隧洞支护效应的探讨

基于弹性理论，对隧洞开挖后和进行喷锚支护后的应力和塑性变形进行分析。运用FLAC 3D模拟了隧道开挖与支护过程中的力学行为，得到隧道在无支护和喷锚支护作用下围岩的塑性及应力变形情况。结果表明，在喷锚支护中，对锚杆施加预应力，其值为当隧道塑性区消失时所需支护力的大小。这种支护提高了围岩的自承能力，使围岩塑性区的扩展在隧道开挖不久就得到有效抑制，能有制止隧道围岩的进一步破坏。

Study of Tunnel Supporting Effect

Based on the elastic theory, an analysis can be made on stress and plastic deformation under tunnel excavation and shotcrete support.FLAC 3D can be used to simulate the mechanical behavior of excavation and support, getting the deformation of surrounding rock stress and plastic without support and shotcrete. The results show that, the prestress applied on the anchor equals to the supporting force when the tunnel plastic zone disappears. This support improves the self bearing capacity of surrounding rock, effectively suppresses the expansion of the plastic zone after the tunnel excavation, and prevents further damage to the tunnel surrounding rock.