Central Plains Residential Building Structures Surveys And Statistical Models

This dissertation is an item about The Survey and Statistics of Loads and Resistances of the Residential Building Structure Reliability Technology in the Central Plains Region , which is a subitem of China's The Tenth Five science and technology key problems item about Residential Building Structure System and Engineering Quality Insure Critical Technology. The aim of the study on loads lies in acquiring a load theoretical model, which must be suitable to the practical transformable discipline , and different kinds of loads value can be derived from the study. The value of the loads is an important target when the structures are designed. It can affect the structural design directly. When it isn't get the proper value , serious effect can be happened. The target of the loads . which is used in the design of building structures in the present stage in China . is derived from the statistic in the 1980's. The loads of building structures have greatly different between the 1980's and now. It is one of the key technology of the residential building systems and engineering quality ensure , that the statistic of live loads is got and the probability distribution model of live loads is established and the statistical parameter is ascertained. It has greatly important signification that this study is carried out. From the survey of the floor live loads of the residential buildings in the Central Plains Region towns , this dissertation expounds how to set up statistical model of live load , and statistical parameters , which can represent the residential building floor live load in the Central Plains Region , can be derived from it. These work would have important reference for establishing the criteria.There are two probably models in common use to describe the loads , one is the stochastic variable probability model and the other is the stochastic process probability model. In regard to dead load , its value variation with time is knee-high to a duck , approximation remain constant. So it can be seen as a stochastic variable which can be going statistical analysis. For live load , it is not only possessed of variability in space but also with time in the wholly design reference period. So live load cannot be adopted from the stochastic variable probability model whereas should be adopted from the stochastic process that relates with time parameter t. As the sample functions of the stochastic process is very complicated and the statistical analysis is very cockamamie , and at present the study is yet not sound about sample functions on the stochastic process of live load. In order to simplify them , according to the Unified Standard for reliability design of building structures (GB 50068-2001), this dissertation adopts calm two-term stochastic process probability model , namely live load sample function modeling isochronous segment square wave function. Utilizing Probability Distribution Function of random time point loadwave amplitude value disciplinarian of variance. Due to adopt limit state design method that based on probabilistic theory in the Unified Standard for reliability design of building structures (GB 50068-2001), namely considering first power second moment limiting state design method base on probability distribution type of basic variable. All kinds of basic variables are considered as the stochastic variables. Therefore the stochastic process of load must be translated into thestochastic variable. If adopting the stochastic variable of random time point load substitute stochastic process, the results will be towards insecurity. In the design reference period of building structures , the stochastic process of loads certainly has one maximal value ofloads. Since loads are fluctuant with time , so maximumof loads is a stochastic variable ,which has relation to the design reference period. Therefore , this kind of stochastic variable implicates the factor of time. For the purposes of security . the stochastic process can be substituted by the maximum of loads in the design reference period , which...