论折射法勘探中的绕射波射线轨迹

根据超声波三维地震模拟实验的结果,研究了绕射波射线轨迹的问题。对绕射波的运动学特征进行了讨论,并引用极值光程律进行了解释。实验和理论的分折指出,绕射点的位置经常按照一定的规律偏离震源--接收点联线的一侧。 本文还提出了“双曲线叠加法”,从而在实际较复杂的情况下,可以用它迅速地确定绕射点的空间位置及波的旅行时间。 文中提出绕射波的运动学特征,从中可以提供一些有关断层或绕射棱结构的情况。至于绕射波的动力学特征及机制将另文阐述。所获的结果及结论有助于物探资料的解释。

ON THE TRAJECTORIES OF DIFFRACTIONAL WAVES IN THE REFRACTION METHOD OF SEISMIC PROSPECTING

Based on the results of three-dimensional ultrasonic wave model experiments, this paper deals with the trajectories of diffractional wave paths. The kinematic na-ture of diffraction has been discussed and explained by means of the principle of extreme time. Experiments and theoretical analysis show that the points of diffraction are usually shifted toward the shotdetecting line according to a certain rule.This paper also employs the "Method of superposition of hyperbolics", with which we can determine easily the positions of the points of diffraction in space and the travelling times for very complicated situations.It is pointed out, that the kinematic nature of diffracted waves will give some idea about the structure of fault or diffraction wedge. As to the dynamic nature and mechanism of diffractions will be discussed in another paper.Results and conclusions obtained may be useful for interpreting data of seismic prospecting.