Note: Descriptions are shown in the official language in which they were submitted.
Description
Detection While Drilling (DWD) Apparatus and Method for Lithological
Composition of Roadway Roof
I. Technical Field
The present invention relates to a detection while drilling (DWD) method for
lithological composition of roadway roof, which is especially applicable to
geological
conditions of roadway roofs with complex and variable lithology in coal mines,
solves
a major problem of quantitative description of lithological composition of
roadway
roof, and is applied in the technical field of roadway supporting in mines.
Background Art
In China, the storage conditions of coal resources are affected by the
sedimentary
environment, and the lithology of roadway roof often varies frequently in the
same
roadway in the same layer. Since the lithological characteristics of the
roadway roof
can't be measured timely, the support design can't be changed timely as the
lithology
of the roof varies. Consequently, sometimes roof accidents may occur owing to
inadequate support strength, or the supporting materials are wasted and the
drilling
efficiency is reduced owing to excessive support strength.
At present, there are mainly three methods for ascertaining the lithology of
roadway
roof: the first method is to obtain a rock core with a geological rock core
drill, carry
out manual analysis according to the columnar structure of the rock core to
obtain
geomechanical parameters of the surrounding rock of the roof, and then carry
out
support design, but such a method is time-consuming and involves high cost,
the
geological drill is large in size and unsuitable for use at the tunneling
working face,
and can't be used anytime and anywhere as the tunneling machine advances; the
second method is a geophysical prospecting method, which utilizes
abnormalities
incurred by rock strata with different physical properties (such as density,
magnetic
properties, electrical properties, elastic wave propagation velocity, and
radioactivity,
etc.) to deduce the geological structure; however, the geophysical prospecting
method
mainly predicts the locations of interfaces (faults and fracture zones
thereof, weak
intercalations, interfaces between different rock strata, and interfaces
between strata),
and can't effectively identify the lithology of roadway roof strata, which is
right a key
and difficult point in roadway anchoring and support engineering; the third
method is
to utilize a roof structure probe as an observation means to probe the
lithology in the
borehole in the roadway roof; however, the borehole image is often not clear
and the
error is severe owing to the complex external environment and the shortcomings
of
the instrument; consequently, the lithological composition of the roof can't
be
ascertained quantitatively. Therefore, further study on methods for detecting
lithological composition of roadway roof is required, and there is an urgent
need for a
method that is applicable to working environments in roadways in coal mines
and can
detect the lithological composition of roadway roof quickly and accurately.
CA 2995113 2018-07-18
Contents of the Invention
Technical Problem: In order to solve the above-mentioned technical drawbacks,
the
present invention provides detection while drilling (DWD) apparatus and method
for
lithological composition of roadway roof, which involve simple steps, solve
the
technical problem that the lithological composition of roof can't be
identified quickly
in the roadway tunneling and supporting process in coal mines, can ascertain
the
lithological composition of roof strata in real time in the roadway tunneling
process,
and are safe and efficient.
Technical Solution: In order to attain the object described above, the
detection while
drilling (DWD) apparatus for lithological composition of roadway roof provided
in
the present invention comprises a rock debris collector, a single-head
jumbolter, and
an enhanced handheld ore analyzer, wherein, the single-head jumbolter is
arranged
vertically and drills a hole in a roof; the rock debris collector comprises a
casing, a
rock debris collecting funnel, a duct, a drying device, a filter tube, vent
holes, and a
drain pipe, wherein, the drying device and the filter tube are arranged
vertically inside
the casing respectively, the drying device is arranged around the filter tube,
an
opening connected to the filter tube is arranged at the top of the casing, a
plurality of
vent holes are arranged on the sides of the casing, the drain pipe is arranged
at the
bottom of the casing, a funnel hole is arranged at the center below the rock
debris
collecting funnel, the duct is arranged on one side of the rock debris
collecting funnel,
a top opening of the rock debris collecting funnel is arranged below the
borehole
drilled by the single-head jumbolter, and the rock debris collecting funnel is
connected to the filter tube via the duct.
The single-head jumbolter is hydraulic or pneumatic; the drill rod is a scaled
drill rod,
grooves in lcm height and 1mm depth are machined along the drill rod in 1m
length
from top to bottom at 20cm interval, and color strips in red, yellow, green,
cyan, and
blue colors are sprayed with light-reflecting paint in the grooves from top to
bottom in
the drilling direction.
The circular funnel hole on the bottom of the rock debris collecting funnel
has a
diameter of 20-30mm, the top opening of the rock debris collecting funnel is a
circular flare opening having a diameter of 50-60cm, and the rock debris
collecting
funnel is fixed to the roof with expansion bolts; the rock debris collecting
funnel is
welded with a first section of 50cm steel duct of the duct, the rock debris
collecting
funnel and the duct are both made of stainless steel, and the joint between
them is at
the lowest end of the rock debris collecting funnel.
The duct consists of a plurality of 50cm short steel ducts connected via
threads. The
drying device consists of two electric heating tubes, each of which has a
built-in
2000W nickel chrome wire respectively. The filter tube has filter holes on its
bottom
and side walls, the filter tube has a mesh number of 80-120 and the filter
holes have a
diameter of 0.125-0.18mm.
A detection while drilling (DWD) method for lithological composition of
roadway
roof, comprising the following steps:
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CA 2995113 2018-07-18
a. Before drilling, lifting the top opening of the collecting funnel of the
rock
debris collector to a position below the borehole, adjusting the position of
the
rock debris collecting funnel so that the funnel hole is right below the
borehole, and fixing the rock debris collecting funnel to the rock wall of the
roof with expansion bolt;
b. initiating a drilling process: leading the scaled drill rod and
drill bit of the
single-head jumbolter through the funnel hole at the center of the rock debris
collecting funnel and drilling into the roof vertically, and lengthening the
scaled drill rod as required according to the drilling depth in the drilling
process;
c. in the drilling process, stopping drilling whenever the scaled drill rod
advances by 20cm, collecting the mixed solution of rocking debris in the roof
by the rock debris collecting funnel, introducing the mixed solution through
the duct into the filter tube of the rock debris collector for filtering,
draining
the water through the drain pipe with the rock debris being deposited in the
filter tube, drying the rock debris deposited in the filter tube with the
drying
device around the filter tube, so as to obtain a sample of the roof rock in
the
drilling segment, replacing the filter tube in the rock debris collector, and
logging and numbering the removed filter tubes orderly, so as to obtain
samples of the roof rock in different depths;
d. repeating the steps b and c according to the drilling depth, till the
desired
drilling depth is reached;
e. ranking the collected filter tubes according to number, detecting and
analyzing the rock debris in the filter tubes with an enhanced handheld ore
analyzer orderly, and ascertaining the lithological characteristics of the
roof
strata in the borehole from shallow to deep by comparing the drilling depth
log.
Beneficial effects:
The method provided in the present invention utilizes a special rock debris
collector
to collect the rock debris produced while drilling in the roof drilling
process with the
jumbolter, an entire process, including rock debris introduction, filtering,
deposition,
and drying, is accomplished at the roadway tunneling working face, and the
lithological composition of the roadway roof within a certain range is
measured with
an enhanced handheld ore analyzer. The method overcomes a drawback that the
same
roadway is usually supported in the same way in the prior art, adjusts the
supporting
scheme timely according to the variation of lithological composition of the
roadway
roof, and is applicable to roadway roofs with complex lithological conditions;
with
the method, the lithological composition of the roof is detected continuously
in the
roadway tunneling process to provide a scientific basis for design and
adjustment of
supporting modes and supporting parameters, so as to avoid the occurrence of
roof-fall accidents as far as possible and provide a safe and reliable working
environment for coal miners; the apparatus and method provided in the present
invention are easy to use, safe and reliable, and can be used conveniently in
the field.
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IV. Description of Drawings
Fig. 1 is a schematic plane layout structural diagram of the present
invention;
In the figure: 1 - rock debris collector; 2 - single-head jumbolter; 3 - rock
debris
collecting funnel; 4 - funnel hole; 5 - duct; 6 - drying device; 7 - filter
tube; 8 - vent
hole; 9 - drain pipe; 10 - roof; 11 - roadway floor
Fig. 2 is a schematic diagram of the scaled drill rod;
Fig. 3 is a schematic diagram of the rock debris collecting funnel.
V. Embodiments
Hereunder the present invention will be further detailed in an example of the
present
invention with reference to the accompanying drawings.
As shown in Fig. l, the detection while drilling (DWD) apparatus for
lithological
composition of roadway roof provided in the present invention comprises a rock
debris collector 1, a single-head jumbolter 2, and an enhanced handheld ore
analyzer,
wherein, the single-head jumbolter 2 is arranged vertically and drills a hole
in a roof
10; the rock debris collector 1 comprises a casing, a rock debris collecting
funnel 3, a
duct 5, a drying device 6, a filter tube 7, vent holes 8, and a drain pipe 9,
wherein, the
drying device 6 and the filter tube 7 are arranged vertically inside the
casing
respectively, the drying device 6 consists of two electric heating tubes that
have a
built-in 2,000W nickel chrome wire respectively, the drying device 6 is
arranged
around the filter tube 7, an opening connected to the filter tube 7 is
arranged at the top
of the casing, a plurality of vent holes 8 are arranged on the sides of the
casing, the
drain pipe 9 is arranged at the bottom of the casing, a funnel hole 4 is
arranged at the
center below the rock debris collecting funnel 3, the duct 5 is arranged on
one side of
the rock debris collecting funnel, and consists of a plurality of 50cm short
steel ducts
connected via threads, a top opening of the rock debris collecting funnel 3 is
arranged
below the borehole drilled by the single-head jumbolter 2, and the rock debris
collecting funnel 3 is connected to the filter tube 7 via the duct S. The
filter tube 7 has
filter holes on its bottom and side walls, the filter tube has a mesh number
of 80-120
and the filter holes have a diameter of 0.125-0.18mm.
The single-head jumbolter 2 is hydraulic or pneumatic; as shown in Fig. 2, the
drill
rod is a scaled drill rod, grooves in I cm height and Imm depth are machined
along
the drill rod-in 1m length from top to bottom at 20cm interval, and color
strips in red,
yellow, green, cyan, and blue colors are sprayed with light-reflecting paint
in the
grooves from top to bottom in the drilling direction, wherein, Li has a length
of
100cm, and L2 has a length of 20cm.
As shown in Fig. 3, the circular funnel hole 4 on the bottom of the rock
debris
collecting funnel 3 has a diameter of 20-30mm, the top opening of the rock
debris
collecting funnel 3 is a circular flare opening having a diameter of 50-60cm,
and the
rock debris collecting funnel 3 is fixed to the roof with expansion bolts; the
rock
debris collecting funnel 3 is welded with a first section of 50cm steel duct
of the duct
5, the rock debris collecting funnel and the duct are both made of stainless
steel, and
the joint between them is at the lowest end of the rock debris collecting
funnel.
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A detection while drilling (DWD) method for lithological composition of
roadway
roof, comprising the following steps:
a. Before drilling, lifting the top opening of the collecting funnel 3 of the
rock
debris collector 1 to a position below the borehole, adjusting the position of
the
rock debris collecting funnel 3 so that the funnel hole 4 is right below the
borehole, and fixing the rock debris collecting funnel 3 to the rock wall of
the
roof with expansion bolt;
b. initiating a drilling process: leading the scaled drill rod and drill bit
of the
single-head jumbolter through the funnel hole 4 at the center of the rock
debris
collecting funnel 3 and drilling into the roof vertically, and lengthening the
scaled
drill rod as required according to the drilling depth in the drilling process;
c. in the drilling process, stopping drilling whenever the scaled drill rod
advances by
20cm, collecting the mixed solution of rocking debris in the roof II by the
rock
debris collecting funnel 3, introducing the mixed solution through the duct 5
into
the filter tube 7 of the rock debris collector I for filtering, draining the
water
through the drain pipe 9 with the rock debris being deposited in the filter
tube 7,
drying the rock debris deposited in the filter tube 7 with the drying device 6
around the filter tube 7, so as to obtain a sample of the roof rock in the
drilling
segment, replacing the filter tube 7 in the rock debris collector 1, and
logging and
numbering the removed filter tubes 7 orderly, so as to obtain samples of the
roof
rock in different depths;
d. repeating the steps b and c according to the drilling depth, till the
desired drilling
depth is reached;
e. ranking the collected filter tubes 7 according to number, detecting and
analyzing
the rock debris in the filter tubes with an enhanced handheld ore analyzer
orderly,
and ascertaining the lithological characteristics of the roof strata in the
borehole
from shallow to deep by comparing the drilling depth log.
CA 2995113 2018-07-18
