【摘要】 严寒地区修建大坝常采用冬季停工保温措施,保温效果事关大坝质量安全。为了监测严寒地区碾压混凝土大坝越冬保温效果,利用分布式光纤测温技术,对丰满大坝保温材料内混凝土表面及内部进行远程在线监测,监测结果与仿真分析结果进行对比。光纤测温测点多、密度大、频率高,全面捕捉到了最不利气温下最不利位置的混凝土表面温度,监测持续时间约5个月,根据混凝土内部埋设的光纤测温数据,计算了混凝土在严寒气温下的内外温差。结果表明:丰满大坝混凝土越冬的保温措施设计合理、施工及时,有效地防止了混凝土的表面开裂;分布式光纤即使在室外气温为-25～-30℃的情况下,也能正常测温。更多还原

【Abstract】 Dam construction in severe cold area usually takes measures to stop the construction and preserve heat before winter comes. The effect of heat preservation is related to dam quality and safety. Distributed optical fiber temperature measurement technique was used to measure dam surface temperature beneath insulating material in order to monitor the insulation effect. The results of remote on-line monitoring were compared with the simulation results. There were infinite monitoring points in optical fiber which could measure in high frequency. Measurement time lasted five months which fully captured the concrete surface temperature especially the most unfavorable position at extremely low temperature. The internal and external temperature differences of the dam were calculated. Data shows that the design of heat preservation measures is reasonable and the insulation is in good time. Dam surface cracking is effectively prevented. It has a certain reference value for winter construction and winter heat preservation of dam in severe cold area.更多还原