Stability Anlysis Of Slope In Blasting Excavation Of Anti-Sliding Pile Hole And Research On The Control Technology

With the continuous development of our country’s economy and engineering construction, in the process of which the blasting method is very widely used in the highway construction in mountain areas. However, in the blasting process seismic effect is induced in the rock mass and soil, and then the seismic wave in the communication process can cause larger negative impact to the structures in working areas, the most prominent one of which is the blasting effect on the stability of the slope in mountainous area. During blasting in mountainous area, the seismic effect is extremely easy to lead to the unstability of the slope as a whole, major economic loss and endanger people’s lives. The current study of slope stability mainly concentrated in the long term stability study after slope excavation, but the stability study in the process of blasting dynamic load is little. So the stability of slope under the action of blasting load is particularly important.On the basis of the research of the slope stability at home and abroad, this paper puts the slope on the side of Yaan near the dadu bridge of Yakang highway as the research object. Through the analysis of the general situation of the engineering slope, the slope engineering geologic condition, hydrogeological condition and the aspects of regional stability and so on,choose the typical profile and establish the three-dimensional numerical analysis model. The safety factor obtained by limit equilibrium analysis method were 1.208 and by finite element strength subtraction 1.133. Then establish the three-dimensional numerical analysis model of slope and respectively discusse the vibration velocity, displacement, plastic zone of slope and coefficient of stability when the depth of blasting excavation is 1.2m,1.4m,1.6m. Determine the 1.4m as the anti-slide pile hole excavation depth according to the displacement of the slope under blasting load, the vibration velocity, the plastic zone characteristics and coefficient of stability. Through the analysis of the residual displacement of interval-hole and adjacent-hole excavation under the blasting load of the 1.4 m penetration depth, the interval-hole excavation is good for slope stability.According to the engineering geological conditions and the blasting scheme, study the law of vibration through decorating monitoring point on the slope. Test results show that the vibration velocity peak value increases with the increases of explosive charge in the same measuring point;while under the same single segment explosive charge, the vibration velocity peak value decreases as the distance from explosive source. Through the statistical analysis of test data, it is concluded that the blasting seismic wave attenuation formula in the slope is obtained in the process of pile-hole blasting excavation, and provides the theoretical basis for the vibration prediction in the later excavation blasting.