广东高速公路软土工程处治技术研究

Study on Soft Soil Engineering Treatment Technology of Guangdong Expressway

高速公路山区软土处治技术目前研究相对较少,开展适用山区软土处治技术的研究具有重要的工程实践意义。文中基于广东省内较有代表性的山区软土高速项目——平兴山区高速项目,分析山区软基路基开裂或滑移的主要原因,提出山区软基处治设计关键内容。针对高速公路K87＋175~K87＋350路段因填筑过快导致路基滑塌问题,进行了换填和抛石挤淤联合处理山区软基方案研究。相对原设计管桩复合地基,片石来自于标段内隧道开挖石料,采用换填＋抛石挤淤法可节省大量工程费用,经济优势明显,因此在片石资源丰富的条件下,挖除部分软弱土层再抛石挤淤也是一种可取的山区软基处理方案,相对刚性桩复合地基有较大的经济优势。但采用此工艺在路基填筑前期稳定性相对较低,应结合稳定监控数据动态控制填土速率。

The research on soft soil treatment technology in expressway mountainous area is relatively rare,and it is of great practical significance to carry out the research on soft soil treatment technology in mountainous area.Based on the Pingxing Mountain expressway project which is more typical with soft soil in Guangdong Province,in this paper the main reasons for the cracking or slip of soft foundation in mountainous area are analyzed,and the key content of mountain soft ground treatment design is put forward.For the highway K87 ＋ 175 ～ K87 ＋ 350 section,in order to solve the problem of subgrade slumping due to filling too fast,the combined treatment of mountainous soft ground by filling and ripfalling is discussed.Compared with the original design of pipe pile composite foundation,it takes the stone in this section of the tunnel excavation stone.The use of forging ＋ rubbing stone silting method can significantly save engineering costs with good economic advantages.So under the conditions with abundant stone,excavation of some soft soil and then dump of stone siltation is also a desirable treatment program to soft base,and it has a better economic advantage compared with rigid pile composite foundation,but the early stability is relatively low when using this process in the roadbed filling,therefore it should be combined with stable monitoring dynamic control of filling rate.