Experimental Study On The Swelling Force Of Filling Clay At The End Of The Main Control Structure Surface Of Dangerous Rock

Dangerous rock collapse disaster is a pan-genetic geological disaster in the world,and its destruction mechanism is an important theoretical basis for disaster monitoring,early warning and engineering governance.Aiming at the failure of the main control structure of dangerous rock,this thesis conducts an experimental study on the expansive force of the filling clay at the tip of the main control structure to solve the key scientific problems in the study of the failure mechanism of the dangerous rock.The topic selection has important theoretical significance and engineering practical value.Its main research work and innovative results are as follows:(1)Establish a physical model of the main control structure surface of the dangerous rock,prepare test soil samples of different groups of montmorillonite content according to the predetermined water content,fill the test clay into the tip of the main control structure surface model,and control each group by heating and cooling devices The temperature change of the test soil sample is based on the constant volume method to measure the change law of the swelling force generated by the tip clay.(2)The test results show that the maximum swelling force of the tip clay of the main control structure surface has a good linear relationship with the water content,and it increases with the increase of the water content;the maximum swelling force and the swelling rate of the tip clay are in a good relationship with the montmorillonite content The linear relationship increases with the increase of montmorillonite content;the maximum swelling force of clay under simulated summer temperature changes is greater than the maximum swelling force under temperature changes in spring and autumn.(3)The swelling of montmorillonite is the main reason for the swelling of the test clay.When the swelling of the clay is constrained by external conditions,it will produce swelling force.When the test clay is not saturated,the expansion of the montmorillonite crystal layer and the expansion of the electric double layer increase with the increase of water molecules,and the macroscopic performance is that the maximum swelling force of the clay increases with the increase of water content;montmorillonite layered The thickness of the electric double layer between the bodies increases with the increase of temperature,and the increase of temperature accelerates the migration of water molecules in the soil.Therefore,the temperature directly affects the maximum expansion force of the test clay and promotes the expansion process.(4)Through the processing and analysis of the test data,the linear relationship between the maximum swelling force and the montmorillonite content of the test clays with different water contents in summer and spring and autumn was fitted respectively,and the influence parameters of water content and the size of the parameters were introduced in the formula.The fitting effect of the relationship with water content is good.(5)The clay expansion force is simplified as a uniform load acting vertically on the main control structure surface,and the mechanical calculation model of slumping,tipping and falling dangerous rocks is improved,and the expansion force of the main control structure surface is considered.The calculation formula for the stability coefficient of dangerous rock.The actual engineering is used to compare the conditions without considering the expansion force,which verifies the rationality of the calculation formula proposed in this paper,which is of positive significance for the management of dangerous rock disasters.