Analysis of pit slope stability in the Quaternary alluvial fan of the Yongding River, western Beijing

The excavation of the foundation of a building of Beijing Dance College has reveals the vertical distribution characteristics and engineering geological properties of the Holocene and late Pleistocene strata in the Yongding River alluvial fan, western Beijing. The engineering geological properties in this area can meet the bearing capacity of general high-rise buildings (h≤100 m), and the bearing strata are mostly in the 5th or 7th layer of the Holocene and Late Pleistocene strata, with no foundation treatment needed. We may directly use the natural foundation. The major engineering geological problem for the general high-rise building in this area is the slope stability of the excavated deep foundation pit. By using pile-anchor supporting system combined with some necessary monitoring means for foundation pit support in this area, the subsidence of the building around the pit, slope displacement and slope stability of the pit can all meet related standards.