共查询到19条相似文献,搜索用时 718 毫秒
1.
2.
3.
4.
结合一实际工程,选取包括断层破碎带和断层影响带在内的沿隧道纵向300m的计算区域,用八节点六面块体单元将计算区域离散化,采用三维弹塑性静力有限元法模拟分析隧道各个施工阶段,以及建成后围岩和衬砌的受力与变形状态。通过分析比较可知:(1)断层破碎带处的坑道变形和围岩塑性区均明显比非断层破碎带处要大;(2)由于断层破碎带的影响,初期支护、二次衬砌内力的增加幅度约为10%~30%。 相似文献
5.
文章根据兰新线兰武段乌鞘岭隧道地处F7断层影响带软弱破碎围岩中的大台竖井工程快速施工的施工经验,简要地介绍了在软弱破碎围岩中竖井的设计、快速施工技术. 相似文献
6.
本文针对红土山隧道与多条断裂破碎带相交,岩体十分破碎,围岩变化多,V级围岩占多数,地质情况复杂,存在F5断层破碎带等地质特点,在采取以TGP206地质超前预报系统进行超前地质预报的基础上,结合探地雷达预报及钻探相结合的超前预报方法,对设计存在岩层破碎带的K24+900~K25+080段落成功地进行了地质超前预报;通过红土山隧道断层破碎带的预报成果与实际开挖围岩地质状况进行对比分析,验证了超前地质预报结果的准确性,从而证明了超前地质预报在隧道施工中的应用的重要性和对复杂围岩情况段落采取多种预报手段结合的必要性。 相似文献
7.
高速公路断层破碎带隧道施工具有施工难度大的特点,严重影响到施工进度。鉴于此,重点探讨了断层破碎带隧道施工中的围岩及涌水问题,并针对此提出了具体的施工方案、施工要点以及注意事项,以保证高速公路沿线隧道工程的高质量建设。 相似文献
8.
双线铁路隧道平缓砂泥岩互层围岩变形机理分析 总被引:1,自引:0,他引:1
文章通过兰渝线四方山隧道平缓砂泥岩互层围岩变形对支护的破坏现象,分析了平缓砂泥岩互层围岩变形机理,以及采取的对策措施,其成果可供以后类似地质条件的工程参考借鉴. 相似文献
9.
10.
为揭示破碎岩层位置对隧道稳定性的影响规律,文章以某节理裂隙岩体隧道为研究对象,根据破碎岩层位置的不同分别建立6个计算模型,采用离散元软件UDEC对各个模型进行仿真模拟,并对比分析破碎岩层不同位置下的隧道开挖后应力和位移响应云图。结果表明:当破碎岩层位移隧道中线以上时,对隧道稳定性影响最大;当破碎岩体层位于隧道中心以下,对隧道稳定性影响较小。 相似文献
11.
12.
13.
节理岩体隧道围岩稳定性判定指标合理性研究 总被引:5,自引:0,他引:5
隧道围岩失稳模式和稳定性判据一直是工程界争论的焦点,迄今没有科学合理的标准,常以洞周位移或塑性区经验值作为稳定性判定指标。洞周位移受围岩弹模、隧道形状等因素影响,而且不同部位变形值差异很大,很难找到统一标准;以塑性区作为稳定性判据优于以位移作为判据,围岩塑性化反映连续介质宏观塑性流动力学动态,而不能用于量化判定由优势结构面控制节理岩体破坏的隧道稳定性。文章结合细观节理形态和变化,通过UDEC离散元程序,研究节理岩体隧道失稳模式及量化的稳定性判定指标,探讨了细观结构机制和宏观力学行为关系。结果表明:(1)结构面极大地削弱岩体力学性质及其稳定性,结构面变形与强度性质对于隧道稳定性起着关键控制性作用;(2)节理岩体隧道扰动区可划分为脱落区、张开区和剪切滑移区,其中脱落区表征围岩失稳模式,张开区围岩处于脱落临界状态,即塌方潜在区域;(3)剪切滑移区是诱发围岩发生渐进性破坏主因,提出将剪切滑移区作为节理岩体隧道稳定性判定指标具有严格力学依据,可以定量化评价围岩稳定程度。最后,以在建兰渝铁路木寨岭隧道为例,对比了锚杆支护前后力学效应,验证了以剪切滑移区作为节理岩体隧道稳定性判定指标的可靠性、合理性和现实性。 相似文献
14.
文章针对福州魁岐2号特大断面小净距隧道工程特点,以Ⅴ级围岩为研究对象,利用离散单元法对节理岩体中断层存在时初始围岩应力分布特征以及断层与隧道不同相对位置情况下围岩变形特征进行了定性分析。结果表明,当节理岩体中有断层存在时,初始围岩应力不再呈水平层状分布,而是出现一定程度的应力集中现象;围岩变形在断层附近区域显著增大,而距断层较远处基本不受影响;对于小净距隧道,当中间岩柱中存在断层时更不利于隧道和中间岩柱的整体稳定。 相似文献
15.
With a total length of about 22 km, Tianshan Shengli Tunnel on Urumqi-Yuli Expressway is currently the longest expressway tunnel under construction in the world. It adopts the construction scheme of "3 tunnels (2 D& B main tunnels and 1 TBM-driven middle pilot tunnel) + 4 shafts", which is characterized by great construction difficulty and high technical standard requirements. The tunnel construction is faced with technical challenges such as TBM passing through large fault fracture zones, long-distance construction ventilation in three tunnels, deep and large shaft construction and logistics organization in two-main tunnel construction assisted by middle pilot tunnel. In the parallel three-tunnel method design of Tianshan Shengli Tunnel, the TBM-driven middle pilot tunnel can not only play the role of advanced pilot tunnel, but also assist the construction of the two main tunnels and speed up the construction progress. For the middle pilot tunnel, the TBM excavation diameter is 8.4 m, and the initial support is designed as 100% force-bearing capacity in construction period, which can meet the requirements for two-way material transportation, ventilation and belt mucking in the pilot tunnel. Vault suspension scheme is adopted for the continuous belt conveyor, which can reduce the impact on the material flow organization in the cross passages. Multifunctional service vehicles (MSVs) independently developed by CCCC Group are used for the transportation of TBM materials and prefabricated inverted arch blocks, which can realize double-headed driving. TBM will pass through two large fault fracture zones F6 and F7. According to the stability of the surrounding rock at the tunnel face, the targeted treatment measures would be adopted. If necessary, the scheme of "steel segment + extruded concrete" shall be used for the initial support. In case of serious machine jamming or rock collapse, the heading expansion excavation method or bypass heading method shall be used. Tianshan Shengli Tunnel adopts phased forced ventilation option, and the ventilation mode is designed in stages with the change of tunnel construction stage. The fans and air pipes used are imported ones, and a ventilation management team is set up to strengthen ventilation management and ensure ventilation quality. Highly mechanized construction is used for the two D& B main tunnels, the application of equipment such as three-arm rock drilling jumbo and wet shotcrete machine is promoted, so as to reduce the number of workers and labor intensity, and improve work efficiency. The deep shafts of Tianshan Shengli Tunnel are constructed by short-section excavation and lining mixed operation method, and the initial support is lined by formwork pouring concrete, so as to realize safe and rapid excavation. According to the research results, the construction technology scheme for Tianshan Shengli Tunnel can meet the needs of tunnel construction. The research results can be directly used to guide the construction of Tianshan Shengli Tunnel, and provide reference for the construction of extra long highway tunnels in high-altitude areas. © 2022, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
16.
17.
18.
19.
文章利用非线性有限元数值计算模型,对宝塔山隧道不良地质段开挖施工过程中的围岩应力及位移变化情况进行了模拟分析。结果表明,隧道围岩应力及变形均满足规范要求,处于稳定状态。 相似文献