considering the thick backfill and soft foundation soil in the cut-and-cover section of jiadi tunnel, a pile-raft foundation is accepted in order to avoid negative effect due to excessive settlement.
浃底隧道出口明洞段回填厚度较大而基础土体软弱,因此采用了桩-筏基础的形式以避免过大沉降带来的不利影响。