CAJ | 학술논문

由于跨海桥梁的环境效应有别于一般桥梁,正常使用极限状态所对应的目标可靠度也必然不同,因此,基于JCSS模式规范建议了目标可靠度指标分别为1.5,2.0和2.3的跨海桥梁基础结构正常使用极限状态三级可靠度水平,并提出了一种可变荷载系数的标定新方法,即通过各类荷载引起的钢筋拉应力对于混凝土裂缝宽度的贡献率不同建立基于钢筋拉应力的正常使用极限状态方程.最后,依据可靠度计算的校准法,结合具体工程进行了基于目标可靠度的可变荷载频遇值系数和准永久值系数的标定,通过设计实践证明所建议的目标可靠度指标值是合理的,采用的标定新方法是可行的.
유우과해교량적배경효응유별우일반교량,정상사용겁한상태소대응적목표가고도야필연불동,인차,기우JCSS모식규범건의료목표가고도지표분별위1.5,2.0화2.3적과해교량기출결구정상사용겁한상태삼급가고도수평,병제출료일충가변하재계수적표정신방법,즉통과각류하재인기적강근랍응력대우혼응토렬봉관도적공헌솔불동건립기우강근랍응력적정상사용겁한상태방정.최후,의거가고도계산적교준법,결합구체공정진행료기우목표가고도적가변하재빈우치계수화준영구치계수적표정,통과설계실천증명소건의적목표가고도지표치시합리적,채용적표정신방법시가행적.
The target reliability indices of the foundation structures of sea-crossing bridges on the serviceability limit state (SLS) are different from those of common bridges due to their different surroundings.Consequently,three levels of the target reliability indices,which are 1.5,2.0 and 2.3,respectively,for those structures on the SLS are suggested based on the Joint Committee on Structural Safety (JCSS) model code,and a new method of calibrating factors of live loads,which is based on the contribution ratio of tensile stresses of reinforcing bars produced by various loads to the maximum crack width of concrete,is proposed.Finally,the calibration of the reliability-based factors of the frequent value and the quasi-permanent value of live loads is conducted by the Joint Committee (JC) method through an actual design,and the indices are proved to be reasonable and the new method is proved to be feasible.