Abstract: There are great risks and difficulties in the construction of cutandcover foundation pits adjacent to existing operating railway. The pileanchor system of the retaining structure of the superlarge deep foundation pit of Shijiazhuang 6track tunnel, as well as the construction technologies and protection technologies, are presented. Countermeasures for raining seasons and systematical monitoring technologies are proposed. The construction practice shows that the risks can be brought under effective control by optimizing the construction technologies and equipments and strengthening the monitoring. The paper can provide references for the design and construction of similar projects in the future.

Key words: being adjacent to operating railway, superlarge deep foundation pit, Shijiazhuang 6track tunnel