Reliability Analysis Of Multi-storey R.C. Frame Structure In Construction Period

This monograph takes an on-going multi-storey R.C. frame structure as the object, defining building structure under construction as time-varying structure system in which structure loads and resistance of members vary with time. The researcher develops site measurement on structure and resistance in construction period, and analyzes the reliability of structure in the entire construction procedure.It analyzes the specific weight time-varying rules of new-cast concrete with account of accurate measurement in site. This paper divides the construction procedure into four phases (or stages), stats construction loads in every phase, set up distribution probability model of live-loads in construction period with parameter estimation and hypothesis testing, and puts forward advice on the determination of live-loads standard value for identifying construction phase.The survey stats the strength of concrete testing blocks, tests the strength of concrete cores in different ages, using drilled core method, analyzes strength different among specimen in different curing conditions, as well as that between concrete cores and blocks with the same strength grade, plots early strength time-varying curve of concrete, tests the yielding strength of reinforcing bars and geometric parameters of structural components, and thus issues its probability distribution.Based on the time-varying feature of early strength and bond effect, the dissertation introduces strength utility coefficient of tensile bars, which is used to reflect the truth that tensile bars may not yield or may occur bond slip in load capacity limit status of early bending members, and establishes computational model for early resisting forces of R.C. bending components.On the basis of analysis on construction structure loads and members' resistance time-varying features, investigator applies SAP2000, a large-scale FEM program, to compute time-varying load effect of structural members, adopts FOSM method to calculate reliability indices of structural members in construction period, and investigates the influences, which is exerted by construction parameters, to the indices mentioned above.