岩溶尺寸及位置对隧道基底加载沉降的影响研究

建立了岩溶隧道概化模型，运用FLAC3D有限差分软件对隧道基底在加载过程中，不同尺寸及位置的全充填性溶洞的影响进行了数值研究。结果表明:溶洞尺寸和位置的影响存在界限值，岩溶顶板安全厚度为0.4倍隧道直径，岩溶上边界影响范围为1倍隧道直径，岩溶下边界影响范围为3倍隧道直径，岩溶左右边界影响范围为2倍隧道直径；当岩溶超过上述影响范围时，隧道设计、施工可不考虑溶洞影响。

Research on the Influence of Karst Cave Size and Position on the Settlement of Tunnel Basement Loading

The generalized model of karst tunnel is established and the FLAC3D finite difference software is used to study the influence of full filling karst cave in different size and position to the tunnel basement during the loading process. The study results show that there are limits for the size and location of karst caves,the safety thickness of karst roof is 0.4 times of tunnel diameter;the influence range of the upper boundary of karst is 1 times of tunnel diameter;the lower boundary of karst is 3 times of tunnel diameter;and the left and right boundary of karst is 2 times of tunnel diameter. When the karst caves boundary exceeds the above scope, the tunnel design and construction may not consider its impact.