板形基础抗冻胀破坏的断裂力学分析

ANALYSIS ON FROST HEAVING OF PLATE FOUNDATION USING FRACTURE MECHANICS METHOD

在冻土地区,板形基础被广泛应用,由于冻胀作用对板基础造成各种冻害破坏。基于断裂力学理论,建立了板形基础与地基广义强度破坏的一般准则,提出了板基础抗冻胀破坏分析的新方法,可以对各种板基础的冻胀破坏进行定量分析。应用此准则分别对埋深超过冻深和小于冻深的板基础进行抗冻拔稳定性分析;给出了水池底板的冻胀破坏的强度分析方法。该方法考虑了冻胀力的作用,考虑了冻土自身存在的缺陷,符合冻土实际状态,因此,该分析方法更趋合理。通过工程算例进行抗冻胀破坏分析,结果表明,断裂力学方法是有效的。

Based on fracture mechanics theory, a general failure criterion is set up and a fully new analysis method is given for plate foundation and ground widely used in cold regions. Frost heaving force and flaws of frozen soil are considered in the criterion, and the criterion would be more reasonable and more practical than conventional one. The stability of frost heaving for plate foundations embedded deeper and shallower than freezing-depth are analyzed, and the strength analysis method for failure of bottom plate of water pool is proposed as well. After that, practical samples are analyzed by different methods, from which the validity of the new method is gotten.