Multi-storey buildings require mitigation of consequences of unexpected or accidental events, to prevent disproportionate collapse after an initial damage. Cross-laminated timber (CLT) in platform-type construction is increasingly used for multi-storey buildings, however, the collapse behaviour and alternative load paths (ALPs) are not fully understood. A 3D non-linear component-based finite element model was developed for a platform-type CLT floor system to study the ALPs after an internal wall loss, in a pushdown analysis. The model, which accounted for connection failure, timber crushing and large displacements, was calibrated to experimental results and then adapted for boundary conditions corresponding to typical residential and office buildings. Subsequently, five parameters (floor span, connection type, vertical location of the floor, tying level, horizontal wall stiffness) were varied, to study their effects on the ALPs in 80 models. The results showed that three ALPs occurred, of which catenary action was the most dominant. Collapse resistance was mainly affected by the floor span, followed by the axial strength, stiffness and ductility of the floor-to-floor connection, the weight of the level above and the floor panel thickness. This study provides an approach to model ALPs in a platform-type CLT floor system to design disproportionate collapse resistant multi-storey CLT buildings.

多层建筑要求减轻意外或意外事件的后果，以防止在初始损坏后不成比例的倒塌。多层建筑中的交叉层压木材（CLT）越来越多地用于多层建筑，但是，对塌陷行为和替代荷载路径（ALP）的了解还不够。针对平台型CLT地板系统开发了基于3D非线性组件的有限元模型，以在下推分析中研究内壁损失后的ALP。该模型考虑了连接故障，木材压碎和大位移，已根据实验结果进行了校准，然后适用于与典型住宅和办公楼相对应的边界条件。随后，五个参数（地板跨度，连接类型，地板的垂直位置，绑扎水平，水平墙的刚度）进行了变化，以研究它们对80个模型中ALP的影响。结果表明，发生了三个ALP，其中链式作用最为明显。抗塌陷性主要受地板跨度的影响，其次是地板至地板连接的轴向强度，刚度和延展性，上方楼层的重量以及地板的厚度。这项研究提供了一种在平台型CLT地板系统中对ALP进行建模的方法，以设计不成比例的抗倒塌多层CLT建筑物。地板到地板连接的刚度和延展性，上方水平的重量和地板的厚度。这项研究提供了一种在平台型CLT地板系统中对ALP进行建模的方法，以设计不成比例的抗倒塌多层CLT建筑物。地板到地板连接的刚度和延展性，上方水平的重量和地板的厚度。这项研究提供了一种在平台型CLT地板系统中对ALP进行建模的方法，以设计不成比例的抗倒塌多层CLT建筑物。