竖向排列地下硐室群动力稳定性的数值模拟分析

以竖向排列地下硐室群为研究对象，将爆破地震波简化为谐波形式，运用三维有限差分程序FLAC^10研究不同速度、不同动荷载频率以及不同硐室间距条件下硐室群隔板位移和围岩塑性区面积的变化规律，以及上方硐室跨度变化对隔板位移和下方硐室稳定性的影响，通过工程实例分析爆破震动作用下地下硐室群的稳定性。研究结果表明：动荷栽速度对地下硐室群稳定性的影响最明显，隔板位移和围岩塑性区面积随爆破地震波速度增大而增大；随着爆破地震波频率的增大，隔板位移先增大后减小；随着硐室间距的增加，隔板位移减小，有利于地下硐室群的稳定；随着上方硐室跨度增加，隔板位移增大；地下硐室群围岩中出现多处应力集中，但最大拉应力小于岩体的抗拉强度，不会出现拉裂破坏；分析结果与实际观测结果相吻合。

Numerical simulation analysis on stability of vertically arranged underground chambers under dynamic load

Based on vertically arranged underground chambers, when blasting seismic wave was simplified to harmonic wave, the law of displacement of interlayer and the area of plastic zone of surrounding rock at different amplitudes, different frequencies of blasting seismic wave and different spaces between chambers was systemically studied by using the program of FLAC30. The influence on the displacement of interlayer and the stability of the bottom chamber by the variance of the span of upper chamber were also discussed. The stability of underground chambers at blasting vibration was analyzed through engineering case. The results show that the influence of amplitude on the stability of underground chambers is the most obvious, and the displacement of interlayer and the area of plastic zone of surrounding rock increase with the increase of amplitude. The displacement of interlayer increases at the beginning and then decreases with the increase of frequency. With the increase of space between chambers, the displacement of interlayer decreases, which is advantageous for the stability of chambers. The displacement increases with the increase of span of above chamber; The stress concentration occurs at many places in surrounding rock, while the maximum tension stress is less than tensile strength of rock mass, so tensile crack does not take place. The analytical results are in accordance with the observed results.