基于动力试验通平高速红砂岩路基处治研究

在湖南省高速公路建设中存在大量红砂岩填料,该类岩石具有崩解特性,其施工质量难以控制。结合湖南通城至平江高速公路工程中遇到的红砂岩地质情况,开展红砂岩工程力学性质及现场试验,掌握该地区红砂岩的工程特性,开展红砂岩路基填筑施工工艺现场试验及动力试验,试验结果表明：通平高速红砂岩属于Ⅲ类红砂岩,但仍会崩解,故不能作为填石路堤对待;下路堤采用＂光静1遍＋羊静1遍＋羊振4～5遍＋光振1遍＋光振1遍＂能将红砂岩最大粒径控制在25 cm以下的能力,上路堤采用以下二次钯压工艺可将红砂岩填料颗粒破碎至20 cm以下,均能满足设计要求;考虑到上部动力荷载的影响深度,路床96区路基不能采用红砂岩直接填筑,应使用符合规范要求的适应性材料或改良土填筑。

Dynamic Test Research for Subgrade Treatment Constructed by Red Sandstone in Tong-Ping Expressway

There are a lot of red sandstone filler in expressway construction in Hunan Province,which have disintegration and difficult in construction quality control.In this paper,combined with the red sandstone geological conditions encountered in the Tongcheng-Pingjiang Expressway Project in Hunan Province,the engineering mechanical properties and field test of red sandstone are carried out.To obtain the engineering properties of red sandstone in this area,the filling construction technology field test and dynamic test of red sandstone subgrade are carried out.Test results show that the red sandstone class III of Tong-Ping expressway is categorized to the red sandstone class Ⅲ,but it will still disintegrate and can not be treated as rockfill embankment filler.The treatment of sub-embankment,which is ＂static rolling by smooth-wheeled roller one times ＋ static rolling by tamping foot vibratory roller one times ＋ vibration rolling by tamping foot vibratory roller 4~5 times ＋ vibration rolling by smooth-wheeled roller one times ＋ vibration rolling by smooth-wheeled roller one times＂,can make the maximum size of red sandstone controlled below 25 cm.And the treatment of up-embankment adopts secondary harrow-compaction process,which can make the red sandstone filler particles broken to below 20 cm.These can meet the design requirements.Taking into account the effect depth of upper dynamic load,the red sandstone can not directly be adopted filling in subgrade of roadbed of 96th area.And it should use the adaptive materials or improved soil to fill,which need to meet the code requirements.