In order that inflow of the ground water to the excavation area is prevented

摘要

PROBLEM TO BE SOLVED: To provide an estimating method for accurately estimating the existence of a risk of the occurrence of water leakage and a position thereof by confirming the soundness of an earth retaining wall before starting excavation, and to provide a ground excavation method for safe and efficient excavation after previously taking necessary countermeasures, based on the estimation.;SOLUTION: The water leakage position estimating method for the earth retaining wall includes calculating a transmissibility coefficient T and a radius R of influence through an initial water pumping test, performing a confirmation water pumping test before starting excavation into an excavation region 2 inside an earth retaining wall 1 to measure a water pumping amount Q and a ground water level reduction amount s in each observation hole, calculating a distance r from each observation hole 4 to a temporary sump water point, based on these values, and estimating a water leakage site 5, based on the distance r. The distance r is calculated, based on a Thiem's steady well theoretical formula. When the occurrence of water leakage is assumed by the above method after starting excavation, repairing work for the water leakage site 5 is previously performed and the confirmation water pumping test is performed again as required, and then excavation is started after no occurrence of the water leakage is estimated.;COPYRIGHT: (C)2013,JPO&INPIT