EPS混合土处理桥台软土地基模型试验

发布时间：2018-05-23 17:45

本文选题：EPS混合土 + 模型试验　；参考：《南京工业大学学报(自然科学版)》2017年06期

【摘要】：聚苯乙烯泡沫颗粒轻质混合土(EPS混合土)具有质轻、强度可调可控及环境友好等特点,作为复合土工材料常用于地基处理。设计并完成了小比尺室内模型试验以研究EPS混合土处理桥台软弱地基的效果。采用粒子图像(PIV)测速技术监测桥台地基的位移场,对比分析了软土地基桥台背后回填砂土、水泥土,以及2%、3%和4%3种不同配比的EPS混合土时的台背侧向土压力及地基土变形特征。结果表明:与传统的砂土填料相比,EPS混合土可以有效减小台背侧向土压力,在本文试验配比范围内,台背侧向土压力随着EPS颗粒含量的增加而减小;EPS混合土可显著减小回填土表面沉降量,其不均匀沉降也较砂土填料大为改善,地表的沉降量与测点距桥台的距离之间趋向于线性关系;回填EPS混合土时,填土表面出现的不均匀沉降主要是由于桥台地基软土层在荷载作用下出现趋向桥台底部的滑移变形,从而引起整体刚度较大的回填EPS混合土层倾斜。工程实践中,应对EPS混合土的回填深度进行综合考虑。
[Abstract]:Polystyrene foam particle lightweight mixed soil / EPS mixed soil has the characteristics of light weight, controllable strength and environmental friendliness. It is often used as a composite geotechnical material for foundation treatment. In order to study the effect of EPS mixed soil treatment on soft foundation of bridge abutment, small scale indoor model test was designed and completed. The displacement field of abutment foundation is monitored by particle image technique (PIV). The backfill of sand, cement soil behind abutment on soft soil foundation and the soil pressure and deformation characteristics of backside of abutment with 2% and 4% EPS mixed soil are compared and analyzed. The results show that the EPS mixed soil can effectively reduce the lateral earth pressure in the back of the platform compared with the traditional sand fillers. The lateral earth pressure at the back of the abutment decreases with the increase of EPS particle content, and the surface settlement of the backfill is significantly reduced, and the uneven settlement is greatly improved compared with the sand filling. There is a linear relationship between the settlement of the ground surface and the distance from the measured point to the abutment, and the uneven settlement on the surface of the fill is mainly due to the slip deformation of the soft soil layer of the abutment foundation towards the bottom of the abutment when the soil is backfilled with EPS. As a result, the EPS mixed soil layer with large overall stiffness is inclined. In engineering practice, the backfill depth of EPS mixed soil should be considered synthetically.
【作者单位】：南京工业大学城市地下空间研究中心岩土工程研究所;
【基金】：国家自然科学基金(51578286)
【分类号】：U443.1

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