Back analysis of displacements for estimating spatial distribution of viscoelastic properties around an unlined rock cavern

• Published in: Computers and geotechnics Vol. 126; p. 103724
• Main Authors: Gao, Xu, Yan, E-Chuan, Yeh, Tian-Chyi Jim, Yin, Xiao-Meng, Cai, Jing-Sen, Hao, Yong-Hong, Wen, Jet-Chau
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01.10.2020; Elsevier BV
• Subjects: Algorithms; Constitutive models; Displacement; Displacement back analysis; Distribution; Dredging; Excavation; Fields; Heterogeneity; Mechanical properties; Modulus of elasticity; Rock masses; Rocks; Shear strain; Spatial distribution; Strain distribution; Successive linear estimator; Time dependence; Unlined rock cavern; Viscoelastic parameters; Viscoelasticity; Displacement back analysis; Heterogeneity; Successive linear estimator; Viscoelastic parameters; Unlined rock cavern
• ISSN: 0266-352X; 1873-7633
• DOI: 10.1016/j.compgeo.2020.103724

A displacement back analysis algorithm is developed, considering the time-dependent effect of the rock mass. It can map spatially distributed the first elastic modulus (E1), viscidity coefficient (η1), and the second elastic modulus (E2) of the Kelvin-Voigt viscoelastic constitutive model (VCM) and the Poynting-Thomson VCM in a rock mass by fusion of the observed displacement data from the excavation of an unlined rock cavern. The algorithm is tested and validated using numerical experiments with a synthetic heterogeneous rock mass. The results of the experiments show that this approach yields unbiased estimates of E1, η1, and E2 fields and quantifies their uncertainty. Further, the estimated fields closely predict shear strain distribution and displacements field in the example.