Geology Prediction Of Unstable Rock Blocks Based On A Close Range Photogrammetry In Excavating Tunnel

As a new measure technique for rock joints, the close-range photogrammetry has been attended in the field of geology and rock mass engineering, which is characterized with a fast measuring speed, a negligible influencing field and a not-touching measuring way. The following research will be unfolded to predict the instable blocks growth by utilizing it with excavating surface going ahead continuously.The paper analyzed the spatial distribution of joint trace and the intersection of the different excavating surfaces by getting joint orientation, at the same time, it produced a calculation method of joint orientation according to the geometrical relationship. The paper simulated the tunnel excavation by applying the random network simulation theory and confirmed the join position, forming and orientation of every surface. Lastly, based on block theory, the paper got a progress in research by predicting and analyzing the segmental blocks.The main results of the paper:1. The paper produced a calculation method on the close-range photogrammetry measuring joints orientation in excavating tunnel based on space analytic geometry according to the joint information of every excavating surface and overcame the difficulty that 3-D joint trace can't be seen only from one image.2. According to the random network simulation theory, the paper simulated 3-D joint rock and validated theoretically the feasibility and applicability of the calculation method in excavating tunnel.3. The paper forecasted fractional blocks of neighbor excavating surface and analyzed their stability after obtaining joint orientation by applying block theory.