新旧路基结合部位沉降特征三维数值分析

新旧路基结合处理技术是确保既有线路改造成功的关键。运用有限元分析的基本原理,采用Adina数值模拟软件模拟了局界到湖沿的新旧路基立体交叉结合的典型断面,对新旧路基结合部位的沉降特征进行综合研究,包括内侧路肩和外侧路肩顶面的纵向沉降、路基结合处三个剖面顶面的横向沉降,并分析产生不均匀沉降的原因。计算结果表明,不均匀沉降主要发生在新路基一侧;地基的固结沉降和新旧路基的相对滑移是造成不均匀沉降的主要原因;沉降量最大值出现在新路基靠近顶点的一侧。结合立体交叉路段的沉降规律,提出了改进措施。

3D Numerical Analysis of Settlement Characteristics at the Joint Part of New and Old Roadbeds

The technique for the joint of new and old roadbeds is the key point to reform the existing lines successfully.By using the basic principle of the finite element analysis,a typical section of graded crossing joints of new and old roadbeds from Jujie to Huyan was simulated with Adina software.The settlement characteristics of roadbed joint parts were analyzed,including vertical settlements of roadbed’s medial and outboard shoulders and lateral settlements of three different sections,and the reasons inducing the non-uniform settlements were analyzed.The results showed that non-uniform settlement mainly occurred at the side of new roadbed;the consolidation settlements of road foundations and the slippages between new and old roadbeds were two major reasons causing non-uniform settlements;the maximum settlement occurred at the side of new roadbed close to its top.By getting settlement regularity of graded crossing,the improvement measures were suggested.