The horizontal stiffness of the isolated layer is reduced substantially by a friction pendulum bearing (FPB) toprotectthe structure from potential damages caused by earthquakes. However, horizontal stiffness is essential to progressive collapse resistance of structures. This paper presents a simplified model to assess the progressive collapse response of beam-pier substructure isolated by FPB. Progressive collapse resistance by flexural action of the beam and additional resistance owing to the horizontal restraining force was achieved. The influences of the equivalent radius and friction coefficient of the FPB, the applied axial force on the FPB, and span-depth ratio of the beam on the additional resistance were investigated. Simulations were conducted to verify the proposed model. The results show that progressive collapse resistance provided by horizontal restraining can be reduced as large as 46% and 88% during compressive arching action (CAA) and catenary action (CA), respectively. The equivalent radius of the FPB shows limited effect on the progressive collapse response of FPB isolated structures, but friction coefficient and applied axial force, as well as depth ratio of the beam, show significant influences on the additional progressive collapse resistance capacity. Finite element method (FEM) results are in good agreement with the result obtained by the proposed method.

隔离层的水平刚度通过摩擦摆轴承 (FPB) 大大降低，以保护结构免受地震造成的潜在损害。然而，水平刚度对于结构的渐进抗倒塌性至关重要。本文提出了一个简化模型来评估 FPB 隔离的梁墩子结构的渐进倒塌响应。通过梁的弯曲作用实现了渐进的抗倒塌性，并通过水平约束力实现了额外的阻力。研究了FPB的等效半径和摩擦系数、FPB上施加的轴向力、梁的跨深比对附加阻力的影响。进行了仿真以验证所提出的模型。结果表明，在压缩拱形作用（CAA）和悬链线作用（CA）过程中，水平约束提供的渐进式抗倒塌能力分别降低了 46% 和 88%。FPB的等效半径对FPB隔离结构的渐进倒塌响应的影响有限，但摩擦系数和施加的轴向力以及梁的深度比对附加的渐进抗倒塌能力有显着影响。有限元法（FEM）的结果与所提出的方法得到的结果非常吻合。FPB的等效半径对FPB隔离结构的渐进倒塌响应的影响有限，但摩擦系数和施加的轴向力以及梁的深度比对附加的渐进抗倒塌能力有显着影响。有限元法（FEM）的结果与所提出的方法得到的结果非常吻合。FPB的等效半径对FPB隔离结构的渐进倒塌响应的影响有限，但摩擦系数和施加的轴向力以及梁的深度比对附加的渐进抗倒塌能力有显着影响。有限元法（FEM）的结果与所提出的方法得到的结果非常吻合。