Abstract: The flexible retaining technology with prestressed anchor has the advantages of safety, short construction duration and economic rationality for retaining excavation in weak rock, which has been widely applied to practice. Owing to the advantages of removal and economization of land resources in excavation projects in urban areas, a method of making centrifugal model with the pressured prestressed anchor is developed combining with the deep excavation project of Dalian Victory Plaza. The centrifugal model tests of flexible retaining structures with pressured prestressed anchor are carried out; the numerical models by FLAC are established for comparison and verification; the influences of the deformation of excavation, the horizontal earth pressure and the anchor types on the design value of the anchor prestress and their influences on the slipping zone are studied. The results show that: the different lengths of unbonded segment in pressured and tensioned anchor resulted in the demand of two types of anchor for the different design value of prestress; the centrifugal models with pressured prestressed anchor and the FLAC numerical model with tensioned prestressed anchor have obtained the linear slip zone with similar position; and the two are verified by mutual verification. The difference in the anchor types does not affect the damage mechanism of the excavation.

Key words: deep excavation, flexible retaining structures with prestressed anchor, centrifuge modeling, pressured anchor, failure mechanism