含泥量对砂砾土冻胀特性的影响

为得到含泥量对砂砾土冻胀特性的影响规律,为实际工程防冻胀设计提供理论依据,利用改进的冻胀实验装置进行室内实验,研究了不同含泥量、相同饱和度条件下及相同含泥量、不同含水率条件下砂砾土的冻胀特性。研究结果表明,在封闭条件下,饱和度一定时,冻胀率随含泥量增大而增大,说明过高的含泥量能够产生较大的冻胀,因此控制含泥量是防止砂砾土冻胀的有效措施;含泥量一定时,冻胀率随含水率增大而增大,说明砂砾土的冻胀率受含泥量和含水率共同影响,因此要同时注意防排水和控制含泥量。传统研究通常认为,砂砾土由于粒径较大冻胀不明显,但本实验结果表明,具有一定量的含泥量和含水率的砂砾土也能产生比较明显的冻胀,对工程建设有较大影响,因此在工程实际中不能忽视砂砾土的冻胀。

Influence of silt content on frost heaving properties of gravel soil

This paper aims to explore the influence of silt content on frost heaving properties of gravel soil, and provide theoretical basis for anti-freezing expansion design in practical engineering. A series of indoor frost heave tests were conducted to study the heaving properties of gravel soil under the same degree of saturation with different silt content, and under the same silt content with different moisture content using the improved experiment device. The test results show that the frost heaving ratio increased with the increase of silt content at unchanged degree of saturation in sealed environment, indicating high silt content can result in large frost heaving, so the control of silt content is an effective measure for prevention of gravel soil frost heaving. The frost heaving ratio increased with the increase of moisture content at unchanged silt content in sealed environment, indicating the frost heaving ratio is influenced by both the silt content and moisture content, so waterproof and drainage and control of the silt content are both important. It is conventionally believed that gravel soil does not have obvious frost heave due to large grain size; however, our research results indicate that gravel soil with a certain amount of silt and moisture can also generate obvious frost heave, which may exert considerable influence on the construction. Therefore, gravel soil frost heave in practical engineering cannot be ignored.