Abstract: Shear deformation of graded crushed stone material is the main failure form of graded gravel base. In order to reduce the occurrence of this kind of disease, a new method of mixing ratio design with shear resistance as the key control index was established by using self-developed direct shear test equipment and using safety factor as the design index. The new index of “safety factor” is derived from the necessary and sufficient conditions of Mohr Coulomb strength theory. The actual application results show that: the proposed index not only conforms to the shear failure mode of granular materials, but also can link the material design and structural design of granular materials such as graded crushed stone, which has strong theoretical value and practical application value.

Key words: highway engineering, graded gravel, safety coefficient, mixing ratio design, direct shear test

摘要： 级配碎石材料的剪切变形是级配碎石基层的主要破坏形式。为了减免这类病害的产生，采用自主研发的直剪试验设备，以安全系数为设计指标，建立了一种以抗剪切性能为关键控制指标的配合比设计新方法。“安全系数”这一全新指标是通过莫尔-库仑强度理论的充分必要条件推导得出的。实际应用效果表明：该指标既符合散粒体材料的剪切破坏模式，又能将级配碎石等散粒体的材料设计与结构设计联系起来，具有较强的理论价值与实际应用价值。

关键词: 道路工程, 级配碎石, 安全系数, 配合比设计, 直剪试验