土石方工程由于施工过程的复杂及受到众多随机因素的影响，很难用人工方法精确计算各道路的行车及排队情况，确定各道路的等级以及施工机械设备的数量。采用循环网络模拟技术，用挖、装、运、卸等仿真节点来模拟实际施工的相应过程，建立能反映土石方实际开挖过程的仿真模型。仿真得出的一系列施工参数为辅助管理人员做出决策提供参考依据。某工程中的成功应用表明，此方法快捷、便利，值得深入研究并推广应用。

For its complexities and randomicities,  it is hard to obtain accurately some important parameters in designing of construction for earthwork project with manual method,  such as traveling density,  queuing condition,  the grade of the road and the number of construction machine.  Actual construction process can be substituted by simulation nodes,  such as digging,  loading,  traveling,  and unloading correspondingly. The technique of Cycle Operation Network (CYCLONE) is used to build the construction model for earthwork project.  The application to an earthwork project shows its shortcut and advantage.  It is worth studying thoroughly and popularizing.