Experimental Study On The Effect Of Ion-interface Reaction On The Cementation Strength Of Loess

The study on the stability and destruction of loess cementitious materials can deeply understand the loess collapsibility,landslide mechanism and landslide process,and then put forward the corresponding natural disaster prevention and control measures and treatment programs.The research objectives of this paper mainly include the following five aspects: 1)The cementation mechanism of dry clay particles under high pressure;2)The effect mechanism of clay mineral hydrochemistry on cement between clay mineral particles and cement strength;3)The influence mechanism of cation concentration on cement strength between clay mineral particles;4)The influence of cation concentration on the interaction energy of loess particles and its influence on the settlement rate of loess particles and its mechanism;5)Micro mechanism of dry density and water content on shear strength of malan loess.In this paper,the cementation strength of loess particles was tested by the following methods :1)Clay hydrochemical interaction test combined with energy spectrum analysis method to explore the cementation mechanism of clay hydrochemical interaction on clay particles;2)The cementation mechanism between clay particles under high pressure was theoretically analyzed by combining with the microstructure of clay cement under high pressure.3)By calculating the influence of the concentration of monvalent metal cation on the interaction force between two adjacent clay particles(electrostatic van der Waals force hydration repulsion),the influence of cation on the cementation between clay particles was analyzed.4)The DLVO theory is used to explain the influence of cation concentration on the sedimentation law of malan loess particles;5)The influence of dry density of water content on cementation strength between particles of malan loess was analyzed through direct shear test.Through the above experiments and theoretical calculations,the following conclusions are drawn in this paper: 1)clay hydrochemistry causes clay particles to cement,and the Yang content of cement between clay particles increases significantly;2)van der Waals force is the main control force for clay cementing under high pressure;3)the main reason for the influence of cation concentration on the cementation between loess particles is that the cation concentration will affect the electrostatic interaction between particles;4)the cation concentration has a significant effect on the settlement of malan loess particles,the main reason is that the cation concentration has an effect on the interaction between the loess particles,and then affects the cementation between the particles;5)the shear strength of remolded malan loess decreases with the increase of water content and increases with the increase of dry density of the loess.The main reason is that hydrochemistry dissolves the cement between the particles of malan loess,resulting in the reduction of the cementing force between the particles and the shear strength of the loess.When the dry density of malan loess increases,the distance between the particles decreases,and the van der Waals force between the particles increases,and the shear strength of malan loess increases.