Abstract: A method and apparatus for lining a pre-existing pipe or passage having at least one curved section or bend along its length with a pipe assembly (10) is disclosed. An assembly is formed from a plurality of pipe sections (11), having axial ends (15,16) which are inclined at non-orthogonal angles (x) with respect to the longitudinal axis of the sections, and having interengagement means, placed end-to-end and engaged together. The pipe assembly is advanced into the passage or pre-existing pipe, pipe sections being vibrated such that the relevant pipe sections rotate relative to one another towards a relative orientation in which the axes of adjacent pipe sections within a curved section of pre-existing pipe or passage lie inclined at an angle to one another such that the pipe assembly can be advanced through the pre-existing pipe or passage.

Abstract: A boring-injection device comprises a fluid supplying hollow rod, a fluid discharge portion at the lower end of the rod, and a packer element inflatable from the rod to seal a space between the rod and a borehole wall at a desired depth position. The rod is surrounded by a sheath so that the packer element and fluid discharge portion can be protruded out of and retracted within the sheath in a body. They are retracted during the boring operation and protruded during injecting or investigating operation. The device can be used for practising a method of ground improvement or a method of ground investigation.

Abstract: A method for improving the ground or foundation by injecting a grouting agent from the tip end of a hollow injection rod inserted into a boring hole formed in the ground at site so as to infiltrate it into the ground to be solidified. The injection is carried out by varying an injection pressure or injection rate depending on the intensity, particularly, the tensile strength, of the ground so that no vein-like coagulation can be formed around the injection rod, and a columnar or spherical coagulation can be formed.

Abstract: This invention relates to an improved stabilizer for excavated surface, and more particularly to a stabilizer for excavated surface which comprises adding at least one of natural cellulose fibers, particularly pulp, defibrated waste paper stock or their mixture to an ordinary stabilizer for excavated surface containing bentonite, etc. as the main component to be used for excavating the ground according to a fluid circulation system.The stabilizer according to the present invention has a good membrane formation ability and good strengthening and reinforcement of the soil structure around the excavated surface and also has a high capacity of suspension and dispersion of the excavated muds and gravels.