FOUNDATION IMPROVEMENT ENGINEERING USING DRAIN MATERIAL BY FORCED DRAINAGE OF WEAK GROUND

摘要

PURPOSE: To quicken work, to reduce cost of a member to use, to heighten a degree of vacuum of a drain line and to improve drainage performance under a foundation improvement engineering method to consolidate a weak ground by forced drainage. ;CONSTITUTION: A drain material 12 with capillaries in it is formed by previously internally inserting vacuum drain capillaries 11 into a lengthy drain material 10, and at the time of burying a large number of the drain materials 12 in a weak ground E vertically by a known means, a lower end opening 11a of the vacuum drain capillary 11 is arranged in the drain material 10. By operation of a vacuum drain pump 17, underground water W of the weak ground E is drained to a drainage channel 17a of the vacuum drain pump 17 from the vacuum drain capillary 11 sequentially through the drain material 10 and the lower end opening 11a. The lower end opening 11a is positioned to exist in the underground water W even when an initial water level WL₁ of the underground water W is lowered to the lowest water level of lower than a lowering water level WL₂, and accordingly, atmospheric air does not permeate into the airtight vacuum drain capillary 11, a high degree of vacuum by the vacuum drain pump 17 is maintained, and satisfactory drain capacity can be secured.;COPYRIGHT: (C)1995,JPO