循环荷载下土工袋加固公路路基动力响应及影响因素研究

Study on the dynamic response of soilbags-reinforced highway subgrade under cyclic loading and influence factors

摘要

土工袋加固路基作为一种绿色公路路基加固方法，在车辆等交通循环荷载作用下的工作性态仍不够清晰。为明确土工袋加固路基在循环荷载作用下的动力响应及其影响因素，开展不同土工袋加固层数、加固层不同埋深以及不同循环荷载频率、幅值工况等条件下土工袋加固路基循环荷载试验，分析不同工况条件下路基的永久沉降、回弹变形及加速度响应。结果显示：土工袋的加筋、应力扩散和耗能作用，能够有效减少路基表面沉降、回弹变形以及荷载引起的振动；循环荷载幅值和频率增大均会导致土工袋加固路基表面沉降、回弹变形以及加速度响应的增大，土工袋在循环荷载幅值和频率较大时的加固效果更为显著；随着土工袋埋深的降低以及土工袋加固层数的增加，土工袋加固路基抗变形能力和减振能力增强。结果表明：多层土工袋组成的加固垫层，可有效提高循环荷载下路基整体抗变形能力和减隔振效果。

Abstract

Although soilbag reinforcement is an established environmentally friendly method for highway subgrade enhancement, its working behavior and the factors influencing its performance remain inadequately understood. Model tests were conducted on soilbag-reinforced highway subgrade subjected to cyclic vertical loads are conducted, considering various reinforcement layers, embedded depths, and cyclic load frequencies and amplitudes. It was found that the reinforcement, stress dispersion, and energy dissipation characteristics of the soilbags effectively reduce surface settlement, resilient deformation, and vibrations induced by cyclic loads. Increases in the amplitude and frequency of cyclic loads were observed to lead to greater surface settlement, resilient deformation, and acceleration responses in the soilbag-reinforced subgrades, with more significant reinforcement effects noted under higher load amplitudes and frequencies. It was also demonstrated that a decrease in the embedded depth of the soilbags and an increase in the number of reinforcement layers enhance the subgrades' ability to resist deformation and vibration. A reinforcement cushion composed of multiple layers of soilbags can significantly enhance the overall anti-deformation capacity and vibration reduction and isolation effect of the subgrade. Consequently, this reduces subgrade and pavement deterioration under heavy traffic loads.

关键词

土工袋 / 公路路基加固 / 循环荷载 / 动力响应 / 影响因素

Key words

soilbag / reinforced highway subgrade / cyclic loads / dynamic response / influence factors

Author summay

廖 洁(1993—), 女, 讲师, 博士, 主要从事水工岩土方面的研究。E-mail: [e-mail]

基金资助

国家自然科学基金项目(52308349)

江苏省高等学校自然科学研究项目(23KJB560022)