基于Mesri蠕变模型的路基工后沉降计算方法研究

Calculation Method for Embankment Post-construction Settlement Based on Mesri Creep Model

路基工后沉降直接关乎铁路行车安全性及乘车舒适性,对工后沉降的可靠预测一直是工程界所追求的目标。本文基于Mesri蠕变模型理论引入路基荷载下受路基宽高比影响的附加竖向应力解析式,提出了一种天然地基条件下路基工后沉降计算方法。与依赖前期沉降观测资料的预测方法不同,本文方法适用性更为广泛,且具有模型参数少、物理意义明确、易于获取以及适合计算机编程等优点。通过与离心模型试验对比,路基工后沉降的计算值与离心机数据吻合较好,计算结果具有较高精度,验证了计算方法的可行性。经过对比发现,在铺轨完成后约2a,路基沉降逐渐趋于收敛,此时的沉降占工后总沉降的80%以上。研究成果可为初步设计阶段路基工后沉降预测提供一种简便算法,具有一定工程意义。

Post-construction settlement of railway embankment,the reliable prediction of which is always pursued by the engineering circle,is directly related to traffic safety and ride comfort.Based on the theory of Mesri creep model incorporating analytical equations of additional vertical stress under embankment load subject to the width-height ratio of the embankment,a calculation method for post-construction settlement in natural ground was proposed.The method is suited for computer programming with the advantages of fewer model parameters,definite physical meaning and easy accessibility.Unlike the other methods dependent on previous settlement observation data,the proposed method is wider in applicability.Compared with the centrifuge model tests,the good agreement between calculation values of post-construction settlements and test data,as well as high accuracy,validated the feasibility of the computational approach.By contrast,the settlements of the embankment converged gradually about 2 years after the completion of track-laying.During the two-year period,the settlements accounted for 80%of total post-construction ones.The research results have certain engineering significance for providing a simple calculation method for predicting post-construction settlement in the preliminary design stage.