原有路基稳定性对高速公路加宽工程的影响分析

通过数值模拟,结合高速公路加宽工程实例,分析了在原有路基未固结稳定情况下新老路基的固结沉降变形特性,并对可能的处理方法进行了分析探讨。结果表明,新老路基的沉降随着老路固结度的减小而逐渐增大,但差异沉降却逐渐减小;当老路固结度较小时,在固结后期差异沉降可能逐渐减小;轻质路堤法和复合地基法分别处理新路地基时,各有优缺点,轻质路堤法对老路附加沉降影响较大,但能较好地控制不均匀沉降,复合地基法对老路附加沉降影响很小,但在老路固结度较低时,差异沉降较大。

Analysis on the Impact of Old Road Stability to Expressway Widening Project

Based on numerical modeling combined with a practical engineering,the characteristics of consolidation settlement and deformation of the new and old road foundations are analyzed for an expressway widening project where the old road is unstable.Some analyses and discussions are made of the possible methods of ground improvement.The analytical results show that the settlements of the new and old embankments increase gradually with the decrease of the consolidation degree of the old road foundation,but the differential settlement decreases gradually.When the consolidation degree of the old road foundation is relatively low during the late course of consolidation,it is probable that the differential settlement decreases gradually.When the new road foundation is improved with the lightweight embankment method and the composite foundation method,the effects of the two improvements have their own advantages and disadvantages.The former method induces much more additional settlement of old embankment,but can control the differential settlement better,while the latter method induces less additional settlement of old embankment,but much more differential settlements when the consolidation degree of the old road foundation is comparatively low.