宜万铁路高坪1#隧道穿越T21j灰岩，处于岩溶垂直循环带内，隧道最大埋深104m。隧道岩溶极其发育，施工中共揭示大小溶洞51个。通过对所揭示的溶洞进行数理分析，探讨了垂直循环带内岩溶发育特征。根据岩溶发育特征和工程结构特点，提出了岩溶规模划分标准，制定了相应的治理措施，并对岩溶治理进行评价。

No. 1 Gaoping tunnel on YiWan railway passes through T21j limestone. The tunnel is located in verticalcirculating karst zones, with the maximum overburden being 104m. The karsts along the tunnel are extremely developed, with a total of 51 karst caves having been discovered during the construction of the tunnel. By means of analysis on the karst caves discovered during the tunnel construction, the article makes a study on the features of the development of the karsts located in verticalcirculating zones. On basis of the features of the development of the karsts and the characteristics of the engineering structures, the article suggests a karst scale determination standard, recommends some karst treatment measrues and makes an assessment on the effect of the karst treatment.