On August 11, with the slow move of cutter head, Yongning, China's first large dip angle (at least 39 degrees) inclined shaft TBM (CREC 1158) jointly developed by State Grid Xin Yuan Company Limited, Sinohydro Bureau 6 Co., Ltd. and China Railway Engineering Equipment Group Co., Ltd. (CREG) under CRHIC passed acceptance in Zhengzhou, Henan Province.
The inclined shaft TBM 'Yongning' has an excavation diameter of 7.23m. The No. 1 and No. 2 diversion inclined shafts used for construction are 927m and 873m respectively, with dip angle being 36.236°and 38.742°separately. The route to be excavated has a buried depth of 184-684m, mainly comprises Class II and III wall rocks such as moderately weathered fresh porphyritic granite, and crosses two fault fracture zones.