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。
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.
[1] Everett D H. The thermodynamics of frost damage to porous solids[J]. Transactions Faraday Society, 1961, 57: 1541-1551.
[2] Vinson T S, Ahmad F, Rieke R. Factors important to the development of frost heave susceptibly criteria for coarse-grained soils[J]. Transportation Research Record, 1986: 124-131.
[3] Chen X, Wang Y. Control of frost heave ingeotechnical engineering[C]// Proceedings of the Eighth International Conference on Offshore Mechanics and Arctic Engineering. New York American Society of Mechanical Engineers (ASME), 1989, 32: 148-153.
[4] Konrad J M, Lemieux N. Influence of fines on frostheave characteristics of a well-graded base-course material[J]. Canadian Geotechnical Journal, 2005, 42(2): 515-527.
[5] Konrad J M. Freezing-induced water migration incompacted basecourse materials[J]. Canadian Geo-technical Journal, 2008, 45(7): 895-909.
[6] 叶阳升, 王仲锦, 程爱君, 等. 路基的填料冻胀分类及防冻层设置[J]. 中国铁道科学, 2007, 28(1): 1-7. Ye Yangsheng, Wang Zhongjin, Cheng Aijun, et al. Frost heave classification of rail subgrade filling material and the design of antifreezing layer[J]. China Railway science, 2007, 28(1): 1-7.
[7] 许建, 牛富俊, 牛永红, 等. 换填法抑制季节冻土区铁路路基冻胀效 果分析[J]. 中国铁道科学, 2011, 32(5): 1-7. Xu Jian, Niu Fujun, Niu Yonghong, et al. Analysis on the effect of replacing-soil method on inhibiting frost heave of railway roadbed in seasonal frozen soil region[J]. China Railway Science, 2011, 32(5): 1-7.
[8] 张以晨, 李欣, 张喜发, 等. 季冻区公路路基粗粒土的冻胀敏感性及 分类研究[J]. 岩土工程学报, 2007, 29(10): 1522-1526. Zhang Yichen, Li Xin, Zhang Xifa, et al. Research on frost heave susceptibility and classification of coarse grained soil of highway subgrade in seasonally frozen ground region[J]. Chinese Journal of Geotechnical Engineering, 2007, 29(10): 1522-1526.
[9] 赵成江, 王晓荣, 夏琼, 等. 不同含泥量与含水率下铁路板结道床的 冻胀特性[J]. 铁道工程学报, 2011, 156(9): 36-96. Zhao Chengjiang, Wang Xiaorong, Xia Qiong, et al. Frost heaving behaviors of hardened ballast beds under different content of clay and water[J]. Journal of Railway Engineering Society, 2011, 156(9): 36-96.
[10] 王天亮, 岳祖润. 细粒含量对粗粒土冻胀特性影响的试验研究[J]. 岩 土力学, 2013, 34(2): 359-388. Wang Tianliang, Yue Zurun. Infuence of fines content on frost heaving properties of coarse grained soil[J]. Rock and Soil Mechanics, 2013, 34(2): 359-388.
[11] 交通部公路科学研究院. JTG E40—2007 公路土工试验规程[S]. 北 京: 人民交通出版社, 2007: 345-349. The Ministry of Communications Highway Research Institute. JTG E40-2007 Test methods of soils for highway engineering[S]. Beijing: China Communication Press, 2007: 345-349.
