结构安全等级

结构设计安全等级不低于三级。

Its structural design safety level is not less than the third grade .

结构的安全等级为二级。抗震设防类别为丙类。

The safety of the structure is in grade two and the earthquake fortification is of C-class .

利用可靠度指标进行结构安全性等级评定，利用可靠度反问题理论进行桥梁结构的寿命预测，从而得出其剩余寿命。

Using the reliability index structure security rating and reliability inverse problem theory of bridge structure , concluded that its service life prediction of residual lifetime .

基于计算可靠度的现有RC结构构件的安全等级划分研究

Study on safety degree for existing RC structural elements based on calculated reliability

现有水工结构系统的安全等级计算方法研究

Study on calculation method for safety classification of existing hydraulic structure system

根据结构体系可靠度计算方法、结构安全性等级评估和划分思路，对水工结构中的构件安全分级与计算安全度之间的关系进行了分析。

According to the reliability calculation method for structure system and the principle of structure safety classification , the relationship between safety classification of hydraulic structure component and calculated reliability is analyzed .

简单描述了建筑结构设计规范中有关建筑耐久年限、建筑结构安全等级与重要性系数以及结构设计中存在的问题，并提出一些修改的建议。

It briefly describes the building lasting year limitation , the Building Structure safety degree and important coefficient in the design criterion of building structure , and the problems happened in structure design . It also gives some suggestions .

针对正在修订的《港口工程结构可靠度设计统一标准》（GB50158-92）中设计使用年限、耐久性设计、结构安全等级、设计状况、设计表达式等进行探讨。

This paper probes into the following points including design service life , durability design , structure safety degree , design status , and design expressions , etc. stipulated in the " Uniform Standard for Port Structures ′ Reliability Design ( GB 50158-92 )" which is under modification .

定义结构失效概率的自然对数的负值为设计性能安全指数，通过计算结构失效概率对各构件可靠指标的一阶偏导数的方法，求出结构的设计性能安全等级。

The safe index of design performance is defined as the negative natural logarithm of structural failure probability in this paper . The safe grade of design performance is got by calculating the one-order partial derivative of the structural failure probability to the reliable indication of every structural element .