有机质含量对水泥搅拌饱和黄土强度影响的试验研究

兰州至中川机场铁路路基地基加固,采用水泥土搅拌桩法处理饱和黄土地基。由于部分区段饱和黄土中存在一定的有机质,通过室内试验研究有机质含量对水泥搅拌饱和黄土强度的影响规律。试验结果表明:土中含有有机质会对水泥搅拌饱和黄土强度有影响;随着有机质含量的增加,水泥黄土试块的无侧限抗压强度明显降低,但强度降低幅度逐渐减小;有机质含量越高,水泥搅拌饱和黄土强度随龄期的增长越缓慢;在含有机质的饱和黄土中,可适当增大水泥粉煤灰掺量来提高水泥搅拌饱和黄土强度。

Experimental Study on Influence of Organic Matter Content on Strength of Cement Mixing Saturated Loess

The subgrade of railway from Lanzhou to Zhongchuan Airport is reinforced in such manner that cement-soil mixing piles are used to tackle with the saturated loess foundation. Because there are certain organic matters in the loess in some sections, how the content of organic matters affects the strength of cement mixing saturated loess was studied by indoor test. The result shows that the organic matter in the reinforced loess may impact the strength thereof to the extent that, as its content increases, the unconfined compressive strength of the cement-loess specimen decreases greatly, but the rate of decrease reduces gradually; the higher the content of organic matter, the slower the growth of the loess strength with its age; for the saturated loess with organic matters, the strength of the loess reinforced by cement-soil mixing piles may improved by adding the content of cement flyash properly.