| Bases on the objective of modifying and solidifying the soil of slop, increasing soil engineering property and scouring resistance ability, combining with the geotechnical and artificial simulation of scouring experiment, the paper has studied the influence of CONAID,LUKANG,EN-1 and SSA solidifying agents on loess's mechanical properties, analyzed the main affection factors of slop stability and protection impaction, elected the appropriate solidify agent, content, age and compactness, discussed the influence of solidifying agent on grass growth and the influence of solidifying agent and grass on scouring resistance ability of loess slop. Main results are shown as follows:1. 4 kinds of soil solidifying agents can remarkably increase the dry density, shear strength and impermeability of loess. Solidifying agent content, age, compactness and water content are the main factors that affect the shear strength and impermeability of solidified soil. In a certain range, along with the increase of solidifying agent content, curing age and compactness, the cohesion and internal friction angle increases and the permeability decreases. Along with the increase of the water content, the cohesion and internal friction angle decreases.2. Flow discharges, slope, compactness are the main factors that effect on slope stabilization and scouring resistance ability. Flow discharges have great influence on runoff ratio, and compactness and slop have little influence on runoff ratio. Runoff ratio increases greatly in initial scour stage and tends to stable gradually. Sediment content is high in initial scour stage. Along with the continuation of scour time, sediment content decreases with a fluctuation tend and finally tend to stabilize. Under the conditions of larger flow discharges and smaller compactness, sediment yield is higher, beginning time of surface (gully) is advanced, and the rill evolution is more significant. Under experiment conditions, critical slops of slope erosion and sediment yield are about 50°. Slope runoff belongs to turbulent and supercritical flow or transition and supercritical flow. Average flow velocity (V), Fr increases with the increasing of flow discharges, slope and compactness of soil. Along with increasing of flow discharges and compactness, Re increases. Along with the increasing of slop, Re increases first and then decreases. Flow discharge has more influence on flow shear stress (τ), lamina flow power (ω) and runoff kinetic energy (F) than that of slope and compactness. It has positive line relationship between sediment yield of slop surface (M) andτ,ωand F.Under experiment conditions, the scouring resistance parameters of plain soil is 0.0747 g/ (N·min), critical average flow shear stress of slop is 0.3646 N/m~2, critical average lamina flow power is 0.0981 N/m·s and critical runoff kinetic energy is 0.0895 J.3. 4 kinds of soil solidifying agents can remarkably enhance the scouring resistance of loess slop, decrease the erosion sediment yield of slop. Along with the increase of solidifying agent content, curing age and compactness, the beginning time of surface erosion and gully erosion of solidified slop is delayed, the rill evolution is not significant, sediment yield decreases and average flow V increases except for the SSA 0.10 % solidified slop. Solidifying agent content, curing age and compactness have little influence on runoff rate of solidified slop. The Re,ωand F of solidified slop are higher than that of plain slop, the f andτof solidified slop are lower than that of plain slop, runoff morphology is turbulence and supercritical flow. Solidifying agent content, curing age and compactness have little influence on Re,F,f,τ,ωand F. In the experiment conditions, the scouring resistance parameters (0.1345 g/ (N·min)) and the critical flow shear stressτ(0.4528 N/m~2) of solidified soil are higher than that of plain soil.4. EN-1 and LUKANG solidifying agent has little stress on rye grass, CONAID and SSA solidifying agent has inhibit effect on rye grass. Sediment content of planted slope is, EN-1 planted slope >LUKANG planted slope>CONAID planted slope >plain planted slope >SSA planted slope. Resistance coefficient f planted slop is, EN-1 planted slope>plain planted slope >LUKANG planted slope>CONAID planted slope >SSA planted slope. EN-1 solidifying agent has little influnce on V of planted slope, the other 3 solidifying agents can increase V of planted slope. Runoff morphology of CONAID, LUKANG, EN-1 and plain planted slope are transition flow and sub critical flow respectively, runoff morphology of SSA planted slope is turbulent flow and supercritical flow. Sediment content of CONAID, LUKANG, EN-1 and plain planted slop is lower than that of unplanted slop and plain slop, Sediment content of SSA planted slop is higher than that of unplanted SSA solidified slop and lower than that of plain slop. Runoff, V, Re, Fr,ωand F of planted slop is lower than that of unplanted slop, f andτof planted slop is higher than that of unplanted slop.5. Comprehensive consideration on 4 kinds solidifying agents affection on shear strength, impermeability, scouring resistance ability of loess and growth of rye grass, the paper suggests that EN-1 and LUKANG solidifying agents can be used in protection engineering of loess slop, and the optimum mix amount is 0.01 %, planting amount of rye grass is 35 g/m2, compactness is 0.85, age adds up to 20 days can increase the ability of slop soil resistance runoff scour significantly, prevent slop instability caused by slop erosion damage, has little stress on slope vegetation, and achieve the double-objective integration of soil fixation and ecological slope protection. It is a new way that protects slop in development and construction engineering project.
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