Lateral soil movement induced by foundation pit excavation might adversely affect any nearby underground pipelines even damage. Based on displacement-controlled theory

the development of free soil movement induced by excavation with retaining walls is studied. By comparison with displacement-controlled finite element method

the displacement-controlled two-stage simplified method is verified. Secondly

the environment protection criterion for foundation pit in current technical code for excavation engineering is discussed; and a new deformation controlling criterion for excavation based on the protection for adjacent pipelines is introduced，in which the relationship between the excavation depth and the allowed maximum lateral deformation of the retaining wall is given. It is hoped that the above work could give theoretical support for the construction of environment protection estimation system in foundation pit excavation.