【作者】 何锋；

【导师】 吴树仁； 曲永新； 张永双；

【作者基本信息】 中国地质科学院 ， 地质工程， 2005， 博士

【摘要】 本文结合实际工程，在收集、分析前人研究结果的基础上，通过野外地质调查，室内试验测试分析和模型计算，运用工程地质学、岩体力学等多学科理论和方法，开展三峡引水工程秦巴段深埋长隧洞开挖地质灾害方面的研究工作，在项目组各位老师和同学的协助下，重点研究：（1）三峡引水工程秦巴段区域稳定性和活动断裂；（2）区构造应力场和秦岭特长隧道段隧道围岩应力场分布特征及其三维有限元的仿真模拟；（3）三峡引水工程秦巴段线路工程地质条件和问题；（4）三峡引水工程秦巴段隧洞岩爆、突水、大变形研究；经过2年多的研究取得了以下初步进展和认识：1、运用工程地质力学的基本理论，以具体工程为例，初步提出了较为系统、全面的、适用于条件差、地质复杂、资料少等可行性研究阶段的深埋长大隧道主要地质灾害预测研究的思路和方法；提出隧道地质灾害预报具有明显的阶段性及其预测研究的基本思路。2、区域现今应力场分析表明：①现今区域应力场方向以NNE向挤压为主，与SN向输水隧道成小角度相交，有利于隧洞的稳定性。②现今最大主压应力量值一般都随深度增加而增加。在离地表100m范围以内，最大主压应力值在16MPa以下；在距地表100—500m范围内，地应力值不超过30MPa。3、三峡引水工程秦巴段线路工程地质条件比较复杂，横向断裂多、岩体变形较破碎、局部软弱夹层多。隧洞开挖存在的主要地质灾害是岩爆、大变形和突水。特别是①秦岭特长隧洞埋深600—1700m，开挖过程中的岩爆灾害将比较突出；②大巴山南部的断裂带和岩溶突水问题比较严重。4、在系统总结分析影响岩爆发生8大因素的基础上，提出以岩石单轴抗压强度R_c与最大主应力σ₁的比值作为判别三峡引水工程秦岭特长隧洞岩爆发生的指标，着重预测了秦岭特长输水隧洞岩爆灾害发生的地段与烈度等级，并对引水工程秦巴段全线可能发生岩爆的区段作出预测。结果表明：①汉江以南的大巴山地区，发生强岩爆的地段少，只有局部厚层白云岩有可能发生小规模岩爆。②汉江北部的凤凰山隧道一带局部可能发生强岩爆，强岩爆可能集中在深埋隧道3—5km的范同内。②秦岭主峰附近深埋隧道发生强岩爆的可能性很大，发生强岩爆的分布范围长达50km左右，其中，秦岭主峰的20km左右范围尤其需要注意。其它大部分地段发生强岩爆的可能性很小。5、三峡引水工程秦巴段隧洞可能发生突水地段预测评价结果表明：秦巴段沿线隧道施工可能发生突水的地段比较多，其中，可能发生大规模突水的地段主要集中在大巴山的断层带与岩溶复合控制地段，特别是大巴山南麓的两河口—岔溪口之间的前河隧道、大巴山北部毛坝—汉江的洪家山隧道需要重视大规模岩溶突水灾害；秦岭深埋隧道主要是断裂带和节理密集带突水，以中等规模为主，局部断裂交叉部位可能存在大规模突水过程。6、秦巴地区从南向北的主要软弱岩土体类型包括：四川盆地的侏罗纪泥岩、大巴山地区的志留系泥质岩，秦岭造山带中的元古界片岩（云母片岩、绿泥石片岩、滑石片岩）和劈理化板岩，古生界的千枚岩、板岩、炭质页岩，月河盆地的白垩纪泥岩、胶结程度不高的断层破碎带及第四纪粘土等都是容易发生大变形及其相关灾害的软弱夹层。更多还原

【Abstract】 On the basis of field geological research, indoor examination analysis and simulativecalculation, using multidisciplinary theory like engineering geology, rock body mechanics and soon, this dissertation, combining with practical project, studies the geological hazards in tunnelingof deep-long tunnels at QingLing-DaBaShan mountain of the water diversion project from thethree gorges reservoir to the yellow river on the base of collecting and analyzing predecessor’sstudying. In the assistance with the teachers and schoolfellows of the project team, it givesemphasis to four points as follows: （1） area stability and active rift at QingLing-DaBaShanmountain of the water diversion project from the three gorges reservoir to the yellow river;（2）Three-dimensional finite element analog simulation of area tectonic stress field and QingLingextra long tunnels wall rock stree field’s distributional characteristics; （3） Geological conditionand problems at QingLing-DaBaShan mountain of the water diversion project from the threegorges reservoir to the yellow river; （4） Rock blasting, water bursting and large deformation studyon the tunnels at QingLing-DaBaShan mountain of the water diversion project from the threegorges reservoir to the yellow river. By more than two years’ study, we have obtained someprogress and conclusion as follows:1. Using engineering geomechanics’ basal theory and concrete project as example, comparativelysystemic and all-round method of deep-long tunnels’ main geological hazards prediction studieshave been put forward preliminarily, which is suit to the feasible study phase like bad condition,complicated geology and few data and so on. Geological hazards prediction with obvious phasecharacter and its prediction studies’ basal method has also been put forward.2. Area present stree field analysis shows:①present area stree field is mainly in the NNEdirection extrusion, and intersects at small angle with water inlet tunnel of SN direction. which ispropitious to the tunnels’ stability.②the present maximal compressive principal stress valueincreases along with the deepness increasing. In the range of 100 meter of the earth’s surface, thevalue is under 16MPa; in the range of 100-500 meter, the value is not more than 30MPa, which isclose to the measured data.3. It is complex of the geological conditions at QingLing-DaBaShan mountain of the waterdiversion project from the three gorges reservoir to the yellow river such as more transversefailure, body distortion being broken and more local weak interbed. The main geological hazardsexiting in the tunnel excavation are rock blasting, large deformation and water bursting. Especiallyin①the rock blasting hazards in the course of excavation being extrusive in the buried depth600-1700 meter of extra deep tunnels at QingLing-DaBaShan mountain;②the problem offracture belt and carst’s water bursting being comparatively serious in south of DaBaShan atQingLing-DaBaShan mountain of the water diversion project. 4. On the basis of systemically analyzing eight influencing factors of rock burst occurrence, Theratio of rock uniaxial compressive strengh Rc to maximal principal stressσ₁, as the targetdistinguishing rockburst occurrence at Qinling extra long tunnel of the water diversion projectfrom the three gorges reservoir to the yellow river, is put forward. The plat of rockburstoccurrence and intensity class at Qinling extra long tunnel are predicted emphatically.Meanwhile, the threatening rockburst segment at Qinling-Bashan full line of the diversion workare predicted. The result shows:①Strong rockburst occurs at few of plats in DaBashan regionfrom southern Han river. None but small scale rockburst is likely to occur at parts of thick layerdolostone.②Strong rockburst occurs around phenix mountain tunnel from northern Han river andconcentrates on 3-5 km inside scope of deep-buried tunnel.③The potentiality that strong rockburst occurs at deep-buried tunnel round Qinling mountain dominant peak is quite high, and thelength of strong rockburst occurrence distributes about 50km along Qinling extra long tunnel.among the rest,it need especial attention to the 20km distribution range of extra long tunnel belowthe qinling mountain dominant peak. The potentianlity that strong rockburst occurs at the majorityof the rest plat is very low.5. The plats where water gushing occurs in Qinling-DaBashan segment of the water diversionproject from the three gorges reservoir to the yellow river are predicted and evaluated. The resultshows: Along the line, water gushing occurs in quite a few segment with tunnels on construction.Among the rest, the segment where industrial scale water gushing occurs mostly concentrates onthe fault zones and karst multiple-unit control plats.Especially to the Qianhe tunnel betweenLianghekou and Chaxikou from southern Bashan mountain and Hongjiashan tunnel betweenMaoba and Han river from northern Bashan mountainThey need to set much value on industrialscale karst water gushing hazard. Water gushing occurring in Qinling deep-buried tunnel mainlyconcentrates on fracture zones and joint congest zones. The scale of water gushing is mostlymoderate, but industrial scale water gushing process is likely to occur in local crippling fractureintersection situs.6. The principle types of weak rock in Qinling-DaBashan region from the south to northinclude:Jurassic mudstone in Sichuan basin; Silurian mudstone in DaBashan mountain region;Proterozoic schist in Qinling orogenic belt （mica schist, chlorite schist, talc schist） and cleavageslate, phyllite,slate and black batt of Palacozoic group; Cretaceous mudstone in Yuehe basin;Low-rise cement degree fault fracture zones and quarternary clay etc. They are all weakintermediate rocks which can easily became large deformation and geological hazards.Argillaceous rock in research region and its engineering geological acttributes were investigated inemphasis.更多还原