论文部分内容阅读
采用一种间接边界元方法求解了球面压缩波入射下深埋球形衬砌洞室的三维动力反应,并与弹性全空间球形空洞精确解及平面波入射结果对比,验证了本文方法具有较好的计算精度;进而分析了入射球面波的频率、波源与洞室距离、衬砌厚度等参数对衬砌洞室动应力集中因子(DSCF)的放大效应。结果表明:近源和较低频率波入射情况下,入射波频率对动应力集中因子和空间分布特征有显著影响。整体上看,球面波入射下衬砌内动应力集中现象更为明显,DSCF值可达到相应平面波入射情况的2倍左右;当波源距离在5倍波长之外,可近似采用平面波模拟球面波入射;衬砌内不同位置频谱幅值差别明显,且峰值频率也有较大差异,迎波面一侧应力集中更为显著;在正常参数范围内,随衬砌厚度增大,衬砌内DSCF值有所降低。
An indirect boundary element method is used to solve the three-dimensional dynamic response of deep-buried spherical lining cavern under the incident spherical compression wave. Compared with the exact solutions of the spherical elastic cavity in full space and the incident wave of plane wave, the proposed method has good calculation accuracy The amplification effects of the incident spherical wave frequency, the distance between the wave source and the tunnel and the thickness of the lining on the dynamic stress concentration factor (DSCF) of the lining cavity are analyzed. The results show that the frequency of incident wave has a significant effect on the dynamic stress concentration factor and spatial distribution under the condition of near-source and lower-frequency wave incident. As a whole, the dynamic stress concentration in the lining under the incident of the spherical wave is more obvious, and the DSCF value can reach about 2 times of the incidence of the corresponding plane wave. When the distance of the wave source is 5 times of the wavelength, the plane wave can simulate the incident spherical wave. The difference of the spectrum amplitude is obvious at different positions in the lining, and the peak frequency also has big difference, and the stress concentration on the wave-facing side is more significant. Within the normal parameters, the lining DSCF value decreases with the increase of the lining thickness.