Disease Mechanism and Treatment Measures of Tunnel with Developed Joint Fissure Containing Weak Mudstone Interlayer
The development of fissure and the existence of weak interlayer in surrounding rock will significantly affect the stress characteristics of tunnel lining structure,resulting in different degrees of tunnel diseases.In view of the diseases such as lining cracking and pavement subsidence of a highway tunnel under complex geological conditions,in-depth analysis of the disease mechanism is carried out and comprehensive treatment measures to address the damage is proposed through the combination of field detection,laboratory test and numerical simulation.Finally,long-term monitoring and evaluation of the mechanical behavior of structure after treatment are conducted.The research shows that the sur-rounding rock of the diseased section is broken,fissures are developed,and there is a huge thick mudstone weak interlayer.Meanwhile,the supporting structure construction has serious defects.The combination of two unfavorable factors leads to the significant stress concentration of supporting struc-ture of the weak interlayer part,and there is a tensile stress that exceeds the tensile bearing capacity of concrete,which causes concrete cracking and further induces tunnel disease generation.