【作者】 王春山；

【导师】 聂德新；

【作者基本信息】 成都理工大学 ， 地质工程， 2010， 博士

【摘要】 溪洛渡水电站建基面开挖阶段已经结束,建基面由610m高程开挖至324.5m高程。在开挖过程中,作者在导师的带领下随施工进度利用先进的仪器设备和方法及时准确的获取了建基面岩体的岩体结构、风化程度、岩体松弛、岩体质量和岩体力学性质等各项数据,对建基岩体由表部至深部有了较为全面的了解。木文通过对已开挖建基岩体的工程地质特征的研究,对前期勘察成果进行反馈研究,以检验可研阶段勘察方法的准确性,进而为其它水电站建设提供一个高效可靠的研究方法和思路,提出今后类似工程的勘察方法和勘察重点,为减少工程地质问题的出现和特高拱坝的勘探提供新的参考方法、技术,意义重大。本文主要从以下几个方面进行研究。(1)利用采用现场精测窗、全裂隙测量和数码摄录相结合的方法对每个开挖梯段建基面岩体的结构面进行解译和岩体结构划分,进而得到了左右岸拱肩槽和河床建基面岩体结构分布特征；(2)利用前期平洞内对裂隙的统计和岩体结构划分的结果与开挖后岩体结构成果相比较,以检验在相同位置岩体结构划分的异同；(3)对建基面上的钻孔分析,爆破松弛对建基面岩体有一定的影响,且不同等级的岩体受影响的深度不同,经统计影响深度在1.2-1.8m范围内；(4)利用钻孔声波划分了左右两岸建基岩体浅表部和深部的风化程度,并与开挖前划分的风化界限进行了比较,结果显示两个阶段划分弱上风化带与弱下风化带界限、弱下风化带和微新风化带界限基本一致；(5)使用了新型发明专利技术——“白载式”变形试验设备对两岸建基面进行了70多个试验,试验成果涵盖了建基面上不同岩性、不同岩级类型岩体的变形模量,同时又进行了同向声波测试,经拟合表明声波与变形模量有很好的相关性；(6)溪洛渡建基面岩体的特点就是随机发育的层内错动带将整个建基面及建基岩体切割成似层状,减弱了建基面岩体的力学性质。通过对山体内部层内错动带原位力学性质试验,利用弹性力学的原理,结合声波与模量的转换公式确定了层内错动带在松弛状况下和未松弛状况下的性状及变形模量；(7)利用岩体结构、完整性系数、波速比和变形模量等多种指标对建基面及建基岩体的岩体质量等级进行了划分,并与开挖前确定的建基面附近岩体质量等级成果进行了比较；(8)利用三维数值模拟计算分析了建基面上部岩体挖除后岩体的应力特征及范围,以及在正常的工程荷载作用下建基面表部和深部的总位移量、最大主应力、中间主应力和剪应力的分布特征。更多还原

【Abstract】 The phase of Xiluodu Hydropower foundation excavation has completed. Base surface excavated from the 610m to 324.5m elevation. In the excavation process, the author acquired rock mass structure, the degree of slack rock, rock quality and nature of rock mechanics etc. of base surface rock mass timely and accurately by using advanced equipment and methods under the leadership of the Professor NieDe xin. Then got comprehensive understanding of characteristics of foundation rock mass from the table to the inside. This article studied engineering geological characteristics of foundation rock mass after excavation, and made comparison of early survey results in order to test the accuracy of survey methods of the feasibility study stage. And provided a highly efficient and reliable research methods and ideas for other Station Construction. It means a great deal to reduce the emergence of engineering geology. This paper studied the following aspects:(1) The rock structures were compartmentalized by using precision measuring window with on-site, full crack measurement and the method of combining digital video recording for structural plane of each bench excavation foundation surface, and then got left and right banks spandrel groove and bed base surface distribution of rock mass structure;(2) We compared the rock structure of exploration hole early stage with the one of excavation stage in order to test the similarities and differences of rock structure in same location in two stages;(3) On the base of analysis of sonic drilling of base surface, the studies show that the blast made rock mass of base surface flabby. And different slack depth belongs to different levels rock mass. The statistical depth of impact were in the range of 1.2～1.8m;(4) Weathering degree of shallow and deep of foundation rock was distinguished by using sonic drilling. The weathering boundaries which including the boundary between weak weathering zone upper segment and weak weathering zone lower segment and boundary between weak weathering zone lower segment and very shallow weathered bedrock were almost same.(5) There are more than 70 test points which were accomplished by using a new patent technology-"self-loading" the deformation of test equipment on the both sides of the base surface. The test results covered different situations modulus of deformation which were affected by different lithology and different types of rock. The deformation modulus showed a good correlation with acoustic velocity which were tested at the same time and place.(6) The characteristics of rock mass on Xiluodu base surface were that the lots of random soft interlayer which cut foundation rock into layers and made mechanical properties of foundation rock weak, distributed on the foundation rock. The test was done to determine the mechanical properties of soft interlayer. By using elasticity theory and acoustic conversion formula and modulus, the characters and deformation modulus of rock mass were determined in relaxation and non-relaxation situation.(7) The rock mass quality of foundation has been classified by several indexes which included rock mass structure, integrity factor, velocity ratio and modulus. And compared the resaults between the before and after excavation.(8) The results were given which included rock mass characteristics and the stress range after the rock excavation and the total displacement, maximum principal stress, intermediate principal stress and shear stress distribution in the normal engineering loads by three-dimensional numerical simulation analysis.更多还原