Study to Damage Effect of In-situ Stress Dynamic Unloading during Drilling and Blasting Ezcavation
The effect of Initial geo-Stress Dynamic Unloading (ISDU) on circular tunnel boundary in the process of drilling and blasting excavation is studied with theoretical analysis method in this paper and the damage zone induced by ISDU during blasting is calculated. The result indicates that the stress adjustment from in-situ stress to the second stress situation during blasting excavation is not a static and slowly process, but a rapidly and dynamic process. Dynamic unloading stress wave is caused by this rapid adjustment of in-situ stress during blasting, and the radial stress unloads first and then rebounds,the tangential stress concentrates when the wave-front goes through. The shearing stress in the surrounding rock increases and the micro-cracks extend because of this dynamic disturbance and then makes the surrounding rock damage. The filed damage data monitored in a deep-buried transportation tunnel of a certain hydropower station in China indicates that the damage zone induced by dynamic unloading of in-situ stress is an important component of the EDZ (excavation-induced damage/disturbed zone) and it is decided by the level of geo-stress.
drilling and blasting initial geo-stress dynamic unloading damage area
YAN Peng LI Xianchen LU Wenbo TANG Xiaojun CHEN Ming SHU Daqiang
East China Investigation and Design Institution Under CHECC, Hangzhou, China State Key Laboratory of Ertan Hydropower Development Company, Ltd., China State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan,
国际会议
The Second Asian-Pacific Symposium on Blasting Techniques(第二届亚太地区爆破技术研讨会)
大连
英文
60-66
2009-07-01（万方平台首次上网日期，不代表论文的发表时间）