重载运输条件下12 m低高度混凝土梁承载力研究

A Study of the Bearing Capacity of the 12-m Low-Height Reinforced Concrete Beam in the Conditions of a Heavy-Load Railway

12 m低高度钢筋混凝土梁在既有铁路运输中占有相当比例,随着重载运输的发展,该类桥梁冲击振动加剧、梁体开裂现象严重。以12 m低高度钢筋混凝土梁为研究对象,采用有限元仿真分析和实桥静动载试验相结合的方法,对其强度、刚度以及动力特性等进行研究,结果表明该类桥梁竖向刚度及横向振动特性满足既有重载运输承载力要求、竖向强度安全储备不足,运营中应重点关注该类桥梁承载能力。

With the development of the heavy-load railway transport, the 12-m low-depth reinforced concrete beams occupy a comparatively large proportion of railway bridges in the transportation of existing railways. However, as the impact vibration of this type of beam bridges is increased, the beam bodies often crack seriously. With the 12-m low-depth concrete beam as the object of our research,the strength and stiffness,dynamic performance and the like of the beam are studied by both the finite element simulation analysis method and the live-and-dead load tests of real bridges. The result of our research shows that the vertical stiffness and the transverse vibration characteristics of the bridge can meet the requirements in the bearing capacity of heavy-load railways, but the longitudinal strength in storage for safety is not sufficient. As a result, in the course of operation,greater attention should be paid to the bearing capacity of such bridges.