In order to discuss the measures of guarding against scour and protecting river bed about large scale pile platform pier foundation,getting across experimentation,this paper studies on selecting scheme,disputing structure,determining the scope of the engineering,understanding the result of preventing scour measures,etc.

Based on soil mechanics theory and pile-soil interaction mechanism, settlement calculation models are suggested for pile-box foundation of the high-rise buildings,and corresponding calculating formulas are derived,and the settlement of pile-box foundation in Shanghai high-rise buildings is calculated.

This paper gives a brief account of design,fabrication and installation of the lightweight boxed cofferdam with bottom for construction of the in-water pile caps of Modaomen Bridge,and also formation of the load-carrying system,internal support system and actual construction application of the cofferdam.

At the time before the steel boxed cofferdams for the elevated pile caps of the Bridge are installed over sea,the regularities of tides,wind and sea waves should be well understood,and the construction should be accordingly organized in a reasonable way so that the time for installation of the cofferdams can effectively controlled and the construction safety risk can be reduced.

The pylon bases of the north channel bridge of Hangzhou Bay Sea-Crossing Bridge are constructed with steel boxed cofferdam with bottom.

The "steel lagged pile vibrating-hamming" technique was adopted to realize redriving of reinforced concrete friction pile with medium to long intermittence in soft soil,and thus the quality of pile foundation was guaranteed.