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为研究双块式无砟轨道连续配筋道床板裂纹扩展的机理,基于钢筋混凝土粘结-滑移理论,建立了适用于连续配筋混凝土道床板裂纹扩展的计算模型.依据该模型计算了道床板裂纹宽度和间距,分析了道床板配筋率、纵向钢筋直径和混凝土强度对裂纹宽度、间距及钢筋应力的影响.分析结果表明:钢筋直径和配筋率直接影响裂纹间距,裂纹间距随钢筋直径增大而增大,随配筋率增大而减小;混凝土抗拉强度、配筋率和钢筋直径是裂纹宽度的主要影响因素,裂纹宽度随混凝土强度和钢筋直径增大而增大,随配筋率增大而减小;裂纹截面处纵筋应力不应超过其抗拉强度,配筋率和混凝土抗拉强度是决定钢筋应力大小的关键因素.
In order to study the crack propagation mechanism of continuous reinforcement bar bed slab in double block ballastless track, a calculation model suitable for crack growth of continuous reinforced concrete ballast slab is established based on the theory of bond-slip of reinforced concrete.Based on the model, Crack width and spacing were analyzed.The influence of the ratio of reinforcement ratio, longitudinal reinforcement diameter and concrete strength on the crack width, spacing and reinforcement stress was analyzed.The results showed that the diameter and reinforcement ratio of reinforcement directly affected the crack spacing and the crack spacing varied with the reinforcement diameter The tensile strength, reinforcement ratio and rebar diameter of concrete are the main factors affecting the crack width. The crack width increases with the increase of concrete strength and rebar diameter. With the increase of reinforcement ratio, The reinforcement ratio increases and decreases; the longitudinal reinforcement stress at the crack cross-section should not exceed the tensile strength, the reinforcement ratio and the concrete tensile strength are the key factors that determine the stress of the reinforcement.