Reported from our correspondents, on December 22, the 1st coal mine inclined shaft constructed by the tunnel boring machine (TBM) designed by SIYUAN--No. 2 Auxiliary Shaft of Bulianta Coal Mine of Shendong Shenhua Group was successfully cut through, which has not only opened a new chapter for the construction mode of coal mine inclined shaft, but also had great significance for the promotion of exploitation of deep coal resources. Mr. Xia Guobin, Vice President of China Railway Construction Corporation, Mr. Jing Shan, Vice President of China Railway SIYUAN Survey and Design Group Co., Ltd. and other managing staff from Shenhua Group and relevant organizations attended the breakthrough ceremony.
This Project is the general contracted design and
construction project on the joint bidding of SIYUAN and China Railway No. 11
Bureau Group. Since the formal driving of the inclined shaft project on June
11, 2015, it has set the world record of the highest drill footage at 639m per
month and made the achievement of a monthly average drill footage over 500m for
four consecutive months. It took only half a year to cut through the No. 2 Auxiliary
Shaft of Bulianta Coal Mine of Shendong, with the total length of 2,733m.
Mr. You Longfei, Design Principal of SIYUAN Project Team for Bulianta Coal Mine of Shendong Project, introduced that there had been a number of difficulties during the design of this project, especially the treatment of large deformation of soft rocks and groundwater discharge, which had been the greatest difficulties among the difficulties.
It was the first time that TBM has been used for the construction of a coal mine inclined shaft nationwide. It is fearless of hard rock but deforms largely in case of soft rock, since TBM driving equipment would get stuck by the caverns after deformation. Just like the a mouse digging holes underground, the holes will become smaller as advancing and the mouse will get stuck in the hole, neither advance nor retreat. The soft rock distributes widely in coal measure strata, so it has become a big difficulty for the design to overcome the impact to TBM equipment brought by the deformation of soft rock.
The lining of a coal mine inclined shaft is different from the TBM lining structure of railway tunnel or large diversion works. The latter adopts the comprehensive diversion for the underground water, while the former is limited diversion. This has brought challenges for the design, which on one hand needs waterproof lining structure, and on the other hand, it should have certain drainage capacity, just like making shoes, which should be waterproof while ventilated, having it both ways.
Centered on the above design difficulties, SIYUAN has played its role as the technical leader and undertaken three subject researches including science and technology supporting projects of National 12thFive-Year Plan Key Technology Study of Coal Mine Long Distance Inclined Shaft Under Shield Construction, on which it focuses on the research, development and mastering of a set of shield construction technology of coal mine inclined shaft with long distance, large slope, great depth and complex strata. The applications for national patent of some key technologies have already been approved.
It is believed that, the monthly drill footage of traditional construction method of coal mine inclined shafts is about 100m. If this project adopts such traditional construction method, it will take at least 28 months, while TBM driving method will take only 6 months and 11 days, consuming only a quarter of the time which the traditional method will take.
Mr. Yang Rongming, Managing Director of China Shenhua Shendong Coal Group Corporation Limited, introduced that the inclined shaft exploitation will be the main shaft construction mode for hundred million tonnes of coal mine areas, as well as the development trend of coal mine engineering in large deep coal measure strata. Applying TBM method in the coal mine shaft construction field will have great significance for the promotion of safety, superior and efficient construction of long distance inclined shafts.
Mr. Xia Guobin, Vice President of China Railway Construction Corporation delivering a speech
Mr. You Longfei, Design Principal of SIYUAN Project Team for Bulianta Coal Mine of Shendong Project briefed the features and difficulties of this project to Vice President of SIYUAN, Mr. Jing Shan.
Mr. Qin Wenjun, Deputy General Manager of Engineering Management Department of Shenhua Group is presenting the medal to SIYUAN
Mr. You Longfei, Design Principal of SIYUAN Project Team for Bulianta Coal Mine of Shendong Project is exchanging the design experience with field test personnel Ms. Yao Jie in the inclined shaft.