Patent attributes
Disclosed is a method of reinforcing a structure (10) having an elongate hole (14) or drilling the hole having an open proximal end (11) and a closed distal end (16). The method comprises the steps of inserting into the open end of the hole an elongate reinforcement core (20) carrying over at least part of its length an expandable sock (30), introducing a settable liquid (40), such as grout, into the sock at a first pressure so as to cause expansion of the sock toward the wall (18) of the hole (14), the sock being formed from a material which is permeable to the grout so as to allow the liquid to seep through the sock, reducing the pressure in the hole by means of a vacuum tube (23), whilst said introducing step is taking place, to at least a second pressure lower than the first pressure so as to encourage the grout to seep through the sock, to substantially fill the hole. The method also includes the step of ensuring that the vacuum tube extends substantially into the distal quarter of the length of the closed hole. Thus in embodiments of the invention, in producing a vacuum within the hole/drilling the seepage of the liquid or grout through the sock to make contact and bond with the wall of the drilling is increased along the whole length of the drilling.
