共查询到18条相似文献，搜索用时 156 毫秒
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导向孔轨迹设计是开展非开挖工作的关键性步骤。本文通过非开挖施工所需最短距离问题的论述,对导向孔轨迹设计的关键性依据,即单根钻杆的最大可调控角度进行了详细的阐述,并且提出了对于轨迹设计工作非常有效的实用计算方法。 相似文献
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对于整个水平定向钻施工过程来说,导向孔施工最为关键,导向轨迹设计必须实时调整,这就需要大量现场计算过程,影响工作效率。手机智能平台拥有更广泛的优越性,使我们依托智能计算平台精确设计导向轨迹成为了可能。为此我们设计了一款基于手机智能平台的计算软件《导向小帮手》。 相似文献
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结合邯郸市集中供热管道工程实例,说明导向钻进非开挖在铺设地下管线施工中的成功应用,对导向钻进非开挖技术、导向孔轨迹设计、施工质量控制及施工效果等作了介绍与总结,为同类工程实践提供参考。 相似文献
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《水文地质工程地质技术方法动态》2009,(5):I0004-I0004
通过浅层低渗透性含水层水平盲井钻进与成井技术的研究,建立了钻孔轨迹设计、导向孔钻进、钻孔轨迹测量与控制、钻孔扩孔施工等水平盲井钻进技术体系和井管安装、填砾、止水封闭、洗井、抽水等水平盲井成井工艺体系。开发出了沿导向杆推进和在冲洗管内推进的井管安装方法。 相似文献
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本文推荐了一种设计分枝定向孔的新方法,其特点是:①据施工地层选择分枝点;②据具体施工条件选择造斜段的弯曲强度;③用标准方程描述钻孔轨迹。这种设计方法较为灵活、简便、施工中易控制。 相似文献
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Post-Cyclic Undrained Behavior of Compacted Composite Clay Subjected to Various Cyclic Loading Paths
H. R. Tavakoli A. Shafiee M. K. Jafari 《Geotechnical and Geological Engineering》2011,29(6):1085-1097
Using a sequential procedure of undrained cyclic and post cyclic tests, the strength and stiffness degradation characteristics
of compacted composite clays are studied immediately after various cyclic loading paths by triaxial and hollow cylinder tests.
The effects of cyclic loading paths, sand contents, cyclic loading amplitude and confining pressure on the post-cyclic mechanical
behavior of the composite clays are evaluated. The results point out different peculiarities which can be of interest in assessing
the mechanical behavior of the composite clays under post seismic shaking. The results show that effect of cyclic loading
on post cyclic pore water pressure build-up is significant when pore water pressure build-up is considerably lower than the
associated value in monotonic loading. The effect of sand content and cyclic loading path on degradation of stiffness is more
remarkable than shear strength. Test results also reveal that the effect of sand content on the post cyclic pore water pressure
build-up is minor. However, when the aggregate content increases the shear strength increases. 相似文献
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我国南海北陆坡水合物富集区广泛发育古滑坡,若水合物开采不当可能导致古滑坡再次滑动。为了探究水合物开采诱发古滑坡再启滑机制,针对含下卧型水合物藏和伴生型水合物藏的两个典型古滑坡体,在边坡极限平衡分析框架内考虑了水合物开采过程中的瞬态孔压与土体抗剪强度变化,分析了水合物开采过程中不同古滑坡体的稳定性演变与失稳模式。研究表明,水合物分解导致所赋存土体的胶结强度弱化,同时逸出气体可能被阻滞于渗透性较低的古滑坡体下方,从而形成横向扩展的高压区。下卧型储层边坡的潜在滑移面贯穿古滑移面,一般表现为滑动型滑坡;开采初期因孔压积聚而导致边坡稳定性降低,开采中后期因二次水合物生成可能导致边坡稳定性有所回升,在本文计算条件下未触发古滑坡复活。伴生型储层边坡的稳定性受土体强度劣化与孔压积聚的共同影响,水合物开采导致古滑坡重新滑动,表现为滑塌型滑坡。 相似文献
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高速铁路要为列车的高速行驶提供一个高平顺性和稳定性的轨下基础,而路基作为轨道结构的基础,必须具有强度高、刚度大、稳定性和耐久性好的特性。由于红层泥岩属于软岩,工程稳定性差,以红层泥岩作为基床的填料,其刚度明显不足,所以为了弥补基床表层的不足,在其顶部添加一层水泥稳定级配碎石。为了验证这些措施的效果,以便指导工程设计和施工,通过足尺动态模型试验,模拟在实际荷载条件下基床的动态变形特性,结果表明,采用水泥稳定级配碎石作为基床表层填料,静态变形明显降低,能够大幅降低动荷载作用时的动变形,减少了基床结构的永久变形,增强了轨道结构的稳定性。 相似文献
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Consistent seasonal snow cover depth and duration variability over the Western Himalayas (WH) 总被引：1，自引：0，他引：1
Precipitation in solid form, i.e., snow, during winter season over the Western Himalayas (WH) leads to the build-up of seasonal snow cover. Seasonal snow cover build-up (snow cover depth and duration) largely depends on atmospheric variables such as temperature, precipitation, radiation, wind, etc. Integrated (combined) influence of atmospheric variables on seasonal snow cover gets reflected in terms of spatial and temporal variability in seasonal snow cover build-up pattern. Hence spatial and temporal variability of seasonal snow cover build-up can serve as a good indicator of climate change in high altitude mountainous regions like the WH. Consistent seasonal snow cover depth and duration, delay days and early melt days of consistent seasonal snow cover at 11 stations spread across different mountain ranges over the WH were analyzed. Mean, maximum and percentiles (25th, 50th, 75th, 90th and 95th) of consistent seasonal snow cover depth and duration show decline over the WH in the recent past 2–3 decades. Consistent seasonal snow cover is found to melt early and snow cover build-up pattern is found to show changes over the WH. Decline in consistent seasonal snow cover depth, duration and changing snow cover build-up pattern over the WH in recent decades indicate that WH has undergone considerable climate change and winter weather patterns are changing in the WH. 相似文献