Traditional submarine tunnels with drainage systems are highly susceptible to water leakage,which is challenging to locate and manage,leading to high maintenance costs.To address this problem,a new controlled drainage...Traditional submarine tunnels with drainage systems are highly susceptible to water leakage,which is challenging to locate and manage,leading to high maintenance costs.To address this problem,a new controlled drainage system for submarine tunnels was proposed in this study.The system utilizes a double-adhesive waterproof membrane instead of traditional waterproof sheets,which not only reduces the likelihood of leakage but also makes subsequent leak detection and repair easier.In addition,replacing blind pipes with drainage sheets significantly improves the clogging resistance of the drainage system.The influence of grouting circles and drainage sheets on the water inflow and the external water pressure on the lining was then analyzed using numerical calculation methods.Finally,the design process of the new controlled drainage system was proposed.The research suggests that the new system allows for a multi-stage control method using grouting circles and drainage sheets,providing greater design flexibility.In the primary control stage,grouting circles effectively reduce the tunnel water inflow and the external water pressure on the lining,with the permeability coefficient playing a crucial role.In the secondary control stage,the spacing and width of the drainage sheets can regulate the water inflow and pressure.Unlike grouting circles,drainage sheets decrease water pressure while inevitably increasing water inflow,and vice versa.These findings can serve as a valuable reference for the design of waterproof and drainage systems in submarine tunnels.展开更多
Double-bonded spray membrane waterproofing materials have excellent waterproofing performance and can improve the load-bearing capacity of tunnel linings,leading to an increasing global application.However,due to the ...Double-bonded spray membrane waterproofing materials have excellent waterproofing performance and can improve the load-bearing capacity of tunnel linings,leading to an increasing global application.However,due to the double-bonded capability of spray membrane materials,traditional interlayer drainage methods cannot be applied.This limitation makes it difficult to use them in drainage-type tunnels,significantly restricting their range of applications.In this regard,a novel tunnel waterproof-drainage system based on double-bonded spray membrane materials was proposed in this paper.The proposed drainage system primarily comprises upper drainage sheets and bottom drainage blind pipes,both located in the tunnel circumferential direction,as well as longitudinal drainage pipes within the tunnel.Subsequently,numerical calculation methods are employed to analyze the seepage characteristics of this system,revealing the water pressure distribution around the tunnel.The results indicate that in the novel waterproof-drainage system,the water pressure in the secondary lining exhibits a“mushroom-shaped”distribution in the circumferential direction,while the water pressure in the longitudinal direction exhibits a“wave-like”distribution.Furthermore,comparative results with other waterproof-drainage systems indicate that under typical working conditions with a water head of 160 m and a rock permeability coefficient of 10^(−6)m/s,the maximum water pressure in the secondary lining of the novel waterproof-drainage system is 0.6 MPa.This represents a significant reduction compared to fully encapsulated waterproofing and traditional drainage systems,which respectively reduce the water pressure by 65%and 30%.The applicability analysis of the double-bonded waterproofing and drainage system reveals that it can reduce at least 40%of the static water pressure in any groundwater environments.The novel drainage system provides a valuable reference for the application of double-bonded spray membrane waterproofing materials in drainage-type tunnels.展开更多
Spray-applied membranes for waterproofing of sprayed concrete tunnels have led to the possibility of shear transfer between primary and secondary linings through the membrane interface,with the potential for reducing o...Spray-applied membranes for waterproofing of sprayed concrete tunnels have led to the possibility of shear transfer between primary and secondary linings through the membrane interface,with the potential for reducing overall lining thickness.Laboratory tests have shown a reasonable degree of composite action in beam specimens.In this study,a numerical model previously calibrated against such tests is applied to a whole tunnel,considering soil–structure interaction and staged lining construction.The model shows composite action,and load sharing between the lining layers is expected in the tunnel as in the beams.Parametric studies over the practical range of interface stiffness values show that composite action is maintained,although at high interface stiffness,excessive bending may be imposed on the secondary lining,requiring additional reinforcement.An effcient composite shell design with minimal additional rein-forcement is achievable if the secondary lining thickness is reduced as compared to current practice.Robustness of the system,measured in terms of the interface’s ability to transfer stress under unequal loading causing distortion on the tunnel,is found to be generally ade-quate.However,adjacent construction in close proximity may provide insuffcient margin on membrane tensile de-bonding,particularly if the membrane is partially or fully saturated.展开更多
基金supported by the Fundamental Research Funds for the Central Universities of Central South University(No.2023ZZTS0183)the Fundamental Research Funds for the Central Universities(No.502802002).
文摘Traditional submarine tunnels with drainage systems are highly susceptible to water leakage,which is challenging to locate and manage,leading to high maintenance costs.To address this problem,a new controlled drainage system for submarine tunnels was proposed in this study.The system utilizes a double-adhesive waterproof membrane instead of traditional waterproof sheets,which not only reduces the likelihood of leakage but also makes subsequent leak detection and repair easier.In addition,replacing blind pipes with drainage sheets significantly improves the clogging resistance of the drainage system.The influence of grouting circles and drainage sheets on the water inflow and the external water pressure on the lining was then analyzed using numerical calculation methods.Finally,the design process of the new controlled drainage system was proposed.The research suggests that the new system allows for a multi-stage control method using grouting circles and drainage sheets,providing greater design flexibility.In the primary control stage,grouting circles effectively reduce the tunnel water inflow and the external water pressure on the lining,with the permeability coefficient playing a crucial role.In the secondary control stage,the spacing and width of the drainage sheets can regulate the water inflow and pressure.Unlike grouting circles,drainage sheets decrease water pressure while inevitably increasing water inflow,and vice versa.These findings can serve as a valuable reference for the design of waterproof and drainage systems in submarine tunnels.
基金supported by the Fundamental Research Funds for the Central Universities of Central South University(No.2023ZZTS0183)the Fundamental Research Funds for the Central Universities(No.502802002).
文摘Double-bonded spray membrane waterproofing materials have excellent waterproofing performance and can improve the load-bearing capacity of tunnel linings,leading to an increasing global application.However,due to the double-bonded capability of spray membrane materials,traditional interlayer drainage methods cannot be applied.This limitation makes it difficult to use them in drainage-type tunnels,significantly restricting their range of applications.In this regard,a novel tunnel waterproof-drainage system based on double-bonded spray membrane materials was proposed in this paper.The proposed drainage system primarily comprises upper drainage sheets and bottom drainage blind pipes,both located in the tunnel circumferential direction,as well as longitudinal drainage pipes within the tunnel.Subsequently,numerical calculation methods are employed to analyze the seepage characteristics of this system,revealing the water pressure distribution around the tunnel.The results indicate that in the novel waterproof-drainage system,the water pressure in the secondary lining exhibits a“mushroom-shaped”distribution in the circumferential direction,while the water pressure in the longitudinal direction exhibits a“wave-like”distribution.Furthermore,comparative results with other waterproof-drainage systems indicate that under typical working conditions with a water head of 160 m and a rock permeability coefficient of 10^(−6)m/s,the maximum water pressure in the secondary lining of the novel waterproof-drainage system is 0.6 MPa.This represents a significant reduction compared to fully encapsulated waterproofing and traditional drainage systems,which respectively reduce the water pressure by 65%and 30%.The applicability analysis of the double-bonded waterproofing and drainage system reveals that it can reduce at least 40%of the static water pressure in any groundwater environments.The novel drainage system provides a valuable reference for the application of double-bonded spray membrane waterproofing materials in drainage-type tunnels.
文摘Spray-applied membranes for waterproofing of sprayed concrete tunnels have led to the possibility of shear transfer between primary and secondary linings through the membrane interface,with the potential for reducing overall lining thickness.Laboratory tests have shown a reasonable degree of composite action in beam specimens.In this study,a numerical model previously calibrated against such tests is applied to a whole tunnel,considering soil–structure interaction and staged lining construction.The model shows composite action,and load sharing between the lining layers is expected in the tunnel as in the beams.Parametric studies over the practical range of interface stiffness values show that composite action is maintained,although at high interface stiffness,excessive bending may be imposed on the secondary lining,requiring additional reinforcement.An effcient composite shell design with minimal additional rein-forcement is achievable if the secondary lining thickness is reduced as compared to current practice.Robustness of the system,measured in terms of the interface’s ability to transfer stress under unequal loading causing distortion on the tunnel,is found to be generally ade-quate.However,adjacent construction in close proximity may provide insuffcient margin on membrane tensile de-bonding,particularly if the membrane is partially or fully saturated.
