气肋组合式冰壳结构受力性能分析与现场监测

Structural performance investigations and field monitoring of an air-rib combined ice shell structure

采用气膜作为施工模板,通过喷射纤维复合冰材料建造的大跨度冰壳结构,具有受力合理、施工高效、新颖美观等优点。由于冰材料具有较强的温度敏感性及蠕变时效特性,因此针对冰壳结构服役期的健康监测与安全性评估至关重要。为此,以2017年冬季开展的气肋组合式冰壳结构为背景,分析了该类冰结构的受力性能,研究了适用于冰壳结构的现场监测技术,并基于监测结果,对冰壳结构服役期间的响应变化规律及成因进行了归纳分析。同时,提出了气肋组合式复合冰壳结构的安全评估意见与建议。结果表明:气肋组合冰壳整体受力性能合理;环境温度和日照辐射是影响冰壳结构长期性能的主要因素,应当重点关注环境温度高于-5℃时冰壳结构响应的变化。

The large-span ice shell structure employing pneumatic membrane as temporary construction formwork and cellulose-water mixture spraying has the advantages of reasonable stress,efficient construction and beautiful shape.Owing to the strong temperature sensitivity and creep characteristics of ice materials,the health monitoring and safety assessment of the ice shell during operation are quite critical.Based on the air-rib combined ice shell structure built in the winter of 2017,comprehensive structural investigations on the mechanical behavior of the ice shell were conducted,and the field monitoring techniques applicable to the ice shell were discussed.The response laws of ice shell structure in service were analyzed based on the monitoring results.Finally,the safety assessment opinions of the air-rib combined ice shell were summarized.The results show that the structural performance of the air-rib combined ice shell is reasonable.The environmental temperature and solar radiation are the key factors affecting the long-term performance of ice shell,and the structural response of ice shell should be specially paid attention to when the ambient temperature is higher than-5℃.