The collapse occurs frequently in the tunnel construction. The important reason for the collapse in Tanyugou Tunnel contruction and its treated measures are discussed on the Badalin Speedway.

• 塌方在隧道施工中经常发生。对八达岭高速公路潭峪沟隧道施工中发生的主要塌方的原因及其处理塌方的措施作了论述。