ORIGINAL ARTICLE Slope creep behavior: observations and simulations Kuang-Tsung Chang • Louis Ge • Hsi-Hung Lin Received: 21 December 2013 / Accepted: 7 June 2014 / Published online: 20 June 2014 Ó Springer-Verlag Berlin Heidelberg 2014 Abstract Rock slopes undergoing long–term effects of weathering and gravity may gradually deform or creep downslope leading to geological structures such as bend- ing, bucking, fracturing, or even progressive failure. This study uses geomechanics-based numerical modeling to qualitatively explain the cause and evolution of slope creep behavior. Constitutive models used include the creep, Mohr–Coulomb, and anisotropic models. The last two models are used with the strength reduction in calculation. First, the results of field investigation around a landslide site occurring in slate are present. The causes and modes of creep structures observed on slopes and underground are studied. Second, the study investigates the influences of slope topography and anisotropy orientations on slope creep behavior. Finally, progressive failure of slopes with different shapes is examined. The simulated results show that the bending type of structures develops near slope surfaces, and the buckling type of structures is associated with the deformation or slides of a slope. The creep pattern varies with the orientation and position of an original planar structure. The shear zone involves a joint or fracture along which displacement has taken place. Moreover, creep behavior is more significant on slopes with greater height and inclination as well as on steeper portions whether on concave or convex slopes. In addition, with the same topographic conditions, consequent slopes with coinciding cleavage and obsequent slopes with steep cleavage result in greater creep behavior. Without the effects of anisotropic cleavage, concave and straight slopes develop failure surfaces from the crowns downwards, whereas convex slopes develop failure surfaces from the toes upwards. Keywords Slope Creep Numerical modeling Progressive failure Slate Introduction Slope creep is the behavior describing slow downward movements of slopes due to long term influence of gravity. The movements may be very slow without surface geo- morphic evidences or can result in abnormal curvature of trees, tilt of poles, or subsidence of structures and roads. Creep–related structures in rocks, which may take geo- logical time to form, have been observed underground and on outcrops. Varnes (1978) related bedrock flow to creep, and Goodman (1993) pointed out that creep involves movement or failure modes of sliding and toppling. Surface displacements of creeping slopes can be inves- tigated using extensometer, GPS, geodetic networks, aerial photographs, LiDAR, InSAR, etc. (Wangensteen et al. 2006). Willenberg et al. (2008) examined the deformation patterns of a slope with comprehensive investigation and monitoring data over numerous years. Using cosmogenic dating of deformation structures, El Bedoui et al. (2009) estimated the surface displacement rates of a rock slope as 4–30 mm/year in the past 10,000 years and as 80 mm/year of higher rate in recent 50 years. Because creep is a time– K.-T. Chang (&) Department of Soil and Water Conservation, National Chung Hsing University, Taichung 402, Taiwan e-mail: [email protected] L. Ge H.-H. Lin Department of Civil Engineering, National Taiwan University, Taipei 106, Taiwan H.-H. Lin Central Geological Survey, MOEA, Taipei, Taiwan 123 Environ Earth Sci (2015) 73:275–287 DOI 10.1007/s12665-014-3423-2
Slope creep behavior: observations and simulations
Jun 14, 2023
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Related Documents
