ABSTRACT

Civil engineers face significant challenges in the safe design and construction of durable road infrastructure in the presence of expansive soils. These problematic soils exacerbate undesirable serviceability concerns induced by pavement distress. Soil stabilisation has been recognised as a sustainable approach to alleviate the problematic nature of expansive subgrades. Road pavements constructed on top of expansive subgrade soils are generally under unsaturated conditions, where the moisture variations can significantly impact the pavement response. However, current pavement design and modelling frameworks overlook unsaturated soil behaviour by adopting simplified approaches. This study examines the hydraulic behaviour of expansive clayey soils stabilised with non-traditional and traditional chemical based additive. Tests were conducted to determine the state variation and stabilisation influence on the soil water characteristic curve using the dewpoint potentiometer for an expansive subgrade commonly found in Melbourne geology. Results show that the stabilisation has strong influence on soil hydraulic characteristics at various initial state conditions tested. Experimental data have been applied to illustrate the significance of incorporating realistic hydraulic response using a simulated practical application in road pavements. The research highlights the significance of incorporating accurate hydraulic characteristics for simulating and assessing the response of pavement constructed with stabilised unsaturated subgrade soils.

摘要

在存在膨胀土壤的情况下，土木工程师在安全设计和建造耐用道路基础设施方面面临重大挑战。这些有问题的土壤加剧了由路面破损引起的不良使用性问题。土壤稳定已被认为是缓解膨胀路基问题性质的可持续方法。在膨胀路基土壤之上建造的道路路面通常处于非饱和条件下，其中湿度变化会显着影响路面响应。然而，当前的路面设计和建模框架通过采用简化的方法忽略了非饱和土的行为。本研究检查了使用非传统和传统化学添加剂稳定的膨胀粘土的水力行为。使用露点电位计对墨尔本地质中常见的膨胀路基进行测试以确定状态变化和稳定对土壤水分特征曲线的影响。结果表明，在测试的各种初始状态条件下，稳定性对土壤水力特性有很大影响。已应用实验数据来说明在道路路面中使用模拟实际应用结合现实水力响应的重要性。该研究强调了结合准确的水力特性来模拟和评估用稳定的非饱和路基土建造的路面的响应的重要性。