BASEMENT EXTENSION METHOD FOR EXISTING BUILDING

PURPOSE:To perform the execution of works safely by installing a water stop and a ground stop in the circumference of an existing building, shifting axial force of a support pile to a support, erecting a permanent steel column, and after the axial force is shifted to this steel column, performing the body construction of a basement extension part. CONSTITUTION:After each of water stop and ground stop walls 4 is executed in the circumference of an existing building 3, the underground is excavated, having a support pile exposed to the extent of support layer ground 1. Next, on the circumference of the support pile, a temporary receiving support 8 is erected on the ground 1 and, after a hydraulic jack is set up in this support 8, this jack is made to work on a subsurface structure body 3A, and bearing axial force of the support pile is shifted to the support 8. Next, after this support pile is dismantled, a permanent steel column 18 is erected on the ground 1 in the same position. The jack is set up in the steel column 18, making this jack work on the body 3A, and axial force of the support 8 is shifted to the steel column 18, and then the support 8 or the like is removed. In succession, body construction for a basement extension part is carried out.