【摘要】 为避免地下硐室仰拱施工期间因高水化热引发温度裂缝，本研究利用ANSYS有限元软件建立模型，模拟仰拱内部温度场，对比分析模拟结果与实测数据，验证模型的准确性.在此基础上，研究浇筑季节、浇筑温度、保温厚度及浇筑方法对地下硐室仰拱温度场和应力场的影响，进而提出最优防裂措施.结果表明：冬季浇筑相较于夏季，地下硐室浇筑仰拱内部降温速率下降13.9%,最大温差下降26.7%;夏季浇筑时，浇筑温度越低，降温速率和内外温差均越小；采用厚度为60 cm的挤塑聚苯板保温时，硐室仰拱降温速率为1.9℃/d;分层浇筑时，地下硐室仰拱温度应力下降63.7%.据此，提出具体优化养护方案：夏季浇筑温度为10℃,冬季采用分层浇筑并均覆盖60 cm厚挤塑聚苯乙烯板保温.优化养护后，冬夏季最高温升分别降低13.2%和15.5%,降温速率分别降低58.1%和66.7%,内外最大温差分别降低47.4%和41.5%.更多还原

【Abstract】 In order to avoid temperature cracks caused by high hydration heat during the construction of the underground cavern invert, this study uses ANSYS finite element software to establish a model to simulate the internal temperature field of the invert. The simulation results are compared with the measured data to verify the accuracy of the model. On this basis, the influence of pouring season, pouring temperature, insulation thickness and pouring method on the temperature field and stress field of inverted arch in the underground chamber is studied, and the optimal anti-cracking measures are put forward. Results show that, compared with the summer pouring, the cooling rate of the underground chamber pouring inverted arch in winter is reduced by 13.9%, and the maximum temperature difference is reduced by 26.7%. The lower the pouring temperature in summer, the lower the cooling rate and the temperature difference between inside and outside. The extruded polystyrene board with a thickness of 60 cm is used for thermal insulation, and the cooling rate of the inverted arch of the chamber is 1.9 ℃/d. When layered pouring is adopted, the temperature stress of the inverted arch of the underground cavern decreases by 63.7%. Accordingly, the specific optimization maintenance scheme is proposed: the pouring temperature in summer is 10 ℃, and the layered pouring is adopted in winter, which covers 60 cm of extruded polystyrene board of thermal insulation material. After optimized curing, the maximum temperature rise in winter and summer decreases by 13.2% and 15.5% respectively, the cooling rate decreases by 58.1% and 66.7% respectively, and the maximum temperature difference between inside and outside decreases by 47.4% and 41.5% respectively.更多还原