Rock mechanical characteristics and landscape evolutionary mechanism of the slit-type Danxia landform on the Chinese Loess Plateau  

作　　者：MEN Huan DING Hua DENG Yahong MU Huandong HE Nainan SUN Pushuo LI Zhixu LIU Yan 

机构地区：[1]School of Geology Engineering and Geomatics,Chang'an University,Xi'an 710054,China [2]School of Architecture,Chang'an University,Xi'an 710061,China [3]Shaanxi Academy of Yellow River Sciences,Xi'an 710054,China [4]Institute of Tourism Planning and Design,Chang'an University,Xi'an 710054,China [5]Key Laboratory of Mine Geological Hazards Mechanism and Control,Ministry of Natural Resources,Xi'an 710054,China

出　　处：《Journal of Arid Land》2024年第10期1327-1343,共17页干旱区科学（英文版）

基　　金：This research was funded by the National Natural Science Foundation of China(42077282).

摘　　要：Since 2015,the newly discovered slit-type Danxia landform on the Chinese Loess Plateau has become a hot topic in the field of geomorphology worldwide.However,the relationships among its formation,evolutionary mechanism,and mechanical characteristics of its strata and rocks are not clear.In this paper,the Ganquan canyon group is used as the research object.Basic physical and mechanical indices of sandstone in the Ganquan canyon group were measured through field investigation and indoor experiments,and the deterioration trends for the mechanical parameters of sandstone in this area under the action of infiltration,acid dry-wet cycles,and freeze-thaw cycles were revealed.Lastly,the formation and evolutionary mechanism of the slit-type Danxia landform were discussed.The results showed that:(1)The sandstone in the canyon group had a low cementation degree and weak cohesive force,which was easily weakened under the action of water,resulting in a decrease in compressive strength and elastic modulus.(2)Acidic dry-wet cycles caused the mineral composition of the sandstone to be dissolved,and the micropores continued to grow and develop until new cracks were produced.Macroscopically,the compressive strength and elastic modulus of sandstone were greatly reduced,and this damage was cumulative and staged.The greater the acidity,the greater the damage.(3)As the number of freeze-thaw cycles increased,the uniaxial compressive strength and elastic modulus of the sandstone decreased continuously.During the freeze-thaw cycle process,the growth and development of cracks were primarily in fracture mode and usually developed along parallel bedding positions.(4)The interaction of tectonic activity and lithology with different weathering processes was a key factor in the formation and evolution of the slit-type Danxia landform.In conclusion,the intricate process of weathering influenced by historical climatic fluctuations has been pivotal in shaping the topography of Danxia landform.

关 键 词：landscape-forming rocks mechanical characteristics landscape-forming effects slit-type Danxia landform Loess Plateau 

分 类 号：P931[天文地球—自然地理学]