广东岭澳核电站爆破开挖岩体损伤特征研究

为控制爆炸荷载作用下岩体的损伤范围,在岭澳核电站二期工程现场进行了爆前、爆后岩体声波测试,得到岩体的损伤范围。以此为基础,根据爆炸荷载作用下岩体损伤发展规律,基于概率形式定义损伤变量,利用有限元程序LS-DYNA和有限差分程序FLAC3D相结合的方法,对现场基岩爆破产生的岩体损伤范围进行数值模拟,并与现场岩体声波实验结果进行比较,确定爆炸荷载作用下岩体损伤门槛值Dcri=0.2,由此得到了岩体损伤范围随装药量的变化规律。结论认为,在柱状装药情况下,岩体损伤范围随装药量的增大而增大;爆炸荷载作用下的岩体损伤区深度小于损伤区半径,二者比例约为1∶3。

STUDY ON DAMAGE CHARACTERISTICS OF ROCK MASS UNDER BLASTING LOAD IN LING''''AO NUCLEAR POWER STATION, GUANGDONG PROVINCE

Sonic wave tests have been conducted in the construction site of Ling'ao Nuclear Power Station(LNPS)in Guangdong Province,China.Based on the change rate of sound wave speed before and after blasting,damage zone size of surrounding rock has been determined.On the other hand,a statistics-based damage variable of rock mass has been proposed based on micromechanics.Damage zone size of rock mass under blasting is thus studied using a hybrid LS-DYNA and FLAC3D scheme.It is reported that the numerical simulation results agree well with the site monitoring results,and the damage threshold for the rock in site of LNPS,Dc ri,is 0.2.The variation of damage zone size with charge weight has been analyzed by numerical simulations.It is observed that the rock damage zone size increases with charge weight.Damage zone depth of rock mass under blasting is less than damage zone radius.The damage zone radius is approximately 3 times of the damage zone depth.