 In the aftermath of the ROK II Corps ' collapse on November 27 , Peng immediately ordered the PVA 38th Corps to cut the road between Kunu @-@ ri and Sunchon in the US IX Corps rear , while the PVA 42nd Corps would surround the entire Eighth Army by rushing south through Pukchang @-@ ni and capture Sunchon . At the same day , Walker shifted the Eighth Army 's line eastward by attaching the US 1st Cavalry Division and the Anglo @-@ Australian 27th Commonwealth Infantry Brigade to the US IX Corps . The US 1st Cavalry Division would contain the Chinese breakthrough at Pukchang @-@ ni , while the 27th Commonwealth Brigade secured the road between Kunu @-@ ri and Sunchon . 
