應用無沖蝕濾料試驗進行地下水觀測井回填濾料配置之研究

Using no Erosion Filter Test on the Deployment of Filter Backfill for Groundwater Monitoring Well

洪耀明(Yao-Ming Hong) ； 蘇苗彬(Miau-Bin Su) ； 謝雲植(Yun-Chih Hsieh)

《水保技術》 5卷1期 (2010/01) Pp. 35-47

https://doi.org/10.30040/JSWCT.201001.0004

摘要

Based on the norm of Soil Conservation Service (1986), United state, this study establishes the grain size distribution design method of filter backfill for Groundwater monitoring well (GMW) located in sand or gravel land. First, the design criteria of grain size distribution are collected. After reduction, we define the upper and lower limit of D15. Assuming the log-linear distribution between D10 and D90, the formulas of D10, D60 and D90 are obtained by uniform coefficient and D15. Liner theory is then used to determine D0and D100. A field example illustrates the design step of grain size distribution for filter backfill. Moreover, no erosion filter test is utilized to verify the design norms of filter backfill. Laboratory experiments showed that 4D15, which is the lower limited of D15 defined by the soil conservation bureau of America, can be a good filter, and poor test results on the limit of 4D85. On the other hand, when the existing norm used in Taiwan is used it is recommended to reduce the lower limit of particle size for filter with C(subscript u)＞6, so as to avoid being washed out of small soil particles.

關鍵字

地下水觀測井 ； 回填濾料 ； 粒徑分佈

並列摘要

Based on the norm of Soil Conservation Service (1986), United state, this study establishes the grain size distribution design method of filter backfill for Groundwater monitoring well (GMW) located in sand or gravel land. First, the design criteria of grain size distribution are collected. After reduction, we define the upper and lower limit of D15. Assuming the log-linear distribution between D10 and D90, the formulas of D10, D60 and D90 are obtained by uniform coefficient and D15. Liner theory is then used to determine D0and D100. A field example illustrates the design step of grain size distribution for filter backfill. Moreover, no erosion filter test is utilized to verify the design norms of filter backfill. Laboratory experiments showed that 4D15, which is the lower limited of D15 defined by the soil conservation bureau of America, can be a good filter, and poor test results on the limit of 4D85. On the other hand, when the existing norm used in Taiwan is used it is recommended to reduce the lower limit of particle size for filter with C(subscript u)＞6, so as to avoid being washed out of small soil particles.

並列關鍵字

Groundwater Monitoring Well ； Filter Backfill ； Grain Size Distribution ； No Erosion Filter Test