Abstract The control of the pressure balance between the fillers in the steel sleeve and the ground is the key to en? suring the project's safety during receiving the shield with the steel sleeve in subway tunnelling. To realize the active regulation of the filling pressure in the steel sleeve, this study improves the fixed cover of a conventional steel sleeve to a piston cover that can slide freely along the longitudinal direction of the sleeve, and puts forward the corresponding methods for hydraulic pressure regulation and mechanical pressure regulation. The steel sleeve model is designed according to the 1∶5 ratio, and model tests are carried out for different working conditions, such as water injection with pressure increase, water release with pressure decrease, mechanical pressure increase under low levels of internal pressure, mechanical pressure increase and decrease under high levels of internal pressure, so as to study the variation pattern and influence mechanism of the filling pressure with the external hydraulic pressure and mechanical thrust, as well as the variation pattern of the jack counterforce and steel sleeve deformation. The results show that the filling pressure inside the steel sleeve varies linearly and proportionally to the external hydraulic pressure during hydraulic pressure regulation. Specifically, the increase of the mechanical pressure at lower filling pressures (≤0.15 MPa) shows multi-segment characteristics where the filling pressure changes to the variations in the jack pressure, while under the condition of high filling pressure (>0.15 MPa), the filling pressure varies steadily with the regulation process of the mechanical pressure. Both methods can achieve controlled active regulation of the filling pressure in the steel sleeve, and shall be chosen flexibly according to the characteristics of the regulation method,the construction ability, and the regulation's technical requirements.
Abstract：
The control of the pressure balance between the fillers in the steel sleeve and the ground is the key to en? suring the project's safety during receiving the shield with the steel sleeve in subway tunnelling. To realize the active regulation of the filling pressure in the steel sleeve, this study improves the fixed cover of a conventional steel sleeve to a piston cover that can slide freely along the longitudinal direction of the sleeve, and puts forward the corresponding methods for hydraulic pressure regulation and mechanical pressure regulation. The steel sleeve model is designed according to the 1∶5 ratio, and model tests are carried out for different working conditions, such as water injection with pressure increase, water release with pressure decrease, mechanical pressure increase under low levels of internal pressure, mechanical pressure increase and decrease under high levels of internal pressure, so as to study the variation pattern and influence mechanism of the filling pressure with the external hydraulic pressure and mechanical thrust, as well as the variation pattern of the jack counterforce and steel sleeve deformation. The results show that the filling pressure inside the steel sleeve varies linearly and proportionally to the external hydraulic pressure during hydraulic pressure regulation. Specifically, the increase of the mechanical pressure at lower filling pressures (≤0.15 MPa) shows multi-segment characteristics where the filling pressure changes to the variations in the jack pressure, while under the condition of high filling pressure (>0.15 MPa), the filling pressure varies steadily with the regulation process of the mechanical pressure. Both methods can achieve controlled active regulation of the filling pressure in the steel sleeve, and shall be chosen flexibly according to the characteristics of the regulation method,the construction ability, and the regulation's technical requirements.
YUAN Jie1 QI Jiarui2 XIAO Xiang1 LI Zanxin1 YU Lixin1 PAN Yiheng2
.An Experimental Study on the Active Regulation of Filling Pressure in Shield Receiving Steel Sleeve[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(2): 230-237
2023, Vol. 60 