Abstract In this study, based on the Dayuan Station - Taihe Station project of the East Ring Tunnel of the Guangfo Ring Line, field test of internal forces on the shield tunnel structure at great depth is performed to explore the change law of the internal forces on the segments during different phases of actual construction. By combining with numerical simulation, a comparative study is conducted on the error between the on-site measured values and simulated values of internal forces on the segments, and the main areas of segments where the internal forces are influenced by construction factors and the related causes are analyzed. The results show that during shield tunnelling, the maximum internal force of the segment occurs during the filling phase behind the wall after the detachment of 4-8 lining rings,and the minimum value occurs during the completion phase of segment assembly. After the detachment of 12 lining rings at the shield tail, the forces on the segment become basically stable. The measured values of internal forces in the segment are greater than the simulated values, and the distribution laws of measured and simulated bending moments are similar. There are certain differences in the distribution of their axial forces, and filling with bean gravel can make the actual axial force more evenly distributed along the circumferential direction. The maximum relative error between the measured value and the simulated value is about 40%, which occurs in the tunnel crown and bottom areas, while the relative error at the arch waist is relatively small. In construction of shield tunnel at great depth,main influencing factors on internal forces of the segment in filling behind the wall and during stabilization phase are filling of bean gravel and creep of surrounding rock.
Abstract：
In this study, based on the Dayuan Station - Taihe Station project of the East Ring Tunnel of the Guangfo Ring Line, field test of internal forces on the shield tunnel structure at great depth is performed to explore the change law of the internal forces on the segments during different phases of actual construction. By combining with numerical simulation, a comparative study is conducted on the error between the on-site measured values and simulated values of internal forces on the segments, and the main areas of segments where the internal forces are influenced by construction factors and the related causes are analyzed. The results show that during shield tunnelling, the maximum internal force of the segment occurs during the filling phase behind the wall after the detachment of 4-8 lining rings,and the minimum value occurs during the completion phase of segment assembly. After the detachment of 12 lining rings at the shield tail, the forces on the segment become basically stable. The measured values of internal forces in the segment are greater than the simulated values, and the distribution laws of measured and simulated bending moments are similar. There are certain differences in the distribution of their axial forces, and filling with bean gravel can make the actual axial force more evenly distributed along the circumferential direction. The maximum relative error between the measured value and the simulated value is about 40%, which occurs in the tunnel crown and bottom areas, while the relative error at the arch waist is relatively small. In construction of shield tunnel at great depth,main influencing factors on internal forces of the segment in filling behind the wall and during stabilization phase are filling of bean gravel and creep of surrounding rock.
CHEN Long FENG Kun WU Baihan GUO Fukang WANG Wei
.Field Measurement and Analysis of Forces on Shield Tunnel Structure at Great Depth[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(5): 148-157
2023, Vol. 60 