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基于AHP和模糊综合评判的TBM施工风险评估 总被引：7，自引：1，他引：6
岩石隧洞建设中面临很大和众多的风险,利用TBM施工的深埋长隧洞受多种不确定因素影响,具有随机性和模糊性,目前的研究方法难以对其进行准确定量分析。通过深入分析影响TBM施工的风险因素,建立了TBM施工风险综合评价指标体系。基于风险影响因素的层次性,提出了TBM施工风险二级模糊综合评判计算模型,并利用层次分析法(AHP)确定各级因素权重,利用模糊集法确定隶属函数,划分了风险接受等级。以南水北调西线工程深埋长隧洞TBM施工为例,应用二级模糊综合评判计算模型对该工程TBM施工风险进行分析,计算结果表明,该方法是合理性实用的。其理论、方法、思路和结论可供同类工程借鉴。 相似文献
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基于颗粒流模型的TBM滚刀破岩过程数值模拟研究 总被引：8，自引：2，他引：6
为了研究全断面岩石掘进机（TBM）盘型滚刀的破岩机制及其影响因素,采用颗粒流方法建立了岩石与滚刀的二维数值模型,实现了对TBM滚刀破岩过程的模拟。分析表明,滚刀的破岩过程可分为冲击挤压破碎、大量微裂纹生成、张拉性主裂纹扩展3个阶段,证实了滚刀破岩的挤压-张拉破坏理论。在滚刀侵入深度相同的前提下,随着刀圈刃角以及刃宽的增加,滚刀下的压碎区也相应增大,张拉性主裂纹数目增多,滚刀的破岩能力提高;与平刃刀圈相比,楔刃刀圈的“楔块劈裂”作用更加显著,使径向裂纹扩展得更快且更深入岩石内部。TBM滚刀对强度较高或较低岩石的破坏损伤较小,而对中等强度的岩石破坏损伤最为显著。 相似文献
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论述了国际地下工程建设动态，指出在地下工程建设中，优先采用全断面隧道掘进机（TBM）进行快速开挖已成料总的发展趋势；对我国开发隧道掘进机的历史和现状进行了综述，提出了存在的问题有利条件，对在我国建立隧道掘进机产业提出了意见和建议。 相似文献
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Influence of Rock Mass Parameters on the Performance of a TBM in a Gneissic Formation (Varzo Tunnel) 总被引：4，自引：1，他引：4
Summary The paper analyses the influence of rock mass quality on the performance of a double shield TBM in the excavation of a tunnel in a gneiss formation which is characterized by high strength and low fracture intensity.As full observation of the rock conditions was prevented by the use of segmental lining, a geomechanical survey of the face was performed during maintenance downtime and the observed conditions were correlated with the machine performance parameters for that same day. A statistical analysis of the data shows that penetration rate correlates well with a slightly modified RMR index (in which the influence of the water conditions and joint orientation were discounted), but the most important factor is by far the partial rating of the RMR classification related to joint spacing only. However in tunnels characterized by greater variability in rock strength and joint conditions, it could be worthwhile using the complete RMR index.Given the toughness of the rock, failure of the cutter bearings and supports were a frequent occurrence during excavation. Owing to this factor the influence of rock quality on the rate of advance was found to be weak and the correlation more scattered.The results obtained for the Varzo tunnel were compared with those relative to other tunnels in granitic rocks and found to be in good agreement. However the relationships obtained should be considered valid only for this type of rock; machine behaviour could be found to be markedly different in other rock types, even where rock material strength and joint frequency are the same. 相似文献
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针对隧道掘进机(Tunnel Boring Machine--TBM)施工隧洞中的围岩分类问题,指出TBM施工条件下的隧洞围岩分类应针对围岩的可钻掘性,充分考虑影响TBM掘进效率的主要工程地质因素,提出了在《工程岩体分级标准》围岩稳定性基本分级的基础上,依据岩石的单轴抗压强度、岩石的耐磨性和岩体的完整性将TBM施工条件下的隧洞围岩分为A(好)、B(一般)、C(差)3个级别的围岩分类新方法。 相似文献
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Additives for Slurry Shields in Highly Permeable Ground 总被引：2，自引：0，他引：2
P. Fritz 《Rock Mechanics and Rock Engineering》2007,40(1):81-95
Summary. For tunneling projects in saturated soils tunnel boring machines (TBMs) with slurry shields are widely used. However, in coarse,
highly permeable soils the suspension penetrates the ground and the required support pressure cannot be built up. For the
Zimmerberg Base Tunnel near Zurich permeabilities much greater than 10−3 m/s were expected. This value is usually considered as the critical limit for the applicability of slurry shields. Therefore
it was aimed to find additives for the bentonite suspension which would allow it to attain a higher suspension pressure.
For these investigations an apparatus has been developed. It allows the maximum attainable support pressure for a given suspension
and a ground to be determined. It reflects the real situation, produces reproducible results and is insensitive to the inevitable
variation of individual parameters.
In the tests the additives polymer, sand and vermiculite were studied and their effects on the attainable maximum suspension
pressure investigated. For the best combination, i.e. with a well defined proportion of the individual components, suspension
pressures could be attained which were about 10 to 20 times higher than those with an ordinary bentonite suspension. Successful
excavation of the Zimmerberg Base Tunnel proved the validity of the laboratory tests containing 200 kg bentonite per m3 water. 相似文献
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隧洞TBM施工过程中的地质编录 总被引：8，自引：0，他引：8
ＴＢＭ越来越多地用于隧洞开挖,有必要对ＴＢＭ施工地质进行研究,本文从现场施工要求的角度出发,概述了ＴＢＭ施工特征,以渣料的地质编录为重点,阐述了ＴＢＭ施工中地质编录方法及应用条件,进而归纳出如何利用各种地质信息指导超前钻探,预测不利地质条件,为ＴＢＭ施工提供地质依据。 相似文献
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