大于40mm颗粒含量对回填土压实系数的影响及校正度研究

Effect and calibration of > 40 mm grain content impacting backfill compaction coefficient

依托浙北1 000 kV变电站新建工程,对28个基槽回填土试样的压实系数试验结果进行研究。试验所用指标主要为干密度、最大干密度、>40 mm颗粒含量等,基于主成分分析法的基本原理,找出对该工程回填土试样试验结果产生较大影响的因素。结果表明,>40 mm颗粒含量对于压实系数的准确测定存在影响,而在普通压实系数测定过程中往往忽略这一因素,因此,有必要根据>40 mm颗粒含量对试样的压实系数进行校正。通过引入校正度这一概念,反映出随着>40 mm颗粒含量的增加,实测结果对理论曲线的离散度增大,试验结果的精度逐渐降低。

Test results of compaction coefficient of samples from backfill of 28 foundation trenches were studied according to the project of 1000 kV Transformer Substation newly built in Northern Zhejiang.Compaction test main parameters include the dry density,maximum dry density,＞ 40 mm grain content and so on.We analyse and determine the main factors affecting the test of backfill samples based on principle of component analysis.The results showed that ＞ 40 mm grain content has great effects on accurate determination of compaction coefficient,which is often neglected in the determination process.It is necessary to calibrate compaction coefficient of samples according to ＞ 40 mm grain content.It shows that dispersion of the measured value and the theoretical curve also increase with the rising of ＞ 40 mm grain content and precision of test result decreases gradually by introducing the conception of calibration here.