Abstract: In order to solve the problem of shield equipment selection in complex geology and surrounding environment, the paper defines and classifies multimode shield according to its development and research status. It is mainly divided into several types, such as earth pressure/mud water dualmode shield, earth pressure/TBM dualmode shield, mud water/TBM dualmode shield. And then combined with the first phase project of Nanning rail transit line 5, the main working principle, characteristics, applicable scope and adaptive design of earth pressure/slurry balance dualmode shield machine are analyzed. The results show that : The earth pressure/mud water balance shield has wide geological adaptability, high equipment utilization ratio and low construction cost, which solves the problem of shield equipment selection under different geological conditions in the same section. To a certain extent, it provides a set of reliable solution for the geological complex and engineering sensitive zone.

Key words: dualmode shield, earth pressure/slurry, working principle, adaptability