某船闸输水隧洞施工期—运行期裂缝成因与分析

Cause and Analysis of Cracking on Concrete Water-conveyance Tunnel of Navigation Lock

为分析某输水隧洞顺流向裂缝产生的原因及其影响,以隧洞衬砌及部分围岩为研究对象,采用考虑缝面接触问题的非线性有限元法,模拟隧洞衬砌混凝土施工及隧洞有水调试过程,对衬砌结构的温度及应力进行仿真分析。结果表明,底板裂缝发生于有水调试前,由温度应力引起;而顶拱裂缝是由早期的温度应力和隧洞有水调试产生的结构应力共同作用引起。裂缝出现后,钢筋应力及裂缝面错动位移满足承载力要求。

In order to analyze the cause and harmfulness of the cracking along water flow direction on the water-con veyance tunnel of navigation lock, taking tunnel and part of surrounding rock for an study object, contact joint face FEM is used to simulate the construction of concrete lining and water regulation in tunnel. And then the temperature and stress of lining structure is analyzed. The results indicate that the cracking on the bottom plate is caused by the thermal stress before water flow regulation while the cracking on the roof arch results from the combined action of thermal stress and water flow regulation; reinforcement stress and shear displacement of cracking surface meet the loading capacity require- ments after the appearance of cracking. Crack reduces the concrete stress nearby, and increases the concrete stress of oth- er area slightly.