垫层材料对泄洪洞衬砌混凝土施工期温度和温度应力影响研究  

The Influence of Cushion Material on Temperature and Thermal Stress of Lining Concrete of Flood Discharge Tunnel during the Construction Period

作　　者：刘琨[1] 段亚辉[1] 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,武汉430072

出　　处：《中国农村水利水电》2013年第12期130-134,138,共6页China Rural Water and Hydropower

摘　　要：以溪洛渡有压泄洪洞为研究对象,采用三维有限元法对施加不同材料垫层情况下的衬砌混凝土施工过程进行仿真模拟,比较了边顶拱衬砌混凝土不同代表点的最高温度、最大内表温差,早期以及冬季最大拉应力,最小抗裂安全系数,经分析表明:所采用的垫层材料导热系数值越小,衬砌混凝土早期水化热向围岩传递所受阻碍作用越明显,衬砌混凝土的温升值越高,内表温差亦随之加大;所采用的垫层材料弹性模量值越小,围岩对于衬砌混凝土的约束程度越低,衬砌混凝土的温度应力水平降低越明显,越有利于衬砌混凝土早期以及冬季温度应力的控制,本研究成果可为隧洞工程衬砌设计提供有价值的参考。The mechanical parameters and thermal properties of cushion materials have great differences, accordingly, although under the same pouring materials and operating conditions, the temperature and the thermal stress of the lining concrete which will affect the occurrence and control of the temperature cracks to a great extent are also different. Taking Xiluodu free-flow tunnel as a re- search object, a 3D finite element method is applied to simulate the construction process using different materials as the cushion for lining concrete. By comparing the maximum temperature, maximum temperature difference between the inner and surface, maximum tensile stress in the early period and winter, the effect of the cushion material on the temperature and thermal stress of the lining con- crete are analyzed. The results show that the cushion materials have significant influences on the temperature field and stress field of the lining concrete. The lower the thermal conductivity is, the more obvious the hindering effect of hydration heat transmission from lining concrete to surrounding rock will show, the value of maximum temperature and the maximum temperature difference between the inner and surface will also increase; the smaller the elastic modulus is, the lower the thermal stress level of lining concrete is, which is beneficial to the thermal crack prevention in the early age and winter. The research results provide a valuable reference for the design and construction of the tunnel projects.

关 键 词：泄洪洞 衬砌混凝土 垫层 温度应力 

分 类 号：TV311[水利工程—水工结构工程]