Forty-two case histories in which the laterally adjacent deep excavation affects the existing tunnel are collected.The typical stratum condition

size

relative position

structure deformation and control measures of deep excavation and tunnel in each case history are counted.By analyzing the influences of important factors on vertical and horizontal displacements of tunnel

the judging criter

ions of tunnel heave and settlement are clarified

and then the zoning of tunnel vertical displacement outside the deep excavation is given.The comprehensive prediction index of tunnel horizontal displacement is proposed

and the practical empirical prediction formulae of tunnel horizontal displacement under three categories of stratum conditions are given.Finally

relying on a specific case study

the deformation of tunnel is predicted using the obtained empirical formula before construction

and the rationality of the prediction formula is verified by comparing the prediction results with the field monitoring results.The results show that the horizontal displacement of tunnel is towards the pit

while the vertical displacement is in the form of heave or settlement

which is related to the buried depth of tunnel crown （H

t

） and the distance between tunnel springline and deep excavation （L

t

）.It is obtained from statistics that the critical value of H

t

is H

e

+R and the critical value of L

t

is H

e

and then considering the vertical displacement distribution characteristics of tunnel

the area outside the pit can be divided into settlement zone

transition area and heave zone.Horizontal displacement of retaining structure (ζ

hm

)

excavation depth （H

e

）

horizontal distance L

t

between tunnel and deep excavation and longitudinal width b of deep excavation along tunnel are all important factors affecting horizontal displacementζ

hm

of tunnel.ζ

hm

increases nonlinearly with the increases of δ

hm

and H

e

;ζ

hm

/δ

hm

decreases with the increase of L

t

as a power function relationship;ζ

hm

has an increasing trend with the increase of b

which means multiple factors should be considered to scientifically predict the horizontal displacement of tunnel.ζ

hm

and bH

e

/L

t

have a good linear relationship under three stratum conditions using bH

e

/L

t

as the prediction index of tunnel horizontal displacement

and the tunnel horizontal displacement prediction formula based on it can achieve good prediction effect proved by an actual engineering case.