最大承载力状态下全风化花岗岩路基变形特性与控制方法

为了研究南方湿热条件下全风化花岗岩填筑路基的科学方法，以提高路基在运营期的耐久性与稳定性，对全风化花岗岩进行了湿法重型击实与加州承载比试验。结果表明：承载力最大状态下全风化花岗岩的含水率比最佳含水率更接近天然含水率。为进一步了解其湿胀特性，通过改变初始含水率进行了膨胀率试验，得到了全风化花岗岩在不同初始含水率下的干密度衰变规律；通过改进的固结试验对比分析了全风化花岗岩在最大承载力和最大干密度状态时的变形特性。结果显示：与常规的以最大干密度控制方法相比，全风化花岗岩在最大承载力状态下抗变形能力和稳定性更好。按最大承载力状态铺筑了全风化花岗岩路基试验段并进行了现场回弹模量和压实度检测，结果表明：最大承载力状态下全风化花岗岩路基完全能满足下路床94区的压实要求，为了满足路面对路基回弹模量的要求，基于变形等效原理提出刚度补偿设计方法，以确保全风化花岗岩路基整体刚度与耐久性。

Deformation characteristics and control method of completely decomposed granite subgrade under maximum bearing capacity

To improve the durability and stability of subgrade on service, we aimed to research on a scientific method for filling subgrade with completely decomposed granite soil under the hot and humid condition in south. Wet heavy compaction test and California bearing ratio test were conducted on the completely decomposed granite. The results show that the moisture content of completely decomposed granite was more similar to natural moisture content than the optimum moisture content under the maximum bearing capacity. Swelling experiment was carried out to obtain the regularity of density decay by variation of initial moisture content. The modified consolidation test was applied to analyze the deformation properties on the maximum bearing capacity and the maximum dry density status respectively. The results show that compared to maximum dry density condition, the resistance of deformation and the stability on the maximum capacity status was enhanced. Moreover, the experimental subgrade filling with completely decomposed granite was constructed on the maximum bearing capacity status. The in-situ bearing plate test and compactness test were conducted, and the results show that the compactness could totally meet the demand of lower road bed which is the 94% compactness region. To meet the design modulus of the subgrade that the pavements demands, we proposed a method of stiffness compensation based on principle of equivalent deformation to ensure the stiffness and the durability of the completely decomposed granite subgrade effectively.