Seismic Reliability Analysis And Design Of Reinforced Concrete Frames

Based on reliability theory, the current seismic design code GBJ11-89 and the previous research results of the same occupation, the seismic reliability analysis and the seismic design for the reinforced concrete frames are studied in this thesis. The major contents are summarized as follows:(1) Seismic reliability of reinforced concrete beams designed following the current seismic design code is analyzed. Influences of load ratio, materials strength and ratio of reinforcement on seismic reliability of beams were analyzed. Based on these, the failure probability ratio of flexure to shear was analyzed under the different shear strengthen coefficient, providing theory reference to proper determining shear strengthen coefficient of "strong shear weak bending" design.(2) The basic design parameters of reinforced concrete columns are considered as random variables. Influences of major design parameters on reliability of columns were analyzed. Comparing and analyzing the reliability of columns under independent or complete correlation of axial force and bending moment, it indicate that seismic design of columns are one-sided unsafely when axial force and bending moment are considered as complete correlation under a rather large load eccentricity. The shear reliability of columns are analyzed, the reliability index under different shear strengthen coefficient are obtained.(3)The basic design variables of reinforced concrete columns are considered as random variables. The probability nature of curvature ductility factor of rectangular reinforced concrete columns with rectangular hoops was analyzed. The probability distribution function and the characteristic values of the curvature ductility factor are obtained. Based on these, the ductility reliability of columns in the lowest layer of the reinforced concrete frames was analyzed, for providing reference to safety hoop reinforced design of cross-section of columns.(4) The failure correlation of beam end and column end under "minor earthquake was analyzed by Monte Carlo simulation method. Based on this, a reliability analysis method for reinforced concrete frames with good conceptual design under "minor earthquake" is presented.(5) A reliability analysis method for reinforced concrete frames under "server earthquake" is presented. The limit-state function is established by global damage indices. The damage capacity is estimated by test data. The randomness of materials and earthquake are considered during process of analysis. Influences of dead load on the structural reliability were considered too.(6) A seismic design method based on reliability theory for reinforced concrete frames is presented. The load and resistance factors design format is adopted for safety check. The target reliability is gained based on research results of previous. The resistance factor and earthquake load factors are determined by optimization. At last, the resistance factor and earthquake load factor for different important buildings are suggested.The research work is supported by the National Key Projects on Basic Research and Applied Research: Applied Research on Safety and Durability of Major Construction Projects and the National Natural Science Foundation of China(59878008).