Keener Harold M, Faucette Britt, Klingman Michael H
Food, Agricultural, and Biological Engineering, The Ohio State Univ./Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA.
J Environ Qual. 2007 Apr 5;36(3):742-52. doi: 10.2134/jeq2006.0359. Print 2007 May-Jun.
Soil loss rates from construction sites can be 1000 times the average of natural soil erosion rates and 20 times that from agricultural lands. Silt fence (SF) is the current industry standard used to control sediment originating from construction activities. Silt fences are designed to act as miniature detention ponds. Research has indicated that SF sediment filtering efficiency is related to its ability to detain and pond water, not necessarily the filtration ability of the fabric. Design capacity and spacing is based on flow-through rate and design height. In addition, increased detention of runoff and pressure from ponding may increase the likelihood of overtopping or failure of SF in field application. Testing was conducted on compost silt socks (SS) and SF to determine sediment filtering efficiency, flow-through rate, ponding depth, overtopping point, design height, and design capacity. Results indicate flow-through rate changes with time, as does ponding depth, due to the accumulation of solids on/in the sediment filters. Changes in depth with time were a linear function of flow rate after 10 min of flow, up to the time the sediment filter is overtopped. Predicting the capacity of SF and SS to handle runoff without the filter being overtopped requires consideration of both runoff rate and length of runoff time. Data show SS half the heights of SF were less likely to overtop than SF when sediment-laden runoff water flow rates are less than 1.03 L(-1) s(-1) m(-1) (5 gpm/ft, gal per minute per lineal foot). Ponded depth behind a 61.0-cm (24 in) SF increased more rapidly than behind a 30.5-cm diam. (12 in) SS, and at the end of the thirty minutes, the depth behind the SF was 75% greater than that behind the SS. Removal of solids by the SF and the SS were not shown to be statistically different. Results were used to create a Microsoft Excel-based interactive design tool to assist engineers and erosion and sediment control planners on how to specify compost SS relative to SF in perimeter sediment control applications.
建筑工地的土壤流失率可能是自然土壤侵蚀率平均水平的1000倍，是农田土壤流失率的20倍。淤泥栅栏（SF）是目前用于控制建筑活动产生的沉积物的行业标准。淤泥栅栏旨在充当小型滞留池。研究表明，SF的沉积物过滤效率与其滞留和蓄积水的能力有关，而不一定与织物的过滤能力有关。设计容量和间距基于流速和设计高度。此外，径流滞留增加以及积水产生的压力可能会增加SF在现场应用中发生溢流或失效的可能性。对堆肥淤泥管（SS）和SF进行了测试，以确定沉积物过滤效率、流速、积水深度、溢流点、设计高度和设计容量。结果表明，由于固体物质在沉积物过滤器上/内的积累，流速和积水深度都会随时间变化。在水流10分钟后，直至沉积物过滤器溢流时，深度随时间的变化是流速的线性函数。预测SF和SS在过滤器不溢流的情况下处理径流的能力需要考虑径流速率和径流时间长度。数据显示，当含沙径流水流速率小于1.03升/（秒·米）（5加仑/（分钟·线性英尺））时，高度为SF一半的SS比SF更不容易溢流。61.0厘米（24英寸）SF后面的积水深度比直径30.5厘米（12英寸）SS后面的积水深度增加得更快，在30分钟结束时，SF后面的深度比SS后面的深度大75%。未显示SF和SS对固体物质的去除在统计学上有差异。研究结果被用于创建一个基于Microsoft Excel的交互式设计工具，以帮助工程师以及侵蚀和沉积物控制规划者了解在周边沉积物控制应用中如何相对于SF指定堆肥SS。
