Volume Loss During the TBM Construction of Metro Line 1, Ho Chi Minh City, Monitoring Data Assessment and New Analytical Model for Prediction

During the TBM construction, volume loss occurs and should be well controlled. This is considered the most critical tunneling factor affecting the movement and ground surface settlement. The empirical method with analytical equations or numerical methods is based essentially on that factor for evaluating the surface settlement trough. This factor, however, depends on different TBM parameters and operation experiences and is sometimes difficult to estimate accurately. Through an assessment of the monitoring data acquired during the construction of metro line 1, Ben Thanh—Suoi Tien of Ho Chi Minh City, this paper proposes an analytical equation for evaluating the volume loss factor based on some basic TBM parameters. A good correlation between the calculation results using this new equation and the in situ monitoring data proves the efficiency of the mathematical model for future prediction in Ho Chi Minh City for example.