旧路拓宽工程往往会涉及到新老路基结合问题.结合合肥铁路枢纽改造工程,利用离心模型试验研究路基高度、拼接台阶断面尺寸、新路基边坡率等因素对新老路线的列车安全运营和路基稳定性的影响,提出适合膨胀土地区的新老路基拼接技术包括设计方法、施工工艺、控制标准等.将对类似的改扩建工程提供理论支持和示范借鉴,对铁路的改扩建工程建设具有较大的指导意义和应用价值. Old road widening project often involves the integration of old and new roadbed.Combining with the Hefei railway hub reconstruction project, the use of centrifugal model test study subgrade height, splicing step cross-section size, the new roadbed slope and other factors on the new and old route train safety operation and The stability of subgrade and the new and old subgrade embankment technology suitable for expansive soil area are put forward, including the design method, construction technology and control standard, etc. It will provide theoretical support and demonstration for similar expansion and expansion projects, Greater guiding significance and application value.