## 1 Introduction  
The development of China's economy and the continuous improvement in its transportation network have resulted in more need than ever for more tunnels to traverse complex geological environments. Specific topographical and geological conditions mean that tunnels are inevitably prone to significant deformation and other disasters when they pass through areas of soft rock mass, such as argillaceous rock and fracture zones. These not only present challenging difficulties during the construction period but also significantly increase the maintenance burden during their operational period [1]. At present, the mainstream idea in tunnel engineering design in a weak surrounding rock remains the concept of \"strong support and timely support\", which inhibits the deformation of the surrounding rock by providing strong structural support [2]. Support structures with high stiffness can tolerate small degrees of deformation, and because it is difficult to fully release the energy stored in the surrounding rock, such support structures require high strength. Engineering practice has shown that this type of support method often fails to effectively solve the problem of significant deformation of soft rock and can only be successfully managed after multiple cycles of supporting intervention, damage, and demolition [3]. However, this design method has generated many serious problems in addition to not being economical, which has impaired the progress of projects. It has also required greater construction safety measures and presented additional problems when dismantling failed supporting members, such as concrete cracking, falling, and collapsing blocks caused by the demolition of the tunnel arch, as shown in Figure 1 below. Following the incidence of numerous large-scale deformation problems, researchers gradually realized the importance of increasing deformation reserves or reducing the stiffness of the supporting structures to facilitate the release of the surrounding rock pressure and began to think about resolving the large-scale deformation issues from the perspective of energy absorption and dissipation. In the 1960s, [PERSON] [4] was the first to propose the notion of energy support when studying rockburst difficulties in African gold mines. In the 1970s and 1980s, [PERSON] [5] enriched and perfected [PERSON]'s theory of energy release rate, which systematically described the energy changes in underground caverns during gradual excavation and gave the energy balance equation. [PERSON] [6] analyzed the law of change in energy form during the excavation process of underground caverns. [PERSON] et al. [7] studied the problem of energy redistribution and automatic energy compensation for the energy released by the surrounding rock and absorbed by the support. At the same time, a system based on the concept of \"energy-dissipation support\" had gradually begun to develop in China and abroad. [PERSON] [8] first proposed the concept of \"yield control\" type support. [PERSON] and [PERSON] [9] pointed out that the only feasible way to deal with the problem of large-scale deformation of extruded surrounding rock was to adopt a supporting structure that allowed significant deformation to occur without ensuing damage and proposed the method of constructing a \"yield control\" type  
Figure 1: Hazards of large-scale deformation: (**a**) buckling deformation of steel frame; (**b**) collapse during dismantling and replacement of steel frame. of supporting structure. [PERSON] et al. [10] summarized the experimental support scheme attempted for deep and high in situ stress strata in Canada and contended that the ideal supporting structure should combine a high initial stiffness with a sound bearing capacity under large deformation conditions and flexibility. In terms of energy support structures, the modus operandi can be divided into radial and circumferential flexible supports along the tunnel chamber.