Through the engineering practice,the author puts forward the method to excavate and increase the dead weight by using the long arm excavator,discusses the construction procedures,the method,the main points and the corresponding technical measures to make the dual-arm steel boxed cofferdam sink 8.

In the light of the cracking accidence of the welding structure of a large type excavator used in the mine, this paper studies on the dynamic fractu re characters of 15MnV steel through simulating the actual working condition, an d analyzes on the reasons of the occurrence of the brittle fracture.

Three-dimensional parametric modeling of excavators boom was completed in this paper by using of Pro/Engineer,and finite element analysis(FIA) is made by using of Pro/Mechanica module,finally through the simulational analysis results,we provide a basis for the optimization of products.