木结构可靠度分析及木材强度设计值的确定方法  

Reliability analysis of wood structures and method for determining design strength value of timber

作　　者：祝恩淳[1,2] 牛爽[1,2] 乔梁[1,2] 潘景龙[1,2] ZHU Enchun NIU Shuang QIAO Liang PAN Jinglong(Key Lab of Structures Dynamic Behaviour and Control of China Ministry of Education, Harbin Institute of Technology, Harbin 150090, China School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China)

机构地区：[1]哈尔滨工业大学结构工程灾变与控制教育部重点实验室,黑龙江哈尔滨150090 [2]哈尔滨工业大学土木工程学院,黑龙江哈尔滨150090

出　　处：《建筑结构学报》2017年第2期28-36,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51278154)

摘　　要：为使结构用木材的强度设计值符合可靠度要求,建立了适用于现代木结构构件的功能函数,对不同荷载组合下的受弯、受拉和受压木构件进行了可靠度分析。鉴于木材的强度变异系数在较大范围内变动,给出了满足可靠度要求的抗力分项系数与强度变异系数间的关系曲线。以安全可靠与经济合理为原则,选取恒载与住宅楼面活荷载组合且在活荷载与恒载比值为1.0情况下的抗力分项系数与强度变异系数的关系曲线为确定木材强度设计值的基准曲线。当恒载与住宅楼面活荷载或与办公楼面活荷载组合且荷载比值小于1.0时,按基准线确定的强度设计值乘以调整系数0.83+0.17ρ(ρ为活荷载与恒载之比);当恒载与风荷载或与雪荷载组合时,按基准线确定的强度设计值乘以调整系数0.83。对不同安全等级木结构抗力分项系数间的关系进行了讨论,强度变异系数小于0.20的木材方可用于安全等级为一级的木结构,或者适用于木结构设计的结构重要性系数的取值范围宜为0.8~1.2。To meet the reliability requirement for structural timber,the performance function for modern wood members was developed and the reliability analysis of the members in bending,compression and tension was conducted. Given a wide range of the coefficient of variation of timber strength,the relationship curves between the resistance partial safety factor and the coefficient of variation which satisfy the reliability requirement were obtained. Following the principle of being safe and reliable,also of being reasonable and economical,the relationship curve under the combination of dead load and residential floor load with a live to dead load ratio of 1. 0 was chosen as the reference curve for determining the design strength value. For combinations of dead load and residential floor load or office floor load with a load ratio less than 1. 0,a strength modification factor（ 0. 83 ＋ 0. 17ρ,where ρ is the live load to dead load ratio） was introduced; for combinations of dead load and wind or snow load,a strength modification factor of 0. 83 was introduced. The relationship between the resistance partial safety factors with respect to the safety class of timber structures was investigated. It is found that timber only with a coefficient of variation of strength smaller than 0. 20 is suitable for building structures of safety class one,or the value of the importance factor for design of timber structures can be from 0. 8 to 1. 2.

关 键 词：木结构 木材强度设计值 可靠度 抗力分项系数 变异系数 

分 类 号：TU366.2[建筑科学—结构工程] TU318.1