浅埋隧道掘进爆破地表震动效应数值模拟

以渝怀铁路人和场隧道爆破施工为背景，采用动力有限元法对浅埋隧道掘进爆破引起的地表震动效应进行了数值模拟．所建立的数值计算模型以地表和隧道已开挖区周边作为自由边界，其余为固定边界，实测隧道壁质点振动波形作为输入荷载．模拟获得的振动波形与实测波形相近，振动速度随时间和距离的衰减规律也与现场实测基本一致．对比分析模拟波形和实测波形的振动特征参数表明，模拟波形能反映质点的实际振动特征，其振幅、主频和持时的相对误差均值分别为9．14％，12．85％和17．57％．

Numerical Simulation of Ground Vibration Effects in Shallow Tunneling Blasting

By taking a shallow tunnel on the Yuhuai railway as the research object, ground vibration induced by blasting was simulated numerically using a dynamic finite element method, in the established numerical model, the ground and excavating boundaries are regarded as free ones, others as fixed ones, and a measured vibration wave is taken as the import load in numerical calculations. The result shows that the simulated wave of ground vibration is close to the measured wave in shape, and the attenuation laws of vibration velocity with time and distance accords with measured results. A further comparison between the characteristic parameters of simulated and measured waves shows that the simulated wave of ground vibration can reflect the characteristics of particle vibration, and the average values of relative errors of amplitude, main vibration frequency and duration are 9. 14% , 12, 85% and 17, 57% respectively.