作用在铁路隧道上的竖向均布围岩压力,在《铁路工程技术规范》第三篇“隧道”(以下简称新规范)中推荐采用下列公式:q=0.45×2~(6-s)γω (1)式中:q——围岩垂直均布压力(吨/米~2);s——围岩类别,如Ⅲ类围岩即 s=3;γ——围岩容重(吨/米~3);ω——坑道宽度影响系数,按下式计算ω=1+i(B-5) (2)其中 B 为坑道宽度(米);i 系以 B=5米的围岩垂直均布压力为准,B 每增减1米时的围岩压力增减率(1 m)。当 B<5米时,取 The vertical uniform distribution of surrounding rock pressure on railway tunnels is recommended in the “Tunnel” in the third chapter of “Technical Code for Railway Engineering” (hereinafter referred to as the new code): q=0.45×2~(6-s) Γω (1) where: q—the vertical uniform distribution pressure of the surrounding rock (t/m~2); s—the type of surrounding rock, such as type III surrounding rock, ie, s=3; γ—the bulk density of surrounding rock (t/m m~3);ω——flux width influence coefficient, calculated as follows: ω=1+i(B-5) (2) where B is the width of the tunnel (m); i is vertical to the surrounding rock with B=5m Uniform pressure prevails, and the rate of increase and decrease of surrounding rock pressure (1 m) per 1 m of increase or decrease in B. When B<5 meters, take