Cutting Wheel Structure Selection of EPB TBM and Its Adaptability Evaluation in Large Particle Size Gravel Strata

Large particle size gravel strata layer is very difficult for TBM construction which brings about a series of problems for EPB TBM advancing in Beijing Metro. Cutting wheel is an important component of EPB TBM and cutting wheel with reasonable structure is essential for EPB TBM to advance steadily and effectively in large particle size gravel strata. In-situ EPB TBM advancing tests are carried out in large two adjacent shield interval where the strata conditions make it possible to find out the most efficient cutting wheel structure by monitoring key parameters through Real-time Information Management System. Based on the analysis and comparison of advancing efficiency, strata adaptability of key parameters and tools wearing, the following conclusions can be obtained: 1) Spoke cutting wheel has better strata adaptability and higher efficiency than panel cutting wheel as well as more advantages in controlling tools wearing. 2) open ratio ranging from 55% to 65% is the reasonable for cutting wheel. 3) Advancing speed and earth pressure are very important for EPB TBM construction. Compared with panel cutting wheel, spoke cutting wheel can obtained higher advancing speed and more stable earth pressure in tests. However the change of earth pressure should also be paid attention when EPB TBM advancing in fast speed. The advancing speed should be controlled in the range of 20 to 60 mm/min.

Cutting Wheel Structure Selection of EPB TBM and Its Adaptability Evaluation in Large Particle Size Gravel Strata

Large particle size gravel strata layer is very difficult for TBM construction which brings about a series of problems for EPB TBM advancing in Beijing Metro. Cutting wheel is an important component of EPB TBM and cutting wheel with reasonable structure is essential for EPB TBM to advance steadily and effectively in large particle size gravel strata. In-situ EPB TBM advancing tests are carried out in large two adjacent shield interval where the strata conditions make it possible to find out the most efficient cutting wheel structure by monitoring key parameters through Real-time Information Management System. Based on the analysis and comparison of advancing efficiency, strata adaptability of key parameters and tools wearing, the following conclusions can be obtained: 1) Spoke cutting wheel has better strata adaptability and higher efficiency than panel cutting wheel as well as more advantages in controlling tools wearing. 2) open ratio ranging from 55% to 65% is the reasonable for cutting wheel. 3) Advancing speed and earth pressure are very important for EPB TBM construction. Compared with panel cutting wheel, spoke cutting wheel can obtained higher advancing speed and more stable earth pressure in tests. However the change of earth pressure should also be paid attention when EPB TBM advancing in fast speed. The advancing speed should be controlled in the range of 20 to 60 mm/min.