关键词: 深基坑, 临近铁路, 锁口钢管桩, 止水, 地表沉降

Abstract: The depth of deep foundation pit of the main pier of Caijiazhuang Large Bridge is 11.25m, the groundwater level is high, and it is close to the Yangshe railway in operation. After analysis and trial calculation, large-diameter Locking steel pipe piles are adopted as the main supporting structure. According to the variation law of soil and water side pressure, the vertical spacing of the purlin surrounding system is reasonably designed. At the same time, in order to prevent water, the construction method of pouring isolated cement mortar in the lock is used to facilitate the removal of the steel pipe pile. The strength, horizontal displacement and settlement of existing railway subgrade outside the pit meet the requirements by using the straightening software to calculate the supporting structure. Moreover, the results of construction monitoring are in good agreement with the theoretical calculation value, and the removal of the protective pile is smooth. This has a good reference significance for the construction and support scheme design of deep foundation pit near the existing line.

Key words: deep foundation pit, adjacent railway, locking steel pipe pile, still waters, surface settlement