The internal energy evolution process and mechanism of high-performance fiber-reinforced shotcrete single-layer lining during layered construction remain unclear. To investigate the influence of layered construction on the energy evolution characteristics of the single-layer lining structure, this study conducted uniaxial compression strength tests on specimens with six different thickness ratios (the thickness ratio of the second layer to the first layer of fiber-reinforced shotcrete). The results indicate that: The uniaxial compression strength of fiber-reinforced shotcrete is significantly affected by the thickness ratio. The peak strength reaches its maximum value of 43.32 MPa when the thickness ratio is 1, with an optimal stress distribution. When the thickness ratio exceeds 4, debonding and crushing phenomena occur due to the excessive thinness of the lower layer. During the uniaxial compression process, the total input energy of the specimens increases with the thickness ratio. The elastic energy storage capacity is optimal at a thickness ratio of 1, while the dissipated energy exhibits significant fluctuations at a thickness ratio of 5, reflecting concentrated energy release due to local instability. Based on the energy dissipation coefficient analysis, the energy dissipation rate decreases during the compaction stage, indicating a significant reduction in structural stability.

In order to verify the suitability and correctness of plane test and curved surface test in studying the frictional mechanical characteristics of pipe jacking in rock stratum under complex contact conditions, large-scale rock direct shear test was used to study the shear frictional characteristics between plane sandstone and new curved sandstone and concrete pipe under seven kinds of complex contact conditions. On this basis, the mechanical effects of pipe jacking under low contact height and variable contact conditions were numerically analyzed. The results show that the difference of the shape of the specimen results in the great difference of the effective friction angle between the plane test and the curved test. In numerical analysis, it is more reasonable to uniformly set the contact range of pipe jacking to 1/2 contact than 1/3 contact. By comparing the jacking force error of 1/2 contact condition in two types of tests, it can be saw that the average jacking force error based on the result of curved surface friction test is smaller than that of plane test. Finally, it is concluded that the curved surface test has better adaptability in the relationship between test conditions and the quantitative accuracy of test results.