CAJ | 학술논문

南京长江第四大桥主桥为主跨1418 m的双塔三跨悬索桥，全桥设置2幅猫道作为主缆施工平台，在主缆主要施工作业完成后需拆除猫道。猫道按照猫道面层、变位钢架、猫道索顺序拆除。猫道面层先采用卷扬机拆除门架处型钢横梁，然后由塔顶向中跨跨中和锚碇方向，边、中跨同步拆除底网和侧网。面层拆除后，用塔吊或汽车吊拆除塔顶两侧和锚碇前方的变位钢架。猫道索拆除按照猫道承载索、扶手索、门架承重索的顺序进行，内侧猫道索下放至主缆内侧钢桥面上拆除，外侧猫道索下放至吊索外桥面检修道上拆除。拆除的猫道索采用收绳架分段收绳、上盘后运输至后场存放。
남경장강제사대교주교위주과1418 m적쌍탑삼과현색교，전교설치2폭묘도작위주람시공평태，재주람주요시공작업완성후수탁제묘도。묘도안조묘도면층、변위강가、묘도색순서탁제。묘도면층선채용권양궤탁제문가처형강횡량，연후유탑정향중과과중화묘정방향，변、중과동보탁제저망화측망。면층탁제후，용탑조혹기차조탁제탑정량측화묘정전방적변위강가。묘도색탁제안조묘도승재색、부수색、문가승중색적순서진행，내측묘도색하방지주람내측강교면상탁제，외측묘도색하방지조색외교면검수도상탁제。탁제적묘도색채용수승가분단수승、상반후운수지후장존방。
The main bridge of the Fourth Nanjing Changjiang River Bridge is a two‐tower three‐span suspension bridge with a main span of 1 418 m .Two sets of catwalks were erected as the construction platforms for main cables ,and dismantled after the primary construction contents of the main cables w ere finished .T he demolition of the catw alks follow ed the sequence of floors , profile‐shifted steel frames and catwalk cables .When the catwalk floors were dismantled ,winches were used first to remove the sectional steel cross beams at the portal frames ,then the demolition was proceeded from the tower tops to the midspan of the central span and to the anchor blocks , and the base screen and side screens were dismantled simultaneously .After the floors were re‐moved ,the profile‐shifted steel frames located at the two sides of the tower tops and in front of the anchor blocks were dismantled using lifting towers or truck cranes .The catwalk cables were dis‐mantled following the sequence of load bearing cables ,hand rail cables and portal load bearing ca‐bles .The inner side catwalk cables were lowered to the steel plate deck next to the inner side of the main cables and removed ,w hereas the outer catw alk cables w ere low ered to the maintenance paths outside the suspender planes and removed .The catwalk cables dismantled were retracted in sections using the rope retracting frame ,and reeled for transportation and stored off the bridge site .