大型地下洞室衬砌混凝土温控防裂研究

Study on Temperature Control and Crack Prevention for Lining Structure of Underground Engineering

随着现代地下工程规模不断增大,地下工程混凝土温控防裂问题也越来越突出,需引起更多重视。采用有限元法对地下洞室衬砌结构进行施工期温度及温度应力仿真,重点对衬砌厚度、分缝长度、围岩弹模及约束情况、洞室气温等进行敏感性分析,归纳影响地下洞室衬砌结构温度裂缝产生的主要因素。结果表明,结构分块尺寸及约束条件等对衬砌结构温度应力影响较大,施工过程中应根据需要采取适当温控措施降低最高温度、减小结构约束情况,进而减小温度应力,以提高地下洞室衬砌结构抗裂安全。

As the increase of underground construction scales, the concrete temperature control of underground construc- tion becomes a more outstanding problem demarding more attention. Here, the finite element method was adopted to sim- ulate the temperature and thermal stress of the construction period for the underground concrete lining structure with the emphasized analysis of the thickness of the lining, the length of the parting, elastic modulus of the surrounding rock, constraint conditions, and cavity temperature. And then the main factors that affected lining structure temperature crack during the construction of underground engineering were summed up according to the analysis. The results indicate that the structure unit size and constraint conditions significantly affect the thermal stress of the structure. Thus, it＇ s neces- sary to take appropriate temperature control measures based on the actual situation, to reduce the temperature and thermal stress and improve the anti - cracking safety for the lining structure of the underground engineering.