Stretching forces in tied bars and suspenders for half-through tied rigid-frame CFST arch bridges

Based on a tied rigid-frame concrete filled steel tubular (CFST) arch bridge with 158 m main span, this paper provides an introduction of the key issues in the construction of tied bars and suspenders for CFST arch bridges. The stretching process of tied bars in the main span has been simulated by MIDAS, which takes account of the pile-soil interaction. According to the results, the deviation of jacking end and the top of piles during the construction will be controlled effectively with the determined stretching force. For the specification of the stretching force in the suspenders of the main span, a computing method is put forward, which can make sure that each suspender has the equal tension at the end of the construction. With this computing method, the stretching force in each suspender of the sample bridge is ascertained. By comparing the analysis results with those got by MIDAS, the rationality and the feasibility of the method mentioned in this paper is verified. It is noted that the order of stretching has a great effect on the specification of the stretching length and force of suspenders, depending on the comparison results of the stretching length got by with or without the consideration of stretching order.