The introduction of neural network system and its applications in rock engineering

The neural network system has been developing very fast recently. It has been widely used in many industries such as automation, nuclear power plant, chemical industry, etc. Neural network systems have a great advantage in dealing with problems in which many factors influence the process and result, and the understanding of this process is poor, and there are experimental data or field data. In rock engineering, many problems are of this nature. In this paper, a brief introduction to neural network systems is given. Problems such as what is a neural network, how it works and what kind of advantages it has are discussed. After this, several applications in rock engineering, made by us, are presented. Case 1 is ore boundary delineation. In this case, the rock are divided into three classes, i.e.: (1) waste rock; (2) semi-ore; and (3) ore for mining purposes. The neural network system built can judge whether it is ore, semi-ore or waste rock along the borehole according its corresponding geophysical logging data, such as gamma-ray, gamma-gamma, neutron and resistivity. Case 2 is aggregate quality prediction. In this case, the quality parameters: (1) impact value; (2) abrasion value I; and (3) abrasion value II are predicted by using a neural network system based on density, point load, content of quarts and content of brittle minerals. Case 3 is rock indentation depth prediction. In this case, the rock indentation depth under indentation load is predicted by the established neural network system based on the indentation load on rock, indenter type and rock mechanical properties, such as uniaxial compressive strength, Young's modulus. Poisson's ratio, critical energy release rate and density. In all these cases, the neural network systems have been applied successfully. The testing results are satisfactory and better than the existing techniques.     

塔里木盆地中—下奥陶统层序地层研究

运用地震、测井等手段,结合岩石学、生物地层学地层对比方法,将塔里木盆地中—下奥陶统层序划分为1个二级层序(SSQ6),4个三级层序:SQ1、SQ2、SQ3、SQ4。对层序地层、沉积相特征研究发现,构造运动、海平面升降和古气候变化为塔里木盆地中—下奥陶统层序发育主要控制因素。     

On Fundamentals Predicting Floods-Landslides

ＣＯＮＣＥＰＴＩＯＮＳＯＦＨＥＡＶＹＦＬＯＯＤＳＣＡＵＳＩＮＧＬＡＮＤ┐ＳＬＩＤＥ／ＳＬＩＤＥＴｈｅｒｅａｒｅｍａｎｙｄｉｓａｓｔｅｒｓ／ｈａｚａｒｄｓｏｃｃｕｒｉｎｇｏｎｔｈｅｅａｒｔｈ’ｓｓｕｒｆａｃｅ．Ｔｈｅｓｅｅｖｅｎｔｓｐｒｅｓｅｎｔｅｄａ...     

Study on rain-runoff process in the peripheral mountainous area of the Sichuan Basin

Studies on rain-runoff process in the peripheral mountainous area of the Sichuan Basin, which is regarded as a key ecological shelter, will contribute to flood control and environmental protection for the Upper Yangtze River Basin. In two typical catchments--the Fujiang River Catchment and the Wujiang River Catchment, rainfall simulations have been conducted to study the rain-runoff processes of yellow soil and limestone soil in three types of land use--forestland, farmland and grassland. Results showed that （1） within the same rainfall process, overland flow occurs first on farmland, then on grassland, and finally on forestland; （2） soil surface coverage has a great impact on the occurrence and amount of overland flow. The runoff amount can increase 2-4 times after the coverage is removed; （3） the infiltration before the occurrence of overland flow will decrease because of higher gravel contents of soil, but it takes no effect on infiltration once overland flow becomes stable; （4） the runoff coefficient of the limestone soil forestland is greater than that of the yellow soil forest land, but less than that of the farmland; （5） three empirical infiltration models, including Horton＇ model, Kostiakov＇ model, and modified Kostiakov＇ model, were compared by using the observed results under rainfall simulation. The results showed that the Kostiakov＇ model performed better than both the Horton＇ model and modified Kostiakov model. According to the results of this research, the Kostiakov＇s model can be used to simulate rainfall infiltration when water erosion is modeled in the peripheral mountainous area of the Sichuan Basin.     

项目后评价在水利工程建设中的应用初探

项目后评价,是项目生命周期的最后一个流程。实施项目后评价,及时总结项目建设的成功经验和失败教训,对于优化以后类似项目的建设程序,提高决策水平、管理水平和投资效果都有着重要的意义。当前国内项目后评价中尚存在一些突出问题:没有将后评价和前评估区分开;后评估系统的独立性不够;后评估的实施部门缺乏必要的调查核实手段,选取的数据资料面窄、量小、时间期限短,缺乏应有的代表性。针对上述问题并结合水利项目自身特点,提出相应的对策和建议。     

岩石圈深部温压条件下萜烷演化的实验研究

在密闭体系中700℃、压力高达3 GPa条件下进行褐煤加水的模拟实验,分析实验产物中的萜烷的变化规律,进而对高压高温下有机质演化进行研究.实验结果表明,相同压力条件下,温度升高有利于有机质的成熟演化;压力增加会抑制或延迟油气的生成和有机质成熟;五环三萜烷ββ生物构型转化为αβ地质构型所需能量比烯烃双键加氢饱和更高.高温超高压条件下,研究样品中C24四环萜烷存在4种同分异构体,含量由高到低依次包括10β(H)-降A-羽扇烷、10p(H)-降A-奥利烷、C24-17,21-断藿烷和10β(H)-降A-乌散烷.高碳数烷烃在地幔高压力条件下仍可以存在,这为认识超压盆地的油气资源与深层油气成藏及保存提供了新的思路.     

新疆阿尔泰塔拉特铁铅锌矿床流体包裹体研究及矿床成因

塔拉特铁铅锌矿位于新疆阿尔泰造山带南缘的阿巴宫多金属成矿带,矿体赋存于克兰盆地下泥盆统康布铁堡组中,为一套海相中酸性火山岩-火山碎屑岩、陆源碎屑沉积岩-碳酸盐岩建造,脉状矿体受阿巴宫大断裂次级断裂控制.根据矿物组合和脉体穿插关系,塔拉特铁铅锌矿可分为4个成矿阶段:矽卡岩,氧化物,硫化物和碳酸盐阶段,后3个阶段均有石英共生.其中,硫化物(方铅矿-闪锌矿±磁黄铁矿±黄铜矿)阶段是铅锌成矿的主要阶段.不同阶段石英中广泛发育流体包裹体,可分为水溶液包裹体(W型)、纯CO2包裹体(PC型)、CO2-NaCl-H2O包裹体(C型)及含子矿物多相包裹体(S型)4类.冷热台显微测温和激光拉曼分析表明,氧化物阶段石英含有4种类型的包裹体,以W型为主,C型和S型包裹体次之,包裹体均一温度介于271～ 426℃,W型和C型盐度范围0.5％～22.4％ NaCleqv,S型包裹体盐度30.5％ ～40.6％ NaCleqv;硫化物阶段的石英流体包裹体为W型、C型和PC型,均一温度为204 ～ 269℃,盐度介于0.2％～15.6％ NaCleqv之间;碳酸盐阶段的矿物只含W型包裹体,均一温度集中在175～211℃之间,盐度为1.1％ ～9.9％ NaCleqv.利用C型包裹体对硫化物阶段成矿压力估算,得到107 ～ 171MPa,对应深度为4～6km.塔拉特铁铅锌矿初始成矿流体具有高温、高盐度、富CO2的特征,但碳酸盐阶段低盐度、贫CO2,流体不混溶和混合作用导致了成矿物质的沉淀.塔拉特铁铅锌矿的地质和成矿流体特征显示其为碰撞造山体制形成的矽卡岩型成矿系统.     

境外桩基工程的施工实践

通过对支援柬埔寨、几内亚桩基工程的施工实践,总结出在境外工程项目的管理中,要制定相应的管理制度与突发事件的应急预案,在施工过程中要注意政局变化,加强卫生疾病的防治,进行必要的物质储备和规避风险等注意事项及解决方法．对地勘单位拓展海外市场提出了建设性意见,具有一定的借鉴意义。     

Cenozoic basement structure of the South China Sea and adjacent areas by modeling and interpreting gravity data

The South China Sea and adjacent areas is a large region with diversely complicated geological conditions. In spite of investigations carried out over the past many years, the marine geological structure in many places has remained poorly understood because of the deficient data, a thick seawater layer as well as of the sensitive areas among the countries in the region. In this paper, the authors study and apply a model-based methodology of the modeling and interpretation of the newest gravity data and others, which are 3D modeling, frequency filtering, horizontal gravity gradient and maximum horizontal gravity gradient, in order to determine clearly the basement structure. The basement features such as the main faults systems, uplift-depression zones and seafloor spreading axis, oceanic boundary in the region have been defined. The achieved results are checked by the seismic data available for the region. From the studied results, the authors have brought out some initial remarks on the structure and form of the basement in the South China Sea and adjacent areas.     

铜仁地区陡山沱期盖帽碳酸盐岩地质地球化学特征及其成因

通过对贵州铜仁地区陡山沱期盖帽碳酸盐岩进行野外地质观察与室内岩石薄片显微镜下观察和研究,发现盖帽碳酸盐岩普遍发育有晶洞构造、帐篷构造、层状裂隙及包卷状构造等特殊沉积构造,重晶石、黄铁矿广泛发育,δ(13C)(2个研究剖面平均值分别为-4.73×10-3,-4.52×10-3)普遍显著负偏。研究区盖帽碳酸盐岩的地质地球化学特征依据"甲烷渗漏"成因假说能够较合理地解释。