高地应力初始裂损仰拱结构动力响应研究

DYNAMIC RESPONSE CHARACTERISTICS OF TUNNEL INVERT UNDER HIGH GROUND STRESS

随着高地应力隧道建设的逐年增多,隧道在地应力作用下难免产生结构裂缝,为研究初始裂缝与列车振动响应传播之间的关系,文中通过数值模拟的方法,研究高地应力环境下,仰拱拱脚、仰拱中心与轨道侧面预设不同尺寸裂损时,仰拱结构内部振动特性与衰减特性。研究结果表明,初始裂损的存在,导致仰拱内部振动响应出现不同程度波动,响应峰值沿仰拱竖向呈现先减小后增大的趋势。不同位置处裂损引起的响应增幅不同,主要表现为裂损宽度变化引起响应增幅大于深度变化引起响应增幅。实际工程中,针对不同位置处不同尺寸的结构裂缝危险程度不同,做相应的开裂控制。

The construction of high ground stress tunnels is increasing over years,and structural cracks are inevita⁃ble in tunnels under the action of ground stress.This paper studies the relationship between the initial cracks and the propagation of train vibration response.The internal vibration and damping characteristics of an arch structure under high ground stress conditions are investigated by numerical simulation methods,considering different sizes of pre-set fractures at the foot and center of the arch and on the side of the track.The research findings indicate that the presence of initial fractures leads to varying degrees of fluctuation in the internal vibration response of the arch,with the peak response showing a decreasing-then-increasing trend along the vertical direction of the arch.The re⁃sponse amplification caused by fractures at different locations varies,primarily due to changes in fracture width caus⁃ing greater response amplification than changes in depth.In practical engineering,appropriate fracture control mea⁃sures should be implemented based on the varying degree of structural fracture risks at different locations.