Research And Practice On Design And Construction Methods Of Outer-Jacketing Frame Structure Building For Storey-Adding

With the transition of construction industry from"mainly constructing new building"to"constructing new building on a par with reconstructing old building"in our country, research on design and construction methods of outer-jacketing structure to add stories around the existing building begins to draw people's attention gradually. Although a number of projects outer-jacketing frame for storey-adding have been accomplished presently, there is little research on design methods for this kind of frame. The outer-jacketing frame for storey-adding is rigid on the top and flexible on the bottom, and the slenderness ratio of the column in the first floor is bigger. So how to ensure the structure be in elastic state under frequent earthquake, no yielding under design earthquake and no collapse under infrequent earthquake has been the focus of people's attention. The outer-jacketing frame for storey-adding need to get across the original building, so its common span is 16~30 m. Both self-weight and construction load are relatively bigger during construction, and the roof of original building can not bear these heavy load. So on condition that through design and construction technique of self-supporting floor during construction making the original building work as usual, how to ensure the security of constructing outer-jacketing frame structure for storey-adding has been another people's attention.State of the art and research on out-jacketing structure for storey-adding at home and abroad are summarized. Combined with the characteristics of outer-jacketing prestressed concrete frame, based on the large-scale finite element method software ANSYS, making use of parameterized design language APDL, programme for calculating internal force and placing reinforcement of outer-jacketing prestressed concrete frame under the combination of frequent earthquake is compiled. This programme will provide base for the following elastic-plastic history analysis and Pushover analysis.Based on the plane rod model, by using of IDARC nonlinear analysis programme, the seismic response of 600 different-placing-of-reinforcements separate outer-jacketing prestressed concrete frames for storey-adding with design earthquake group one ,two and three, situated in Classâ… ,â…¡andâ…¢soil...