Abstract: With the development of urban underground spaces, the horizontal deformation of retaining wall induced by braced excavations has increasingly become a focal point for engineers and technicians. Due to the lack of comprehensive studies on the horizontal deformation of retaining walls and their characterization methods, this paper introduces set of characterization functions and an indicator system suitable for the deformation curve of braced excavations. Through extensive data analysis, the deformation of retaining walls caused by braced excavations is categorized into four modes: upper concave-type mode, lower concave-type mode, upper and lower concave-type mode, and no concave-type mode. By considering the deformation modes and characteristics of the upper and lower segments of the retaining wall, a representation method for the horizontal deformation curve of the retaining wall is proposed using the piecewise normal distribution function. An indicator system for characterizing the deformation curve of retaining walls is presented, focusing on the maximum value of horizontal deformation, the position value of two segmented reverse bending points and the envelope area of deformation curve. Finally, the least square method is applied to carry out regression analysis to verify the characterization method of piecewise normal distribution function, demonstrating its applicability and effectiveness in characterizing the horizontal deformation of retaining walls. Although the proposed deformation characterization method using the piecewise normal distribution function does not currently involve deformation prediction, it offers a new perspective for future research on predicting horizontal deformation of retaining walls.

Key words: braced excavation, horizontal deformation of retaining wall, mode classification, piecewise normal distribution function, characterization indicator