Load Sharing and Its Time Effect on Piled Raft Foundations under High Embankment

The piled raft foundation is being initially attempted in recent years for special soil ground of high speed railway. The interaction and load sharing mechanism, as well as its time effect should be studied primarily in order to design the piled raft structure rationally. Specific to the piled raft foundation of high speed railway, this paper adopts field tests and simplified calculations and integrates the two methods to analyzing the load sharing mechanism and its time changing law. The results show that: The construction process is the load sharing adjustment process; the main vertical load is undertaken mainly by piles and rafts, and is transferred to the substratum by piles, the soil between piles only bears a small amount of load (about 3.7%) and is suggested to considering as a safety margin in the design; the raft shares about 14∼20% of the upper load, which should be considered in the structure design.