地质与岩土工程分布式光纤监测技术及其发展

本文分析了地质和岩土工程监测的特点和常规监测技术方法的不足,定义了分布式监测的内涵,介绍了光纤传感(FOS)监测技术的类型,重点阐述了分布式FOS技术的特点、种类和国内外的进展,最后提出了今后需要进一步研发的关键技术课题。     

鄱阳湖"斩秋湖"水位调控方式对湖泊湿地的影响及启示

鄱阳湖由于其长期的水文和地质过程形成了独特的碟形湖泊群。人类活动历史演变形成的、与大型通江湖泊节律性水文特征相互协调的"斩秋湖"水位调控是长江中下游季节性湖泊中的一种重要渔业方式。采用PRA方法调查和统计渔业数据,分析了"斩秋湖"人工调控的成因和调控方式;基于"斩秋湖"渔获物组成和年龄结构,分析其对湿地生态系统和关键物种生境的影响。结果表明:"斩秋湖"水位调控会显著改变湖泊湿地物种组成和群落生物量,提出了该调控方式对湖泊湿地保护与管理的启示。     

The formation and failure of debris flow-dams,background, key factors and model tests: case studies from China

Temporary dams can be formed by the sudden injection of debris flow into main streams by some favorable geomorphologic and hydraulic conditions, resulting in extensive inundations upstream and catastrophic floods downstream due to dam breaches and consequently dramatic changes of channels and valleys. Expeditious means of assessing dam-forming potential are necessary, particularly in geologically active regions. Complete blockages or dam formations are significantly related to the discharge ratio and velocity ratio between the tributary and the main stream, the bulk density of the debris flow, confluent angles and the degree of unevenness of grain sizes. In order to set up a critical index/C for dam formation, 19 groups of flume tests were conducted. The results showed that there were three types of blockage in the intersections, and dam-forming processes were mainly controlled by the product of the dimensionless momentum ratio and the degree of unevenness of grain sizes in the debris flow. Complete blockages or dam formations occurred when C > 83.4, whereas semi-blockages were formed or no dams were formed when C < 71.5, which had been judged to be feasible by historical instances of dam formation in China. Dam failures commonly resulted from overtopping. No piping was observed in the course of dam failure, and the time elapsed between dams can be denoted by a linear relation with the momentum ratio.     

煤化作用与构造 热事件的耦合效应研究——盆地动力学过程的地质记录

煤是一种对温度、压力等地质环境因素特别敏感的有机岩。煤化作用实质上是煤与外界进行能量和物质交换的一个开放系统。地质历史演化过程中的各种构造 热事件必然导致煤发生一系列物理、化学、结构和构造变化,煤中有机组分和无机组分在各种地质营力作用下迁移、分异和改造,从而影响煤层现今赋存状况、煤化程度和煤质特征,在一定程度上记录了沉积盆地动力学过程的地质信息。文中介绍了国内外在煤化作用与构造 热事件的耦合效应方面的研究进展,讨论了存在的问题,提出了重点研究课题。