本研究收集台灣中部不同類型土壤,進行地下水監測井設計回填濾料設計。首先收集台灣中部10處之表層土壤,計算土壤粒徑d10、d60及d90。再透過Hong (2012)之濾料設計方法,推算濾料粒徑D15,並以線性假設,推算濾料D10和D100。然後進行壓密試驗,推算最大乾密度,以模擬土壤受壓之情況,隨後以無沖蝕濾料試驗,以高壓測試測試過濾料管湧情況。測試的結果據以修正過濾料設計,預計提供台灣中部地區不同類型土壤之濾料設計依據。 This study designed the backfill filter for groundwater monitoring well (GMW) under the different types of soil from the middle area of Taiwan. Firstly, 10 soil samples were collected, and the grain size of soil sample d d10, d60, d90 were calculated. The distribution range of filter grain size D15 is initially estimated based on the typical design criteria. D10 and D100 can be obtained by linearity assumption. The design method of backfill filter is then tested by a practical example. The first test will be the proctor compaction test, which will be used to simulate the pressure condition of base soil under the ground. The second test is the no erosion filter test, which is adopted to deploy filter grains to prevent piping when the high groundwater pressure applies on the crack. And results of these test can be referred for backfilling filters design method into the groundwater monitoring well. The validation and appropriate upper and lower limits of D15 will be observed. Outcome can also supply the design criteria for the various soil types in the middle area of Taiwan.