中文摘要：

2．5-D拟柱坐标法是一种新兴的2．5-D问题的处理方法，该方法最大的优点在于拓宽常规柱坐标法数值模拟的应用范围，能够处理非轴对称模型，而且计算简便，尤其适宜解决大尺度地震勘探耗时多的难题。笔者发展了基于拟柱坐标系采用交错网格高阶有限差分法求解2．5-D拟柱坐标声波方程的数值模拟算法，并分别通过简单的单倾斜界面模型和较复杂的非轴对称模型的数值实例验证该方法的正确性和可行性。

英文摘要：

The 2.5-D quasi-cylindrical method has been proposed recently for simulation of 2.5-D case. The remarkable advantage of the quasi-cylindrical approach over the common cylindrical approach is that it can deal with non-rotationally symmetric situation, aiming at broadening this range of application. In addition, for large-sized surveys the quasi-cylindrical approach is very efficient as compared with the conventional 2.5-D methods. In this paper, the authors have developed an implementation of this approach which is based on quasi-cylindrical acoustic wave equation, using the higher-order staggered finite-difference method. With some numerical examples including axisymmetric and non-axisymmetric models, this paper demonstrates the validity and feasibility of the authors＇approach.