Study On Influence Factors Of Slope Erosion With Scouring Experiment In Pisha Sandstone Region

Indoor scouring experiment is used to study the scouring resistance ability of slop in Pisha sandstone region. The thesis is focused on studying the factors of slope how to effect the scour stability and runoff hydraulic characteristics. The reinforcement effect of W-OH, PVA or EVA with W-OH on Pisha sandstone are also analyzed to select the appropriate dosage and combation. Main results are shown as follows:Flow discharge and slope gradients were the main factors that had influence on slope stabilization. Runoff, sediment yield, flow velocity, Reynolds number (Re) and Froude number (Fr) increased with the increase of scrour flow. While sediment concentration decreased with the increase of scrour flow. Sediment yield, sediment concentration, flow velocity, Re and Fr increased with the increase of slope gradients. However, slope gradient had no significant effect on runoffThe concentration and spraying amount of W-OH were also the main factors that had influence on slope stabilization. The concentration and spraying amount had no significant effect on runoff. Sediment yield and sediment concentration had an apparent decrease after spraying W-OH solution. There was almost no sediment when the concentration of W-OH was 2% and the spraying amount was 1.5L/m2. Flow velocity, Re and Fr of slopes treated with W-OH at 1% concentration was close to no treated slope. If the W-OH concentration was greater than 1%, it had a smaller flow velocity and Re, and a bigger Fr than no treated slope. Runoff, sediment yield, sediment concentration, flow velocity, Re and Fr of slopes treated with W-OH at 1% concentration had the similar variation law with scouring time that compared with the original slope:Initially, they changed dramatically, then a fluctuant and stable trend were appeared. Flow velocity treated with W-OH at above 1% concentration and untreated slope had the similar variation law. In the condition of spraying greater concetration than 1%, sediment yield, runoff sediment concentration, flow velocity, Re and Fr had a fluctuant and stable trend with scouring time. Therefore, the optimum W-OH concentration is at least 2%, spraying amount is at least 1.5L/m2 in the engineering practice in this region.PVA and EVA had great influence on reinforcement effect of W-OH solidified agent, while they had little influence on runoff. The sediment yield and sediment concentration had an apparent increase after adding PVA or EVA. Runoff of slope had a similar variation law both in untreated and treated slopes by W-OH+PVA or W-OH+EVA:Initially, it changed dramatically, then it had a fluctuant and stable trend with scouring time. Sediment yield and sediment concentration of slope treated with W-OH+PVA were higher in intial scouring time. Along with the continuation of scouring time, sediment yield and runoff sediment concentration decreased with a fluctuation trend and finally they tended to stabilize. Sediment yield and runoff sediment concentration of slope treated with W-OH+EVA had a fluctuant and stable trend with scouring time. Flow velocity, Re and Fr of slop treated with W-OH+PVA or W-OH+EVA had a tiny fluctuation at the beginning and tended to stabilize later.