Abstract: In this paper, a user material subroutine (UMAT) of time-dependent UH model is written and embedded into the finite element software ABAQUS. Then a numerical back-analysis platform is established by combining multi-island genetic algorithm. In actual projects, factors such as rainfall, snowmelt and temporary loading will disturb the settlement law of normal creep. During this period of disturbance, the settlement rate is accelerated to form abrupt settlement, which has a great impact on the accuracy of numerical calculation. By introducing the concept of abnormal creep and analyzing the mechanism of settlement acceleration during this period, a numerical prediction method considering abnormal creep is proposed. When the fill body is lack of zoning basis and the settlement data of multiple monitoring points is taken as the back-analysis target, the distribution function of back-analysis parameters is introduced to replace the zoning of geometric model. On this basis, the influence of abnormal creep during the period of disturbance is further considered, and a numerical prediction method of settlement considering abnormal creep at multiple monitoring points is proposed. Finally, the accuracy and practicability of the numerical prediction method considering the abnormal creep under the condition of multiple monitoring points are verified by the settlement data of Chengde airport high fill.

Key words: high fill, creep settlement, abnormal creep, time-dependent UH model, numerical back-analysis