Although sophisticated techniques have been used to prospect the geological structures, imponderables such as gas, underground water, and changes in earth strata occur from time to time. Engineers must therefore be continuously on the alert.
因為即使有最精密的地質探勘設備，也無法準確地預測出在工程進行時可能遭遇到的狀況，如湧泉、瓦斯崩出、地層變動等，隨時都可能發生，而工程負責人必須隨時根據經驗，當機立斷予以處理，以免發生災變。」