Abstract：
There are abundant examples of the application of Double-O-Tube (DOT) shield methods both at home and abroad, and some of these exhibited unusual ground surface settlement during construction in soft ground. Based on experience and data analysis, some suggestions are put forward, including the following: it is favorable to control settlement with spoke-type cutter heads if the settlement is not significantly controlled by the brim; using a modified tail shield grouting apparatus, such as an apex hybrid grouting pipe, along with a soil pressure gauge at the grouting hole and proper grouting material is effective at controlling the ground settlement induced by shield construction; and it is easy to solve the shield rotation problem using a combination of jacks, over-breaking cutters, and ballasting. The above measures lay the foundation for improvement of Double-O-Tube shields for use in soft ground and will contribute to the promotion and application of DOTs in the future.
2013, Vol. 50 