Scaled model test for the influence on an existing shield tunnel induced by surface surcharge is carried out

and vertical earth pressure and soil settlement for the stratum above the shield tunnel are analyzed. Results show that under uniform surface surcharge

the less of the vertical distance from the top of the tunnel

the more extent for the nonuniform vertical earth pressure in the stratum above the shield tunnel

and the more extent for the nonuniform soil settlement of overlaying soils of the shield tunnel. The overlaying soils show vertical earth pressure transference for vertical shearing force among soil elements

which is induced by vertical relative movement among soil elements as the stratum above the shield tunnel has nonuniform soil settlement

so the vertical earth pressure in the stratum above the shield tunnel is nonuniform. As vertical shearing force among soil elements for overlaying soils is related to vertical relative movement among soil elements and soil mechanical property

the extent of nonuniform vertical earth pressure in the stratum above the shield tunnel is affected by the extent of nonuniform soil settlement and soil mechanical property of overlaying soils when the tunnel suffers from surface surcharge

so the tunnel deformation is influenced.