文档介绍：: .
水力发电学报 射-反射联合测定方法并以此开展混凝土凝结状态的监测试验研究，构建基于 L-M（Levenberg-
Marquaredt）算法的神经网络模型并以能量指标确定的时间点数据集进行训练，用以精确计算大
坝混凝土凝结时间。将该方法用于 C25 大坝混凝土的凝结试验中，并同基于能量分析的反射法、
透射法和基于波速分析的透射法进行了对比，结果表明：本文所提的方法相比上述方法计算所得
凝结时间的最大相对误差降低了 %-%，且计算所得初凝时间和终凝时间与真实值的相关系
数分别为 和 ，验证了超声波透射-反射联合法的准确性。本文提出的“透射-反射”联合
法能够准确监测大坝混凝土凝结过程，可为大坝混凝土施工质量控制提供新的有效手段，具有重
要的理论意义与实用价值。
关键词：大坝混凝土；凝结时间；超声波；透射-反射联合法；L-M 神经网络；能量
中图分类号：TV43 文献标志码：A
Research on setting process of dam concrete based on ultrasonic
combined method
CUI Bo, WANG Zijun, LIU Changxin, REN Bingyu
(State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300350, China)
Abstract: The determination of the condensation state of fresh concrete is crucial to the quality control
of dam concrete construction. The traditional method for measuring the setting time of concrete is the
penetration resistance method, which is detrimental to monitoring and is difficult to achieve continuous
and real-time monitoring of the concrete setting process. The emerging ultrasonic nondestructive
monitoring mainly adopts a single transmission method or reflection method. However, the reflection
method is greatly affected by the incident angle, and the calculation of the wave velocity of the
transmission method needs to manually determine the first wave occurrence time accurately. In view of
the above problems, this paper puts forw