Seismic Response of Bridges Subjected to Different Earthquake Types Using IDA

Incremental Dynamic Analysis (IDA) was used to evaluate the seismic response of straight, continuous 4-span bridges with different sub-structure configurations. Three different record sets were chosen to represent three different earthquake types which can occur for a site such as Vancouver (i.e., crustal, subduction interface, and subduction inslab earthquakes). Seventy eight records were considered in each set (i.e., a total of 234 records) and the capacities of the bridges were evaluated using a fast IDA algorithm. A simplified method to account for the effects of spectral shapes was used. Different subsets of the records with specific characteristics were also used in the IDA. The bridges were designed and evaluated for two different design force modification factors and bridges with different degrees of irregularity were studied. Comparisons of the IDA results obtained indicated that in most of the cases the interface record sets resulted in lower median collapse capacities and hence were the most critical of the ground motions studied.     

从立法视角审视“文物”概念——以《文物保护法》的修订为契机而展开

《文物保护法》中的“文物”作为法律概念,承载被普遍认同的“历史”、“科学”和“艺术”等重要价值,其必须有形、可控,且范围确定,而“文物”概念本身亦应具备法律规定性和明确性两方面的重要特征。故此次修订《文物保护法》不宜将类似“文化线路”、“文化景观”等范围模糊概念仓促纳入“文物”范畴;而以“文化遗产”概念取代“文物”的观点也值得商榷。