返回Google圖書搜尋

Geotextile Filter Design Critique

出版	ASTM International, 1996
URL	http://books.google.com.hk/books?id=cC15zgEACAAJ&hl=&source=gbs_api

註釋The current status of design of geotextile filters in highway drainage applications is challenged in this paper by virtue of having the actual performance behavior of 91 exhumed field sites. The drainage systems investigated involved mainly highway edge drains in addition to some selected cases of retaining wall drains and erosion control systems. Considering the field data as "ground truth" information, they are compared with the existing permeability, soil retention and excessive-clogging criteria that have been proposed in the literature for design purposes. The current Federal Highway Administration (FHwA) guidelines are shown to be very suitable and perform well against the results of the field exhumed sites. It is suggested, however, that the gradient ratio test recommended by FHwA be replaced by the long term flow test or the hydraulic conductivity ratio test in evaluating the possibility of excessive clogging.