Ballastless tracks have been widely used in construction of high-speed railways in China . The damage issue of ballastless tracks mainly in the form of carcks is becoming gradually evident , especially prominent is the influence of rainwater to the damages . In this paper , applying the unified governing equation and mathe-matical model established in the solid and fluid domains , on the principle of the two-way coupled field computa-tion ,extension of water-bearing cracks below bedding mortar of the CRTSⅡ type track slabs under the loading action of high-specd trains were simulated . By numerical analysis , the upper and lower surface pressures of cracks and the stress-intensity factor of crack tips were calculated . The results show as follows :The crack height and length are the important factors to affect surface pressures of cracks and so to cause further crack ex-tension ;the crack height and length directly affect surface pressures of cracks which rise basically linearly with increasing of the stress-intensity factor of crack tips ;the crack length of 0.6 m and crack height of 3 mm are the ultimate state of crack extension ;when the crack length exceeds 0.6 m or the crack height exceeds 3 mm , the tendency of crack extension becomes more distinct .%无砟轨道在我国高速铁路中广泛应用，但以裂纹为主要形式的伤损问题也逐步凸显，特别是雨水对伤损的影响尤为突出。本文应用流固耦合理论及其统一控制方程，基于双向二维流固耦合场计算原理，建立高速列车荷载作用下CRTSⅡ型板式无砟轨道砂浆层下含水裂纹扩展问题的模拟；应用数值分析方法对裂纹上下表面压力和裂纹尖端强度因子进行计算分析。结果表明：裂纹开口量和长度是影响裂纹表面压力致使裂纹继续扩展的重要因素；裂纹长度与开口量直接影响表面水压力，而裂纹尖端强度因子与表面压力基本呈线性关系增加；裂纹长600 mm和开口量3 mm是裂纹扩展的极限状态，当裂纹长度大于600 mm或开口量大于3 mm时，裂纹扩展趋势明显。
展开▼
