Abstract To address the problem of muck-induced blockage in the construction of vertical shafts through the raiseboring method, this paper uses the 3D discrete element simulation method to simulate the muck-dropping process in vertical shafts and pilot shafts. The results show that when the muck diameter is larger than 0.2 m, it is easy for the muck to block the shaft (v=0), and when the muck diameter is smaller than 0.2 m, the muck above the pilot shaft can be smoothly discharged to the pilot shaft, with part of the muck accumulated at the bottom of the shaft. Also, if the diameter of the pilot shaft increases from 1.5 m to 3 m, it can effectively expand the arching range of the muck in the shaft, speed up the muck-dropping speed in the shaft, reduce the probability of arching and blockage (v≈0), and improve the muck falling rate, while the pilot shaft encounters muck blockages several times, reducing the muck falling rate. When the muck size is larger than 0.3 m, it is easy for the muck to cause the blockage of the pilot shaft if the shaft diameter is 1.5 m. In a long pilot shaft, large-size muck with higher velocity will still block the pilot shaft under the arching effect.
Abstract：
To address the problem of muck-induced blockage in the construction of vertical shafts through the raiseboring method, this paper uses the 3D discrete element simulation method to simulate the muck-dropping process in vertical shafts and pilot shafts. The results show that when the muck diameter is larger than 0.2 m, it is easy for the muck to block the shaft (v=0), and when the muck diameter is smaller than 0.2 m, the muck above the pilot shaft can be smoothly discharged to the pilot shaft, with part of the muck accumulated at the bottom of the shaft. Also, if the diameter of the pilot shaft increases from 1.5 m to 3 m, it can effectively expand the arching range of the muck in the shaft, speed up the muck-dropping speed in the shaft, reduce the probability of arching and blockage (v≈0), and improve the muck falling rate, while the pilot shaft encounters muck blockages several times, reducing the muck falling rate. When the muck size is larger than 0.3 m, it is easy for the muck to cause the blockage of the pilot shaft if the shaft diameter is 1.5 m. In a long pilot shaft, large-size muck with higher velocity will still block the pilot shaft under the arching effect.
LI Yao1 DONG Xing1 CAO Xiaoyong2 XU Ping2
.A Study on Control Size of Blast Muck for Vertical Shaft Construction Using the Raise-boring Method[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(2): 194-202
2023, Vol. 60 