冻土抗拉强度研究现状与展望

Research status and prospect of tensile strength of frozen soil

全面掌握冻土抗拉强度研究现状是进一步深化研究的基础。首先,分类介绍了目前可用于冻土抗拉强度测试的各典型方法,详细阐述了不同测试方法的试验条件、试样形式和受力机理,对比列举了典型抗拉强度测试方法优缺点。其次,归纳总结了基于不同试验方法已进行的研究工作和不足。然后,全面分析了温度、含水量、加载(变形)速率、土质及试样尺寸等影响因素对冻土抗拉强度变化规律影响的最新研究进展。最后,提出发展并完善冻土抗拉强度研究方法和体系,增加高温冻土抗拉强度测试研究,从而获得更加准确模拟冻土张拉破坏行为的展望。指出应结合冻土微细观结构和数字图像技术研究手段,深入揭示冻土抗拉强度形成内因和张拉破坏机制。阐述以多影响因素试验为基础,探寻更为完善的冻土抗拉强度预测方法。同时,拓展冻土抗拉强度的现场原位测试研究,加强室内外双轨并行式研究思路。通过对国内外研究现状及发展趋势的分析,为冻土抗拉强度试验研究、冻胀理论模型完善、寒区岩土工程设计和人工冻结加固工程等提供参考和指导。

A comprehensive grasp of the research status of tensile strength of frozen soil is the basis for further research. Firstly, the typical methods that can be used to test the tensile strength of frozen soil are introduced, and the test conditions, sample forms and stress mechanism of different test methods are described in detail. The advantages and disadvantages of typical tensile strength test methods are compared and listed. Secondly, the research work and shortcomings based on different test methods are summarized. Then, the latest research progress of the influence of temperature, water content, loading(deformation) rate, soil quality and sample size on the change law of frozen soil tensile strength is comprehensively analyzed. Finally, it is proposed to develop and improve the research method and system of frozen soil tensile strength, and increase the testing research of warm frozen soil tensile strength, so as to obtain the prospect of more accurately simulating the tensile failure behavior of frozen soil. It is pointed out that the internal cause of the formation of the tensile strength and the tensile failure mechanism of frozen soil should be thoroughly revealed by combining the research methods of microstructure and digital image technology of frozen soil. Based on the multi-factor test, a more perfect prediction method of frozen soil tensile strength is explored. Meanwhile, expand the in-situ test research on the tensile strength of frozen soil, and strengthen the parallel research ideas of indoor and outdoor double tracks. Through the analysis of the research status and development trend at home and abroad, it provides reference and guidance for the experimental study of frozen soil tensile strength, the improvement of theoretical model of frost heave, geotechnical engineering design in cold regions and artificial freezing reinforcement engineering.