Engineering Measures On The Slope Surface Erosion And Sediment Yield And Water Dynamics Research

According to statistics shows,only waste soil and residue of the total development andconstruction activities caused by“15”period of about9.21million tonnes,resulting in soilerosion up to252million tonnes(Lin Minghua2008).the problem of soil and water loss indevelopment and construction projects has become an increasingly prominent issue.Accumulation as production construction project activities produces of waste heap reset,isadded soil erosion of main sources(Lin Minghua2008).By studying the different slopes(24°,28°,32°) and the soil conservation measures (CK,scales pit,and horizontal bands)conditions engineering accumulation slope surface of soil erosion process, runoff waterdynamics characteristics and dynamic processes of erosion in sediment yield.Deepening hason production construction district soil erosion features of awareness and understands,indoor simulation test scientifically proven predecessors and checking their correspondingdata.To better improve its prediction on soil erosion amount of precision and controlproduction accumulation provides the basis for construction projects. In the paper,study ofwangdonggou spoil ground simulation, simulated runoff scouring experiment through thewild, accumulation of engineering processes, hydrodynamic characteristics of slope soilerosion, runoff water dynamics characteristics and dynamic processes reached are asfollows:(1) Horizontal bands and scales pit have delayed runoff effects, while also can reducesrunoff flow, reduced velocity; runoff strength with slope, and runoff time increased hasfluctuations rose of trend, and horizontal bands, scales pit conditions fluctuations than nowater insurance measures conditions more obviously; in test slope24°,28°,32°conditions,accumulation slope surface sediment yield process including3stage: sediment yield volumeof mutations-fluctuations-stable output. Sediment yield can be described with powerfunction of run-off over the same time-interval (exponent＞1, linear trend): M=0.2889q0.9628(R2=0.8733,n=66), accumulative sediment yield Msis linearly related to cumulative run-offQ during each runoff event: Ms=0.2746Q-7.9332(R2=0.8802,n=66), and Zhang Letao (2013)research results.(2) Average velocity with runoff time of increased is first fast increased (0～3min) fluctuations sexual reduces (3～30min), soil conservation measures for low slope (24°,28°)of slope surface runoff velocity has better of reduced fuction, With the increase of slope, theeffect is significant, when it comes to an32°slope, effect of the approximate disappear;Average flow velocity of different slope segments shows power function trend with theincrease in slope length: V=aLb(R2>0.86,n=22,0<b<1). Under the condition of low grade(24°,28°) level bands on runoff velocity has better of reduced role; water depth h with timeof increased is fluctuations rose of trend, and has soil conservation measures of depth isgreater than no, depth and along drive distribution situation is simple of binomial typerelationship; runoff depth along drive changes of overall features is depth gradually changedsmall; slope surface runoff more is turbulence state; Slope surface runoff was basicallyunder the condition of the Froude number Fr>1, indicates that slope surface runoff is rapidscategory, Fr with scour lasted is power function descending, with slope long is firstincreases to reduces of trend; runoff resistance coefficient at any time between of increasedhas overall increases of trend, average resistance coefficient f along the distance obeysexponential function of slope length L to increase: f=aLb(b<0, absolute near1,R2>0.7581,n=22); Flow shear stress τ with increasing runoff trends showed a steep rise ofmutation. The same slope conditions, scale pits, horizontal bands under the condition offlow shear stress than non-Community water conservation measures adopted. Average flowpower increases with the drain time has shown an overall increasing trend, when the sametiming and gradient, scale pits and horizontal bands measure conditions the flow of power isgreater than the not.Relationship betweenresistance coefficient f and Reynolds number Reaccords with positive power function: f=0.0019Re0.9539(R2=0.9052).(3) Relationships between sediment concentration and main hydraulic parameters such ashydrodynamic radius, unit stream power, Reynolds number, resistance coefficient inaccordance with the equations of power function. Relationships between sediment yieldover different time-intervals and Reynolds number, flow shear stress, stream power appeardifferent trends including power-function ascending exponential ascending and exponentialascending respectively, sediment yield process of engineering accumulation in steep slopecan be better described with runoff energy parameters.(4) With the extension of runoff scouring time, runoff sediment rate overall growth in afluctuant way and finally tends to be stable; In the flow shear stress model, water erosionsoil erodibility parameters1.1246s·m-1, and critical shear stress of carrying rickle on surfaceis7.8363pa. In the stream power model, average stream power of soil erosion is0.3958N·m-1·s-1, and average soil erodibility parameter is3.1877s2·m-2under test conditions, soil erosion rate and water power there were significant linear relationships, the critical unitcritical of rill erosion is0.4042m·s-1,and Soil erodibility parameter is3.2023kg·m-3.Unitenergy of water-carrying section can be used to describe dynamic process of sedimenttransport of rill erosion, which can be expressed with the following equation: Dr=a(E-b),critical unit energy of water-carrying section of rill erosion is0.013cm under test conditions.(5) The talus slope surface conditions of complexity of the project, typically in separateresearch on the dividing method of disturbance and to the extent, and production under theconstruction of guiding idea is that runoff regulation of soil and water loss control theory,existing models and equations are able to better describe works of talus slope surfaceerosion dynamics.