The new specification version PKPM2010 design software V2.1 version has been published. A lot of test and trial showed that the new version of the software's analytical ability, efficiency have been improved dramatically. It is more close to the design requirements, and the operation of the software interface more friendlily. This paper introduced the improvement of software structure V2.1 version of the technology and the new feature, which provide a reference for the design personnel.

Progressive collapse of building structure which may lead to great damage usually occurs under the extreme events. Considering the nonlinear dynamic simulation of building progressive collapse, the difficulties of computational mechanics were studied.Then the advantages and disadvantages of normal numerical methods to simulate the process of building progressive collapse were compared. Finally, the particle element method was introduced.