###### Abstract
In order to increase the advance efficiency and avoid accidents, a conveyor belt to help transport the soil needs to be installed, which causes the position of the jumbolters to move up and the operation space to reduce, thus the supporting scheme of the blots should be changed from perpendicular to the wall (radial support) to inclined to the wall (non-radial support). Theoretically, this change could weaken the support effect for stabilizing the tunnel. With comprehensive consideration, the improvement in the tunneling efficiency could shorten the construction period and reduce the cost, and for this purpose the weaker support effect is worthy and a greater cost to stabilize the tunnel is acceptable. Understanding the law of supporting action and variation of the support effect of different schemes is critical to evaluate the security and feasibility of the preceding operation. In rock engineering, the rock mass is usually regarded as a combination of intact rock and discontinuities. Continuum and discontinuum modeling are two commonly used numerical approaches. The discontinuum modeling approach models the rock mass with the existence of discontinuities in order to simulate the reality. There are a number of researchers using the discontinu modeling approach ([PERSON] et al. [10]; [PERSON] et al. [11]; [PERSON] et al. [12]; [PERSON] et al. [13]; [PERSON] et al. [14]; [PERSON] et al. [15]). The equivalent continuum modeling approach considers the rock mass as the continuous medium, and the minor discontinuities are considered to be a weakening of the strength, which is represented as a reduction in the parameters of the intact rock. As a common numerical method, equivalent continuum modeling has already been used by many researchers to study various geotechnical problems. [PERSON] et al. [16] investigated the stability of a tunnel under a high in situ stress condition. [PERSON] et al. [17] used the back-analysis method to study the rock mass mechanical property values for different tunnel shapes. [PERSON] et al. [18] studied the subsidence due to underground excavation and backfilling during open stoping operations. [PERSON] et al. [19] investigated the stability of the tunnels under different in situ lateral stress ratios by estimating the rock mass properties using the Hoek-Brown equation. Moreover, [PERSON] et al. [20; 21] used a numerical method. Figure 1: (a) TBM and (b) TBM-excavated tunnel with bolt anchorage. Most previous studies regarding the support effect of the rock bolt were based on small-scale analysis, such as the pullout tests of the bolts, the numerical simulations, and the corresponding theoretical analysis. [PERSON] et al. [22] investigated the influence of the structure plane surface situation and bolt inclination on the strength and deformation characteristic of the structure plane. [PERSON] et al. [23] studied the anchorage performances and affecting factors of resin bolts through the combination method of theoretical analysis, laboratory tests, numerical modeling, and field measurement. Because of the limitation of the small scale of study, this kind of research cannot provide direct guidance for the design of a support scheme for underground excavation. On the other hand, not much research supports this effect and the performance of the support scheme at an overall engineering scale. In 2021, based on the real engineering data, [PERSON] et al. [24] used two-dimensional discrete element code UDEC to study the performance of two different support schemes. However, because of the limitation of the two-dimensional analysis, the numerical simulation results only referred to a cross section of the tunnel, which was not enough to obtain an overall evaluation about the change in the support schemes. Therefore, in order to guide the design of the support scheme of underground excavation project, a stability analysis at a three-dimensional level and based on the overall engineering scale to evaluate the performance of the different support schemes is important to carry out.