确定土体破坏准则的一个新方法

A New Strategy for Determining Failure Criteria of Soil

为了完全解决理论上和工程应用中土体破坏准则的合理选用问题,总结了国内外106种土体在平面应变和常规三轴试验下摩擦角的试验结果,发现结果具有明显的规律性。同时,这些试验结果所体现出的规律与统一强度理论和统一滑移线场理论得出的理论结果高度吻合。根据这一发现,建立了破坏准则与平面应变、常规三轴试验条件下材料的强度参数之间的定量关系,由此提出了一个确定土体破坏准则的新方法。该准则具有简单的线性表达式,只需要用平面应变试验和常规三轴试验得到的摩擦角差值即可构建,便于工程应用。该研究结果也可推广应用于岩石材料、混凝土材料、工程塑料以及拉压强度不等的其他材料,更复杂的结果有待进一步验证。

To completely solve the problem of reasonable selection of failure criteria in theory and engineering application,the test results of friction angles of 106 kinds for soils at home and abroad under plane strain and conventional tri-axial tests are summarized,and an obvious regularity is found.The experimental results well coincide with the theoretical results of unified strength theory and unified slip line field theory.Analyzing the conclusion,the quantitative relationship of failure criterion with material strength parameters under plane strain and conventional tri-axial tests is established.Therefore,a new strategy for determining the failure criterion of soils is proposed,where the criterion with a simple linear expression is constructed in terms of only friction angle difference obtained from the plane strain test and the conventional tri-axial test.This strategy can also be applied to rock materials,concrete materials,engineering plastics and other materials with different tensile and compressive strength,and more complex results remain to be further verified.