In this study, a five‐span fully integral reinforced concrete (RC) bridge has been investigated for fatigue life assessment of its RC piles considering the effects of environmental temperature variation and nonlinear soil characteristics. The effect of daily temperature variation on the abutment wall and pile foundation has been estimated. Multilayers of soil along the abutment pile depth have been considered in the formulations. The soil has been represented as 3D nonlinear springs. A new fatigue model has been used for crack initiation and propagation in the RC piles. In this model, a crack has been assumed to progress successively in three stages from the tension side of the pile. Finite element (FE)‐based modeling and analyses have been carried out to determine the longitudinal displacements and bending moment in piles, abutments, and piers. Furthermore, taking the bending moment as input crack mouth opening distance, crack propagation and fatigue life of pile have been assessed using the FE method‐based software. It is seen that the abutment piles suffer fatigue damage earlier as compared to the pier‐piles as a result of thermal and vehicular loads effects. Also, thermal fluctuation has shown little or no fluctuations in the longitudinal displacements of abutment and piles in the multispan fully integral bridge (FIB). It is expected that the proposed method will be helpful for the bridge engineers in designing the pile foundation passing through multiple soil layers against fatigue damage of a FIB in particular subjected to thermal and vehicular loading.

中文翻译：

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考虑非线性土-结构相互作用的钢筋混凝土整体桥桩温度驱动疲劳寿命

在这项研究中，考虑到环境温度变化和非线性土壤特性的影响，研究了五跨全集成钢筋混凝土（RC）桥梁的RC桩疲劳寿命评估。估计了每日温度变化对桥台壁和桩基的影响。在配方中考虑了沿基台桩深度的多层土壤。土壤已被表示为3D非线性弹簧。一种新的疲劳模型已用于RC桩中的裂纹萌生和扩展。在该模型中，假设从桩的受拉侧开始三个阶段连续发生裂缝。已经进行了基于有限元（FE）的建模和分析，以确定桩，基台和墩中的纵向位移和弯矩。此外，使用弯矩作为输入裂缝口张开距离，使用基于FE方法的软件评估了桩的裂缝扩展和疲劳寿命。可以看出，与桥墩相比，由于热荷载和车辆荷载的影响，桥墩桩遭受的疲劳破坏更早。同样，在多跨度完全一体式桥（FIB）中，热波动显示基台和桩的纵向位移几乎没有波动。预期所提出的方法将对桥梁工程师设计穿过多个土壤层的桩基础以抵抗FIB的疲劳损伤特别是在热和车辆载荷下有帮助。使用基于有限元方法的软件评估了桩的裂纹扩展和疲劳寿命。可以看出，与桥墩相比，由于热荷载和车辆荷载的影响，桥墩桩遭受的疲劳破坏更早。同样，在多跨度完全一体式桥（FIB）中，热波动显示基台和桩的纵向位移几乎没有波动。预期所提出的方法将对桥梁工程师设计穿过多个土壤层的桩基础以抵抗FIB的疲劳损伤特别是在热和车辆载荷下有帮助。使用基于有限元方法的软件评估了桩的裂纹扩展和疲劳寿命。可以看出，与桥墩相比，由于热荷载和车辆荷载的影响，桥墩桩遭受的疲劳破坏更早。同样，在多跨度完全一体式桥（FIB）中，热波动显示基台和桩的纵向位移几乎没有波动。预期所提出的方法将对桥梁工程师设计穿过多个土壤层的桩基础以抵抗FIB的疲劳损伤特别是在热和车辆载荷下有帮助。热波动表明，在多跨度完全一体式桥梁（FIB）中，基台和桩的纵向位移几乎没有波动。预期所提出的方法将对桥梁工程师设计穿过多个土壤层的桩基础以抵抗FIB的疲劳损伤特别是在热和车辆载荷下有帮助。热波动表明，在多跨度完全一体式桥梁（FIB）中，基台和桩的纵向位移几乎没有波动。预期所提出的方法将对桥梁工程师设计穿过多个土壤层的桩基础以抵抗FIB的疲劳损伤特别是在热和车辆载荷下有帮助。