CRTSⅡ型板式无砟轨道底座板施工监控技术研究

A Study of the Monitoring Techniques for the Construction of the Base Slab for Type-II Plate-Type Ballastless Tracks

对于长大桥梁而言,CRTSⅡ型板式无砟轨道底座板的施工工艺复杂而繁琐。以石武客专无砟轨道底座板为研究对象,从施工角度对底座板施工的前期准备、质量要求、段落划分以及施工工序进行了详细描述,并进行了底座板施工应力监控研究。研究结果表明:对于长大的底座板结构而言,温度变化、混凝土的水化热及收缩徐变是导致混凝土开裂的原因;收缩徐变系数和摩擦系数的变化对结构应力影响较小,可以通过掺加钢纤维或采用分级加载技术等措施来控制裂纹产生和减小裂纹宽度。相关经验可为轨道板铺设、精调,水泥乳化沥青砂浆灌注施工奠定良好基础。

As far as large or long bridges are concerned,the construction processes for Type-CRTS-II plate-type ballastless base slabs are both complex and troublesome.With the ballastless base slab for the Shi-Wu Passenger-oriented Railway as an object of our research,the preliminary preparatory work,the quality requirements,the section-dividing and the construction processes for the construction of the base slab are described in detail from the angle of construction in the paper,with the stress-monitoring and stress control for the construction of the base slab studied.The results of our research show that,with long or large base slabs,the change in temperature,the hydration-caused heat of concrete,and the contraction creep often result in the cracking of concrete.The change in the coefficients of creep and friction has a relatively small effect on the structural stresses.Some technical measures,such as adding steel fibers to concrete and classified-loading,can help prevent concrete from cracking,or lessen the width of the cracks in concrete.The related techniques described in this paper may help lay anice foundation for the construction of laying and precisely adjusting track slabs,and slip-casting cement-emulsified asphalt mortar.