基于响应异常的素填土勘察试验方法可靠性分析

受素填土极不均匀特性的影响,不同的勘察试验方法获得的试验结果不但不能相互印证,甚至互相矛盾,以至影响到对素填土工程特性的准确评价。因此,评价勘察试验方法的可靠性和选择适宜的勘察试验方法是获取可靠试验结果、准确评价素填土工程特性的前提和基础。对同一场地素填土(强夯填土和自固填土)的室内土工试验和重型圆锥动力触探试验所获的试验成果及试验成果的变异系数进行了对比、分析,分析结果表明:间断性取样的室内土工实验所获取的信息不连续、不全面,不能全面反映素填土的力学性状,因此试验结果异常,试验结果的变异系数也异常;分段贯入的重型圆锥动力触探试验尽管也不连续,但试验长度较室内土工试验大,试验结果基本反映了素填土的力学性状,可跳跃性大,因此试验结果正常,变异系数异常;连续贯入的重型圆锥动力触探试验能够连续、全面获取素填土的力学性状信息,综合反映试验点土体的力学性状,故试验结果及变异系数均未出现异常。因此重型圆锥动力触探试验方法比室内土工试验方法的可靠性高,更适宜于素填土的勘察评价。

Reliability analysis of survey and test methods based on the response abnormal plain fill

Because of uneven features of plain fill, test results obtained by the different survey and test methods fail to confirm each other, even is contradictory, which affect the evaluation of the engineering properties of plain fill. Therefore, the appropriate choice of survey and test methods and reliability of test methods evaluation is basis and premise to obtain reliable test results and accurately evaluate the engineering properties of plain fill. In this paper , through comparative analysis of the coefficient of variation of the test results and test results of plain fill in same venue(dynamic compaction fill and dead-weight consolidation fill) obtained by indoor soil test and heavy cone dynamic penetration test, analysis conclusion is as follows: information obtain by the intermittent sampling indoor geo-experimental methods is discontinuous and far from comprehensive, which can not fully reflect the mechanics traits of the plain fill. As a result, test results and the coefficient of variation of the test results is abnormal; although the heavy cone dynamic penetration segments penetration test method is discontinuous, the test length is longer than that of indoor geotechnical test. So the test results reflect the mechanical properties of plain fill and the test results are normal, but the coefficient of variation is abnormal because of non-continuity; continuous penetration of heavy cone dynamic penetration test methods are capable of continuously and fully getting the mechanical traits information of plain fill, and synthetically reflect the soil physical traits of test point, so the test results and the coefficient of variation were not abnormal. In conclusion, heavy cone dynamic penetration test methods is more suitable than indoor soil test method for survey and evaluation of plain fill.