Investigation into the Large Deformation Mechanism and Control Technology of Variable Cross-Section Tunnel in Layered Mudstone Stratum

Buildings (structures) with various structural forms are becoming increasingly prevalent and encountering more challenging engineering issues. Field investigations, laboratory tests, numerical simulations were used to study the disaster-causing mechanism control technology for a variable cross-section tunnel passing through layered, expansive mudstone stratum. The deformation stress characteristics of surrounding rock supporting structure examined by both simulation field monitoring. results indicated that was complex at different section positions; underwent substantially in broadened sections. mean values rock’s horizontal convergence vault settlement 15.71% 16.36% higher than those general section, respectively, value lining 35.51% higher. Additionally, under improved construction measures matched measured results. maximum reduced 16.95% 40.04%, scheme, while 45.38%. state secondary significantly improved; particular, tensile original scheme converted into compressive new measures, fully utilizing bearing effect. Finally, rationality effectiveness adopted reinforcement evaluated, experiences lessons learned summarized provide insights preventing similar incidents from reoccurring.