基床系数测试的室内试验法与K_(30)法的差异性分析及修正

实践表明,三轴、固结2种室内试验进行基床系数测试的结果与现场K30试验方法所获得的基床系数值之间有巨大的差异,通过对它们的加载方式、荷载选取范围,以及土体的排水状态、受力状态和几何尺寸的综合对比分析发现,受力体几何尺寸上差异及其对测试结果造成的影响最为显著。经过理论分析,以荷载的变形效应等效为原则,提出K30试验法与三轴试验法和固结试验法对应的等效厚度。对2种室内试验方法而言,其试件高度较K30试验法的等效厚度明显偏小是造成它们的测试结果明显偏大的根本原因。以等效厚度的概念为基础,提出对2种室内试验方法的结果进行试件高度修正的方法。

Analysis and Modification of Difference on Subgrade Reaction Coefficient Testing between Laboratory Testing Method and K30 Testing Method

Practice shows that,there is a wide difference on testing result of subgrade reaction coefficient between on-site k30 test method and two laboratory test methods which include triaxial testing and consolidation testing.For this reason,in this paper,their load method,range of load,soil sample's drain condition,stress condition and the size are compared and analyzed.The analysis indicates: it is the difference on the size of stressed soil body that exerts the most significant influence on testing result.Therefore,through theoretical analysis,based on the principle of equivalent deformation effect,the paper suggests the equivalent thicknesses of K30 test method corresponding to triaxial test and consolidation test.The paper thinks that,the test results obtained by both two laboratory methods are obviously larger than that obtained by K30 test method,mainly because the thickness of soil samples in laboratory is significantly smaller than the equivalent thickness of K30 test method.And then,based on the theory of equivalent thickness,a method of modifying the testing results obtained by two laboratory methods is proposed in this paper by means of modifying the thickness of laboratory soil sample.