某机场红层强-全风化砂岩的力学特性大型原位试验研究

我国西南地区广泛分布有厚度较大的红层风化砂岩，修建高填方机场工程时，能否以其作为填料成为亟待解决的问题。通过浅层平板载荷和原位大型浸水剪切试验，研究了风化程度和含水率对风化红层砂岩的力学强度的影响。结果表明:强-全风化红层砂岩地基承载力特征值小，沉降量大，且强风化红层砂岩的承载力特征值和变形模量约为全风化红层砂岩的2倍；强-全风化红层砂岩抗剪强度参数（c，φ）随含水率的增加而不断降低，尤其是黏聚力c对含水率的变化极为敏感；随着风化程度的增加，水对其强度特性影响越来越弱。总之，风

Study on Large-scale In-situ Test of Mechanical Properties of Strong and Whole-weathered Sandstone in Red Rock of an Airport

Weathered sandstone is widely distributed in red bed in Southeast China, and a problem demanding prompt solution is whether weathered sandstone may be used in construction of filling for high fill work. The impact of weathering degree and moisture content on the mechanical strength of weathered sandstone in red rock is researched by shallow plate loading tests and large in-situ soaking shear tests. The test analysis shows that strong and whole-weathered sandstone in red rock foundations have small characteristics value of bearing capacity and large settling volume, and the strong sandstone foundation has 2 times characteristics value of bearing capacity of foundation the whole-weathered sandstone in red rock; the shear strength parameters (c, φ) of strong and whole-weathered sandstone reduces continuously with the increase in the moisture content, and in especial cohesion force C is extremely sensitive to changes in moisture content. With the increase of weathering degree, the impact of water on the strength characteristics of weathered sandstone becomes weaker and weaker. In short, under the condition of continuous rainfall, the load capacity and stability of the weathered sandstone decline sharply with the increase of moisture content. The weathered sandstone must be improved if it is used as the filling for airfield runway, but may be directly used as the fillers of other roads or building foundation.