EP1256692A1

EP1256692A1 - Drilling method and means for a direct survey of geotechnical parameters

Info

Publication number: EP1256692A1
Application number: EP01111042A
Authority: EP
Inventors: Massimo Sacchetto
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-05-08
Filing date: 2001-05-08
Publication date: 2002-11-13

Abstract

On a self-moving means equipped with a rotating tower having a vertical translation device of a rotation head (1), a steel tubular body (2) is provided having axially a measure instrument to be lowered by a cable (3) driven by a winch hoist (4) to be fixed inside the tubular body (2) by means of a radial set of some projecting parts (5) inserted into a reference cavity (6) so fixing the instrument inside said tubular body (2). Said instrument is pushed in rotation downward while in its interspace (7) water is injected by a pump (8) having a duct (9) connected to the rotation head (1) of the tubular body (2). In the upper part an outside coaxial part (10) is provided to be solidly connected to the tubular body (2) having at the bottom the disgregation tool (11). A measure instrument is axially set on the outside coaxial part (10). Said measure instrument has on the upper part a collar bearing (12) and in the lower part an electronic measure element (13), formed by a drill.

Description

The invention refers to a new ground drilling method and to a suitable means for the direct survey of geotechnical parameters. Said method characterized by using in succession a series of means that actuate step by step ground breakup and consequently greatly increase the ground penetrability grade so permitting greatest depth to be reached at a parity of the thrust given on the steel drill actuating the penetration. The invented method and the realized means are to be extremely important for example in subsidence calculus and, in general, for geologic studies on the ground on a large scale. for direct survey of the geotechnical data a method is currently known that uses a self-moving device with a rotation tower acting in combination with a cylinder actuator able to determine a thrust on a tool-holder. Said tool-holder pushes a vertical drive with an electrically-instrumented steel bit that plots, with reference to measured strength, ground resistance and water pressure of the soil. This known method allows to reach a maximum depth of 50 metres inside soft ground, depth resulting to be insufficient in particular for the above-cited calculus and studies regarding the territory. The invented method gives a solution to the problem by using a new combination means actuating an integrated effect that determines, in sequence, a rotation movement and a thrust on a steel drill arranged for the penetration and a water injection with axial emission that, together, breaking up the ground, are to greatly increase its penetrability grade. In essence the invented method provides, on a suitable self-moving means equipped with a rotating tower having a vertical translation device of a rotation head 1, a steel tubular body 2 having axially a measure instrument to be lowered by a cable 3 driven by a winch hoist 4. Said instrument to be fixed inside the tubular body 2 by means of a radial set of some projecting parts 5 that are inserted into a reference cavity 6 so fixing the instrument inside said tubular body 2. Said instrument i s pushed in rotation downward while in its interspace 7 water is injected by means of a pump 8 having a duct 9 connected to the rotation head 1 of the tubular body 2. The water falls through the interspace 7 and it flows out into the ground through the slot 9. In the upper part an outside coaxial part 10 is provided. Said part to be solidly connected to the tubular body 2 having at the bottom the disgregation tool 11. Morevoer a measure instrument is axially set on the outside coaxial part 10. The said measure instrument has on the upper part a collar bearing 12 and in the lower part a measure element 13, electronically-instrumented, which is formed by a drill for ground breaking mechanical strenght, and water pressure detection (piezocone). Said drill 13 protrudes from the tubular body 2 for about 40 centimetres so as to permit ground characteristic detection before disgregation. After having carried out the survey, the outside coaxial part is retrieved by a tool 14 supported by the cable 3. Said tool 14 enters the cylindrical body 15 and it unhooks the projecting parts 5 of the hollows 6. In an embodiment, instead of the drill 13 screwed onto the body 16, a different drill type is mounted for detection of chemical parameters or otherwise for ground sampling to be analyzed. In particular in the invented method the movement system and the water injection system are continuously monitored. Moreover the drilling parameters, like thrust energy, rotational energy, injection fluid pressure and the speed of travel in operation to the found revolution, are used together with the strength parameters measured by the drill 13 so as to directly determine the majority of ground geotechnical parameters. The suitable means to be used in the invented method is illustrated in a nonlimiting form in the drawings of sheets 1 and 2. In sheet 1 fig. 1 is schematicall shown an essential view of the self-moving means while working. In sheet 2 fig. 2 the longitudinal section view of the survey means ready to be used with the view of the upper part of the fool 14 supported by the cable 3 is shown. In realization the invented means is to be adapted according to necessity of use.

Claims

Drilling method and means for a direct survey of geotechnical parameters consists of a suitable self-moving means equipped with a rotating tower having a vertical translation device of a rotation head (1); characterized in that

on the self-moving means a steel tubular body (2) is provided having axially a measure instrument to be lowered by a cable (3) driven by a winch hoist (4); said instrument to be fixed inside the tubular body (2) by means of a radial set of some projecting parts (5) that are inserted into a reference cavity (6)so fixing the instrument inside said tubular body (2); and that

the instrument is pushed in rotation downward while in its interspace (7) water is injected by means of a pump (8) having a duct (9) connected to the rotation head (1) of the tubular body (2); and that

the water falls through the interspace (7) and it flows out into the ground through the slot (9); and that

in the upper part an outside coaxial part (10) is provided, said part to be solidly connected to the tubular body (2) having at the bottom the disgregation tool (11); and that

a measure instrument is axially set on the outside coaxial part (10), said measure instrument has on the upper part a collar bearing (12) and in the lower part a measure element (13), electronically-instrumented, which is formed by a drill for ground breaking mechanical strenght, and water pressure detection, said drill (13) protrudes from the tubular body (2) for about 40 centimetres so as to permit ground characteristic detection before disgregation; and that

after having carried out the survey, the outside coaxial part is retrieved by a tool (14) supported by the cable (3), said tool (14) enters the cylindrical body (15) and it unhooks the projecting parts (5) of the hollows (6).
Drilling method and means for a direct survey of geotechnical parameters, as per claim 1, characterized in that instead of the drill (13) screwed onto the body (16), a different drill type is mounted for detection of chemical parameters or otherwise for ground sampling to be analyzed.