Abstract The rapid discharge of rock mucks from the air cushion chamber of a slurry balance shield machine is crucial for ensuring construction safety and improving tunneling efficiency. To explore the impact of different slurry and rock muck characteristics on rock muck discharge, a numerical calculation model that can fully reflect the discharge of rock mucks form the air cushion chamber was established based on the CFD-DEM coupling method and actual project. The study investigates the discharge patterns of rock mucks with varying bentonite content in the slurry,rock muck diameter (d), and shape factor (Sf), and analyzes the degrees of influence of these factors. The results show that as the bentonite content in the slurry increases from 8% to 16%, the rock muck discharge rate increases from 10.0% to 21.9%. Larger diameter rock mucks are more difficult to discharge; as the diameter increases from20 mm to 40 mm, the discharge rate decreases from 14.4% to 7.9%, attributed to the higher slurry flow velocity required to start movement of larger rock mucks. The rolling tendency of rock mucks decreases as the shape factor decreases, thus rock mucks with smaller shape factors cannot be directly discharged by rolling mode. When the shape factor decreases from 1 to 0.6, the discharge rate drops by about 59.5%. The research results can provide guidance for assessing the discharge efficiency of rock mucks during slurry shield construction.
Abstract：
The rapid discharge of rock mucks from the air cushion chamber of a slurry balance shield machine is crucial for ensuring construction safety and improving tunneling efficiency. To explore the impact of different slurry and rock muck characteristics on rock muck discharge, a numerical calculation model that can fully reflect the discharge of rock mucks form the air cushion chamber was established based on the CFD-DEM coupling method and actual project. The study investigates the discharge patterns of rock mucks with varying bentonite content in the slurry,rock muck diameter (d), and shape factor (Sf), and analyzes the degrees of influence of these factors. The results show that as the bentonite content in the slurry increases from 8% to 16%, the rock muck discharge rate increases from 10.0% to 21.9%. Larger diameter rock mucks are more difficult to discharge; as the diameter increases from20 mm to 40 mm, the discharge rate decreases from 14.4% to 7.9%, attributed to the higher slurry flow velocity required to start movement of larger rock mucks. The rolling tendency of rock mucks decreases as the shape factor decreases, thus rock mucks with smaller shape factors cannot be directly discharged by rolling mode. When the shape factor decreases from 1 to 0.6, the discharge rate drops by about 59.5%. The research results can provide guidance for assessing the discharge efficiency of rock mucks during slurry shield construction.
YU Wenduan1 DING Wantao2 WANG Chengzhen1 SUN Tengyun1 GUO Chentao1 WANG Zhicheng1
.Study on the Influence of Slurry and Rock Muck Characteristics on Rock Muck Discharge from the Air Cushion Chamber of Slurry Balance Shield Machine[J] MODERN TUNNELLING TECHNOLOGY, 2024,V61(4): 192-201
2024, Vol. 61 