The high slope of the permanent shiploek of the Three Gorges Project (TGP), excavated on the left bank of the mountain body, is one of the major technical issues of the Project construction. The excavation of the slope on each side 170m in depth had maximum consisting of a 68m high vertical wall on its lower part. Several aspects of the permanent shiplock slope are described in the paper including the general description, design principles and outline, construction procedures, seepage prevention and drainage system, consolidation and support measures, stability analysis, deformation prediction. monitoring data verification as well as some significantSCientific and technical achievements.
The two-way five-step continuous permanent shiplock is one of the major structures of the Three Gorges Project. Thanks to its unique structural requirements, the shiplock was cut deeply on the North side of the Tanziling Hill in the granite mountain body, the highest on the left bank of the dam-site was a double way with high rock slope of maximum 170 in depth with its lower vertical Wall of 68m. A high vertical rock pier with section of 57 X 68m was remained in the middle between the two chamber channels. The three longitudinal conveyance tunnels needed for the permanent shiplock structure passing through the chamber sections and the 36 shafts excavated on both sides of each lock head were constructed in the side slopes and in the central pier. The venlcal wall was a concrete liner structure, 1. 5–2.4m in thickness with high strength anchor bolts. The characteristics and difficulties of the permanent shiplock slope having been concerned by domestic and foreign specialists and scholars, are quite different from others, mainly they are: a. a steep high slope, deeply cut in the mountain body. It is huge In height, complex in form and structure, extending in a large range. and the stress was fully released, indicating distinct behavior of unloading and non-homogeneity. b. strict requirements for slope stability, especially for deformation property. The Yangtze is the golden waterway in china, the slope of the permanent shiplock, shall ensure the stability both integral and local, at the same time, the rheology of slope must be strictly controlled so as to meet the normal operation of the miter gates of the shiploek. e. difficult in construction a lot of disturbance and limited ConStruction time. The shiplock works had high intensity ofconstruction on surface and the excavation of the vertical wall ~vas very difficult in the narrow, deep and steep chamber ~n~ennore. it was operated simultaneously with the excavation o A c underground tunnels and shafts. Therefore, how to solve the br uenee of excavation blasting, minimize the damage of the rockbody and ensure construction safety were the difficult issues to be dealt With.Impact of rock slope displacement on the operation state of large miter gates.
