宋二祥, 孔郁斐, 杨军. 土工结构安全系数定义及相应计算方法讨论[J]. 工程力学, 2016, 33(11): 1-10. DOI: 10.6052/j.issn.1000-4750.2016.06.ST12
引用本文: 宋二祥, 孔郁斐, 杨军. 土工结构安全系数定义及相应计算方法讨论[J]. 工程力学, 2016, 33(11): 1-10. DOI: 10.6052/j.issn.1000-4750.2016.06.ST12
SONG Er-xiang, KONG Yu-fei, YANG Jun. DISCUSSION OF SAFETY FACTOR DEFINITIONS AND COMPUTATION METHODS FOR GEOTECHNICAL STRUCTURES[J]. Engineering Mechanics, 2016, 33(11): 1-10. DOI: 10.6052/j.issn.1000-4750.2016.06.ST12
Citation: SONG Er-xiang, KONG Yu-fei, YANG Jun. DISCUSSION OF SAFETY FACTOR DEFINITIONS AND COMPUTATION METHODS FOR GEOTECHNICAL STRUCTURES[J]. Engineering Mechanics, 2016, 33(11): 1-10. DOI: 10.6052/j.issn.1000-4750.2016.06.ST12

土工结构安全系数定义及相应计算方法讨论

DISCUSSION OF SAFETY FACTOR DEFINITIONS AND COMPUTATION METHODS FOR GEOTECHNICAL STRUCTURES

  • 摘要: 以地基承载力、土坡稳定等常见土工结构问题为例,讨论土工结构安全系数的两种不同定义,一是极限 荷载与容许荷载之比,一是已有强度参数与保持稳定所需强度参数之比。分析表明,前一定义仅对某些结构适用, 而后一定义原则上可用于各种结构,具体选用要看结构及其所处环境的情况。当两种定义均适用时,允许安全系 数的取值可有较大差别,具体设计时应予注意。此外,还对两种安全系数的计算方法进行了讨论,包括滑移线法、极限平衡法、极限分析法等传统方法以及近年来应用日趋广泛的弹塑性有限元法、有限元极限分析法等,对各类 方法的优缺点及应用时需注意的问题给出自己的看法。

     

    Abstract: Taking common geotechnical problems, such as the bearing capacity of soil foundations and slope stability, as examples, two different definitions for the safety factor of structures, i.e. the ratio of limit load to allowable load and that of the available strength to required strength, are discussed. It is noted that the first definition is valid only for certain types of structures, whereas the second can be used for any type of structures. When both definitions can be employed, the proper choice depends on the characteristics as well as the loading environment of a specific structure, and different values for the required safety factor should be specified to reach the same level of reliability when a different safety factor definition is adopted. Moreover, the available methods for the computation of safety factors are reviewed, including the classical methods such as the slip line method, the limit analysis method, and the limit equilibrium method; as well as the modern methods such as the ordinary elasto-plastic finite element method, the strength reduction finite element method, and the finite element limit analysis method. The advantages and disadvantages of each method are discussed, and some suggestions are also presented with regard to their applications.

     

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