In this paper,three new technology-the closed cutting off water technology,rotary spray pile with inserting a steel tube as early supporting and framing supporting structure with bi-rows of mini-steel tube piles,were introduced and analyzed,which have been first used in the practice of deep foundation pit engineering in Japan,these cases can serve as referenc to similar engineering.

In this paper,the necessity for steam condese -water full closed redeem technique is analyzed, the steam condense-wa-ter full closed redeem system based on PLC is developed,and the structure diagram,signal detect method,control logic relation,the keypoint of PLC program project as well as boiler priority supply electrical circuit chart are given.