高含水率有机质河道底泥压缩性状试验研究

One-dimensional compression behavior of reconstituted river sediments with organic matter

河道底泥的压缩性状是影响河道底泥环保疏浚设计及处置的一个关键因素,采集了4条河道的底泥,针对4种城市河道底泥和过氧化氢处理的底泥开展了一系列物理和压缩试验,研究河道底泥的压缩性状,探讨有机质含量对河道底泥压缩性状的影响规律。试验结果表明,河道底泥的有机质含量变化范围大,河道底泥的压缩性状与底泥的物理性状密切相关,与无机质土类似,初始孔隙比和液限孔隙比是河道底泥压缩性状的两个关键控制因素。有机质对底泥压缩性状的影响可以归结于液限孔隙比的改变,有机质含量主要影响河道底泥的液限和比重,进而导致河道底泥重塑屈服应力σ′yr和压缩性状发生改变。有机质含量越高,液限孔隙比越大,压缩指数越大,呈现出的压缩性越高。

The compression behavior of river sediments is an important factor affecting the design and disposal of environmental dredging of river sediments. To investigate the compressibility of four river sediments, the consolidation tests of four kinds of river raw sediments and river sediments with hydrogen peroxide treated were performed in adapted odometers. The compression behavior of river sediments was studied and the effect of organic matter content on compression of sediments was discussed. The results show that the contents of organic matter in river sediments varies widely, and the compression behavior of river sediments is closely related to the physical properties of sediments. It is found that the main factors of influencing the compression behavior of reconstituted river sediments are initial void ratio and void ratio at liquid limit. The effect of organic matter on the compression behavior of river sediments can be attributed to the change of the liquid limit void ratio. The organic matter content affects the liquid limit and specific gravity of the river sediments, which leads to the change of remoulded yielding stress and compression behavior of river sediments. With increase of organic matter content, void ratio at liquid limit and compression index of river sediments increases, and the compressibility of river sediments is higher.