高拱坝掺合氧化镁膨胀变形对横缝开度的影响  

Effects of expansional deformation of MgO mixed in concrete on transverse joint aperture in high arch dam

作　　者：王琼[1] 常晓林[1] 赖国伟[1] 张超[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,湖北武汉430072

出　　处：《武汉大学学报（工学版）》2013年第5期588-592,共5页Engineering Journal of Wuhan University

摘　　要：运用三维瞬态非线性有限元方法,考虑不同掺量氧化镁自生体积变形的影响,对李家峡双曲拱坝进行全过程动态仿真敏感性分析,详细探讨掺合氧化镁膨胀变形对横缝开度的影响.同时将横缝开度仿真结果与李家峡实测结果相对比,吻合良好.根据仿真分析,外掺氧化镁对拱坝横缝开度的影响主要表现在一期冷却之后,由于早期膨胀变形产生预压应力,增大了后期横缝张开的阻力.相同条件下,氧化镁掺量越大横缝开度终值越小,甚至不满足灌浆要求.并根据仿真计算指出横缝开度是高拱坝氧化镁掺量的控制性因素,对李家峡双曲拱坝及相类似工程,氧化镁掺合量宜取2.5%.Concrete mixed with MgO will result in expansional autogenous volume deformation. For Lijiax- ia double curvature arch dam, effects of different contents of MgO in concrete on transverse joint aperture are studied with 3D transient nonlinear FEM. Simulation results are compared with the practical ones~ it is proved to be quite good. And effects of MgO on transverse joint aperture during the whole process are dis- cussed in detail. According to the simulations, earlier expansional deformation increases the later resist- ance, so the more the content of MgO, the smaller the transverse joint aperture. And transverse joint ap- erture is one of the main important factors which control the content of MgO mixed in concvete for high arch dam. For Lijiaxia double curvature arch dam and the similar ones, our suggestion is 2.5% MgO.

关 键 词：高拱坝 氧化镁 自生体积变形 横缝开度 温度应力 掺量 

分 类 号：TV311[水利工程—水工结构工程] TV315