Viscoelastic-plastic Solution for Circular Tunnels Based on the Three-stage Creep Model with the D-P Criterion
(1.School of Emergency Management, Xihua University, Chengdu 610039; 2.Sichuan Transportation Construction Group Co., Ltd.,Chengdu 610039; 3.State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics,Chinese Academy of Sciences, Wuhan 430071; 4.National Dam Safety Engineering Technology Research Center, Wuhan 430010;5.Sichuan Provincial Key Laboratory of Civil Engineering Comprehensive Utilization of Industrial Solid Waste, Panzhihua 617000;6.China Railway Academy Co., Ltd., Chengdu 610032)
Abstract：
The rheological properties of surrounding rock significantly influence the long-term deformation of tunnel structures. To better describe the viscoelastic-plastic mechanical behaviors of the surrounding rock after circular tunnel excavation, a fractional-order creep model is used to characterize the rheological properties, and the DruckerPrager criterion is used to represent the plastic characteristics of the surrounding rock. The theoretical solution of the stress-displacement of the surrounding rock, considering the support effect after circular tunnel excavation, is derived. Through specific examples, the influence of rheological parameters on viscoelastic-plastic deformation of the surrounding rock is analyzed. The results show that: (1) The creep displacement curve of the surrounding rock obtained analytically matches well with the average curve of field measured results, proving the correctness of the theoretical derivation; (2) When the dilatancy effect of the surrounding rock in the viscoplastic zone is considered,the deformation value of the surrounding rock increases. The more pronounced the dilatancy effect, the greater the increase in the deformation value of the surrounding rock; (3) When the viscosity of the viscoelastic or viscoplastic body increases, the creep displacement value and rate of the surrounding rock also increase accordingly.
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.Viscoelastic-plastic Solution for Circular Tunnels Based on the Three-stage Creep Model with the D-P Criterion[J] MODERN TUNNELLING TECHNOLOGY, 2024,V61(4): 105-111
2024, Vol. 61 