某建筑修缮改造工程抗拔桩设计及讨论

Design and Discussion of Uplift Piles in a Building's Retrofitting

南京某民国文物建筑原为2层砖混结构,无地下室,现因修缮改造需要,拟改为异形柱框架结构,且增设1层地下室,基底埋深为5.2～6.8m。由于地下水位较高,需考虑地下室的抗浮问题。结合该工程讨论了抗拔桩数量的确定、桩身配筋计算及裂缝宽度验算等需要注意的问题,建议采用单桩安全系数法分区抗浮以及利用预留腐蚀余量(增加纵筋直径3mm)的方法代替裂缝宽度验算等。

A historic building built during the Republic of China in Nanjing is a two-floor masonry structure residence without basement.Now for the sake of repairing and reconstructing,it needs to be changed into frame structure with specially shaped columns,and single floor basement,whose foundation base is buried to the depth of 5.2~6.8m,is to be added.For the water level underground is high,the anti-floating design of the basement need to be considered.Combined with this project,some problems about determination of the quantity of uplift pile,calculation of the reinforcement and checking of crack width are discussed.It is advised that designer use factor of safety method of single pile and add 3mm to bar diameter to ignore the checking of crack width and so on.