涵闸工程施工期混凝土温度监测系统与水化热参数反演

针对涵闸工程混凝土温控防裂需要,研制了全自动化数字测温系统。该系统的硬件部分由数字式温度传感器、采集单元、GPRS DTU组成,软件部分包括中心服务器软件和客户端软件。系统实现了GPRS公用无线网络覆盖范围内无人值守、多测点远程测量和数据实时共享,具有体积小、无需布线、运行稳定、精度高等特点。经过实际工程多次应用,系统运行稳定可靠,达到预期性能。基于以上系统的测量数据,结合三维非稳定温度场数值计算,对特定工程的水化热参数进行了反演。规范给出普硅42.5水泥水化热参数为m=0.69,n=0.56;而根据实测数据反演的结果为m=1.85,n=0.79。根据两组参数分别进行了三维温度应力计算,得到完全不同的计算结果,前者温度应力未超标,后者多处超标需要采用温控防裂措施才能保证结构防裂安全。因此对实际工程进行温度监测和水化热参数反演是非常必要的。

Automatic monitoring system for concrete temperature and inversion analysis of hydration heat parameters in culvert projects

To control the temperature and prevent cracks of concrete in culvert projects, we developed a fully automatic digital temperature measurement system. The hardware was composed of digital temperature sensors, an acquisition unit, and GPRS DTU. The software part included the central server and client software. The system has realized unattended operation, multi-point remote measurement, and real-time data sharing within the coverage of GPRS public wireless network. It is small in size, requires no wiring, runs steadily, and has high accuracy. Through several practical applications, it was proved to be stable and reliable. Based on the measured data and the numerical calculation of 3D unsteady temperature field, we retrieved the hydration heat parameters of a specific project. The specifications for P.O 42.5 were: m = 0.69, n = 0.56; and the inverted results were: m = 1.85, n = 0.79. According to these two groups of parameters, we calculated the 3D temperature stress, and obtained completely different results. The former did not exceed the standards, but the latter exceeded several standards and required crack-control measures to ensure the safety of the structure. Therefore, temperature monitoring and parameter inversion are very necessary for practical projects.