新老路基不协调变形模拟试验研究

道路拓宽工程中,新老路基之间的不协调变形是导致路基路面病害的根本原因,路基处治的核心是新老路基不协调变形的控制。在路基拓宽室内试槽试验中,采用在路堤底部预填一定厚度的易溶性化肥,再注水溶解的方法来模拟新老路基不协调变形的形成,并重点研究新老路共同作用层设置和路基加筋的作用。结果表明,设置一定厚度的新老路共同作用层可以明显减小新老路基的工后差异沉降;土工格栅加筋可以显著降低地基顶面所受的土压力,从而减小新老路基不协调变形。

Experimental Research on Incoordinate Deformation Between Existing Subgrade and the Widening One

The incoordinate deformation between the existing subgrade and the widening one essentially results in many distresses in road widening engineerings.So how to control this deformation is the key point in these subgrade treatments.During the laboratory test,a certain thick layer of soluble ammonium sulphate was placed at the bottom of the widening subgrade.After filling was completed,this layer was dissolved,thus simulating this incoordinate deformation.During the test,a certain thick of the common subgrade layer was constructed,and two layers of geogrid were laid.The test shows that a common layer between the existing subgrade and the widening one distinctively alleviates this discrepant after-construction settlement,and the geogrid-reinfocing treatment evidently decreases the soil pressure on ground base surface,consequently it reduces the incoordinate deformation.