基于孔内摄像的湘江长沙综合枢纽坝基岩体结构面判译与验证

坝基勘察期间，难以直接观测到坝基岩体中的结构面特征．通过在勘探孔中进行孔内摄像，能观测到孔壁各类裂隙面的特征．基坑开挖后，对揭露的岩体结构面进行编录统计．将两种方法获得的成果进行比较，验证了孔内摄像成果能较好地反映坝基岩体结构面特征．工程实例证明：孔内摄像可用于解决勘察期间坝基岩体结构面勘探这一难题，具有高效、直观、可靠的特点．通过孔内摄像，容易发现基坑中出露少的缓倾不利结构面．使用孔内摄像勘探坝基岩体结构面特征时，应注意“一孔之见”的局限性及岩体结构面在空间上的不均匀性．勘探时，一方面要保证有合适的孔内摄像点数量，另一方面要及时分析孔内摄像成果，判断岩体结构面的变化规律．

Using borehole camera to survey rock mass discontinuity of dam foundation in Changsha navigation-power junction

During surveying,it is difficult to directly observe rock mass discontinuity of dam foundation. However, using borehole camera can survey rock mass discontinuity of dam foundation. During the foundation pit excavation, we can directly observe rock mass discontinuity of dam foundation. By comparison, borehole camera surveying and ob serving directly show consistent results. Attested by the project, borehole camera can be applied to survey rock mass discontinuity of dam foundation, the method has advantages of visibility and high efficiency and credulity. We can survey gently dipping rock mass discontinuities which is difficult to be observed in the dam pit. Because a borehole has the limitation and rock mass discontinuities distribute non-uniformly in the space, there must have adequate boreholes. On the other hand,we must analyze borehole camera re- sult on time.