U.S. patent application number 11/858317 was filed with the patent office on 2009-03-26 for microtunneling method.
This patent application is currently assigned to Taiwan Water-Jets Technology Co. Ltd.. Invention is credited to Piin-Tsung Cheng.
Application Number | 20090078464 11/858317 |
Document ID | / |
Family ID | 40470431 |
Filed Date | 2009-03-26 |
United States Patent
Application |
20090078464 |
Kind Code |
A1 |
Cheng; Piin-Tsung |
March 26, 2009 |
MICROTUNNELING METHOD
Abstract
A microtunneling method includes: (a) forming a working well;
(b) boring a tunnel from the working well through waterjet
techniques which use at least one waterjet cutter including a jet
seat and a jet nozzle mounted rotatably on the jet seat, the tunnel
being bored by moving progressively the jet seat along a circular
path and by rotating the jet nozzle relative to the jet seat; (c)
removing excavated soil, rocks or gravel from the tunnel; and (d)
advancing the waterjet cutter along an axis of the circular
path.
Inventors: |
Cheng; Piin-Tsung;
(Kaohsiung City, TW) |
Correspondence
Address: |
BUTZEL LONG;IP DOCKETING DEPT
350 SOUTH MAIN STREET, SUITE 300
ANN ARBOR
MI
48104
US
|
Assignee: |
Taiwan Water-Jets Technology Co.
Ltd.
Kaohsiung City
TW
|
Family ID: |
40470431 |
Appl. No.: |
11/858317 |
Filed: |
September 20, 2007 |
Current U.S.
Class: |
175/67 |
Current CPC
Class: |
E21B 7/18 20130101; E21B
7/20 20130101 |
Class at
Publication: |
175/67 |
International
Class: |
E21B 7/18 20060101
E21B007/18 |
Claims
1. A microtunneling method comprising: (a) forming a working well;
(b) boring a tunnel from the working well through waterjet
techniques which use at least one first waterjet cutter including a
first jet seat and a first jet nozzle mounted rotatably on the
first jet seat, the tunnel being bored by moving progressively the
first jet seat along a first circular path and by rotating the
first jet nozzle relative to the first jet seat; (c) removing
excavated soil, rocks or gravel from the tunnel; and (d) advancing
the first waterjet cutter along an axis of the first circular
path.
2. The microtunneling method of claim 1, wherein the first waterjet
cutter further includes a first circular rail that defines the
first circular path, the first nozzle seat being mounted slidably
on the first circular rail, and being moved progressively and
intermittently along the first circular rail during the boring
operation.
3. The microtunneling method of claim 2, wherein in step (b), a
second waterjet cutter is further included to bore the tunnel, the
second waterjet cutter including a second circular rail that is
disposed coaxially with the first circular rail, a second nozzle
seat that is mounted slidably on the second circular rail, and a
second jet nozzle that is mounted rotatably on the second jet seat,
the second nozzle seat being moved progressively and intermittently
along the second circular rail and the second jet nozzle being
rotated relative to the second nozzle seat during the boring
operation.
4. The microtunneling method of claim 2, wherein the first circular
rail is received in and is secured to a tubular tunnel support,
advancement of the tubular tunnel support in the tunnel along the
axis being conducted using pipe jacking techniques.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a microtunneling method, more
particularly to a microtunneling method using waterjets
techniques.
[0003] 2. Description of the Related Art
[0004] Conventional contact-type tunnel boring machines normally
have disadvantages, such as the inability of providing sufficient
friction and abutment force during cutting a hard rock structure or
the problem of undesired attachment of cement onto the cutting head
during cutting a cement structure, which results in a decrease in
cutting efficiency. As a consequence, there is normally required
additional manpower to bore the tunnel and to remove the attached
cement on the cutting head. In microtunneling (tunnel diameter less
than 900 mm), particularly, for tunnel diameter less than 600 mm,
the aforesaid drawbacks become more severely, and result in an
increase in the operation cost, a decrease in boring efficiency,
dust and noise pollution problems, safety concerns, insufficient
emergent response space, etc.
[0005] FIG. 1 illustrates a conventional semi-contact type tunnel
boring machine that includes a tubular tunnel support 10, a front
end plate 11, a disc cutter 12 mounted rotatably on the front end
plate 11 and provided with a drilling head 121, a motor 13 for
driving rotation of the disc cutter 12, a screw rod conveyor 14 for
removing excavated soil, rocks or gravel from a collecting chamber
15, a first waterjet unit 16 having a plurality of first jet
nozzles 161 mounted on the front end plate 11, and a second
waterjet unit 17 having a plurality of second jet nozzles 171
mounted on the drilling head 121. When working on a hard working
surface of a cement structure (not shown), such as a gravel layer
structure or a grouted soil, rocks or gravel structure, in a
working well (not shown) to bore a tunnel into the ground, the
first and second waterjet units 16, 17 are actuated to provide
water jets through the first and second jet nozzles 161, 171 so as
to pre-weaken the structure of the hard working surface of the
cement structure. Note that the water jet can be plain water jet or
abrasive water jet. The disc cutter 12 is then actuated by the
motor 13 to rotate in order to cut through the weakened hard
working surface, and to move the excavated soil, rocks or gravel
into the collecting chamber 15. The screw rod conveyor 14 extends
into a bottom of the collecting chamber 15 so as to remove the
excavated soil, rocks or gravel therefrom.
[0006] Although the structure of the hard working surface of the
cement structure can be pre-weakened before the actual cutting
operation, only a limited area of the hard working surface covered
by the first and second jet nozzles 161, 171 is pre-weakened, and
the structure of the remainder area of the hard working surface
remains relatively strong. Hence, the effect of facilitating the
subsequent cutting operation through pre-weakening of the structure
of the hard working surface using the first and second waterjet
units 16, 17 is limited.
SUMMARY OF THE INVENTION
[0007] Therefore, the object of the present invention is to provide
a microtunneling method that can overcome the aforesaid drawback
associated with the prior art.
[0008] According to this invention, there is provided a
microtunneling method that comprises: (a) forming a working well;
(b) boring a tunnel from the working well through waterjet
techniques which use at least one waterjet cutter including a jet
seat and a jet nozzle mounted rotatably on the jet seat, the tunnel
being bored by moving progressively the jet seat along a circular
path and by rotating the jet nozzle relative to the jet seat; (c)
removing excavated soil, rocks or gravel from the tunnel; and (d)
advancing the waterjet cutter along an axis of the circular
path.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Other features and advantages of the present invention will
become apparent in the following detailed description of the
preferred embodiments of this invention, with reference to the
accompanying drawings, in which:
[0010] FIG. 1 is a schematic view of a conventional tunnel boring
machine;
[0011] FIG. 2 is a flow chart illustrating consecutive steps of the
first preferred embodiment of a microtunneling method according to
this invention;
[0012] FIG. 3 is a fragmentary schematic view to illustrate a state
where a working well is formed according to the first preferred
embodiment and where a tunnel boring machine is installed in the
working well;
[0013] FIG. 4 is a fragmentary schematic view to illustrate another
state where a tunnel is bored using the tunnel boring machine
according to the first preferred embodiment;
[0014] FIG. 5 is a schematic view to illustrate the configuration
of a waterjet cutter of the tunnel boring machine used in the first
preferred embodiment;
[0015] FIG. 6 is a schematic view illustrating a boring pattern on
a working surface of the tunnel bored by the waterjet cutter used
in the first preferred embodiment;
[0016] FIG. 7 is a schematic view to illustrate the configuration
of a waterjet cutter of the tunnel boring machine used in the
second preferred embodiment of the method of this invention;
[0017] FIG. 8 is a schematic view illustrating a boring pattern on
the working surface of the tunnel bored by the waterjet cutter used
in the second preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Before the present invention is described in greater detail,
it should be noted that same reference numerals have been used to
denote like elements throughout the specification.
[0019] FIG. 2 illustrates consecutive steps of the first preferred
embodiment of a microtunneling method according to this invention
for boring a tunnel. The method includes the steps of: (a) forming
a working well 100 (see FIG. 3); (b) boring a tunnel 200 from the
working well 200 (see FIG. 4) through waterjets techniques which
use a first waterjet cutter 3 including three first jet seats 332
and three first jet nozzles 331 mounted rotatably on the first jet
seats 332, respectively, the tunnel 200 being bored by moving
progressively the first jet seats 332 along a first circular path
300 (see FIG. 5) and by rotating the first jet nozzles 331 relative
to the respective first jet seats 332; (c) removing excavated soil,
rocks or gravel from the tunnel 200; and (d) advancing the first
waterjet cutter 3 along an axis of the first circular path 300. A
high water pressure generator 30 is connected to the first jet
nozzles 331 through a supply line 301 (see FIG. 3) for supplying
high pressure water jets through the first jet nozzles 331.
[0020] In this embodiment, the first waterjet cutter 3 further
includes a first circular rail 31 that defines the first circular
path 300. The first nozzle seats 332 are mounted slidably on the
first circular rail 31, and are moved progressively and
intermittently along the first circular rail 31 during the boring
operation. Each of the first nozzle seats 332 is moved a
predetermined pace on the circular path 300 each time. Each of the
first jet nozzles 331 is then actuated and is rotated 360 degrees
relative to the respective first nozzle seat 332 so as to form a
circular groove 34 in a working surface 201 of the tunnel 200 each
time (see FIG. 6). Hence, by repeating the alternating movements
and operations of the first nozzle seats 332 and the first jet
nozzles 331, it is possible to bore through the entire working
surface 201 of the tunnel 200. It is noted that the predetermined
pace each first nozzle seat 332 is advanced on the first circular
rail 31 each time is adjusted such that each circular groove 34
thus formed overlaps the adjacent circular grooves 34 (see FIG. 6)
to an extent that permits boring of the entire area of the working
surface 201 of the tunnel 200.
[0021] The first circular rail 31 is received in and is secured to
a tubular tunnel support 2 (see FIGS. 3 and 4) through a plurality
of abutting springs 32. Each abutting spring 32 abuts against the
first circular rail 31 and the tubular tunnel support 2 so as to
hold the first circular rail 31 onto the tubular tunnel support 2
and to provide a cushioning effect. Advancement of the tubular
tunnel support 2 in the tunnel 200 along the axis is conducted
using pipe jacking techniques. When the tubular tunnel support 2 is
entirely thrusted into the tunnel 200, an extension support 8 is
subsequently inserted into the working well 100 and is connected to
a rear open end of the tubular tunnel support 2 (see FIG. 4). The
tubular tunnel support 2 and the extension support 8 are thrusted
into the tunnel 200 using a hydraulic jack 4 (see FIGS. 3 and 4).
The rear open end of the tubular tunnel support 2 is closed by a
door 51. The hydraulic jack 4 includes a rear abutment 42 and a
plurality of hydraulic cylinders 45 extending from the rear
abutment 42 and a butting against the door 51 of the tubular tunnel
support 2 (or abutting against a rear open end of the extension
support 8 when the tubular tunnel support 2 is entirely received in
the tunnel 200) so as to urge a front open end 23 of the tubular
tunnel support 2 (see FIG. 3) to abut against the working surface
201 of the tunnel 200. The hydraulic jack 4 further includes a
pressure sensor 41 for detecting the pressure of the hydraulic
cylinders 45 acting on the tubular tunnel support 2 or the
extension support 8, and an alignment control servo mechanism 43
connected to the front open end 23 of the tubular tunnel support 2
and having equiangularly disposed radial hydraulically adjusting
elements 431 for keeping alignment of the tubular tunnel support 2
along the axis. An optical positioner 7 is used to assist alignment
of the tubular tunnel support 2.
[0022] A pumping unit 6 includes a pump 63 connected to a chamber
defined by the tubular tunnel support 2 through a mud pipe line 61
and a water pipe line 62 so as to remove the excavated soil, rocks
or gravel collected in the chamber of the tubular tunnel support
2.
[0023] FIG. 7 illustrates the second preferred embodiment of the
microtunneling method according to this invention. The second
preferred embodiment differs from the previous embodiment in that
in step (b), a second waterjet cutter 9 is further included to bore
the tunnel 200. In this embodiment, the second waterjet cutter 9
includes a second circular rail 91 that is disposed coaxially with
the first circular rail 31, three second nozzle seats 932 that are
mounted slidably on the second circular rail 91, and three second
jet nozzles 931 that are mounted rotatably on the second jet seats
932, respectively. Each of the second nozzle seats 932 is moved
progressively and intermittently along the second circular rail 91.
Each of the second jet nozzles 931 is rotated relative to the
respective second nozzle seat 932 during the boring operation. The
second circular rail 91 is secured to the tubular tunnel support 2
through a plurality of abutting springs 92.
[0024] FIG. 8 illustrates a boring pattern on the working surface
201 of the tunnel 200 bored by the second waterjet cutter 9.
[0025] By virtue of the configuration of the first and second
waterjet cutters 3, 9 used in the microtunneling method of this
invention, the aforesaid drawback associated with the prior art can
be eliminated.
[0026] While the present invention has been described in connection
with what are considered the most practical and preferred
embodiments, it is understood that this invention is not limited to
the disclosed embodiments but is intended to cover various
arrangements included within the spirit and scope of the broadest
interpretation and equivalent arrangements.
* * * * *