Based on the method of images

the three-dimensional soil loss additional load formula caused by DOT shield tunneling soil loss is derived by using non-uniform soil movement model. The distribution regularity of total additive load from additive thrust force

the friction between DOT shield machine and soil together with soil loss on existed adjacent tunnel is researched. The results show that: the distribution regularity of additive load is closely related with the relative position of existed adjacent tunnel and DOT shield tunnel; and it is a three-dimensional problem. In the thrust direction

the additive stress changes from tension behind into pression ahead of the excavation face. Soil loss is the main factor in total additional load

followed by friction and thrust additional force; the additional load that the existed adjacent tunnel subjected to is closely related to its net spacing away from DOT shield machine S; and additional load increases rapidly when S decreases; the existed adjacent tunnel is subjected to the greatest additional load in the axis position of DOT shield machine with the variation of axis buried depth of the existed adjacent tunnel.