Development And Application Of Seismic Appraisal And Strengthening CAD System For Masonry Structure

In our country, masonry structure has entered the period of strengthening. It is an inevitable trend that computer aided design will be utilized to realize appraisal and strengthening for masonry structure. In this dissertation, requirement analysis, system function design and module design were carried out to develop JDJG CAD system for masonry structure(JDJG). This system, which took QITI-08 as original vesion, has been developed successfully using Fortran and VC++ mixed-language programming based on CFG graphical platform.JDJG system can be used for appraisal and calculation based on the standards of 95 series, 89 series and 01 series. It is appropriate in seismic appraisal and strengthening design for multistory masonry structure and sublayer-shear structure. The main achievements of this system include: (1) The seismic performance evaluation of original structure are realized by the two-step appraisal and seismic checking, while the results and main parameters can be displayed in both gragh and text. (2) Surface layer and concrete wall are disposed interactively. Default parameters are set, and the parameters modified by users will be checked automatically and feedback will be given. Effective guidance is offered to lay out surface layer and concrete wall in numerical and graphic forms. The functions for interlaminar duplication and arranging over again are also provided. (3) Seismic capacity of reinforced structure can be calculated. Intensification factors for walls and layers are calculated, and the second appraisal is completed. Seismic checking according to Code 89 or Code 01 is finished by taking account of the influences of seismic action, distribution and seismic capacity resulted from reinforcement measures. (4) Shop drawings are protracted automatically.Techical condition and application of the project have also been studied. The main conclusions are: (1) From the aspects of structural system and construction measure, Code 01 is stricter than Code 89, and sesmic codes are stricter than appaisal standard, but seismic calculation is not always the case. (2) When thickness of strengthening with concrete wall range from 60mm to 100mm, the effectivest method is to adjust the thickness in all parameters. (3) Three typical practical projects are gived out, and sugestion on spacious and other masonry building are put forward. Spacious building should be strengthened as weak frame, other masonry structure should be ensured that there are enough walls in both horizontal and vertical directions. (4) The applicability of"stiffness convert model"is endorsed with the absence of JDJG software.Although there are some functions and even calculation methods to be improved, main part of the system has passed operability, stability and correctness testing carried out by CABR, and as a commercial software has entered the market, which shows that it is a practical system.