G98环岛高速公路大茅隧道改扩建总体方案

海南省G98环岛高速公路大茅隧道近年来交通拥堵状况越发凸显，交通事故发生率居高不下。本文从多个角度对现状大茅隧道存在的问题进行了调研，对规划三亚第二绕城高速公路与大茅隧道改扩建的关系进行了解读，并结合三亚市公路网规划和现场建设条件，对3个大茅隧道改扩建总体方案进行了比选论证，为高等级公路山岭隧道改扩建工程提供设计参考。

Overall Scheme for Reconstruction and Extension of Damao Tunnel in G98 Isle Ring Expressway

In recent years, the traffic congestion in Damao Tunnel of the G98 Hainan Isle Ring Expressway has become increasingly prominent, and the traffic accident rate remains high. The existing problems of the current Damao Tunnel are investigated and surveyed from the multiple angles. The relationship between the planned Sanya No.II Ring Expressway and the reconstruction and extension of Damao Tunnel is interpreted. And combined with the highway network planning and the site construction conditions in Sanya, three overall schemes for the reconstruction and extension of Damao Tunnel are compared and demonstrated, which provides the design reference for the reconstruction and expansion engineering of mountain tunnels in the high-grade highways.