一种新型装配式桥梁人-车隔离防撞护栏

近年来，由于失控机动车坠桥事故频发，对人民生命财产安全带来了一系列重大损失。基于此，迫切需要切实采取可行的措施来提高桥梁防撞护栏的防护性能，从而有效控制该类事故的发生风险和降低其后果。为此，本文首次提出了一种新型桥梁人车隔离防撞护栏，采用倒U形的截面形式并将锚固座与混凝土路缘石连接成为整体。通过精细化有限元模型对新型防撞护栏的力学性能进行了探讨。研究结果表明：在标准碰撞荷载作用下，两类护栏均满足规范要求,且新型护栏最大变形值仅为传统护栏的52%，达到最大位移值时，新型护栏的极限承载力相较于传统护栏提升了约58%，此时螺栓应力与变形分别为传统护栏的48%与70%，证明新型护栏在充分发挥圬工自重对车辆冲击的抑制作用和锚固螺栓的抗剪性能的同时，倒U形截面可大幅增加护栏的横向刚度，相比于传统护栏防撞性能有明显提升。此外，装配式的设计可有效减小施工和维护成本，为大量桥梁防撞护栏的设计和施工提供了新的解决方案。

Research on a New Type of Prefabricated Bridge Human-Vehicle Isolation Crash Barrier

In recent years, the accidents of out-of-control vehicles falling off bridges appeared frequently, which caused huge losses to people''s lives and properties. To improve the protection performance of bridge anti-collision guardrail, some feasible methods should be taken into consideration, so that the risk of such accidents can be reduced. Therefore, a novel bridge road-car isolation guardrail was proposed, and the inverted U-shaped section was adopted, and the anchorage was connected to the concrete curb as a whole. The mechanical properties of the guardrail were discussed by applying a refined finite element model. The results show that the two guardrails satisfy the requirements under the standard impact load effects, and the maximum deformation of the novel guardrail is approximately half of the traditional one. When the deformation reaches the maximum value, the ultimate bearing capacity of the new guardrail increases by 58% compared with the traditional one, and the bolt stress and deformation declined by 52% and 30% respectively. This proves that the new guardrail could not only give full play to the suppression effect of masonry weight on vehicle impact and the sheer performance of anchor bolts but also significantly increase the lateral stiffness of the guardrail with the inverted U-shaped section. Compared with the traditional guardrail, the collision resistance of the new was significantly improved. In addition, the prefabricated form can effectively reduce the construction and maintenance costs, providing new solutions for the design and construction of many bridge crash guardrails.