Add Layer Reinforced Concrete Frame Structure Appraisal

With the progress of the society and the continuous development of theeconomy, the existing building structures have more or less problems withapplicability and safety. While the old buildings can not be torn down due to variousreasons, so they need to be identified and strengthened, especially those needstory-adding of original structures. This paper takes adding stories of reinforcedconcrete frame structure as the research object, and analyzes the reliability of anengineering project. The main contents are as follows:(1) The existing buildings identification technology at home and abroad isdiscussed briefly, and its method and purpose are shown clearly, the developmenttrend of this industry in China is introduced, the significance and necessity of theresearch on testing evaluation are clear-cut.(2) The basic knowledge of the structure reliability is introduced briefly. Bycomparing the reliability of the existing buildings with that of the proposedbuildings and the difference between them has been discussed in detail; the existingbuilding structural load and resistance are studied, the design method at the presentstage in China are briefly illustrated, the approximate limit state design method isadopted, the reliability index is used for measuring and controlling the structurereliability.(3) The reliability identifying and rating process and related requirements of theexisting buildings are discussed, the stress state of the practical engineering can beobtained through the analysis of the structure mechanical properties. The JDJGmodules of PKPM finite element analysis software is used to establish the modeland analyze, the comprehensive reliability of the project is rated according to thecomputing results and《civil construction reliability identification standard》,and thecomponents which do not meet the requirements were put forward.(4) The identifying the reinforcement module of PKPM was used for modelling,analyzing and calculation of bearing capability of the engineering project, therelationship between the load effect design value S and resistance design value Rwas calculated, when (R/(0S)≥1.0),the structure meets the requirements of bearing capacity; when (R/(0S)＜1.0),the structure does not meet the requirements, thenthe opinion for reinforcement was put forward.