Failure Mode And Dynamic Response Of The Bedrock And Overburden Layer Slope

In the southwest of our country,where the terrain is dangerous and the geological conditions are complex,landslide disasters occur frequently,which brings great losses to the safety of people's lives and property.The bedrock and overburden layer slope is not uncommon in nature.because of the large volume of its sliding body,once the landslide is destroyed,it will often cause serious natural disasters.Therefore,it is very necessary to analyze and master the stability of the bedrock and overburden layer slope.Based on the relevant equipment of the Geotechnical Test Center of Southwest Jiao Tong University,this paper makes a preliminary discussion on the static stability of the bedrock and overburden layer slope.21 groups of indoor model static surcharge tests are designed and completed.The failure modes and bearing characteristics of the slope under different geometric characteristics and interface friction conditions are studied,and the effects of various factors on the static stability of the slope are compared and analyzed by using the finite element static simulation results.Based on the static model test conditions of the bedrock and overburden layer slope,and Dynamic calculation Module with finite element Software.The dynamic failure process,failure mode,failure mechanism and dynamic response law of slope are studied.The dynamic stability of the slope under the influence of ground motion parameters,geometric characteristics of the slope and interface friction is discussed and analyzed.the following conclusions are obtained:?1?There are three modes of instability and failure of bedrock and overburden layer slope under static surcharge load:local slip,transition slip and global slip.Interface friction,interface angle?₂,slope and slope height have significant effects on slope failure mode,but interface angle?1 and slope top length will not change the failure mode of slope,but only have certain influence on the position of slope slip line and foundation interface.?2?Under the influence of different factors,the ultimate load of the bedrock and overburden layer slope presents different laws.With the increase of interfacial friction strength and slope top length,the ultimate load of slope increases.With the increase of interface angle,slope and slope height,the ultimate load of slope decreases.The numerical simulation results are basically consistent with the model test law.?3?Under the action of sine wave,there are four modes of instability and failure of bedrock and overburden layer slope:Integral tension crack of slope top-Cut from the foot of the slope,Foot collapse-Internal fracture of soil-Slide body slide,Trailing edge tension-Internal fracture of soil-Cut from slope,Slide along the interface as a whole.The influence of interface friction and angle,slope and slope top length on the dynamic failure mode of slope is significant,but the influence of slope height change on the dynamic failure mode of slope is not obvious.?4?Under the action of sine wave,the acceleration amplification effect of slope surface is affected by ground motion parameters,slope geometric characteristics and interface friction.The slope acceleration magnification factor decreases with the increase of input acceleration amplitude.The acceleration magnification factor of the slope varies with the increase of frequency,but the dynamic response of the slope to low frequency load excitation is not obvious in this paper.