Research On The Stability Of Large Excavation Rock Mass In Front Of The Pile Under The Action Of Blasting

The anti-sliding action of anti-sliding pile is to balance the landslide thrust by using the anchoring action and passive resistance of stable stratum,Therefore,the strength and width of the rock mass in embedded segment are very important.Because this can make it work better.At the same time,blasting excavation will affect the stability of rock mass in front of the pile to some extent,and then affect the anti-slide working better.By means of theoretical analysis and numerical simulation,this paper takes the kaichuangdiecui project in Sichuan province as an example to carry out the following research:Based on the theory of elastic and plastic mechanics,deducing when using static excavation method in front of pile the stress distribution characteristics of rock mass in front of pile under different lateral stress conditions and proposing the relationship between width,height,stress and tensile strength of rock mass.According to the calculation,the minimum width of rock mass before pile is obtained,and the rock mass before pile is judged to be in a safe state under static action.Based on the theory of elastic and plastic mechanics,deducing when using dynamic excavation method in front of pile the stress distribution characteristics of rock mass in front of pile under different lateral stress conditions and proposing the relationship between width,height,stress and tensile strength of rock mass and programing the corresponding program on the mathematica software platform.From the program,the analytical solution of the maximum principal stress in front of pile is obtained.Analyzing the failure location of rock mass when the stress on rock mass exceeds its own strength limit.Based on geotechnical analysis software FLAC3D,analyzing the distribution of displacement field,stress field,velocity field and plastic zone of rock mass under blasting load in front of pile.According to the maximum vibration velocity and maximum displacement of rock mass in front of pile obtained from numerical simulation results,the rock in front of pile is judged to be in a safe state under the action of blasting load.In conclusion,based on the elastic and plastic theory in this paper the analytical solution of minimum width of rock mass in front of pile is obtained.The deformation and failure mode of rock mass under dynamic excavation condition in front of pile is studied.It can provide reference for the later design and construction of similar projects.