河南科技大学学报：自然科学版

在公路工程中，不同土质过渡区因地质条件突变导致的路基不均匀沉降问题日益突出，针对这一问题，以某跨岩质与沙土过渡区公路工程为背景，基于有限差分方法，建立分层填筑数值模型，分析岩石与沙土路基的沉降规律及应力集中效应。研究结果表明：岩石路段的路基沉降较小，最大沉降量为2 cm,而沙土路段的路基沉降较大，最大沉降量达到15 cm。在岩石和沙土过渡区域，由于土质性质的突变，出现了明显的应力集中现象，最大沉降梯度达1.2 cm/m,远超规范允许值。施工顺序和边端效应对上层路基的沉降和应力分布有显著影响。基于研究结果，提出了针对不同土质过渡区路基沉降问题的改进建议，包括设置梯度过渡层、优化填筑顺序和采用土工格栅加固等措施，可降低沉降差至规范允许范围内(<5 cm)。研究结论可为类似工程的设计与施工提供理论依据和技术支持，有效降低不同土质过渡区路基的沉降差异，确保路基的稳定性和行车安全。

In highway construction projects, the uneven settlement of roadbed caused by the abrupt change of geological conditions in different soil transition zones has become increasingly prominent problem. To solve the problem, a highway construction project in the transition zone between rock and sandy soil was taken as the background, based on the finite difference method, a numerical model of layered filling was established, and the settlement rule and the stress concentration effect of rock and sandy soil foundation were analyzed. The research results show that the subgrade settlement of the rocky section is small, and the maximum settlement is 2 cm, the subgrade settlement of the sandy soil section is large, and the maximu m settlement reaches 15 cm. In the transition zone between rock and sandy soil, obvious stress concentration occurs due to the abrupt change of soil properties, and the maximum settlement gradient reaches 1.2 cm/m, which is far beyond the allowable value of the specification. The construction sequence and the side-end effect have a significant impact on the settlement and stress distribution of the upper subgrade. Based on the research results, the improvement suggestions for subgrade settlement in different soil transition zones are put forward, the measures including setting the gradient transition layer, optimizing filling sequence and adopting geogrid reinforcement, which can reduce the settlement difference to the allowable range of the specification(<5 cm). The research conclusion can provide theoretical basis and technical support for the design and construction of similar projects, effectively reducing the settlement difference of subgrade in different soil transition zone, and ensuring the stability of the subgrade and driving safety.