【摘要】 高海拔地区的高速铁路桥墩在早龄期经常出现表面热开裂的问题。本研究结合现场实验和数值模拟方法，考虑胶凝材料用量、水泥种类和模板类型三个变量，计算并分析了高铁桥墩的早期温度场、变形场及开裂风险。结果表明：在常用范围内提高胶凝材料用量时，混凝土开裂风险的增加率不超过10%；选用水化热较低的水泥和导热系数较高的模板材料可有效缓解早期开裂风险。通过整合上述三个变量，提出一个组合变量“水化-热阻耦合温升”，以综合反映带保温层混凝土所固有的热工性能。回归分析表明，新变量与桥墩最早可行拆模龄期之间为强线性关系。基于该组合变量，初步建立了三个预测高铁桥墩拆模龄期的线性回归模型。在限定的环境条件下，这些预测模型可直接确定高铁标准化桥墩的最早可拆模龄期，无需复杂的有限元计算分析。更多还原

【Abstract】 High-speed railway(HSR) bridge piers in high-altitude areas frequently face the challenge of early-age thermal cracking. This study employed numerical simulation methods to analyze the early-age temperature field, deformation field, and cracking risk of HSR bridge piers, considering three factors: binder content, cement types, and formwork types. The results show that the cracking risk slightly increases with a higher content of cementitious materials. However, this risk can be mitigated by selecting cements with lower heat of hydration and formwork materials with higher thermal conductivity. A variable termed “representative temperature rise for unit concrete” was proposed to integrate these three factors and comprehensively reflect the inherent thermal property of the pier. Subsequently, three linear regression models for predicting the demolding age of HSR bridge piers were established. These models empower engineers to determine the earliest feasible time for formwork removal without the need for complex computational analyses.更多还原