过湿冰水堆积土路基振动压实变形特性研究

Vibration Compaction Deformation Characteristics of Over-wet Glacial Deposit Soil Subgrade

为改善冰水堆积土填料因其高含水率而存在压实困难的问题,在路基施工中使用生石灰予以改良,并结合特定的施工压实方式控制压实土体变形,以达到高效填筑路基的目的。通过数值模拟研究了不同掺灰比过湿冰水堆积土松铺层的振动压实变形规律,开展现场试验对模拟结果进行验证,并基于改良冰水堆积土松铺层压实变形规律,对不同厚度松铺层随压实遍数的压实变形规律进行数值研究,确定改良冰水堆积土的最佳掺灰比例以及相应的路基填筑施工参数。结果表明:当松铺层厚度不小于40 cm时,掺灰改良可有效加快松铺层振动碾压时的沉降稳定速率。路堤填料改良可选用6%掺灰比,而压实度要求较高的路床应选用8%掺灰比的改良土填筑,施工时需采用静压不小于25 t的压实机械强振碾压至少6遍,可使过湿冰水堆积土达到路基填筑压实度的要求。

In order to address the compaction challenges arising from the high moisture content of over-wet glacial deposit soil(OGDS),lime was utilized as a soil stabilizer during subgrade construction,along with specific compaction techniques,to facilitate roadbed construction.This research investigated the deformation characteristics of vibratory compaction in the loose layer of OGDS with varying lime content ratios through numerical simulations.Field experiments were conducted to validate the simulation outcomes.Drawing insights from the compaction deformation patterns of the improved loose layer of OGDS,numerical investigations were undertaken to analyze the compaction deformation characteristics of different loose layer thicknesses concerning the compaction pass count.The optimal lime content ratio and corresponding construction parameters for roadbed construction are determined.The results show that for loose layer thicknesses exceeding 40 cm,lime mixing effectively accelerates the settlement stabilization rate during vibratory compaction.For embankment fill material improvement,a lime mixing ratio of 6% can be selected,whereas roadbeds with stringent compaction requirements necessitate an 8%lime mixing ratio for soil improvement during construction.Employing a static compaction machine with a minimum pressure of 25 tons for at least 6 compaction passes is essential to meet the compaction specifications.