Abstract：As an efficient supporting method，prestressed anchor cable composite soil nailing is widely adopted in geotechnical engineering. But the analysis of prestressed anchor mechanism is not sufficient. And the research on in-situ test of prestressed anchor cable composite soil nailing is seldom seen. Firstly，a brief introduction to the mechanism of prestressed anchor cable composite soil is given. Then，the horizontal and vertical displacements of foundation pit supported by prestressed anchor cable composite soil nailing are presented. The stresses of soil nailing and anchor head of prestressed anchor cable under excavation are also attained. Finally，the characteristics of stress and deformation of the prestressed anchor cable composite soil nailing with ANSYS10.0 are analyzed. Conclusions can be drawn as follows：(1) the results from in-situ test are in accordance with those from FEM simulation；(2) cohesion and elastic models of the soil in foundation pit，which is supported by prestressed anchor cable composite soil nailing，will be improved；(3) more earth pressure is shared by the anchor cable，and earth pressure shared by soil nailing is reduced for prestressed anchor cable composite soil nailing supporting；(4) earth pressure on the side of foundation pit is smaller when prestressed anchor cable composite soil nailing supporting is introduced；(5) the stress and deformation of soil nailing and prestressed anchor cable both have the excavation effect，time effect and space effect；(6) the horizontal deformation of the side of foundation pit is drum-shaped，and the vertical deformation of the side of foundation pit agrees well conventional rule；(7) the deformations of foundation pit，including the horizontal displacement and the vertical displacement，are better controlled when using prestressed anchor cable composite soil nailing supporting；and (8) prestressed anchor cable composite soil nailing supporting technique can gradually improve the supporting capacity during excavation，which satisfies the requirements of variations of the stress and deformation induced by the construction process and some uncertain factors. The achieved results can provide some references to the design and construction of similar projects.
