改扩建高速公路新老路面拼接设计研究

Research on Design of New and Old Pavement Splicing for Expressway Reconstruction and Expansion

摘要:

某高速公路拟从双向四车道改扩建为双向8车道，新老路面的拼接是改扩建过程中至关重要的一环，依托该项目进行保通施工条件下的新老路面拼接设计研究。首先对老路硬路肩拟定了加铺和挖除新建2种处理方案，通过路面结构验算得到2种方案的半刚性层疲劳开裂对应的累积当量轴次分别为1.41×10⁹、7.58×10⁹，加铺方案无法满足要求，故采用挖除新建方案。对新老路面采用台阶式拼接，拟定了2种不同台阶宽度的方案，通过有限元软件计算，分析了2种方案路面拼接缝处的应力应变，得到最大应力应变产生在底基层拼接缝处，且拼接缝越远离轮迹带，应力应变越小，推荐采用拼接缝避开轮迹带的方案。此外还阐述了路面拼接施工期间的保通方案，可为类似工程提供参考。

Abstract:

An expressway is proposed to be reconstructed and expanded from two-way four lanes to two-way eight lanes. The splicing of new and old pavements is a crucial part of the reconstruction and expansion process. Relying on this project, the research is conducted on the splicing design of new and old pavements under the construction condition of continuous traffic. Firstly, two treatment schemes of overlay and excavating new-building are proposed for the hard shoulder of the old road. The cumulative equivalent axial times corresponding to fatigue cracking of the semi-rigid layer in the two schemes are obtained through pavement structure verification as 1.41×10⁹ and 7.58×10⁹ respectively. Since the overlay scheme is hard to meet the requirements, the excavating new-building scheme is adopted. The step-style splicing is adopted for the new and old pavements, and two schemes with different step widths are proposed. Through the finite element software, the stress and strain at the splicing of new and old pavements are calculated and analyzed, which shows that the maximum stress and strain are generated at the splicing of the subbase layer, and the farther the splice seam is from the wheel path, the smaller the stress and strain. It is recommended to adopt the scheme of avoiding the wheel path by splicing the seams. In addition, the scheme of continuous traffic during the splicing construction of pavements is set forth, which can provide reference for similar projects.