Title Analysis of natural rock slope deformations under temperature variation; a case from a cool temperate region in Japan
Author Mufundirwa, A.; Fujii, Y.; Kodama, N.; Kodama, J.
Author Affil Mufundirwa, A., Hokkaido University, Graduate School of Engineering, Sapporo, Japan. Other: Hakodate National College of Technology, Japan
Source Cold Regions Science and Technology, 65(3), p.488-500, . Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0165- 232X
Publication Date Mar. 2011
Notes In English. Based on Publisher- supplied data GeoRef Acc. No: 309949
Index Terms bedrock; deformation; freezing; mass movements (geology); rock mechanics; slope stability; slopes; stresses; temperature; thermal properties; Japan; Asia; chemically precipitated rocks; chert; expansion; Far East; finite element analysis; fractures; mass movements; monitoring; numerical analysis; pore water; sedimentary rocks; stress; temperate environment; two- dimensional models
Abstract In this paper, natural rock slope deformation across fractures predominantly in a chert rock mass was monitored using six surface fracture displacement sensors, and the deformations arising from thermal stresses were predicted using (5 m5 m) two- dimensional (2D) finite element (FE) plane strain analysis coupled with a model for rock mass expansion due to freezing of pore water. A new and simple method to minimize displacement proportional to temperature (due to thermal response of chert rock mass and sensor) was proposed. By applying the method, the corrected displacement, u', can be well recognized. Under u', clear rock mass movement, which could be related to fracture growth, was observed. In addition, progressive fracture opening and closure were noted. Results from this study indicate insignificant influences of weather conditions on fracture/rock mass movement. Furthermore, under numerical analysis (FE), in the rock mass model (with 1-m deep fracture), tensile stresses that were large enough to induce fracture growth appeared at the fracture tip when temperature lowered. And in the rock slope model (with 1-m deep fracture), small tensile stresses, which were sufficient to cause fracture growth along the planes of weakness, were observed. This research suggests that freezing effects on deformation of chert rock mass are insignificant, and we tentatively suggest that thermal fatigue predominantly caused the permanent fracture deformations.
URL http://hdl.handle.net/10.1016/j.coldregions.2010.11.003
Publication Type journal article
Record ID 65006903