合肥北环高速公路路用膨胀土性能试验研究

以合肥北环高速公路建设项目为依托,采用室内实验方法,对路用膨胀土特性进行系统研究。通过自由膨胀率等物理特性指标判定该路用膨胀土主要为弱膨胀土,同时也是高液限粘土。但是在高稠度状态下,弱膨胀土体表现出很高的膨胀势,其CBR值无法达到高速公路路基填筑的最小强度要求。必须对填筑高速公路路基的弱膨胀土进行适当的技术处理,其中提高膨胀土填筑路基的控制含水量,降低密实度,是降低路基膨胀土体膨胀势的重要路线之一。

A Testing Study on Properties of Expansive Soils Used in Hefei City North Ring Freeway

Based on the construction of Hefei North Ring Freeway,primary characteristics of the expansive soil was studied in systematic ways with extensive physical tests in laboratory.On the basis of free swelling ratio and some other physical index,the soil can be identified as weak expansive soil with lower volume change potential,but high liquid limit.However,the weak expansive soil displays high swelling potential under high degree of consistency,and maintains the CBR values much lower than the requirements of minimum strength for the fillings used in embankment of highways.Although the weak expansive soil displays lower potential for massive volume change,its stabilization by proper treatment is rational in filling embankment of highways.In addition,it is worth noting that the compacted expansive soil mass decreases the volume change potential with proper increasing its water content and decreasing its consistency.