Abstract: In current researches, although the calculation method of the foundation pit enclosure structure based on p-y curve has considered the actual situation for which the inside soil of the foundation pit may enter into the plastic state, it has not considered the lateral displacement of the retaining wall when the internal bracing is erected, which starts working after the retaining wall has occurred the initial displacement. In view of the above-mentioned shortcomings, this paper presents a calculation model of the foundation pit enclosure structure based on p-y curve, considering the initial displacement of the retaining wall where the internal bracings erect at the time of bracing. The finite difference equations and methods for lateral displacement calculation of enclosure wall are established; and then the rationality of the proposed method is verified by case studies. Theoretical analysis and case studies are all shown that the calculation method of the foundation pit enclosure structure based on p-y curve is reasonable.

Key words: foundation pit, p-y curve, internal bracings, lateral displacement, finite difference