轻质土换填路堤地基侧向变形非线性算法研究

Research on the Nonlinear Algorithm for Lateral Deformation of Foundation under Lightweight Soil Replacement Embankment

研究目的:目前对于轻质土路堤下地基侧向变形方面的研究仍缺乏相配套的理论算法,因此本文考虑轻质土换填路堤荷载的特殊性,推导地基侧向位移理论解;基于Walsh公式和土体单元球形孔隙假定提出考虑土体非线性的变形模量修正模型,综合构建轻质土换填路堤下地基侧向变形非线性算法。结合工程算例验证算法的有效性,并开展参数敏感性分析。研究结论:(1)通过对比验证,本文理论算法计算值接近现场实测值,整体误差为15.3%,具有合理性;(2)轻质土换填路堤荷载作用下,坡脚处的侧向位移在竖向上呈“弓”形曲线分布;(3)越靠近路堤外侧位置,地基侧向位移越大;随着地基土泊松比增大,地基整体侧向位移增大,最大侧向位移位置也逐渐上移;地基土变形模量越大,侧向位移值越小;轻质土路堤越宽,侧向位移越小;(4)本研究结果可为泡沫轻质土路基稳定性分析提供理论参考。

Research purposes: At present, the research on the lateral deformation of the foundation under the lightweight soil embankment still lacks the corresponding theoretical algorithm. Therefore, this paper considers the particularity of the load on the embankment replaced by lightweight soil, and derives the theoretical solution of the lateral displacement of the foundation;Based on the Walsh formula and the assumption of the spherical pores of the soil element, a correction model of the deformation modulus considering the nonlinearity of the soil is proposed, and the nonlinear algorithm for lateral deformation of foundation under lightweight soil replacement embankment is comprehensively constructed. The effectiveness of this algorithm is verified by engineering examples, and the parameter sensitivity analysis is carried out.Research conclusions:(1) Through comparison and verification, the calculated value of the theoretical algorithm in this paper is close to the actual measured value, and the overall error between the two is 15.3%, which is reasonable.(2) Under the load of lightweight soil replacement embankment, the lateral displacement at the toe of the slope is vertically distributed as a "bow" curve.(3) The closer the position to the outer side of the embankment, the greater the lateral displacement of the foundation;As the Poisson’s ratio of the foundation increases, the overall lateral displacement of the foundation increases, and the position of the maximum lateral displacement gradually moves upward;The larger the soil deformation modulus, the smaller the lateral displacement value;The wider the lightweight soil embankment, the smaller the lateral displacement.(4) The research results can provide a theoretical reference for the stability analysis of foam lightweight soil subgrades.