Design and application of lightly mounted steel sheet piles for deep foundation pits in red sandstone

The excavation depth of pier cofferdam of Taiyuan-Zhongwei Yinlu River Bridge is 11.4 m, using Larsen steel sheet piles of 12 m as the temporary protecting and sealing structures for foundation pits. The embedded depth in the red sandstone is 0.6 m, and the embedded ratio is only 0.05, which is much smaller than 0.3~1.0. Specific calculations indicate that the internal force, deformation and overall stability of the support structures all meet the specifications. The regular vibro-sinking methods can not drive the sheet piles into the high-strength red sandstone. Through field tests and explorations, the vibro piles of high-pressure water injection solves the above problem that sheet piles can not be driven into red sandstone. The vibro piles of high-pressure water injection and the construction technology are introduced. It has certain significance for foundation pits with steel sheet piles under similar geological conditions.