Abstract: In view of great difference between the predicted final ground settlement and the measured ground set? tlement during shield tunnelling, the conditions of soil arching effect in the process of shield tunnelling and its influence on ground settlement are considered on the basis of the Terzaghi theory. The back analysis is carried out to obtain the relationships between the tangent of ground influence angle tanβ, tunnel convergence area and tunnel buried depth, then the effects of cohesion, internal friction angle and tunnel buried depth on ground settlement are discussed, and the simplified formula of stochastic medium theory is modified accordingly. The comparison with monitored data from the actual project shows that the modified calculation method is more accurate for predicting ground settlement during shield tunnelling, the settlement caused by uneven soil stress decreases along with the increase of the tunnel buried depth and finally tends to be stable. The buried depth of the tunnel has the greatest influence on ground settlement in the construction phase, followed by internal friction angle and cohesion.