落石冲击混凝土板与缓冲层组合结构的动力响应          下载免费PDF全文

吴建利  胡卸文  梅雪峰  许泽鹏  罗刚  韩玫 《水文地质工程地质》2021,48(1):78-87

钢筋混凝土（RC）板与一定厚度的土颗粒缓冲层组合结构被广泛用于山区高位单体及群发性崩塌落石的防治,为研究此类防护结构在落石作用下的冲击力衰减规律及RC板的破坏模式,开展了室外系列落石冲击试验。结果表明,增大缓冲层厚度能够有效减小最大冲击力,峰值加速度随缓冲层厚度减小而增大,尤其在缓冲层厚度为0.1 m及0.2 m时,最大值急剧增大,峰值加速度与缓冲层厚度的变化满足指数函数关系;根据量纲分析原理得到缓冲层最大冲击深度与动能的平方成正比、与最大入射冲击力成反比的计算公式,且与实测值较吻合;入射冲击力在缓冲层内的衰减率随缓冲层厚度的增加以指数函数递增,在0.6 m缓冲层厚度下可使峰值冲击力衰减70%左右;随累积冲击能级的增大,RC板经历了弯曲起裂及扩展、次级弯曲裂纹和剪裂纹产生及跨中弯曲裂纹贯通的过程,试验结束时RC板整体表现出典型的弯曲破坏特征。  相似文献   

KT178型取心钻具在共和干热岩钻井中的应用          下载免费PDF全文

张恒春  王稳石  李宽  王跃伟  闫家  曹龙龙  胡晨 《探矿工程》2021,48(2):29-34

共和干热岩资源富集于花岗岩地层,硬度高,研磨性强,部分层段裂隙发育,取心困难。针对干热岩地层和取心需求特点,研制一套KT178取心钻具,并配套设计了孕镶金刚石取心钻头。该钻具为单动双管取心钻具,可配套井底动力钻具使用,设计中注重对钻具外管、卡簧等关键部件的强度校核。在GH-01井和GH-02井中,经过两轮实验和优化,钻具逐渐成熟,获取了较完整的岩心样本,满足干热岩勘探取心要求,具备了向页岩气、水资源勘察等具有间断取心需求的同类工程推广应用的条件。  相似文献   

高温硬岩空气潜孔锤钻头设计          下载免费PDF全文

罗宏保  李俊萍  吴金生 《探矿工程》2021,48(4):60-65

干热岩试验性开发井钻井施工,在高温硬岩的地层条件下,如何实现高效钻进仍存在很多技术难点。空气潜孔锤钻进技术是解决硬岩地层钻进的有效方法之一,潜孔锤钻头是空气潜孔锤钻进的关键器具。根据青海共和干热岩GH-01井空气潜孔锤钻进技术应用情况,分析探讨了空气潜孔锤钻头断齿、掉齿、磨损严重、使用寿命短等问题,从钻头结构设计、钻头材料选取、钻头冷压固齿工艺等几个方面对空气潜孔锤钻头进行了优化。固齿优化过程中采用有限元分析方法,对钻头冷压固齿过盈量进行仿真分析计算,根据分析计算结果确定最优固齿过盈量。通过对潜孔锤钻头结构、材料、加工等优化,为适用于高温硬岩的空气潜孔锤钻头研制提供了借鉴。为提高空气潜孔锤钻进综合效率,为干热岩钻探开发提供了技术支持和技术储备。  相似文献   

基于市场化的矿山生态修复模式浅析以江西省某县废弃矿山为例          下载免费PDF全文

孙晓东  曹占强  葛亚军  许飞  许莽  林文成 《探矿工程》2021,48(S1):386-390

废弃矿山占用土地资源,带来诸多生态环境问题,废弃矿山的生态修复迫在眉睫。当前各级政府财政对于矿山生态修复投入不足,亟须社会资本参与。2019年自然资源部发布《关于探索利用市场化方式推进矿山生态修复的意见》,为社会资本参与矿山生态修复市场化运作打开了大门。通过在江西省某县采用市场化方式进行矿山生态修复的实践,分析了废弃矿山生态修复的开发利用方向和不同修复方式的适用范围,明确了社会资本投资参与矿山生态修复的运行及收益模式,为区域矿山生态修复市场化项目提供参考。  相似文献   

复合动力钻进工艺在干热岩钻井中的应用研究          下载免费PDF全文

谭现锋  马哲民  段隆臣  刘肖  李颖  郭明义 《探矿工程》2021,48(7):1-8

2011年山东省地矿局在山东省利津县实施了国内第一个干热岩调查评价项目,采用转盘回转钻进,但钻效低、能耗高。为提高在高温硬岩条件下的钻进效率、缩短钻井周期、降低生产成本,2015年在福建省漳州市实施的中国地质调查局东南沿海深部地热HDR-1干热岩科学钻探工程井（井深4000.86 m,孔底温度109 ℃）和2017年在青海省共和县完成的GR1干热岩科学勘探井（井深3705 m,孔底温度236 ℃）,在施工中均探索使用了“转盘+螺杆钻具”复合钻进工艺,并在高温取心段首次测试应用了“转盘+涡轮钻具”复合取心钻进工艺,取得了良好的效果并就下一步研究方向提出了意见和建议,为螺杆钻具和涡轮钻具的深入研究提供了宝贵的高温施工经验,也将为我国干热岩科学钻探与深部地热资源勘探提供新的技术支撑。  相似文献   

基于优化经验模态分解和聚类分析的滑坡位移智能预测研究     

张凯  张科  保瑞  刘享华  齐飞飞 《岩土力学》2021,(1):211-223

针对三峡库区"阶跃式"滑坡的变形特征,提出了一种新的滑坡位移预测方法。以白水河滑坡ZG118和XD-01监测点位移数据为例,采用基于软筛分停止准则的经验模态分解(SSSC-EMD)将累计位移-时间曲线和影响因子时间序列自适应地分解为多个固有模态函数(IMF),并采用K均值(K-Means)聚类法对其进行聚类累加,得到有物理含义的位移分量(趋势性位移、周期性位移以及随机性位移)和影响因子分量(高频影响因子和低频影响因子)。使用最小二乘法对趋势性位移进行拟合预测;采用果蝇优化-最小二乘支持向量机(FOA-LSSVM)模型对周期性位移和随机性位移进行预测。将各位移分量预测值进行叠加处理,实现滑坡累计位移的预测。研究结果表明,所提出的(SSSC-EMD)-K-Means-(FOA-LSSVM)模型能够预测"阶跃式"滑坡的位移变化规律,且预测精度高于传统的支持向量机回归(SVR)、最小二乘支持向量机(LSSVM)模型;并通过改变训练集长度,进行单因素分析,发现其与预测精度之间呈正相关关系。  相似文献   

Comparative Study of Acid and Alkaline Stimulants with Granite in an Enhanced Geothermal System     

XU Jianan  FENG Bo  CUI Zhenpeng  LIU Xiyao  KE Zunsong  FENG Guanhong 《《地质学报》英文版》2021,95(6):1926-1939

The Enhanced Geothermal System (EGS) is an artificial geothermal system that aims to economically extract heat from hot dry rock (HDR) through the creation of an artificial geothermal reservoir. Chemical stimulation is thought to be an effective method to create fracture networks and open existing fractures in hot dry rocks by injecting chemical agents into the reservoir to dissolve the minerals. Granite is a common type of hot dry rock. In this paper, a series of chemical stimulation experiments were implemented using acid and alkaline agents under high temperature and pressure conditions that mimic the environment of formation. Granite rock samples used in the experiments are collected from the potential EGS reservoir in the Matouying area, Hebei, China. Laboratory experimental results show that the corrosion ratio per unit area of rock is 3.2% in static acid chemical experiments and 0.51% in static alkaline chemical experiments. The permeability of the core is increased by 1.62 times in dynamic acid chemical experiments and 2.45 times in dynamic alkaline chemical experiments. A scanning electron microscope analysis of the core illustrates that secondary minerals, such as chlorite, spherical silica, and montmorillonite, were formed, due to acid-rock interaction with plagioclase being precipitated by alkaline-rock interactions. Masking agents in alkaline chemical agents can slightly reduce the degree of plagioclase formation. A chemical simulation model was built using TOUGHREACT, the mineral dissolution and associated ion concentration variation being reproduced by this reactive transport model.  相似文献   

Effect of the Dry Ashing Method on Cadmium Isotope Measurements in Soil and Plant Samples     

Wei‐Xin Lv  Hao‐Ming Yin  Meng‐Shu Liu  Fang Huang  Hui‐Min Yu 《Geostandards and Geoanalytical Research》2021,45(1):245-256

A dry ashing method is commonly used to remove organic material from samples prior to geochemical analysis. In the course of this study, the Cd isotope ratios of a series of soil and plant reference materials and samples were studied to evaluate the effect of the dry ashing method on measurement results of Cd isotope ratios. The samples were pre‐treated using the dry ashing method and high‐pressure bomb for comparison. The results show that the digestion using high‐pressure bombs did not lead to Cd loss, but using the dry ashing method would cause different proportions of Cd loss. The whole range of Cd isotope difference between two methods was from ?0.07‰ to 3.01‰. There was also an obvious difference in measured Cd isotope ratios from the same leaf sample pre‐treated independently by the dry ashing method, indicating that the amount of Cd loss and the effect on Cd isotope measurement during dry ashing is related to the properties of the samples. Therefore, dry ashing may not be appropriate for the removal of organic material in Cd isotope ratio measurement, especially for samples with high organic contents. The δ^114/110Cd values of reference materials NIST SRM 1573a and GSD‐30 are reported for the first time in this study.  相似文献   

Three-dimensional publication mode of Journal of Palaeogeography(Chinese Edition)          下载免费PDF全文

Li Xin-Po  Zhang Xi-Juan  Zheng Xiu-Juan 《古地理学报》2021,22(6):1233-1234

The network technology has provided impetus and channels for the development of sci-tech periodicals and promoted the transformation of the publication mode of Journal of Palaeogeography(Chinese Edition). Through the independent website construction,providing readers with diversified access to articles,diversified communication methods,personalized accurate article push,joining the OSID open science program,etc.,a three-dimensional publication mode adapted to the development of periodicals has been gradually formed.  相似文献   

我国华南江南春季雷暴气候特征分析     

杨波  王园香  蔡雪薇 《热带气象学报》2019,35(4):470-479

基于我国华南江南地区274个基本地面气象观测站数据、全国闪电定位数据以及欧洲中心的全球大气再分析数据(ERA-Interim),对1981—2017年华南江南地区的春季雷暴日采用经验正交函数分解方法(EOF),并与气象要素场做回归分析。得出以下主要结论:(1)我国华南江南地区春季雷暴活动高发区主要在广西东部至广东西部;其高峰期在下午18:00和凌晨4:00左右,且大多数雷暴活动持续时间不超过3 h;山区雷暴活动主要在傍晚至夜间;平原雷暴活动主要在白天,高峰在17:00及06:00前后;(2)华南江南地区的雷暴活动存在着3~5年的短周期和16年左右的长周期变化;(3)雷暴日距平EOF分析的前3个主成分累计方差贡献达到72.3%。按其向量场的方差贡献分型,Ⅰ型表现为华南江南雷暴活跃特征呈现较统一的变化规律。深厚西南低涡槽前、上干下湿的水汽层结、上冷下暖的温度层结为华南江南地区发生大范围雷暴天气提供良好的动力、水汽和位势不稳定条件,是华南江南雷暴活跃异常的主要模态;Ⅱ型表现为从华南南部到江西与浙江南部有一条西南-东北向、下宽上窄的雷暴活跃正距平异常区,而两侧为负距平异常区。其环流特征表现为温度整层偏冷,水汽整层偏湿,而西南槽前动力抬升有利于水汽抬升凝结触发对流形成雷暴;Ⅲ型表现为华南和江南地区雷暴活跃特征呈南北反位相异常,其分界线在26 °N附近。其环流特征表现为较强的干冷空气南下与南方暖湿空气在南岭山区对峙形成异常的垂直环流圈。在其上升支,低层干冷空气被卷入中高层使得中高层暖湿空气凝结释放潜热形成对流,造成华南地区多雷暴发生,而江南地区处于垂直环流的下沉支,整层湿度偏干,造成江南地区雷暴相对偏少。   相似文献