黏滑断层隧道刚柔并济抗减错技术研究   总被引：1，自引：1，他引：0       下载免费PDF全文

崔光耀  魏杭杭  王明年 《地震工程学报》2021,43(2):380-385,395

为提高强震区黏滑断层隧道的结构安全性和稳定性,以都汶高速友谊隧道F1黏滑断层段为研究背景,对黏滑断层隧道采用刚柔并济抗减错技术进行研究。研究结果表明:采用结构加强措施抵抗断层黏滑错动影响,结构位移抗减错效果不显著,结构内力的平均抗减错效果在23%~33%之间;施设减错层有利于消减断层黏滑错动对隧道结构的影响,其拱顶沉降、边墙收敛抗减错效果分别达到20%以上,结构内力平均抗减错效果在37%~47%之间,优于结构加强措施;刚柔并济抗减错措施在抵抗及消减断层黏滑错动影响方面效果显著,其拱顶沉降、边墙收敛抗减错效果均能达到30%以上,而结构内力平均抗减错效果达到80%以上。研究成果可为强震区黏滑断层隧道抗震减灾设防设计提供参考。  相似文献   

PGE distribution in massive sulfides from the P<Emphasis Type="SmallCaps">ACMANUS</Emphasis> hydrothermal field,eastern Manus basin,Papua New Guinea: implications for PGE enrichment in some ancient volcanogenic massive sulfide deposits     

Jan?Pa?avaEmail author  Anna?Vymazalová  Sven?Petersen  Peter?Herzig 《Mineralium Deposita》2004,39(7):784-792

The distribution of platinum group elements (PGE) in Cu- and Zn-rich samples from the Roman Ruins and Satanic Mills vent sites in the PACMANUS hydrothermal field (Papua New Guinea) was studied and compared to that from selected ancient volcanogenic massive sulfide (VMS) deposits. Samples from the Satanic Mills site are enriched in Pd and Rh when compared to samples from Roman Ruins and reach highest values in active and inactive Cu-rich black smoker chimneys and chalcopyrite-cemented dacite breccias (up to 356 ppb Pd and up to 145 ppb Rh). A significant positive correlation was established between Cu and Pd and Rh in samples from both vent sites. Comparisons of chondrite normalized patterns and values of Pd/Pt and Pd/Ir ratios in Cu-rich sulfides and probable source rocks (felsic volcanic rocks/MORB) along with the evidence for a magmatic component in the PACMANUS hydrothermal system indicate that leaching of back-arc volcanic rocks together with addition of magmatic volatiles to the convecting hydrothermal system was the most important factor for PGE enrichment at PACMANUS and likely at some PGE-enriched ancient VMS deposits.An erratum to this article can be found at Editorial handling: B. Lehmann  相似文献   

LG植物胶泥浆在煤田复杂地层钻探中的应用研究          下载免费PDF全文

张晓静乌效鸣  蔡记华张家军韩书记  周文波 《探矿工程》2006,33(12):42-44,49

在河南省驻马店汝南县林楼一正阳县张楼一带的煤田勘探中，第三、第四系地层厚达700m，经常遇到水敏性粘土、砂质粘土、砂质泥岩、粉砂岩和卵砾石等地层，易造成缩径、超径、坍塌和掉块等孔内复杂情况。结合该地区的地层特征，采用新型LG植物胶泥浆来解决钻探的“瓶颈”难题。应用实践表明，LG泥浆起到了显著的抑制缩径、超径和防塌作用，大大减少了孔内事故的发生，提高了钻进效率。  相似文献   

民勤绿洲边缘带灌丛沙丘防风作用研究   总被引：7，自引：1，他引：7  

王升堂  邹学勇  张春来  程宏 《地理科学》2007,27(1):104-108

对民勤天然绿洲边缘带的固定、半固定及半流动风速灌丛沙丘实地观测表明,气流通过单个固定灌丛沙丘时,近地面平均风速降低4.4%,在965 m观测样线内降低57%,且风是连续降低的,愈靠近内侧降低得愈多,到绿洲内部农田边缘处时,平均风速仅有对照点的21%。深入了解灌丛沙丘对绿洲的防护机理,对于合理保护和恢复绿洲边缘带灌丛沙丘,避免绿洲遭受风沙侵袭具有重要意义。  相似文献   

小波降噪技术的Loran-C/INS组合导航技术研究     

林雪原  徐宇茹 《武汉大学学报(信息科学版)》2007,32(10):895-898

运用小波降噪技术提高Loran-C输出的信噪比,并进一步进行组合导航系统的滤波运算。基于实测数据的试验结果证明,采用该技术后,组合系统的各导航参数精度得到了显著的提高。  相似文献   

New insights into the Re-Os systematics of sub-continental lithospheric mantle from in situ analysis of sulphides   总被引：1，自引：0，他引：1  

Olivier Alard  William L. Griffin  Norman J. Pearson 《Earth and Planetary Science Letters》2002,203(2):651-663

The Os isotopic compositions of mantle rocks generally are considered to be established during melt-depletion events and to be robust to subsequent disturbances (e.g. metasomatism). Consequently, Os isotopes are used to date the main melting event that a mantle section has undergone, i.e. transformation of fertile asthenospheric material into a depleted, buoyant lithosphere. However, Os resides almost entirely in Fe-Ni-Cu sulphides, which can be very mobile under mantle conditions. In situ laser ablation multi-collector ICP-MS measurement of Re/Os isotopic ratios in sulphides from spinel peridotite xenoliths demonstrates that whole-rock Os-isotope signatures record the mixing of multiple sulphide populations. Sulphides residual after melting events have unradiogenic Os isotopic compositions reflecting ancient melt depletion; those introduced by later metasomatism events contain more radiogenic Os. Therefore, the whole-rock Os isotopic signature can be strongly altered by metasomatic processes, and studies of mantle-derived xenoliths show that such disturbance is quite common in the lithospheric mantle. Because melt-depletion ages estimated from individual sulphide inclusions are systematically older than those obtained from whole-rock analysis, caution is essential in the interpretation of the Os model ages derived from whole-rock analysis, and their use and abuse in geodynamic models. This work suggests that sulphide could become a key phase in unravelling the formation and evolution of the lithosphere.  相似文献   

河道开挖效果预测方法初步研究          下载免费PDF全文

杨国录  吴虹娟  余明辉  李纪泽  王昌慈 《水科学进展》2002,13(3):345-350

针对河道开挖后挖河效果预测的重要性,初步提出了预测挖河效果的三个评判标准:挖沙减淤比、复原率和稳定坡.引用黄河山东河段“挖河固堤工程”资料,通过数学模型计算结果对挖河效果预测的三个评判标准进行了说明,并展示使用三个评判因子分析挖河效果的有效性和应用潜力.  相似文献   

应用反射波法对基桩完整性进行定量评估   总被引：2，自引：0，他引：2  

黄文清 《矿产与地质》2001,15(Z1):610-620

利用应力波在一维杆中传播的机理对应力波在不同介面和变截面状态下的反射、透射与能量耗散之间的关系进行分析的基础上,用反射系数、透射系数、波幅衰减比等参数之间的关系及计算公式,对振动测桩中的实测波幅进行定量计算,得出面积削减率,以此值为依据进行桩身缺陷程度的判断.  相似文献   

流量测次精简对洪水预报的影响分析     

沈起鹏  黄爱莲 《水文》2001,21(5):16-19

通过对潼塘、大西滩、五里牌、坑口、龙家山站流量测次精简引起的误差对新安江三水源预报模型影响的分析，论述了流量测次精简误差对洪水预报的影响，提出了流量测次精简误差与洪水流量预测误差之间的关系。对《水文巡测规范》（SL195－97）的精度指标进行了论证。  相似文献   

论企业的成本管理与控制     

王景峰 《吉林地质》2003,22(2):66-69

指出了企业成本管理所存在的问题,论述了降低产品成本是企业管理的关键所在,提出了降低产品成本的主要途径。只有降低了产品成本,才能提高企业经济效益,并在激烈的竞争中立于不败之地。  相似文献