EXPERIMENTAL STUDY ON ANTI-SEEPAGE OF POLYPROPYLENE FIBER-REINFORCED LOESS

The fiber infiltration effect will accelerate the water infiltration and cause the weakening of soil impermeability,which is not conducive to the long-term protection of loess slopes under concentrated rainfall conditions. To comprehensively evaluate the influence law of fiber loess,ber length,and dry density on the permeability coefficient was studied,the vertical infiltration law and model of fiber soil column under different compaction conditions were revealed,and the moisture monitoring test was carried out in the field combined with the fiber loess treatment thickness obtained from the test to explore the moisture variation characteristics and impermeability effect of the shallow soil of fiber protection slope. The results show that the infiltration coefficient of fiber loess decreases with decreasing fiber admixture,increasing length,and dry density,and the sensitivity of variation is from strong to weak in order of dry density,fiber admixture,and fiber length,among which dry density as the main controlling factor can play a suppressive role in fiber infiltration effect; adequate compaction is a necessary condition to ensure that fiber loess maintains good infiltration resistance. Compared with the fiber soil column with 80% compaction,the fiber soil column with 90% compaction has 36.36% more stable infiltration time,50.00% less initial infiltration rate,83.33% less stable infiltration rate,and about 15% ~50% more delayed initial moisture response time. When the water-soil mass ratio is 0.37,the slope platform and the thickness of fiber loess treatment on the slope surface is 15 and 10 cm,the volumetric water content of each measurement point inside the slope remains stable,and the coefficient of variation is 0.78% ~1.36%,which is only 1/9 of that of the unprotected slope.