Study On The Effect Of Smooth Blasting Under Condtions Of Different Surrounding Rock Mass Stress And Joint Angles

Drilling-blasting is adopted for excavating more than 95% tunnels home and abroad.With the blasting construction technology to improve, except for ensuring construction quality, reducing security requirements of chamber collapse accidents,avoiding over break phenomenon, there are higher requirements for the effect of rock blasting.The most significant factors affecting blasting effect is the presence of joints and the geological conditions of the weak interlayer structure, so study influence of joint fissure of smooth blasting molding effect has profound academic significance and engineering significance.This paper relies on the National Natural Science Foundation of China project"deep high stress rock dynamic properties and explosive stress wave propagation research and major research projects"Baihetan Hydropower Station Underground Powerhouse of blasting vibration test".Through studying on the theory of smooth blasting, the rock structural plane characteristics and its influence on smooth blasting surface formation, collection and analysis of the Baihetan Hydropower Station Underground Workshop on-site blasting data, conditions of the dynamic finite element numerical analysis software to simulate the different joint angle and surrounding rock stress under the blasting process three aspects, carries on the elaboration and thecreation of the purpose of the study.The main research contents are as follows.(1) Studying on theory of smooth blasting and smooth blasting mechanism, to find out parameters need to consider forming which effects smooth blasting. With these parameters as the starting point, we can demonstration and evaluation the smooth blasting engineering.(2) To investigate the characteristics of rock structural plane and rock blasting damage theory.From the explosion stress wave factors affecting blasting surface formation of joint structure,surface characteristics of the explosion should affect the propagation of stress wave and structure surface transfer effect on explosion forming effect.(3) Based on the engineering geological data and the characteristics of smooth blasting,constitutive model, tensile fracture, equivalent load method and the equation of state for selection of blasting rock materials. Using the dynamic finite element analysis method and the software, the lateral pressure coefficient of different initial stress is the existence of the joints and the joint angle and the practical engineering case corresponds to the surrounding rock stress condition, damage states simulation of jointed rock mass under the explosive load, study and analysis the relationship between smooth blasting and smooth blasting surface forming effect.