小净距隧道爆破振动危害的主动控制研究

发布时间：2019-01-10 12:46

【摘要】：为了研究小净距下复线隧道的施工爆破对既有隧道的影响并采取合理的主动控制,采用LS-DYNA动力有限元软件建立了不同净间距时新建隧道和既有隧道的数值模型。将测点峰值振速作为判据,得到了小净距下新建隧道爆破施工时既有隧道的振速测点布置方案及相应的爆破药量优选方案:既有隧道振速测点应布置在迎爆侧边墙距地面1.2m处;随两隧道净间距L的不断减小,应分别在L为9m、8m、7m时合理降低爆破装药量,相应的爆破炸药量建议值分别为48kg、30kg、24kg。数值试验和实测数据对比分析结果表明:在两隧道净间距L从11.9m逐渐减小为6.6m的过程中,既有线实测质点峰值振速与数值分析结果的变化趋势基本一致;合理有效地控制爆破药量,是降低既有隧道爆破振动响应、保证其安全运营的关键。研究所得结论可用于指导小净距条件下新建隧道的爆破施工,实现爆破振动效应危害的主动控制。
[Abstract]:In order to study the effect of construction blasting on existing tunnel under small net distance and take reasonable active control, the numerical model of new tunnel and existing tunnel with different net spacing was established by using LS-DYNA dynamic finite element software. The peak vibration velocity of the measuring point is taken as the criterion. The layout scheme of vibration velocity measurement points and the corresponding optimal blasting charge selection scheme for the existing tunnel during blasting construction under small clear distance are obtained: the vibration velocity measurement points of the existing tunnel should be arranged at 1.2m from the ground level on the side wall of the existing tunnel; With the decrease of the net distance L of the two tunnels, the blasting charge should be reduced reasonably when L is 9mt / 8mt / 7m, respectively, and the corresponding recommended blasting explosive quantity is 48kg / 30kg / g respectively. The results of comparison and analysis of numerical and measured data show that the variation trend of peak vibration velocity of measured particle on existing railway lines is basically consistent with that of numerical analysis when the net spacing of the two tunnels decreases from 11.9 m to 6.6 m; Reasonably and effectively controlling blasting charge is the key to reduce blasting vibration response of existing tunnel and ensure its safe operation. The conclusions of the study can be used to guide the blasting construction of the new tunnel under the condition of small clear distance and to realize the active control of the damage of blasting vibration effect.
【作者单位】：西安建筑科技大学土木工程学院;
【分类号】：U455.6

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