【作者】 范猛；

【导师】 张金喜；

【作者基本信息】 北京工业大学 ， 道路与铁道工程， 2009， 硕士

【摘要】 针对高速公路施工中台背回填质量难以保证的现状,本文从回填材料方面进行了探索和研究,提出了一种新型回填材料——非压实回填土。非压实回填土具有自密实的特点,并且可以就地再生利用挖方弃土,不需要新的取土场,具有显著的环境效益和经济效益。本文通过对非压实回填土的工作性进行试验探讨,确定了非压实回填土的原材料选择要求,并提出了水固比的概念,将其作为非压实回填土配合比设计参数之一,基于此提出了非压实回填土的配合比设计方法。其次,依据本文提出的配合比设计方法,对非压实回填土的基本力学性能开展了相应的室内试验研究,主要包括抗压强度试验、CBR承载能力试验和应力-应变试验。着重分析了各个因素对强度的影响,得出了强度随龄期增长的发展规律,并提出了以水固比和灰土比为主要参数的强度预测模型。本文还开展了不同配合比非压实回填土的耐久性能试验,包括抗冻融循环试验和抗干湿循环试验。试验结果显示,在两种不同外界破坏作用下,非压实回填土具有相似的劣化规律:随着强度的提高,其抵御外界环境破坏的能力也不断提高。最后在室内试验的基础上成功的把非压实回填土应用到实际工程中,取得了较好的工程效果和经济环保效益,并据此提出了非压实回填土的施工方法和质量管理方法。更多还原

【Abstract】 Abutment jump is one of the most frequent quality problems encountered in high way construction. In order to improve the quality of backfill, a new backfill material:self-compacting backfill was introduced. The new material can reuse excavation soil, also with good workability.Firstly, based on a lot of workability experiments, the raw materials of self-compacting backfill is determined. And the water solid ratio is proposed as one of mix-design parameters. After that, the mix design method of self-compacting backfill is proposed.According to the mix design method above, experiments of the basic mechanical properties including compressive strength, CBR and stress-strain characteristic were carried out. It is obtained, that the rule of strength growth with age, and that the strength empirical formula with two parameters: the water solid ratio and the cement soil ratio.The freezing and thawing experiment and wetting-drying experiment were also carried out. The results show that self-compacting backfill has similar degradation rule in two different external damage functions. Its ability to resist the external damage increase with compressive strength rising.Finally, based on the indoor experiments, self-compacting backfill was successfully applied in practical example. The new material made good project effects, environment protection and economic profit. And the construction and quality management methods are proposed based on the construction experience.更多还原