Abyssal Region Oversea Bridge Piers Maintenance Equipment Study

With the rapid developing of China economy,many oversea bridges were built to connect islands and the continent or cross gulf and estuaries in the last three decades.The harsh environment make these piers need to be repaired periodically,especially those parts beyond the water,which relay on the coating to protect them from the sea water erosion.The piers need to be cleaned and recoated after the coating failure.This study dedicated to design a kind of highly effective cleaning equipment for the cleaning work during the piers maintenance,which can automotive clamb to the pier,with the abrasive water jet and automatic climbing robot technology.Abrasive water jet equipment was used as removal equipment after analyzed the technology and equipments were used in the last decades.Automatic climbing robot was used as a carrier of the abrasive water jet equipment based on the shape and location characteristic.The mainly parts such as the nozzle and large diameter revolve nozzle and high pressure rotary joint were designed.The removal effective equations were given in the study.The clearance seal theory was studied,and analyzed the deformation of the clearance seal part under the high water pressure with ANSYS.Studied the abrasive water jet removal theory and did the explicit dynamic analysis of the process of the sand crush the material which should be removed.Analyzed the flow field of the nozzle with FLUENT to find out the influence of the parameters of the nozzle to the jet speed and select a series of parameters for the nozzle based on solid-liquid two-phase flow theory.Studied the effective range of the jet,by analyzed the flow field out of the nozzle.Designed an automatic wall climbing robot,used as the carrier of the abrasive water jet.Analyzed the mainly parts of the robot to make sure it has enough strength.