浅埋隧道爆破施工中邻近框架结构的振动响应分析

为研究隧道爆破作用下邻近框架结构的振动响应机制,以某5层框架结构住宅楼为例,借助ANSYS/LS-DYNA建立基于隧道爆破-围岩-框架结构的三维耦合数值计算模型,分析隧道爆破施工中邻近框架结构的振动响应。研究结果表明： 数值模拟清晰地展示了隧道爆破作用下围岩和框架结构应力场、位移场的变化情况,给出了爆破振动波从围岩至框架结构的传播过程。通过对比实测测点与数值模拟中对应测点的振动速度时程曲线和频率分布,验证了数值模拟方法的可靠性。在隧道爆破作用下,邻近框架结构梁、柱以及外墙等构件的振动响应并不一致,随结构高度呈现出不同的变化规律。此外,应力集中现象主要发生在建筑物底层外墙、外墙与柱结合处、外墙与梁结合处以及外墙与楼板结合处等非承重部位,表明这些部位更易在隧道爆破过程中发生损伤开裂。

Vibration Response Analysis of Adjacent FrameStructure toShallowBuried Tunnel Blasting Construction

In order to study the vibration response mechanism ofadjacent frame structure to tunnel blasting, taking a five storyframe structure residential building as an example,athree dimensional numerical calculation model based ontunnel blasting, surrounding rock and frame structure is established with thehelp of ANSYS/LS DYNA to analyze the vibration responseof adjacent frame structure to tunnel blasting construction. The results showthat the numerical simulation clearly demonstrates the change of stress fieldand displacement field of surrounding rock and frame structure under blastingaction, and gives the propagation process of blasting vibration wave fromsurrounding rock to frame structure. Combined with the field measured data andnumerical calculation results, the time history curveand frequency distribution characteristics of vibration velocity at somelocations are compared and analyzed, and the reliability of the numericalsimulation method is verified. Under the blasting action of tunnel, thevibration response of beams, columns and external walls of adjacent framestructure is not consistent, and the vibration response varies with the heightof the structure. The blasting of the tunnel results in obvious stressconcentration in some parts of frame structure, which mainly occurs at thebottom of external wall and the joint of external wall with column, beam andfloor, etc.[KG-*3], indicating that these positions are more likely to sufferdamage or even crack during tunnel blasting.