基于分项系数法的既有框架结构可靠性鉴定表达式的研究

采用全随机过程模型的简化模型，根据既有结构抗力与荷载的特点，建立了既有框架结构基于分项系数法的可靠性鉴定表达式，采用现行规范计算目标可靠度的校准法，在不降低结构可靠性指标的前提下，推导了不同目标使用期下最优荷载和抗力分项系数的计算公式，编制程序计算了不同目标使用期的抗力和荷载分项系数。该鉴定表达式可以比较方便的应用于既有框架结构的可靠性评估。

Research of reliability checkup expression of existing frame structure based on partial coefficient method

By adopting a simplified fully stochastic process model and on the basis of the characteristics of structural resistances and the loads, a reliability appraisal formula for existing frame structures based on the partial coefficient is established. Then, by applying the calibration method of target reliability specified in the current design code and without reducing the reliability of the structures, calculation formulas for partial coefficients of both optimum load and resistance for different object serviceable life are deduced. Finally, the partial coefficients of both the resistance and load for different object serviceable life are calculated through program. It is note that this reliability appraisal formula can be conveniently applied to reliability assessment for existing frame structures. Keywords：existing structure, item coefficient, reliability checkup expression.