软弱地质层桩基旋挖钻机钻孔施工工法

详细论述了在软弱地质段,采用旋挖钻机进行桩基钻孔施工的施工工艺和操作要点.     

深圳地铁富水软弱地层工程性质及开挖后沉降特征研究

为研究富水软弱地层工程性质及开挖后沉降特征,文章通过室内试验对深圳地铁国贸至老街区间隧道的地层物理力学参数进行了测定和分析,结果表明:(1)该区域地层存在较大孔隙和微裂隙且相互贯通,土体压缩性高,固结沉降大;(2)地层倾向于散粒体,含水量大且含砂多,施工排水易冲刷夹带松散颗粒而导致地层损失难于控制;(3)地层强度低,隧道开挖时围岩稳定性差。以上因素导致此类地层具有开挖影响范围广、地层沉降大并易发生地表塌陷的显著特征。实测地层沉降验证了试验结论的正确性,国贸至老街区间隧道开挖引起的地表沉降最大值约为193.5 mm,地表沉降槽宽度约为80 m,并发生了2次地表塌陷事故。可见,隧道开挖引起的地层沉降与地质条件密切相关,通过地层物理力学特性预测隧道开挖引起的地层沉降是必要的和可行的。     

如何做好弱电工程的旁站监理

旁站监理是建设监理工作中的一项重要内容,是建设工程质量控制的一项重要手段,是监理人员在现场进行的监督活动。根据弱电工程特点,提出如何做好旁站监理,以及注意事项。     

软弱围岩隧道施工中大变形的产生及对策

介绍软弱围岩受地质构造作用,在隧道施工中产生大变形的机理和特点。根据现场施工情况,总结运用常规施工手段控制变形的施工措施,为类似地质条件下的隧道施工控制大变形的出现提供参考。     

软弱围岩隧道CD法和台阶法施工力学行为分析

为分析软弱围岩隧道在不同开挖方法过程中稳定性以及拱顶沉降变化规律,以某隧道工程实例为背景,借助有限差分软件FLAC~(3D)数值模拟并和实际监测数据对比分析,研究软弱围岩隧道在CD法和台阶法两种不同开挖方法施工过程中围岩变形、应力变化和围岩塑性区分布规律。实际监测数据和模拟计算结果均表明,采用CD法开挖断面关键点位移和应力明显小于台阶法,随开挖步影响范围也比台阶法要小。总之CD法较台阶法能更好控制围岩变形和应力发展,塑性区分布范围也明显小于台阶法。     

Airline energy efficiency measures considering carbon abatement: A new strategic framework

In this paper, airline energy efficiency is divided into two stages: Operations Stage and Carbon Abatement Stage. This new two-stage operating framework is a modification of existing ones. Then the model, Network SBM with weak disposability, is presented to evaluate the efficiency of 22 international airlines from 2008 to 2012. The results show that: (1) Most airlines’ energy efficiencies have not declined in the period. (2) The average efficiency of European airlines is higher than that of non-European airlines. (3) Non-European airlines have smaller advancements in efficiency score than European airlines. (4) Most airlines’ efficiencies in Operations Stage are higher than Carbon Abatement Stage.     

浅谈浅埋隧道施工要点及注意事项

结合宜巴高速公路26标段铜矿岭隧道的地质情况、施工过程及控制措施,介绍了浅埋隧道软弱围岩的施工方法及注意事项。     

软弱土质在地基处理中的应用

提出了软土、盐渍土地基路基换填处理方案,在实际工程中采用粒料石灰土换填层和土工布、荆笆帘、粒料换填层两种换填层结构处理软土盐渍地基.     

高地应力软弱围岩隧道挤压型变形和可让性支护原理

软弱围岩深埋隧道修建遇到的挤压型围岩大变形问题,是山岭隧道工程中的难题。文章在对挤压型变形机制、判识方法和变形特征进行分析的基础上,介绍了挤压型变形围岩支护的可让性原则,从地层特征曲线和支护-围岩相互作用出发,阐述了可让式支护的原理并给出了相关的设计施工要点。     

Measuring the energy efficiency for airlines under the pressure of being included into the EU ETS

In 2008, European Union (EU) announced that from 2012, each international flight taking off and landing in EU would be given an emission permit. Therefore, the period of 2008–2012 can be regarded as a buffer period for global airlines. Although EU formally decides to exclude non‐EU airlines from the EU Emission Trading System on March 4, 2014, it is necessary to investigate the impacts of the policy on airline energy efficiency in this period. Airline energy efficiency is divided into three stages—operations stage, service stage, and sales stage—and Greenhouse gas emission is treated as an undesirable output of service stage. Two models, network range‐adjusted measure model with weak disposability and network range‐adjusted measure model with strong disposability, are established to evaluate the efficiencies of 22 international airlines from 2008 to 2012. The results show that (i) most airlines' efficiencies have decreased in the period, and the EU Emission Trading System is not effective for the efficiency improvement; (ii) the average efficiency of European airlines is almost the same as that of non‐European airlines; and (iii) the model with weak disposability is more reasonable in distinguishing efficiency differences, while strong disposability is a more reasonable way in treating undesirable outputs. Copyright © 2016 John Wiley & Sons, Ltd.