【摘要】 从构件角度对既有大跨度空间钢结构的安全性评定方法进行研究,根据《建筑结构可靠度设计统一标准》(GB50068—2001)规定的结构构件承载能力极限状态的可靠度指标,提出既有钢结构构件的安全性等级应划分为安全与不安全两等级.基于荷载模型和抗力模型,确定了作用于既有大跨空间钢结构的各类荷载标准值.以分项系数确定的抗力与可靠度指标确定的抗力相对误差最小为原则编写可靠度程序,得到适合既有大跨空间钢结构评定的γG=1.2,γQ=1.3,以及各类构件的最优抗力分项系数.在综合考虑构件权重的基础上,提出了以整体性、承载安全性和整体稳定性的最低等级作为结构安全性等级的安全性评定方法.更多还原

【Abstract】 The safety assessment method of existing large span steel structures is studied from the level of members.According to the reliability index of the structural members under ultimate limit state specified in the unified standard for reliability design of building structures(GB 50068—2001),a new two-level safety assessment principle of existing steel structure members,in which the members are defined as safe and unsafe,is put forward.The load model and the resistance model are discussed and the nominal values of loads of existing large span structures are obtained.Based on the minimum error principle between the resistances deduced from partial coefficients and reliability index,γG=1.2,γQ=1.3 and partial coefficients which meet the assessment of existing large span structures are obtained by the reliability program.The safety assessment method taking the lowest grade of the entirety,the safety of load-bearing capacity and the structural overall stability as the structural safety grade is proposed by considering the member weighing.更多还原