Effects of freeze-thaw cycles on sandstone in sunny and shady slopes  

作　　者：Dian Xiao Xiaoyan Zhao Corrado Fidelibus Roberto Tomás Qiu Lu Hongwei Liu 

机构地区：[1]Academy of Railway Sciences Corporation Limited,Beijing,China [2]Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu,China [3]Department of Civil Engineering,University of Alicante,Alicante,Spain [4]Department of Innovation Engineering,University of Salento,Lecce,Italy [5]Department of Earth and Environmental Sciences,University of Milano Bicocca,Milan,Italy

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第7期2503-2515,共13页岩石力学与岩土工程学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.41672295);the Major Systematic Project of Scientific and Technological Research and Development Plan of China Railway Corporation(Grant No.P2018G047);supported by a PhD fellowship from the China Scholarship Council.Roberto Tomás was partially funded by the Conselleria de Innovación,Universidades,Ciencia y Sociedad Digital de la Generalitat Valenciana(CIAICO/2021/335).

摘　　要：A growing rock engineering activity in cold regions is facing the threat of freeze-thaw(FT)weathering,especially in high mountains where the sunny-shady slope effects strongly control the difference in weathering behavior of rocks.In this paper,an investigation of the degradation of petrophysical characteristics of sandstone specimens subjected to FT cycle tests to simulate the sunny-shady slope effects is presented.To this aim,non-destructive and repeatable testing techniques including weight,ultrasonic waves,and nuclear magnetic resonance methods on standard specimens were performed.For the sunny slope specimens,accompanied by the enlargement of small pores,100 FT cycles caused a significant decrease in P-wave velocity with an average of 23%,but a consistent rise of 0.18%in mass loss,34%in porosity,67%in pore geometrical mean radius,and a remarkable 14.5-fold increase in permeability.However,slight changes with some abnormal trends in physical parameters of the shady slope specimens were observed during FT cycling,which can be attributed to superficial granular disaggregation and pore throat obstruction.Thermal shocks enhance rock weathering on sunny slopes during FT cycles,while FT weathering on shady slopes is restricted to the small pores and the superficial cover.These two factors are primarily responsible for the differences in FT weathering intensity between sunny and shady slopes.The conclusions derived from the interpretation of the experimental results may provide theoretical guidance for the design of slope-failure prevention measures and the selection of transportation routes in cold mountainous regions.

关 键 词：Sunny-shady slope Freeze and thaw Pore structure Tight rocks Talus slope Cold regions 

分 类 号：TU45[建筑科学—岩土工程]