拱坝深孔特殊材料分区温度应力敏感性分析

Sensibility analysis on thermal stresses of special material zones of bottom outlet of arch dam

通过三维有限元温度应力仿真分析,研究了某特高拱坝深孔特殊材料分区及不同温控措施对深孔周边温度应力的影响。孔口周边一般采用高标号的混凝土材料,其弹模高、绝热温升也偏高,计算结果表明:(1)应尽量避免高温季节浇筑孔口混凝土,尤其是材料分区复杂的孔口混凝土;(2)采用低热混凝土材料代替泵送混凝土、加密冷却水管间距以及适当增加同时中期冷却和二期冷却的高度均对改善深孔底部及周边高标号混凝土的温度应力水平有明显效果。

With 3D FEM thermal stress simulation analysis, the impacts from both the spacial material zones and the temperature control measures on the thermal stress around the bottom outlet are studied herein, as the high strength concrete with high elastic modulus and higher adiabatic temperature rise is normally adopted at the areas near the orifices. The study shows that（ 1 ） it is better to avoid the placement of the concrete of orifice in high temperature season, especially for the concretes of orifice with complicated material zones; （2）it is better to replace the pumped concrete with the low heat concrete, densify the spacing of cooling water pipes and increase the heights of the mid-stage cooling and the second stage cooling properly; all these measures have significant effects to improve the thermal stress levels of the high strength concretes at the bottom and the surrounding areas of the orifice.