应投影长度变形的不同处理方案,提高了测量成果的转换精度,避免了施工测量中烦琐的投影长度变形计算,为高精度施工提供了数据保障,同时也为水利、铁路、公路等线性工程测量提供了可借鉴的经验。     

铁屑微电解法深度处理医院废水

用铁屑微电池原理深度处理了医院废水 ,分析了废水pH、铁屑用量、反应时间对处理效果的影响。结果表明 ,最佳的反应条件为 :废水进水pH为 3.5 ,铁屑用量为 12 .5 % ,常温反应 80min。     

黄金新药源与豫西含金植物

黄金可以入药，历代本草均有记载。但因不溶性金被人体吸收极微，内服有一定毒性，加之其价格昂贵及一些药理学和比较复杂的检测处理与技术加工问题，不能普遍应用。自然界许多动植物都是聚金能手，特别是生长于富金岩石及金矿床风化土壤中的植物含金一般较高，部分动物因以含金植物为食，体内也含一定量的金，并且有些动植物本身就是中药材和食物。据此建议采取一定手段将含金较高、但未达工业品级的岩石，通过生物循环把金聚集至动、植物体内，金与动植物体内蛋白质等有机质结合成金的有机络合物，将此类动植物用于医疗或食疗，既可减小金的毒性，便于人体吸收，又可把未达工业品级的含金岩石利用起来。豫西某构造蚀变岩金矿，其上覆土壤中生长着含金植物，这些植物灰分中含金４×１０－９～９８×１０－９，其中以野苋菜的籽和叶灰分中含金最高（含金７５×１０－９～９８×１０－９），看来在本区用野苋菜籽和叶灰分中金含量进行找矿是可行的     

柴达木盆地东北缘地质灾害及防治

青海省柴达木盆地东北缘地貌类型复杂,新构造运动强烈,由各种内外应力造成的地质灾害具有类多、发生频繁等现象,集中反映在土地荒漠化、水土流失、草场退化、湖泊萎缩、地震、泥石流及滑坡等面,人类生存环境日趋恶劣。通过对该区各类地质灾害及生态环境现状进行评述,提出了治理建议。     

河南省马山口镇青山河泥石流灾害区首期治理工程竣工

针对河南省内乡县马山口镇青山河泥石流灾害防治工程的泥石流灾害现状、治理工程设计依据、工程设计标准、治理措施、工程效益等方面进行了论述。该项工程的竣工取得了较为显著的社会效益,成为中国地质调查局“典型地质灾害勘查与治理示范”工程。     

水源林区人工湿地污水处理技术的应用示范

针对水源林区的污水处理和循环利用等问题,设计了水平潜流人工湿地+垂直流人工湿地污水处理工艺,该工艺依靠重力作为动力,无需能耗,管理简单,污水处理效果较好,抗冲力负荷能力较强。运行结果表明,工艺出水主要指标达到了《地表水环境质量标准》(GB3838-2002)规定的I类水质标准。     

采用偏心割刀处理小口径钻孔掉钻事故实践

偏心割刀切割钻杆、钻具,多应用在大口径工程施工钻中,在地质钻探施工中,偏心割刀可以用来切割套管、岩心管。在贵州省普安县青山镇泥堡二矿的钻探施工中,使用偏心割刀从钻杆的外面将钻杆切割掉,成功处理了一次复杂的钻孔事故。介绍了采用偏心割刀处理钻孔事故的技术措施及注意事项。     

Solid phase characterization and metal deportment in a mussel shell bioreactor for the treatment of AMD,Stockton Coal Mine,New Zealand

The Stockton Coal Mine, located on the West Coast of New Zealand, is evaluating the use of a mussel shell bioreactor (MSB) to treat acidic metalliferous runoff from acid forming overburden. This novel approach is similar in concept to vertical flow wetlands (VFWs) and successive alkalinity producing systems (SAPS). The MSB system is a trapezoidal pit 2 m deep, 35 m long, 3–10 m wide with 60° angle sides. During operation it contained 160 tonnes (240 m³) of mussel shell material and was saturated with a 100–200 mm water cap. Influent flowed through the reactor at a mean rate of 0.3 L s⁻¹ resulting in a hydraulic retention time (HRT) of ≈6 days. The prototype MSB was in operation for a total of 1027 days, from June 2009 through March 2012, and effectively sequestered 99.7% of Al, 99.3% of Fe, 98.8% of Ni, 98.4% Tl and 99.3% of Zn, as determined from a previous evaluation of MSB performance. The MSB also effectively neutralized acidity, which resulted in an increase in influent pH from 2.8 to 6.9 in the effluent. Based on an examination of several excavated pits, five distinct reaction zones developed within the MSB. The reaction zones consisted of an allochthonous sediment layer (0–330 mm), an oxidized iron-rich ocherous layer (at 330–350 mm depth), an aluminum layer (at 350–600 mm depth) with geochemical variations throughout (350–500 mm and 500–600 mm); and a chemically reduced bottom shell layer (at 600–1100 mm). Representative samples were collected from each layer and analyzed using a combination of geochemical and physical methods to assess the stability of the secondary minerals and trace metal deportment within the MSB. Major elements Fe, Al, Ni, Tl, and Zn where preferentially associated with particular layers within the MSB. Elevated concentrations of Fe (110,000 mg kg⁻¹) were observed in the allochthonous sediment and ocherous precipitate layers, while Al (27,816 mg kg⁻¹), Ni (55 mg kg⁻¹), and Zn (655 mg kg⁻¹) were elevated within the aluminum and lower reduced depths within the MSB. Trace Tl (21 mg kg⁻¹) showed varying concentrations throughout the MSB, but was strongly correlated to lower layers of the system. Microbial biofilms were observed within the reduced portions of the shell layers often proximal to bacterial shaped sulfides. The geochemical assessment of the MSB presented in this study is the first of its kind for a MSB, and supports the argument that this system is another viable option for passive treatment of AMD.     

川藏公路藏东段边坡稳定性研究与治理评价

川藏公路是一带一路南亚通道的主要干线,其藏东段地质灾害频发,如何有效治理、保障安全畅通意义重大。文章在详细调查的基础上,对取得的藏东段沿线所有边坡数据进行统计及特征分析,利用随机森林理论建立了边坡稳定性评判模型,根据计算出的影响因素重要性大小对边坡的稳定性进行判别,模型检验表明其准确率超过94.44%,同时结合实地验证,对边坡的治理提出了可行性建议,为川藏公路藏东段的有效治理提供实用参考资料。