Tunnel Mechanical Behavior Under Action of Novel Inflatable Compression Layer
In view of the large deformation disaster of surrounding rock that is prone to occur when a tunnel passes through complex geological environments,and considering the limitations of existing compressible layer support structures,the novel inflatable compression layer structure is proposed to effectively absorb the surrounding rock deformation energy and fully adjust the rock pressure distribution,as well as uniformly transmit the rock pressure to the lining structure.This support structure decouples the surrounding rock deformation from the lining deformation,preventing the excessive deformation of surrounding rock that may lead to the damage to lining structure.Considering the combined supports with inflatable compression layer and lining under the action of both high ground stress and low ground stress,the analytical solutions for tunnel stress field and displacement field were derived based on the elasticity theory.The result indicates that under low ground stress,the surrounding rock deformation increases with the thickness of inflatable compression layer,while the lining deformation and equilibrium pressure decrease with thickness increasing.This trend becomes more moderate as the inflatable compression layer thickness increasing.Under high ground stress,the support resistance and lining deformation are controlled by the equilibrium pressure,and are not related to the inflatable compression layer thickness.When the ground stress is low,the inflatable compression layer plays a role in increasing deformation resistance,and the initial pressure becomes the tunnel deformation controlling factor.The surrounding rock deformation increases with the ratio of ground stress to initial pressure,while the lining deformation and equilibrium pressure decrease with the ratio increasing.When the ground stress is high,the inflatable compression layer exhibits a role of increasing resistance and constant resistance to deformation,and the preset pressure becomes the tunnel deformation controlling factor.The surrounding rock deformation increases with the ratio of ground stress to preset pressure,while the lining deformation decreases with the ratio increasing.The proposed structure can be well adapted to different geological conditions,and provide the valuable insights for supporting tunnels with large deformations under high ground stress and low-carbon support approaches.
tunnel engineeringnovel support designtheoretical derivationparametric analysisinflatable compression layer
NETL
NSTL
万方数据
