基于改进型TSP观测装置的地震波场数值模拟

Numerical simulation of seismic waves based on reformulated TSP observation device

随着隧道技术的快速发展,工程上对地质超前预报的可行性和准确性也提出了更高的要求。首先分析了现有以及改进后的定向探测系统的优缺点;然后利用一阶速度—应力弹性波动方程和高阶交错网格法,导出用于改进后的TSP地震波场数值模拟的差分计算方程,并构建倾斜软弱夹层和空洞地质模型,对上述模型进行正演模拟,获得相应的波场快照和单炮记录,进而对地震波场进行分析。结果表明:改进后的TSP观测装置易于实现;有限差分法可有效地模拟改进后的TSP地震波场,其模拟结果清晰可靠地揭示了隧道地质中地震波的传播规律。

With the rapid development of tunnel technology,higher feasibility and accuracy on geological forecast has been re-quired for tunnel engineering.In this paper,both the merits and drawbacks of the conventional and newly designed geometries are analyzed,and then a set of finite difference equations are deduced-which is suitable for the newly designed TSP geometry-for wave field simulation based on the one-order velocity-stress elastic wave equations and high-order staggered-grid method.Two artificial geological models are constructed to study the algorithm and the geometry,which are characterized in a tilt soft stratum and a single hollow respectively,and both snapshots and single shot gathers recorded from the models are ana-lyzed.As a conclusion,the improved TSP geometry is easy to be actualized,besides it is reliable to modeling the TSP wave field with finite difference method,since it clearly reveals the wave propagation in tunnel geological mediums.