中文摘要：

确定松动荷载的方法多为规范法和理论公式法，这些方法都建立在对以往隧道松动荷载统计和分析的基础上。双洞八车道扁平大跨度公路隧道是近几年发展起来的一种隧道形式。由于其跨度增加、扁平率降低，现有松动荷载的算方法是否适用于双洞八车道公路隧道，已成为隧道建设者面对的重要问题之一。以广州龙头山双洞八车道公路隧道为研究背景，概括和总结了各种松动荷载的计算方法；应用这些方法计算龙头山隧道的松动压力，分析和对比计算结果，并通过数值计算和实测围岩压力对各种方法的合理性进行了分析；根据各种方法的产生背景和内容，分析其各自的适用性；根据研究结果，对扁平大跨度公路隧道进行了适应性分析和讨论。

英文摘要：

Theory equations and norm equations are primary methods to calculate loose load of tunnel. They are established based on the statistic and analysis of loose load from finished tunnels in general. With the development of road tunnel construction, the two-way and large-span road tunnel with eight-lane in either way become a new shape in recent years. The eight-lane tunnel has an increase in excavation area and a decrease in excavation height relatively for the aim of curtailing the cost of construction and has a smaller ratio of height to width. For this reason, current calculation method of loose load whether or not apply to barge-span tunnel has been significant for tunnel design. In this paper, firstly, various calculation methods are summarized and applied to Longtoushan Road Tunnel with eight-lane and barge-span. And then, calculation results are analyzed and compared. Secondly, rationality of calculation methods for Longtoushan Tunnel is analyzed based on numerical calculation and measured data. Finally, the paper presents and discusses applicability of various methods, especially for the eight-lane and barge-span tunnel, based on its own background and above study course. The purpose of the article is to provide reference for the design of extra-large cross-section and barge-span road tunnel.