硬岩地层中滚刀失效分析及适应性选型方法

盾构法施工在隧道工程中广泛运用,滚刀的性能对其施工效率和成本有着重大影响。硬岩地层中滚刀存在破岩效率低、使用寿命低的问题。基于深圳市铁岗—石岩水库水质保障工程中硬岩地层滚刀失效情况,建立基于单位消耗滚刀数量的破岩体积统计方法,分析滚刀失效规律和原因。结合滚刀破岩机理,从刀圈截面、刀刃宽度、刀圈过渡圆弧、滚刀尺寸、刀圈材料、安装半径等方面提出硬岩地层中滚刀地层适应性选型方法和刀盘改造措施。所提出的方法在工程实际中运用效果良好,可为硬岩地层中的盾构施工提供重要参考。

不同刀盘在富水砂卵石地层的盾构掘进适应性分析

为了实现富水砂卵石地层盾构隧道的安全、优质、高效施工,盾构机刀盘结构必须尽量适应工程地质条件。本文基于成都地铁典型的富水砂卵石地层盾构隧道现场实践,通过对三种不同刀盘盾构机在类似地质条件下的实际掘进时的掘进参数(掘进速度、刀盘扭矩、推力、刀盘转速)进行单参数和整体适应性的比较分析,得出了不同刀盘在富水砂卵石地层盾构隧道掘进时的适应性,且机型2刀盘的适应性是最好的;通过对实际掘进效率的差异原因分析,得出了富水砂卵石地层盾构隧道刀盘选型的关键因素为开口位置与最大开口尺寸。

深部金属矿山巷道TBM掘进技术应用现状及研究进展

未来10年,我国将有30%以上金属矿山开采深度达到或超过千米。深部金属矿山开采面临高地应力、高地温、地层多变、采掘强扰动等复杂地质环境,给巷道掘进带来严峻挑战。传统钻爆法巷道掘进非连续作业、效率低、灾害频发,难以满足建设需求,采用隧道掘进机(TBM)进行机械化连续掘进是深部金属矿山巷道建设的未来发展方向。然而,因深部金属矿山独有工程地质特点和巷道掘进需求,TBM技术在深部金属矿山巷道掘进中仍存在一些技术难题和挑战。本文首先总结了TBM技术在深部金属矿山巷道掘进中的三个应用难点:1)缺乏适用于深部金属矿山巷道的TBM适应性选型设计理论;2)缺乏适用于深部金属矿山巷道的TBM高效掘进技术;3)缺乏适用于深部金属矿山巷道的TBM掘进灾害监测预警与防控技术。然后,从六个方面介绍了深部金属矿山巷道TBM掘进技术应用的研究进展:适应性选型与设计技术、刀盘刀具高效破岩理论、掘进性能精准预测与评价方法、小半径转弯和倾斜巷道掘进技术、掘进灾害智能预警与防控技术、智能决策和辅助驾驶技术。上述研究成果为推动TBM掘进技术在深部金属矿山巷道中的广泛应用,实现深部金属矿山巷道快速掘进指明了发展方向。

In nomen omen:the effect of flower distance on female reproductive success of the lax-flowered orchid Anacamptis laxiflora(Orchidaceae)

Aims In multiflowered species,the architecture of inflorescences is of primary importance in shaping plant attractiveness.The aim of this study was to disentangle the role of inflorescence traits in plant female reproductive success and pollination patterns along the inflorescence in the lax-flowered orchid Anacamptis laxiflora,a terrestrial species exploiting a deceptive pollination strategy.We also evaluated whether the relationship between inflorescence traits and female reproductive success was modified by the height of surrounding vegetation and/or by population density.Methods We delimited experimental plots in a natural population of A.laxiflora.We tallied the individuals within each plot and categorized low-density plots and high-density plots;then,in part of the plots we manually removed surrounding grass thus producing an equal number of plots with high grass and low grass.Within these plots,we recorded inflorescence traits and female reproductive success(i.e.the number of fruit and their position along the inflorescence).We analyzed these data using generalized linear mixed-effects models(GLMMs)and calculated selection gradients.Important Findings We found that all the investigated inflorescence traits influenced female reproductive success.In particular,our GLMMs showed that'average flower distance'was the best predictor for shaping reproductive success patterns.We detected significant positive selection on the investigated inflorescence traits,but these selective trends were strictly linked to both the height of the surrounding vegetation and the population density,suggesting a significant influence of local environmental context in shaping selective patterns.Female reproductive success was not linked to the position of flowers along the inflorescence,suggesting that pollinators visit flowers randomly along the inflorescence without a detectable preference for a specific part.This study highlights the importance of inflorescence traits in shaping female reproductive success of multiflowered deceptive orchids,and confirms a primary role for the environmental context in modifying pollinator-mediated selection patterns.