To obtain a method of boring a deep well having no filled up state by pulling out an inner pipe, inserting a protecting pipe having a strainer wound with fabric after pulling out an inner pipe, and placing a sand of filter material having a predetermined grain size and grout material to the upper impermeable layer.
Boring is executed to a lower impermeable layer by a double pipe, and thereafter, an inner pipe 12 is pulled up. In the next place, a protecting pipe 21 is inserted to the bore bottom. A strainer 22 is arranged on the protecting pipe 21, and fabric 30 is wound round its outer periphery to then be stuck thereto by rubber paste. Following this, as pulling out an outer pipe, a sand of grain size of about 1-2 mm is placed therein. At the lower end of the protecting pipe 21, a sand trap 23 having its clogged lower end is disposed, and a pair of claws 51, 51 penetrating through a sand trap 23 is provided in a curved manner. After that, a grout material of cement is put and then cured to the depth of an upper impermeable layer (c) for forming a seal grout 61. In this way, blinding is avoided, and a pumping property is precluded from lowering due to clogging of the well with sand.
Tanaka, Hiroshi
Kaneko, Yutaka
Next Patent: SOUND PROOF STRUCTURE OF ROTARY PERCUSSION DRILL