(西南交通大學(xué)地下工程及巖土工程系，成都 610031)
摘 要: 在分析現(xiàn)有巖體爆破機(jī)理與塊度計(jì)算模型的基礎(chǔ)上，提出了考慮工程巖體的尺寸效應(yīng)、將宏觀結(jié)構(gòu)弱面引入巖體爆破物理過程來建立塊度模型的觀點(diǎn)。為此，按照損傷力學(xué)的處理方法，應(yīng)用連續(xù)介質(zhì)損傷理論研究爆破過程中巖體弱面的破裂機(jī)制，給出了巖體沿節(jié)理破裂的損傷發(fā)展方程。從爆破巖塊具有分形特征的思想出發(fā)，通過提出“巖體破裂比率” 概念，將爆破塊度計(jì)算同節(jié)理巖體爆破機(jī)制相聯(lián)系，建立起巖體爆破塊度的損傷力學(xué)模型(BDM)，該模型反映了巖體沿節(jié)理面破裂和巖石本身破裂的巖體爆破本質(zhì)。
關(guān)鍵字: 節(jié)理巖體；爆破；損傷機(jī)理；塊度
（Department of Underground Engineering and Geotechnical Engineering,
Southwest Jiaotong University, Chengdu 610031, P. R. China）
Abstract:Based on the analysis and discussion of both the mechanism of blasting in rock masses and the model of fragment-size calculation in existence, the viewpoint that the fragment-size model for blasting should take the dimension effect of engineering rock into consideration and introduce the macro weakness planes in rock masses into the physical process of blasting was advanced. According to damage mechanics, therefore, the original cracks in a rock mass can be treated as initial damage and the joints as a latent source of damage developing. The breaking mechanism of weakness planes in blasting process was studied by using the continuum damage theory and the developing equation of rock masses breaking along joints was deduced. Proceeding from the thought of blasted fragments having the fractal characteristics, the calculation of blasted fragment sizes was related to the mechanism of blasting in jointed rock masses by the new concept of "rock mass fracture ratio" presented and, thus, the model of damage mechanics for blasting in rock masses(BDM) was established, which reflects the blasting essence of both rock masses breaking along joint planes and rock breaking.
Key words: joint rock mass; blasting; damage mechanism; particle size
