中文摘要：

借助弹塑性力学滑移线理论分析了隧道底鼓的机理，确定了底板塑性区发展区域及底板的极限承载力；采用普氏理论，确定了深埋隧道松动围岩的深度，进而利用极限平衡理论推导出保持底板稳定所需的支护荷载；在此基础上，分析了锚杆在塑性区和塑性区以下岩层中的受力情况，从理论上确定了防治隧道底鼓锚杆长度的取值，为制定隧道底鼓防治方案提供理论依据，该项工作具有一定的实际意义和工程应用价值。

英文摘要：

By means of the slip line theory of plasticity, the mechanism of tunnel floor-bulge was studied, and the plastic developing area as well as the ultimate bearing capacity of the floor was determined. Based on Protodyakonov g theory, the depth of loose surrounding rock of deep tunnel was established and the supporting load for keeping floor stable was deduced by using limit equilibrium theory. On these bases, the stress states of rockbolt in rock lay- ers in and below plastic area were analyzed, and the length of rockbolt which can prevent and control tunnel floor- bulge was theoretically derived. The above study provide theoretical basis for controlling tunnel floor-bulge, which have certain practical significance and applicable value of engineering projects.