为研究软弱地质小净距隧道围岩压力计算方法及不同隧道净距和埋深对围岩压力的影响规律，引用三塌落拱理论，确立深浅埋隧道分界深度，基于公路隧道设计规范，建立隧道荷载计算模型，推导出围岩压力理论计算公式，并讨论不同的隧道净距和埋深对隧道内外侧围岩压力的影响规律。最后，结合工程实例，针对受力薄弱的中夹岩柱部位提出有效的加固措施。结论如下： 1)极浅埋和浅埋小净距隧道围岩压力采用规范法中的全土柱和谢家烋理论公式，深埋隧道采用修正后的比尔鲍曼计算方法更为安全合理； 2)小净距隧道施工过程偏压特性显著，围岩压力与埋深近似呈线性关系； 3)左右洞室施工相互影响随净距增大而呈现减弱趋势，当净距大于1倍洞跨时，围岩压力可按单洞计算； 4)中夹岩柱是软弱地质小净距隧道受力的关键、薄弱部位，采用中空注浆锚杆并合理确定锚杆长度，能有效抑制中夹岩柱塑性应变发展，提高围岩抗拉及抗剪强度。

To study the calculation methods for surrounding rock pressure of tunnels with small spacing in weak stratum and the influence of different tunnel spacing and buried depth on surrounding rock pressure, the theory of three collapse arch is introduced and the boundary depth of deep and shallow tunnels is established. Then, a tunnel load calculation model is established based on the road tunnel design specification, the theoretical calculation formula of surrounding rock pressure is deduced, and the influence of different spacing and buried depth on pressure of surrounding rock inside and outside the tunnel is discussed. Finally, a case study is conducted, and effective reinforcement measures are proposed for the weak middle rock pillars. The results show the following. (1) The surrounding rock pressure of extremelyshallow and shallowburied tunnels with small clear spacing can be calculated by entire soil column and Xie Jiaxiao′s theoretical formulas in the standard, that of deepburied tunnel can be calculated by modified Bill Bowman calculation method. (2) The asymmetrical pressure characteristics of tunnel with small clear spacing are prominent, and the surrounding rock pressure is approximately linear with the buried depth. (3) The interaction between the left and right tunnels decreases with the increase of the clear spacing. When the clear spacing is greater than one time of the tunnel span, the surrounding rock pressure can be calculated as a single tunnel. (4) The middle rock pillar is the key and weak part of the tunnels with small clear spacing in weak stratum. The hollow grouting bolts and reasonable anchor rod length can effectively restrain the development of plastic strain, and improve the strength of tensile and shear strength of surrounding rock.