U.S. patent application number 11/472592 was filed with the patent office on 2007-01-18 for equipment and method for mixing in loco for the formation of diaphragms.
This patent application is currently assigned to SOILMEC S.p.A.. Invention is credited to Davide Trevisani.
Application Number | 20070014637 11/472592 |
Document ID | / |
Family ID | 36729256 |
Filed Date | 2007-01-18 |
United States Patent
Application |
20070014637 |
Kind Code |
A1 |
Trevisani; Davide |
January 18, 2007 |
Equipment and method for mixing in loco for the formation of
diaphragms
Abstract
Described herein is excavation equipment for mixing in loco
excavated soil and for the formation of diaphragms within the
excavated hole of the type constituted by a plurality of rods for
drilling soil (10) arranged alongside one another; each rod
performs a rotary and translational motion about and along its own
axis; supplied along the rods is a thickening fluid that exits with
high kinetic energy through nozzles (23 and 24) made in positions
corresponding to bits of a set of bits (11) located at the free
ends of the rods (10) and rendered fixed in rotation and
translation therewith; the bits are interconnected and separated by
means of fixed structures (16, 16') that guarantee non-interference
and maintenance of the distance between them; the bit of each rod
(10) is equipped, at its ends, with disgregating means (14) and, at
the centre, with means (18, 21) for mixing the soil and said
aggregating fluid; the bits are enclosed at least partially within
a quadrilateral caisson (12), designed to line the walls of the
excavated hole as the equipment advances with the excavation in the
soil; the nozzles (23, 24) are directed in positions corresponding
to the <<dead>> areas of the caisson not reached by the
bits (14).
Inventors: |
Trevisani; Davide; (Cesena
(FO), IT) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
SOILMEC S.p.A.
Cesena (FO)
IT
|
Family ID: |
36729256 |
Appl. No.: |
11/472592 |
Filed: |
June 22, 2006 |
Current U.S.
Class: |
405/258.1 |
Current CPC
Class: |
E02D 19/18 20130101;
E02D 3/12 20130101; E02D 3/126 20130101 |
Class at
Publication: |
405/258.1 |
International
Class: |
E02D 3/12 20070101
E02D003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 28, 2005 |
IT |
TO2005A000447 |
Claims
1) Excavation equipment for mixing in loco the excavated soil and
for the formation of diaphragms within the excavated hole of the
type comprising a plurality of rods for drilling soil arranged
alongside one another, each rod performing a rotary and
translational motion about and along its own axis; wherein supplied
along the rods is a thickening fluid that exits with high kinetic
energy through nozzles made in positions corresponding to bits of a
set of bits located at free ends of the rods and rendered fixed in
rotation and translation therewith; the bits are interconnected and
separated by fixed structures that provide non-interference and
maintenance of the distance between them; the bit of each rod being
equipped, at its ends, with disgregating means and, at the centre,
with means for mixing the soil and said aggregating fluid; the bits
being enclosed at least partially within a quadrilateral caisson,
configured to line the walls of the excavated hole as the equipment
advances with the excavation in the soil; the nozzles being
directed in positions corresponding to areas of the caisson not
reached by the bits.
2) The excavation equipment according to claim 1, wherein the
drilling rods are equipped with rotary motion about their own axis
in opposed pairs.
3) The excavation equipment according to claim 1, wherein connected
to each rod is a bit of the set of bits comprising, starting from
the bottom up: a disgregating blade provided with teeth, designed
to remove the underlying soil; a non-rotating structure for
connection between the bits to keep the distance between them
fixed; a first rotating blade with mixing members oriented in the
direction of the fixed structure; the fixed structure also being
equipped with mixing members in positions interspersed with respect
to those of the first blade; and a second mixing blade being set
between the fixed structure and the disgregating blade; mixing
members being positioned under the second blade and similar mixing
members being positioned under the fixed structure.
4) The excavation equipment according to claim 3, wherein the
aggregating fluid is sprayed through first radial nozzles, set
between the disgregating blade and the first mixing blade, and
second radial nozzles, which are oriented in a downward direction
under the disgregating blade; both the first and the second nozzles
rotating together with the bits.
5) The excavation equipment according to claim 1, wherein the
caisson comprises a perimeter of vertical metal plates that delimit
a rectangular section of excavation; the diameter of the blades of
the bits being such as to excavate partially overlapping columns of
diameter substantially equal to the smaller side of the rectangular
section; the areas at the four extreme corners and the areas not
excavated by the bits, but comprised within the rectangle, being
demolished by the radial jets of aggregating fluid, the position of
which in height is at the level of the bottom rim of the perimetral
metal plates.
6) The excavation equipment according to claim 1, wherein the rods
are substantially as long as the depth of the excavation that it is
intended to be obtained.
7) The excavation equipment according to claim 1, wherein the rods
are substantially shorter than the depth of the excavation that it
is intended to obtain.
8) The excavation equipment according to claim 7, wherein means are
provided for controlling the speed of the motors that set in
rotation the rods that do not ensure a perfect synchronism;
consequently the individual bits of the set of bits have the blades
arranged at different heights to prevent any accidental
interference, and wherein the motors are located at different
heights to facilitate the vertical movements of the device within
the mixture of soil and aggregating fluid.
9) The excavation equipment according to claim 8, wherein the
lateral rods are longer than the central ones, so that the central
motors are set lower than the lateral ones.
10) The excavation equipment according to claim 9, wherein the set
of bits has two fixed overlapping and parallel structures;
consequently the set of bits carried by the left-hand long rod and
the one carried by the right-hand short rod are sent back in by the
top structure and carried by the bottom structure, wherein the
individual bits of the set of bits carried by the right-hand long
rod and the one carried by the left-hand short rod are carried by
the top structure and sent back in by the bottom one.
11) A method for mixing in loco excavated soil during the formation
of diaphragms within the excavated hole using equipment according
to claim 1, wherein the rods advance in the hole in the earth that
is progressively excavated by the disgregating bits, the caisson
copies with its outer walls the quadrilateral hole that the
disgregating bits make, and the nozzles directed in positions
corresponding to the areas of the caisson not reached by the bits
complete the disgregation of the soil in said areas not reached by
the bits.
Description
BACKGROUND OF THE INVENTION
[0001] The subject of the invention is equipment and a method for
mixing in loco for the formation of curtains, cutoff walls or
similar diaphragms.
[0002] Techniques are known for mixing natural soil with
aggregating fluids, for example with a base of water-cement or
grout mixes, for the formation of columns of consolidated soil.
Said mixes are made directly in the soil that is disgregated by
means of mechanical bits, the rotation of which also brings about
mixing with the aggregating fluid. This fluid, pumped at a pressure
of 0.1-0.3 MPa, is conveyed through the drilling rods as far as the
bit and exits in the proximity of the disgregating blades.
[0003] In more advanced versions of the method, the aggregating
fluid is pumped at a pressure of 20-40 MPa and exits from special
nozzles in the form of a jet with extremely high kinetic energy,
which contributes markedly to the disgregation and mixing with the
soil. The disgregating blades move in a mix already rendered soft
by the action of the jets and can turn with less effort and at a
higher speed, and guarantee a minimum diameter of the column and a
high rate of advance (see, for example, the publications
EP-1.045.073 and U.S. Pat. No. 5,396,964).
[0004] Also known from the patent No. EP-1.452.645 is a method for
the formation of diaphragms of soil mixed with aggregating fluids
based upon equipment with drums rotating about horizontal shafts
equipped with teeth. The horizontal cross section of the excavation
is then rectangular in shape. The arrangement of a number of
excavations alongside one another enables the construction of
underground walls or curtains (diaphragms) of consolidated soil. In
this case, the low pressure of the fluid and the fixed direction of
delivery do not facilitate penetration or mixing.
SUMMARY OF THE INVENTION
[0005] The purpose of the present invention is the construction of
diaphragms of soil consolidated by means of mixing with aggregating
fluids, characterized by an excellent mixing quality and by a rate
of advance enhanced by the action of jets with high kinetic
energy.
[0006] To achieve this and other purposes that will emerge more
clearly from what follows, the invention proposes providing
equipment for mixing in loco for the formation of diaphragms
according to Claim 1 and a method for carrying out mixing in loco
for the formation of diaphragms using said equipment according to
Claim 11.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention will now be described with reference to the
attached plate of drawings, in which:
[0008] FIG. 1 illustrates the side view of a first machine provided
with equipment for excavation using rods for drilling soil,
according to the invention;
[0009] FIG. 2 is the front view of the set of rods/device of FIG.
1;
[0010] FIGS. 3 and 4 are, respectively, the longitudinal
cross-sectional view and plan view of the equipment according to
the invention;
[0011] FIG. 5 is the cross section according to the trace V-V of
FIG. 3;
[0012] FIG. 6 is the side view of a second machine provided with
equipment for excavation using rods for drilling soil, different
from that of FIGS. 1 and 2, but once again according to the
invention;
[0013] FIG. 7 is the front view of the set of rods/device of FIG.
6;
[0014] FIG. 8 is the side view of the second machine provided with
equipment for excavation using rods for drilling soil, different
from that of FIGS. 6 and 7, but once again according to the
invention; and
[0015] FIGS. 9 and 10 are, respectively, the enlarged side view and
enlarged front view of the equipment for excavation using rods for
drilling soil, illustrated in FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] First of all, from FIGS. 1 and 2 it may be noted that the
excavation equipment carried by the machine 9 consists of a
plurality of vertical and parallel drilling rods 10 that perform a
rotary motion about their own axes in opposed pairs, in the sense
that each rod 10 turns in a direction opposite to the adjacent
ones.
[0017] Positioned at the bottom end of the rods 10 is a set of bits
11 that may be seen more clearly in FIGS. 3, 4 and 5.
[0018] Arranged within a quadrilateral (rectangular) caisson 12 are
bits 13 which, being fixed each to the bottom end of the rods 10,
turn the first in a clockwise direction, the second in a
counterclockwise direction, and so forth.
[0019] Each bit comprises, starting from the bottom up:
[0020] a disgregating blade 14 provided with teeth 15, designed to
remove the underlying soil;
[0021] a non-rotating structure 16 for connection between the bits
to keep the distance between them fixed; and
[0022] a first rotating blade 17 with mixing members 18 set in the
direction of the fixed structure 16.
[0023] The fixed structure is also equipped with mixing members 19
in positions interspersed with respect to those 18 of the blade 17,
so as to entrap and break down (grind) the debris of larger
dimensions.
[0024] A second mixing blade 20 is set between the fixed structure
16 and the disgregating blade 14.
[0025] Mixing members 21 are positioned under the second blade 20,
and similar mixing members 22 are positioned under the fixed
structure so that they too can entrap and break down (grind) the
debris of larger dimensions.
[0026] First radial nozzles 23 conveniently find space for their
accommodation between the disgregating blade 14 and the first
mixing blade 17.
[0027] Second radial nozzles 24 are set in a downward direction
under the disgregating blade 14. Both the first nozzles 23 and the
second nozzles 24 turn together with the bits.
[0028] The nozzles 23 and 24 are supplied with an aggregating fluid
that arrives, through channels inside the rods 10, as far as the
set of bits 11.
[0029] The set of bits 11 is, at least in part, enclosed in the
caisson 12 constituted by a perimeter of vertical metal plates that
delimit a rectangular section of excavation. The diameter of the
blades is such as to excavate partially overlapping columns of
diameter substantially equal to the smaller side of the rectangular
section.
[0030] The areas at the four extreme corners 25 and the areas 26
not excavated by the bits, but in any case comprised within the
rectangle, are demolished by the radial jets 23 of aggregating
fluid, the position of which in height is at the level of the
bottom rim 27 of the perimetral metal plates. The jets reach with
their action up against said metal plates and are by these hindered
or limited. The high kinetic energy with which the fluid is sprayed
through the nozzles 23 and 24 is a determining factor in
demolishing the soil in the <<dead>> areas of the
caisson 12.
[0031] Arranged at the top end of the rods 10 (see FIGS. 1 and 2),
substantially as far as the envisaged depth of the excavation, are
motor means 28 and means of synchronism 29 (for example gears)
designed to impart on the rods rotation at the same speed and each
in a direction opposite to the adjacent ones.
[0032] In this way, the device is substantially balanced to
rotation. The power-drive assembly is then guided on a tower-guide
30 that prevents undesirable rotation thereof. The height of said
guide constitutes a limit to the depth of treatment that can be
reached.
[0033] In an alternative embodiment illustrated in FIGS. 6 and 7,
the rods 42 are decidedly shorter than the depth of excavation, but
carry once again at their free ends the set of bits 11 previously
described and contained within the caisson 12. The assembly 40,
comprising the motors 28 and the means of synchronism (gears) 29
(they bear the same reference numbers as in FIGS. 1 and 2 since
they correspond thereto) is then immersed in the mixture of soil
and aggregating fluid and hangs from ropes 43 for the vertical
movement of sinking and extraction. In this way the depths that can
be reached are decidedly greater.
[0034] For the eventuality of caving-in of the walls or early
hardening of the aggregating mixture hindering extraction of the
device immersed in the treated soil, located at its top are milling
systems 44 capable of disgregating the aforesaid obstacles and
enabling extraction of the equipment from the ground.
[0035] For the orientation of the system at the start of excavation
a known guide device is used. It is constituted by an external
guide 45 hanging from the machine (crane), with hollow prismatic
cross section, and an internal guided element 46, also with
prismatic cross section. The external guide is orientable by means
of a motor-driven assembly 47 at the point of suspension. When the
disgregating device or set of bits 11 is out of the soil and even
when it is buried for the first few metres of drilling, the two
guides 45 and 46 are engaged. At greater depths, the device becomes
independent and guides itself along the walls of the excavation
made. For control of the direction of excavation guide devices 48
are used, which are also known, such as for example those described
in the patent No. EP-0.791.690.
[0036] Located in the external guide are drums 27 for winding
thereon hydraulic pipes 28 (or electrical cables) that supply power
for the device.
[0037] FIGS. 8, 9 and 10 show a variant of the embodiment of FIGS.
6 and 7, in which, in order not to create an obstruction of the
section of excavation, the mechanical means of synchronism 29 are
eliminated and replaced with known (hydraulic or electrical)
systems 50 for controlling the speed of the various motors 28.
[0038] Said systems do not ensure a perfect synchronism, so that
the bits of the device 11 must have blades arranged at different
heights to prevent any accidental interference.
[0039] Also the motors 28 are located at different heights to
facilitate the vertical movements of the device within the mixture
of soil and aggregating fluid.
[0040] In particular, the lateral rods 42' are longer than the
central ones 42'' (which are almost inexistent), so that the
central motors 28'' will be located lower than the lateral ones
28'.
[0041] As may be noted more clearly in FIGS. 9 and 10, the set of
bits 11 has--unlike what has been described with reference to FIGS.
3, 4 and 5--two fixed overlapping and parallel structures 16' and
16''. In this way, the set of bits carried by the left-hand long
rod 42' and the one carried by the right-hand short rod 42'' can be
sent back in 51 by the top structure 16'' and be carried by the
bottom structure 16' so as to project further on the outside of the
caisson 12, but at the same time as not to interfere with the
individual bits of the set of bits carried by the right-hand long
rod 42' and the one carried by the left-hand short rod 42'', which,
instead, are carried by the top structure 16'' and sent back in 52
by the bottom one 16''.
* * * * *