水泥偏高岭土复合稳定粉砂土渗透特性试验研究     

王盛年  高新群  吴志坚  惠洪雷  张兴瑾 《岩土力学》2022,43(11):3003-3014

水泥稳定粉砂土抗渗性能受粉砂土自身渗透性能、水泥用量、水灰比等因素影响显著,如何在提升其抗渗性能的同时降低水泥用量是提升工程经济效益的关键。通过开展不同水泥偏高岭土掺比、初始用水量、水泥偏高岭土总掺量以及养护龄期条件下的室内渗透试验,研究了上述因素对水泥偏高岭土复合稳定粉砂土抗渗性能的影响规律,探讨了上述因素及无侧限抗压强度与渗透系数之间的经验关系。结果表明：水泥与偏高岭土掺比为5:1时,水泥偏高岭土复合稳定粉砂土抗渗性能最佳,且该掺比不随水泥偏高岭土总掺量的改变而变化;水泥偏高岭土复合稳定粉砂土渗透系数随初始用水量增加呈非线性递增,随水泥偏高岭土总掺量增加和养护龄期发展呈先快后慢降低;基于试验结果归纳提出了4个关于初始用水量、水泥偏高岭土总掺量、养护龄期和无侧限抗压强度的水泥偏高岭土复合稳定粉砂土渗透系数经验模型。研究成果可为水泥稳定粉砂土抗渗性能提升提供理论参考与借鉴。  相似文献   

粉细砂地层防渗帷幕综合施工方法          下载免费PDF全文

丁跃军 《探矿工程》2015,42(4):76-78

四川省武都水库右岸EL574 m灌浆平洞揭露出厚度2.3～9.8 m的粉细砂层,普通水泥高压灌浆无法形成可靠的防渗帷幕。采用高压旋喷、湿磨细水泥、化学灌浆的组合处理方式,取得了较好的施工效果。通过钻孔压水、大功率声波CT、单孔声波、钻孔全景数字成像等方法检测,表明达到了设计防渗要求。  相似文献   

2019/2020年冬季我国暖湿气候特征及成因分析     

赵俊虎  宋文玲  柯宗建 《气象》2020,46(7):982-993

2019/2020年冬季,我国大部分地区气温显著偏高,降水异常偏多,气候总体表现为“暖湿”的异常特征。异常成因分析表明：2019/2020年东亚冬季风强度较常年同期偏弱,西伯利亚高压异常偏弱,季节内冬季风强度阶段性变化特征显著;北极极涡收缩于极地,强度偏强,AO为异常偏强的正位相,乌拉尔山阻塞高压活动偏弱,东亚槽偏弱,欧亚中高纬以纬向环流为主;西太平洋副热带高压强度偏强、位置偏西偏北,印缅槽阶段性活跃,二者有利于太平洋和印度洋水汽向我国输送。受北半球环流异常的影响,我国冬季出现了“暖湿”的异常特征。进一步对东亚冬季风偏弱的可能原因分析表明：2019年秋冬季赤道中太平洋暖海温发展,2019年10月至2020年1月Ni〖AKn~D〗o3.4指数均大于0.5℃,这种类中部型El Ni〖AKn~D〗o海温异常有利于激发偏强、偏北的西北太平洋反气旋,进而抑制了东亚冬季风的发展和南下;此外,冬季北半球极涡收缩于极地,强度偏强,AO持续异常偏强的正位相,均不利于乌拉尔山阻塞高压的发展,且东亚大槽明显偏弱,共同导致了欧亚中高纬地区以纬向环流为主,东亚冬季风偏弱。  相似文献   

基于分段函数法计算湿球温度研究     

朱业玉  陈辉  姬兴杰 《气象与环境科学》2013,36(4):6-9

核电厂冷却塔设计气象条件中,湿球温度是重要的设计气象参数之一。近年来,由于实行自动观测,相对湿度值由仪器自动测定,因此不少气象站已经停止了湿球温度的观测,这给电厂气象参数的分析计算造成了一定困难。为此,根据气压分布型特点和分段函数,提出利用干球温度和相对湿度来计算湿球温度的新方法,经河南省郑州、南阳和商丘3站的应用,效果良好。  相似文献   

Changes in Daily Climate Extremes of Observed Temperature and Precipitation in China          下载免费PDF全文

WANG Ai-Hui  FU Jian-Jian 《大气和海洋科学快报》2013,6(5):312-319

Daily precipitation for 1960–2011 and maximum/minimum temperature extremes for 1960–2008 recorded at 549 stations in China are utilized to investigate climate extreme variations.A set of indices is derived and analyzed with a main focus on the trends and variabilities of daily extreme occurrences.Results show significant increases in daily extreme warm temperatures and decreases in daily extreme cold temperatures,defined as the number of days in which daily maximum temperature(Tmax)and daily minimum temperature(Tmin)are greater than the 90th percentile and less than the10th percentile,respectively.Generally,the trend magnitudes are larger in indices derived from Tmin than those from Tmax.Trends of percentile-based precipitation indices show distinct spatial patterns with increases in heavy precipitation events,defined as the top 95th percentile of daily precipitation,in western and northeastern China and in the low reaches of the Yangtze River basin region,and slight decreases in other areas.Light precipitation,defined as the tail of the5th percentile of daily precipitation,however,decreases in most areas.The annual maximum consecutive dry days(CDD)show an increasing trend in southern China and the middle-low reach of the Yellow River basin,while the annual maximum consecutive wet days(CWD)displays a downtrend over most regions except western China.These indices vary significantly with regions and seasons.Overall,occurrences of extreme events in China are more frequent,particularly the night time extreme temperature,and landmasses in China become warmer and wetter.  相似文献   

Statistical approach to determine the salinized ground water flow path and hydrogeochemical features around the underground LPG cavern,Korea     

Jeongho Lee  Ji‐Hoon Kim  Hun‐Mi Kim  Ho‐Wan Chang 《水文研究》2007,21(26):3615-3626

The ground water flow path of the coastal area in the Yellow Sea, Korea, was interpreted using both the cross‐correlation analysis of hydraulic properties and the principal component analysis (PCA) of ground water chemistry. Data was obtained from observation wells in the underground liquefied petroleum gas (LPG) cavern constructed in the coastal area of Pyeongtaek. Cross‐correlation results showed that the operating pressure became more influenced on artificial factors for the variation of the groundwater level of the study area (45–66% of correlation coefficient) even though its affecting area was limited to the region with fractures or faults, and also showed that the delay time from the variation of operating pressure to the fluctuation of ground water level were relatively long periods (28–31 days). Three hydrogeochemical events (encrusted cement dissolution, host rock dissolution, and seawater intrusion), which were dominantly influenced on ground water quality, could be induced from the result of PCA. Quantitative evaluation for these events using the mixed equation with principal component scores suggest that the dissolution of encrusted cement materials was the predominant factor (39·0% of the total mixed proportion) to change the chemical composition of the seepage water during the ground water flow from the observation wells to the cavern. Integration of the statistical results also imply that ground water flow and hydrogeochemistry were predominantly affected by artificial factors such as cavern operation pressure and dissolution of encrusted cement materials, which were interdependent factors on the observation wells with high cross‐correlation coefficients and pH. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

湿浸硫酸镍工艺中的二次浸取     

李天才 《青海国土经略》1997,(1)

湿法浸取硫酸镍工艺研究中,净化提纯工艺采取了蒸发浓缩浸液、分步沉淀杂质的技术方案。中试表明,采用此种工艺生产效率很低,还导致生产流水线上的设备匹配性差。为此,作者提出了二次浸取的技术方案。实验室及中试试验表明:采用二次浸取工艺替代蒸发浓缩工艺,行之有效。  相似文献   

巴彦淖尔市水泥混凝土施工冻害指数分析     

高贵荣  毕炜  杨北华  杨青  张静  王瑞红 《内蒙古气象》2012,(5):33-35

为了便于开展冬季水泥混凝土施工气象服务,选用临河和海流图（乌拉特中旗）测站近10a的气象资料分别作为河套和后山地区的气象数据．选取逐日最高气温、最低气温、定时相对湿度、最小相对湿度、降水量、定时风速,经过筛选、统计、计算,得出河套地区水泥施工适宜时段为4月上旬末至10月中旬,后n1地区水泥施工适宜时段为4月中旬末至10月上旬．这一研究结果町以提升冬季建筑施工气象服务的针对性和实用性。  相似文献   

GPS/MET水汽反演中T_m模型的本地化研究     

单九生  邹海波  刘熙明  吴琼 《气象与减灾研究》2012,35(1):42-46

利用江西省南昌和赣州两探空站12年(1999—2010年)每日2次(08时和20时)的探空资料,运用最小二乘法建立了江西地区的加权平均温度Tm模型(江西本地化Tm模型)。基于探空资料计算得到的Tm值,对比分析了江西本地化Tm模型、武汉本地化Tm模型和GAMIT默认Tm模型的模拟结果,发现江西本地化Tm模型的模拟效果最好,武汉本地化Tm模型相对较差。利用GAMIT软件,分别采用江西本地化Tm模型、武汉本地化Tm模型和GAMIT默认Tm模型,对2010年1月至2010年12月南昌、赣州等地的GPS大气可降水量进行了解算,并与探空计算的大气可降水量作了对比分析,结果发现采用江西本地化Tm模型后解算得到的GPS大气可降水量精度最高,而采用GAMIT默认Tm模型的精度相对较差。  相似文献   

新疆天山南麓一次冰雹天气成因分析   总被引：1，自引：0，他引：1  

张俊兰  罗继 《气象科技》2012,40(3):436-444

利用常规观测资料、NCEP 1°×1°的6h再分析资料和地面加密自动气象观测资料,分析了2010年5月15日发生在新疆沙雅县境内的一次强冰雹天气。分析显示,巴尔喀什湖低槽、冰雹区上游的中尺度切变线是冰雹天气的直接影响系统,其水汽源于塔里木盆地西部和中部地区,水汽在低层集中和输送,冰雹区上空的辐合上升运动为冰雹出现提供了水汽和动力条件,强冰雹产生在地面高能区附近,冰雹发生前低层和整层大气存在不稳定能量。此次强冰雹过程中对应地面上有中尺度低压、中尺度辐合线和中尺度涡旋,强冰雹是由γ中尺度对流单体产生的,中尺度辐合线维持5h,中尺度涡旋维持3h,γ中尺度对流单体的生命史为30min左右。  相似文献