片岩隧道爆破对本洞和邻洞围岩的扰动分析

Perturbation Analysis of Hole and Adjacent Tunnel Surrounding Rock Induced by Schist Tunnel Blasting

隧道爆破扰动会引起本洞或邻近隧道的围岩振动和应力重分布,致使既有隧道的结构遭受破坏,从而危及行车安全。为探究隧道开挖引起的截面围岩质点振速峰值和拉应力峰值的关系及其分布规律,结合十白高速公路碳质片岩隧道爆破工程,运用LS-DYNA软件对连拱隧道掘进爆破和单隧道掘进爆破工况进行了计算,探明了典型截面围岩质点振动峰值和动拉应力峰值分布特征,分析得出了在爆破近区隧道围岩质点振速峰值方向和拉应力峰值方向之间相互垂直及其分布规律,在爆破中远区隧道围岩质点振速峰值方向和拉应力峰值方向相同并在一定范围类存在比例关系,为隧道开挖过程中最佳测点布设提供理论依据,并能为类似实际工程提供参考依据。

The tunnel blasting disturbance will cause the surrounding rock vibration and stress redistribution of the hole or the adjacent tunnel, and resulting in the destruction of the existing tunnel structure, then endangering the safety of traffic. In order to explore the relationship and the distribution of surrounding rock particle vibration peak and tensile stress of typical section caused by tunnel excavation ,it is ,based on carbonaceous schist tunnel blasting project of Shibai highway, and through calculating the excavation blasting conditions of multi-arch tunnel and single tunnel by LS-DY- NA,proved that the distribution characteristic of surrounding rock particle vibration peak and dynamic stress of typical section during tunnel excavation. It also is obtained in the area near blasting that the direction of particle vibration peak and stress peak of tunnel surrounding rock is perpendicular to each other and distribution from analysis, meantime, in the area far from blasting the direction of particle vibration peak and stress peak of tunnel surrounding rock is the same and have proportion relation in certain range, which provides theoretical basis for the best layout of measurement points in the process of the tunnel excavation, and reference for the similar practical engineering.