CONSTRUCTING METHOD FOR LOWERING OF GROUNDWATER LEVEL IN GROUND WITH WATER-PERMEABILITY

摘要

PURPOSE: To improve the function and safety of permanent measures against groundwater for a structure set-up on the ground water-permeability, and to reduce the cost of construction therefor. ;CONSTITUTION: For a building 1 set-up on gravel soil 2 with water-permeability, under normal conditions, groundwater at the inside of a low-permeable layer 4 is drained outside from the gravel soil 2 by the operation of drainage 5 and a groundwater level is usually at the position lower than the level of the low- permeable layer 4 by the operation of drainage 7. In an earthquake, even if the drainage 5 function stops the low-permeable layer 4 can retard the rising of the groundwater level lowered since the layer U intercepts the rising thereof. On the other hand, even in the case where the drainage 7 function stops, the low-permeable layer 4 can similarly fulfill its function. That is, until the function of the drainage stopping is recovered, sufficient time is provided against after- shock much the same as the earthquake by operating either the drainage 5 or the drainage 7 and sufficient safety can be ensured against imaginable seismic force.;COPYRIGHT: (C)1995,JPO