地质条件不确定性下TBM管片结构失事概率计算     

刘东海  黄培志  冯守中 《岩土力学》2010,31(4):1181-1186

不良地质条件是影响TBM施工隧洞管片结构安全的重要因素。综合考虑围岩地质条件和衬砌结构的不确定性,提出了一种定量分析TBM管片结构失事概率的新方法。在基于Markov过程估计隧洞沿程地质岩性变化概率的基础上,建立了隧洞任意位置处管片选型不匹配的概率模型;考虑围岩和管片参数的不确定性,采用随机有限元方法计算某一类型管片在不同围岩下的失事概率;由此,采用全概率公式,可计算隧洞沿程任意位置处管片结构的失事概率。结合实际工程,针对施工期工况,确定了该隧洞管片沿程的失事概率、最大失事概率及其所对应的位置等,为管片选型、优化设计及TBM施工期的风险防范提供了依据。  相似文献   

Source parameters of four strong earthquakes in Bulgaria and Portugal at the beginning of the 20th century   总被引：1，自引：0，他引：1  

S. Dineva  J. Batllo  D. Mihaylov  T. van Eck 《Journal of Seismology》2002,6(1):99-123

Using original seismograph records and bulletin data we re-determined theorigin time, location, seismic moment (M₀) and magnitudes(M_S and M_w) for four earthquakes in the beginning of the20th century. These are two strong earthquakes April 4, 1904 nearKrupnik, Bulgaria (M_w = 6.8, M_S = 7.2 respectively), the April 231909 earthquake near Benavente, Portugal (M_S = 6.3), and the June14, 1913 earthquake near Gorna Orjahovitza, Bulgaria (M_S = 6.3).Twenty-nine traces from original records have been analysed, a largenumber of original station bulletins have been consulted and a consistentmethodology for analysing these early 20th century instrumentalinformation is presented.In spite of a thorough effort in re-assembling and quality control of theoriginal data, large inaccuracies remain in the improved instrumentalepicentre locations and origin times. The seismic moment estimates weobtained (2.3 10¹⁸ M₀ 3.9 10¹⁹Nm) are the first ever determined for these events. The magnitudeestimates (6.3 M_S 7.2 and 6.2 M_w 7.0) are robust and systematically lower than most of previousestimates for all earthquakes (Gutenberg and Richter, 1954; Christoskovand Grigorova, 1968; Karnik, 1969). For the largest Krupnik event ourestimates agree with those of Abe and Noguchi (1983b) and Pacheco andSykes (1992). The studied earthquakes all occur in moderately seismicactive regions, therefore our results may have significant consequences forhazard estimates in those regions.  相似文献   

面向地下煤火热场模型的遥感技术体系初探   总被引：5，自引：0，他引：5  

谭海樵  王作棠  季景贤 《国土资源遥感》2002,13(3):54-57

鉴于地下煤火的特殊性,传统的卫星、航空乃至地面遥感手段在对其热场的探测研究应用中都有一定的局限性。本文在分析地下煤火基本特征的基础上,探讨了建立面向地下煤火热场模型遥感技术体系的必要性和可行性,提出了基于遥感技术的地下煤火热场模型的构建方法和工作流程,特别强调了对地下煤火时空演变趋势的预测研究。  相似文献   

Geologic site characterization (GSC) principles derived from storage and mining projects in salt, with application to environmental surety     

J. T. Neal  T. R. Magorian 《Environmental Geology》1997,29(3-4):165-175

 The source of many environmental incidents involving engineering works has been traced to inadequate geologic site characterization (GSC). Even though critics may argue that hindsight is almost always clearer than foresight, what is reasonable to some geologists may be overkill to others and GSC is often underperformed. Communication between designers, geologists, engineers, and regulators is paramount at all stages of a project, each recognizing the essential needs of the other. For large projects having substantial longevity, it is essential to periodically review initial conclusions because assumptions and criteria change as the geosciences evolve, engineering precepts are refined, and analytical capabilities increase. A brief consideration of the changing geological paradigms of the 1950s and 1960s as compared with the 1990s should leave little room for debate on this. Geologic site characterization should be a dynamic, continuing process. A balanced approach must be sought, to provide adequate information for safety of operations, neither slighting or overdoing the effort. Several examples are taken from the salt mining and storage industry, which illustrate these principles, but there is widespread application to other geological media and engineering projects. The ultimate benefit of valuing site characterization efforts may be more than just enhanced safety and health – costs not expended in lost facilities and ligation can become profit. Received: 13 September 1995 · Accepted: 21 November 1995  相似文献   

Study on Typical Characteristics of Short-Term Precursors in Underground Fluid     

Liu Yaowei 《中国地震研究》2005,19(2):170-180

INTRODUCTION Existingresearchresultsindicatethattherearecloserelationsbetweenundergroundfluidandseismicactivity,especiallyintheshort termanomaliesofearthquakes.Anomalyinthefluidisobvious andthequantityislarge.Duringearthquakepreparation,thedrivingforcemec…  相似文献   

多层次跟踪预报法在地下流体会商中的应用     

张清秀  陈小云  薛飞 《福建地震》2005,(Z1)

本文介绍利用多层次跟踪预报方法之短期预测法在多次福建地下流体资料会商中的应用。水化多层次跟踪预报方法以“水化的多层次跟踪加速前兆图象”为依据进行分析,主要对地震的发震时间进行预测。该图象说明了水化的异常群体随时间的演变趋势与地震活动有关;异常群体的演变与地震之间具有“增长———地震”或“加速———地震”的关系。这种关系,同彭德银等指出的地震总是处于接近或偏离临界状态的演化进程中的理论相适应。  相似文献   

地下管线动态更新管理体系的建立     

江贻芳 《中国勘察设计》2005,(8):55-57

本文从地下管线动态更新存在的问题入手,系统地分析了实现地下管线动态更新的五个必要条件,并从基础、核心、重点、保障和环境等方面详细介绍了如何建立地下管线动态更新体系。  相似文献   

我国城市地下空间资源利用浅析     

吴彤  倪绍祥 《江苏地质》2006,30(3):204-207

城市地下空间是城市建设的新型资源,它的合理开发与利用对城市的建设与发展有着重要的意义。探讨了我国地下空间资源利用的现状、已具备的条件,并阐述了我国地下空间资源发展的战略对策。  相似文献   

岩爆与围岩分类   总被引：12，自引：2，他引：12  

王广德  石豫川  葛华  寇佳伟  单治钢  周春宏 《工程地质学报》2006,14(1):83-89

岩爆是高地应力条件下完整脆性硬质围岩失稳的一种表现型式,岩爆烈度如何影响围岩类别尚不清楚,探索岩爆与围岩分类的关系,对准确判别高地应力条件下的围岩类别有着重要意义。本文以某深埋隧洞围岩分类为依据,对我国水利水电地下洞室围岩分类中岩爆烈度与围岩类别的关系、岩爆判别指标的选取等问题进行了探讨。  相似文献   

调湿板在地下工程中应用的研究     

朱培根  张兵  焦建六 《中国勘察设计》2006,(5):43-45

介绍了调湿板调节工程内湿度的原理和特点，以及调湿板的制作过程；比较了调湿板与其它材料的吸放湿能力；结合某地下工程实例分析了应用调湿板的经济性能。结果表明，调湿板的吸放湿能力远强于普通混凝土材料，应用调湿板能很好地解决地下工程内部的湿度调节问题，并且可以延缓除湿机的开启频率，减少设备初投资以及运行费用。  相似文献