Abstract: The rebar cages of extremelydeep diaphragm walls always have large geometric dimensions, small integral rigidness, large hoisting weight and great difficulty in quantitative control of errors. The selection of the hoisting machines, the checking of the hoisting tools and the connection of the rebar cages at high position in the air are the key points in the construction of diaphragm walls. The manufacturing standard for the rebar cages of the extremelydeep diaphragm walls of Tianjin Cultural Center Metro works is established on basis of technical specifications and engineering practice. The key points of the hoisting of the extralong rebar cages are obtained by means of calculation and analysis. Conclusions drawn are as follows: 1) The strict control of the errors in the manufacturing of the rebar cages is the key to guarantee the successful inserting of the rebar cages into the diaphragm wall trenches. 2) The combination of a 400t caterpillar crane and a 150t caterpillar crane can meet the hoisting requirements. 3) The safety checking of the hoisting tools includes the steel cable strength checking, the pole checking of the major and assistant cranes and the hook checking. 4) Extralong rebar cages must be manufactured section by section, hoisted section by section and connected at high position in the air. Compared to connection by connectors, welding is better in terms of quality and operation. 

Key words: extremelydeep diaphragm wall, rebar cage, hoisting