Study on TBM Jamming Problems in Jurassic and Cretaceous Argillaceous Sandstone Strata in Northern Xinjiang

In order to study the TBM jamming issues in the Jurassic and Cretaceous argillaceous sandstone strata in northern Xinjiang, rock mechanical and rheological tests were conducted to obtain relevant physical and mechanical parameters, followed by numerical calculations regarding TBM construction. The results show that the strength, elastic modulus, and internal friction angle of Jurassic argillaceous sandstone are significantly higher than those of Cretaceous argillaceous sandstone, while their Poisson's ratio and cohesion values are similar. Under sustained loading,the strength of Jurassic argillaceous sandstone decreases significantly over time, and the deformation gradually increases. After TBM shutdown, the frictional resistance on the shield shell will experience a process of slow growth,rapid growth, and eventual stabilization. Compared to Jurassic argillaceous sandstone, TBM shutdown in Cretaceous argillaceous sandstone occurs earlier, with the shield-rock contact time and jamming accidents happening sooner.The creep characteristics of Cretaceous argillaceous sandstone are more pronounced than those of Jurassic argillaceous sandstone. After TBM shutdown, the longer the shield shell, the greater the frictional resistance, and the greater the over-excavation, the smaller the frictional resistance. Based on numerical results, the minimum design values for the rated thrust of TBM to prevent jamming and the safe shutdown time under different working conditions are derived.