Abstract: To clarify the effects of combined active-passive support, load-bearing arch tests were conducted on a 40° crown segment of a tunnel cross-section under Grade V surrounding rock conditions using a specially developed arch loading test system. The mechanical behaviour of the load-bearing arch under combined active-passive support was compared with that under fully passive support. The results show that combined active-passive support performs markedly better than fully passive support in terms of surrounding rock pressure and structural response, reducing the surrounding rock pressure by at least 35% and the maximum stress in the steel arch by at least 20%. During deformation of the surrounding rock, the maximum increase in the axial force of non-prestressed rock bolts is less than 0.2 kN, indicating a limited contribution to support. In contrast, the axial force in prestressed rock bolts varies by no more than 10% during loading, and these bolts maintain effective support throughout the loading process. Compared with fully passive support, combined active-passive support improves the structural safety of shotcrete, increasing its factor of safety by at least 28%.