不同起爆点位置对基坑爆破效果影响分析

ANALYSIS OF THE IMPACT OF DIFFERENT INITIATION POINT LOCATIONS ON FOUNDATION PIT BLASTINGEFFECTS

为研究起爆点位置不同时基坑的爆破效果与动力响应特征,文中以山东大学齐鲁医院二期项目基坑工程为例,利用ANSYS/LS-DYNA有限元软件对正向起爆与反向起爆下岩质基坑进行爆破模拟分析,分析得出:采用反向起爆方式时,在岩体自由面产生的损伤区域范围明显大于正向起爆;反向起爆方式下,地表各监测点的最大振速值均大于正向起爆,且距离炮孔越近,两种起爆方式下的振速差值越大;两种起爆方式下桩顶最大振速值接近,起爆点位置变化对桩的振动响应影响较小。研究结果对基坑爆破工程中起爆点位置的选取具有指导作用。

To investigate the blasting effects and dynamic response characteristics of foundation pits with varying initiation point locations,this paper examines the Shandong University Qilu Hospital Phase II project foundation pit engineering.By utilizing ANSYS/LS-DYNA finite element software,we conducted a blasting simulation analysis of rock foundation pits under both forward and reverse initiation methods.The primary findings are as follows:The re-verse initiation method results in a significantly larger damage area on the free surface of the rock mass compared to the forward initiation method.Under the reverse initiation method,the maximum vibration velocity values at all sur-face monitoring points are greater than those under the forward initiation method.Furthermore,the closer the dis-tance to the blast hole,the more pronounced the difference in vibration velocity between the two methods.The maxi-mum vibration velocity values at the pile tops are similar under both initiation methods,indicating that the location of the initiation point has a minimal effect on the vibration response of the piles.The findings from this study offer valuable guidance for selecting initiation point locations in foundation pit blasting engineering.