| 摘要 |
<p>A drainage system for a sports field uses pipes embedded in filtering matter covered with a layer of earth mould having drainage trenches partly cutting through the filtering matter, these drainage trenches being filled with granules of an expanded material with open cells. Pref. expanded clay, and/or an expanded material with closed cells, pref. granules of expanded polystyrene. The combination of the two materials provides good drainage and irrigation.</p> |
