CAJ | 학술논문

深埋隧洞开挖形成的二次应力场与爆破开挖卸荷诱发的动力扰动组合作用，是导致围岩损伤破坏的主要原因。首先对深埋圆形隧洞开挖二次应力场静力作用下围岩损伤进行分析，然后以溪洛渡水电站城门洞形导流洞上层中导洞爆破开挖为背景，采用动力有限元方法模拟，对高地应力条件下二次应力场作用下爆炸荷载和开挖荷载瞬态卸荷动力扰动诱发损伤区进行计算，并基于实测的爆破振动速度资料对围岩的本构模型进行对比。结果表明，采用随动强化本构模型的计算结果更符合实测资料；随着地应力的增大，围岩二次应力场与动力扰动组合作用诱发的损伤范围也增大，符合理论分析的结果；考虑瞬态卸荷作用的工况与考虑爆炸荷载的工况相比，诱发损伤围岩的体积有较大增加，因此，随着隧洞埋深的增加，瞬态卸荷将成为诸多动力扰动中的主要因素。对围岩损伤的控制，不仅包含减小进尺和单响药量，还可以考虑将掌子面分成多个小断面进行开挖，或利用超前孔释放地应力等减弱开挖荷载瞬态卸荷强度的方法。
심매수동개알형성적이차응력장여폭파개알사하유발적동력우동조합작용，시도치위암손상파배적주요원인。수선대심매원형수동개알이차응력장정력작용하위암손상진행분석，연후이계락도수전참성문동형도류동상층중도동폭파개알위배경，채용동력유한원방법모의，대고지응력조건하이차응력장작용하폭작하재화개알하재순태사하동력우동유발손상구진행계산，병기우실측적폭파진동속도자료대위암적본구모형진행대비。결과표명，채용수동강화본구모형적계산결과경부합실측자료；수착지응력적증대，위암이차응력장여동력우동조합작용유발적손상범위야증대，부합이론분석적결과；고필순태사하작용적공황여고필폭작하재적공황상비，유발손상위암적체적유교대증가，인차，수착수동매심적증가，순태사하장성위제다동력우동중적주요인소。대위암손상적공제，불부포함감소진척화단향약량，환가이고필장장자면분성다개소단면진행개알，혹이용초전공석방지응력등감약개알하재순태사하강도적방법。
The combination of statistic secondary stress field and dynamic disturbance induced by blasting excavation is the major cause of internal damage of rock mass. The static secondary stress field was calculated for a circle tunnel. Then based on the up-layer excavation of city-gate section diversion tunnel of Xiluodu hydropower station,dynamic analysis was conducted. The damage area induced by the combination of static secondary stress field and dynamic disturbance was calculated. During this process,a comparison was made for different material models,based on regression analysis of calculated blasting vibration values and monitored data in field. Result calculated with kinetic-hardening model complies better with the monitored data. As the in-situ stress field increases,the damage area induced by the combination of static and dynamic effect. However,with in-situ stress transient unloading considered,the volume of damaged rock mass is largely increased. Therefore,the transient process of in-situ stress unloading should be considered in blasting excavation of deep underground tunnels. Besides reducing step length or total charge in one delay,prolong the unloading process for in-situ stress is also a measure applicable for controlling rock mass damage.