【作者】 邓林；

【导师】 邓荣贵；

【作者基本信息】 西南交通大学 ， 岩土工程， 2010， 博士

【摘要】 本论文结合交通部西部交通建设科技项目“大相岭泥巴山深埋特长隧道关键技术研究”。采用现场测绘、室内外试验、理论分析与数值模拟等方法,对四川雅安～泸沽高速公路的控制性工程——大相岭泥巴山深埋特长隧道的重大岩体工程问题进行了深入研究,主要的研究内容及在导师和课题组的提示和启发下获得的成果如下：(1)通过收集分析泥巴山地区现有基础地质资料、勘探测试资料和现场详细调绘,弄清了隧址区的工程地质环境,结果表明：隧道所穿过的大相岭背斜并非为倒转的背斜,而是一似“箱”形构造模式；隧址区地质环境条件极为复杂,岩性种类多,空间分布多变,现代构造应力量值较大,不同规模与期次的褶皱构造和断裂构造发育并叠加改造。因构造影响,岩体破碎及结构复杂。(2)利用单轴压缩试验、单轴拉伸试验、常规三轴压缩试验以及卸围压试验对隧址区主要岩石进行了岩石力学试验,结果表明：完整岩石强度较高,单轴抗压强度最高达250MPa,岩石强度明显受微裂隙影响,微裂隙发育的岩石单轴抗压强度最低为20MPa左右,一般在70-100MPa；岩石单轴抗压强度有随埋深而增加的趋势；岩石三轴压缩变形及强度受加载路径的明显影响。(3)采用现场钻孔水压致裂测试法、室内Kaiser效应测试法和震源机制解对泥巴山隧址区初始地应力进行了测试及分析,结果表明：地应力值随深度呈近似线性增加,隧道高程附近最大主应力量值40-45MPa；整体趋势为埋深约0-300m段垂直向地应力小于两个水平向地应力,约300-850m段垂直地应力介于两个水平向主应力之间,大于850m时,垂直应力大于两个水平向主应力,其中最大水平主应力总体方向为N55°W,与隧道轴线整体方向N47°E近垂直。(4)根据现场测试结果,采用数值模拟反演分析得到：隧址区地应力场受地形的明显影响,隧道进、出口应力较小,埋深较大的中段地应力水平较高,其中最大主应力多为30MPa-45MPa,中间主应力多为20MPa～30MPa,最小主应力为10-20MPa,断层带对局部地应力场大小及方向有显著影响。(5)以现场实测地应力及室内岩石试验为基础,根据传统能量理论及提出的岩爆潜指数法、改进的强度理论观点,采用理论方法及数值模拟方法,对隧道围岩岩爆危险性进行了定性及定量的预测分析。结果表明,泥巴山隧道围岩存在岩爆危险的洞段长度约占整个洞长的29%,其中弱岩爆危险洞段长度约占20%,中等程度岩爆危险的洞段长度约占7%,强烈岩爆危险的洞段长度约占2%,因岩性分布及岩体结构的差异性,产生岩爆洞段不连续,沿隧道呈带状分布。(6)将交通隧道大变形界定为隧道变形非脆性破坏的变形量超出了规范规定的预留变形量,根据Ⅲ级围岩标准,当隧道边壁的相对变形量Db≥0.013时,定义为大变形。利用岩体力学理论和数值模拟分别计算预测隧道典型断面的相对变形量,结果表明,断层带及其附近围岩可能产生严重的大变形,个别埋深及宽度大的断层带产生大变形程度为严重或极严重；断层带围岩大变形受断层带宽度、断层岩工程特性及结构特征和两盘岩体工程性质影响；断层带宽度大于19m洞段,围岩大变形较明显。更多还原

【Abstract】 This dissertation combining with practical project, studies the critical technology of the NIBASHAN deep buried and extra-long tunnel of Bei Jing-Kun Ming highway. The key rock mass engineering problem along tunnel, which is the key and bottleneck project of Ya’an to Lu Gu, were researched according to the field sketch, experiment both in laboratory and field, simulative calculation and theoretical analysis. By more than three years’study, some progress and conclusion were given as follows:(1) On the basis of collecting and analyzing exsting basic geological data and filed geological work, it is included that:The Daxiangling articline is not overturned,but similar to the outline of "box";there is a varied topography, numerous stratum and complex spatial distrbution, the modern tectonics stress is high, complex formation condition; The rock mass structure is complex because of the tectonic influence in tunnel area; well-developed fold and faults which is exert an influence to geostress.Tectonic damage in NIBASHAN tunnel area is obviously distributed in belt, including strong tectonic damage zone, medium tectonic damage zone and weak tectonic damage zone.(2) A series of rock mechanics experiments were carried include uniaxial compression test, uniaxial tensile test, triaxial compression and unloading tests.the following results have been drawn:Integral rock with high compressive strength, the max compressive strength is about 250MPa, Microcracks cast influence on the compressive strength,and the strength is about 20MPa if microcracks are well developed,the average is between 70MPa to 100MPa. With the increase of buried depth, the peak strength become higher; Loading paths influence on the triaxial compressive strength and deformation.(3) To get the geostress, Hydraulic fracturing method, focal mechanism solution and Kaiser effect were used. Results as follows:The geostress increase with the depth of burial, the max principal stress is between 40MPa to 45MPa; the vertical stress less than horizontal stress,when the depth lower 300m,the vertial stess lies in bwtween the min principal and the max principal stress if the depth ranges from 300m to 850m,the vertical stress more than horizontal stress,when the depth greater 850m; The direction of max principal stress in tunnel area is N55°W, it is intersect trend of tunnel with large angle.(4) Based on the site test results,numerical calculation shows that:Topography have an obvious effect on geostress, the grostress of import and exit is low, tunnel of middle is larger; The maximum principal stress in deep-buried tunnel is between 30MPa to 45MPa, the intermediate principal stress is between 20Mpa to 30MPa, the min. principal stress is between 10Mpa to 20MPa.(5) Based on the site tests and the rock tests, numerical simulation and theoretical analysis were carried to predict the fatalness of rockburst. Analysis by energy theory and theory of strength showns that:the length that rockburst may occur in Nibashan tunnel is 29% of total tunnel, including:weak rockburst tunnel is about 20%, medium rockburst tunnel is about 7%, serious rockburst is about 2%. Because of fault zone and difference of rock joint, the tunnel that rockburst may occur is un-continuous, and belt-distributed along the tunnel.(6) Large deformation is defined as non-brittle failure, the deformation exceed the reserved deformation, when the relative deformation of the side is more than 0.013(Db≥0.013),it is intitule large deformation. This essay separately calculates out the variables of each section in tunnel through rock mechanical theory and FLAC3D. The results shows that:the sections with serious large deformation are all with high in-suit stress and in fault zone of surrounding rock, three is serious large deformation in individual sections; Engineering characteristic and texture characteristics of rock mass in fault zone influence large deformation, there be obvious large deformation, when the width of fault zone is over 19m.更多还原