Method for observing and calculating depth of newly-generated swelling shrinking deformation of excavation expansive soil slope surface

The invention discloses a method for observing and calculating depth of newly-generated swelling shrinking deformation of an excavation expansive soil slope surface. The method comprises the following steps of: carrying tracking observation by embedding a displacement meter in a shallow shaft, carrying out time effect statistic analysis on an observation result based on assumption of linear attenuation of the swelling shrinking deformation along the depth of the slope surface, and calculating the depth of the swelling shrinking deformation of a slop surface soil body under the action of weather by utilizing a linear equation on the premise of reasonable linear assumption verified by observation data. The method for observing and calculating the depth of the newly-generated swelling shrinking deformation of the excavation expansive soil slope surface, disclosed by the invention, overcomes difficulty that a fixed point is hard to exactly arrange by a surface mark measurement method, also has the advantages of high precision of the observation data and small influence by personal factors compared with the surface mark measurement method, and is reasonable in calculating method and simple and convenient to calculation; and analysis parameters of a protection design matching conditions of local weather can be provided for a protective barrier of the excavation expansive soil slop surface through the results obtained by the observation and the calculation according to the method disclosed by the invention.