摘要
以衬砌薄壁混凝土结构开裂为研究对象,进行了隧洞衬砌混凝土裂缝监测设计,并对混凝土应力应变、温度、结构缝开合度等物理量进行了实时监测。监测结果显示:衬砌在浇筑完成后1个月内出现贯穿性裂缝,裂缝从拱肩至边墙分布,甚至延伸至整个断面,但裂缝开合度较小,且无明显张开趋势。从监测数据分析来看,薄壁混凝土散热较快,混凝土温降梯度较大,混凝土内部温度应力较高,加之混凝土表面未进行养护,表面干缩缝进一步加剧了混凝土内部裂缝的产生,裂缝产生后衬砌混凝土应力重分布,裂缝无进一步发展的趋势。
For studying the cracking of thin-wall lining concrete structure, the concrete lining crack automatic monitoring system of a hydraulic tunnel is designed, which is able to real-time monitor the stress, strain, temperature, crack opening of concrete. The monitoring results show that the lining has penetrated cracks within one month after the completion of pouring, and the cracks are distributed from arch to side walls, even to whole tunnel section, but the crack opening is small and there is no obvious enlarging trend. From the analysis of monitoring data, i! is found that the heat dissipation of thin-wall concrete is faster, the temperature drop gradient of concrete is larger and the internal temperature stress of concrete is higher. As lining concrete surfaee curing is not carried out, the dry shrinkage of surface concrete further promote the development of cracking m internal concrete. After the eraeking, the stress in lining concrete will be re-distributed, so the cracks will not further develop.
出处
《水力发电》
北大核心
2017年第9期45-48,共4页
Water Power
关键词
隧洞
混凝土衬砌
裂缝
安全监测
tunnel
concrete lining
crack
safety monitoring
