Abstract In order to study the influence of shield cabin opening at ordinary pressure on the structural deformation of the existing line when the slurry balance shield is under-passing the existing subway tunnel in the full-section weathered mudstone layer, the shield tunnel of Guangzhou Metro Line 14 underpassing the existing Line 3 subway tunnel is taken as a study case. The fluid-solid coupling calculation is carried out using the finite difference analysis software (FLAC 3D), and on-site monitoring data are combined to study the influence of underpassing process and shield cabin opening at atmospheric pressure on the deformation of existing line structures. The results indicate that the slurry balance shield is prone to the problem of mud cake forming on the cutterhead during tunneling in the full-section mudstone strata. Based on the simulation, both settlement and section deformation of the existing line,which are caused by shield cabin opening at ordinary pressure and cleaning of mud cakes after tunneling every day as per the construction plan, meet the control requirements. In actual construction, the method of shield cabin opening at ordinary pressure for cleaning mud cakes after daily tunneling has increased the average advancing speed by 41% compared to the method of continuously tunneling for multiple days and then cleaning mud cakes, greatly shortening the construction period. The shield cabin opening method at ordinary pressure can be used in the full-section weathered mudstone, and the settlement of the existing line structure caused by shield cabin opening process can be controlled at around -5 mm.
Abstract：
In order to study the influence of shield cabin opening at ordinary pressure on the structural deformation of the existing line when the slurry balance shield is under-passing the existing subway tunnel in the full-section weathered mudstone layer, the shield tunnel of Guangzhou Metro Line 14 underpassing the existing Line 3 subway tunnel is taken as a study case. The fluid-solid coupling calculation is carried out using the finite difference analysis software (FLAC 3D), and on-site monitoring data are combined to study the influence of underpassing process and shield cabin opening at atmospheric pressure on the deformation of existing line structures. The results indicate that the slurry balance shield is prone to the problem of mud cake forming on the cutterhead during tunneling in the full-section mudstone strata. Based on the simulation, both settlement and section deformation of the existing line,which are caused by shield cabin opening at ordinary pressure and cleaning of mud cakes after tunneling every day as per the construction plan, meet the control requirements. In actual construction, the method of shield cabin opening at ordinary pressure for cleaning mud cakes after daily tunneling has increased the average advancing speed by 41% compared to the method of continuously tunneling for multiple days and then cleaning mud cakes, greatly shortening the construction period. The shield cabin opening method at ordinary pressure can be used in the full-section weathered mudstone, and the settlement of the existing line structure caused by shield cabin opening process can be controlled at around -5 mm.
ZHOU Zhou1 ZHONG Changping2 XIE Wenda1
.Study on Influence of Shield Cabin Opening at Ordinary Pressure on Deformation of Existing Tunnel Structures in Mudstone Strata[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(5): 205-212
2023, Vol. 60 