CN109763483B - Up-going type sectional grouting process for thick fourth-system deep-buried mining cave-in broken stratum - Google Patents

Up-going type sectional grouting process for thick fourth-system deep-buried mining cave-in broken stratum Download PDF

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CN109763483B
CN109763483B CN201910058885.3A CN201910058885A CN109763483B CN 109763483 B CN109763483 B CN 109763483B CN 201910058885 A CN201910058885 A CN 201910058885A CN 109763483 B CN109763483 B CN 109763483B
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grouting
pipe
hole
diameter
orifice
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CN109763483A (en
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刘小平
李宁
刘新星
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Xian University of Technology
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Xian University of Technology
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Abstract

The invention discloses an upstroke type sectional grouting process for a thick fourth-system deep-buried mining cavity collapsed stratum, which specifically comprises the following steps: firstly, forming a hole, drilling a hole with the aperture of phi 150mm, adopting slurry to protect the wall in a fourth series loose layer, drilling the hole to be 5m below a stable bedrock, pouring cement paste into the hole bottom through a hole pipe, lowering the hole pipe to be 5m below the stable bedrock before the cement paste is initially set, fixing the hole pipe by adopting a sitting slurry method, carrying out primary diameter changing, drilling the bedrock section by adopting clean water, continuously drilling the hole to the bottom of a water-flowing fracture zone, and carrying out secondary diameter changing; after the hole is formed, a grouting pipe is put in, and the hole opening is welded through a flange plate; and (4) performing lower-section grouting through the grouting pipe, after the lower-section grouting is finished, performing upper-section grouting from a gap between the orifice pipe and the grouting pipe until the final hole standard is reached, and finishing the grouting. Through sectional grouting, the filling compactness of the goaf can be obviously enhanced, the grouting uniformity is improved, the drilling utilization efficiency is improved, and the goaf treatment engineering quality is ensured.

Description

Up-going type sectional grouting process for thick fourth-system deep-buried mining cave-in broken stratum
Technical Field
The invention belongs to the technical field of goaf grouting, and particularly relates to an upward sectional grouting process for a thick fourth-system deep-buried mining subsidence broken stratum.
Background
With the rapid development of the economy of China, the infrastructure construction is continuously perfected, and the land resources are in short supply at an accelerated speed. Particularly in mining areas, the land resources are increasingly tense, and more roads, railways, bridges, tunnels, dams and the construction of industrial and civil buildings inevitably meet the goaf foundation.
The goaf foundation is unstable and is easy to destabilize and deform under the factors of dead weight stress, earthquake, underground water and the like; after the earth surface builds a building (structure), under the action of an external load, the original balance state of the goaf can be broken, the goaf is activated again, and the deformation of the goaf foundation is accelerated, so that the building (structure) is damaged.
The existing goaf treatment methods mainly comprise 6 methods, namely a filling method, a crossing/crossing method, a masonry method, a stripping and digging backfill method, a dynamic compaction method and a preloading method. Among them, the most commonly used method is the perfusion filling method. Usually, the goaf treatment adopts a construction process of 'primary hole forming and full-section grouting'.
In the fourth system of engineering construction of thick covering layer, deep burying, stratum crushing and multilayer goaf treatment, stratum fractures are uneven in development degree and drilled holes are easy to collapse, a construction process of 'primary hole forming and full grouting' is adopted, grouting section hole collapse is easy to cause, a collapse zone is full of incompact, grouting is uneven, the utilization rate of the drilled holes is reduced, and engineering quality is difficult to guarantee.
Disclosure of Invention
The invention aims to provide an upstroke type sectional grouting process for a thick fourth-system deep-buried mining cavity collapsed and broken stratum, which solves the problems that a grouting section is easy to collapse, a collapse zone is not densely filled and grouting is not uniform in the prior art.
The technical scheme adopted by the invention is that an upward type sectional grouting process for a thick fourth-system deep-buried mining subsided and broken stratum is implemented according to the following steps:
step 1, forming holes, drilling holes with the aperture of phi 150mm, adopting slurry to protect walls in a fourth loose layer, drilling until the hole diameter is 5m below a stable bedrock, lowering a phi 127mm hole opening pipe to a position 10m away from the hole bottom, and pouring 1 from the hole opening pipe to the hole bottom: 1.5, cleaning cement paste, namely lowering the orifice pipe to be 5m below stable bedrock before the cement paste is initially set, and fixing the orifice pipe by adopting a sitting method for not less than 24 h;
step 2, after the grout setting is finished, carrying out first diameter changing, wherein the diameter of the diameter changing hole is phi 110mm, drilling a bedrock section by using clean water, continuing to drill to the bottom of a water flowing fractured zone, carrying out second diameter changing, wherein the diameter of the diameter changing hole is phi 91mm, and taking a rock core within a range of 20m above the bottom of a final hole;
step 3, after the hole is formed, rapidly putting down a grouting pipe, binding a guide pipe on the outer wall of the grouting pipe, installing a steel tray on the grouting pipe corresponding to the second reducing position, welding a perforated pipe above a coal seam bottom plate below the steel tray, and pouring 1 through a pipeline for 3-5 m on the upper part of the steel tray: 1.5, cleaning cement slurry, finally, welding a flange plate of an orifice pipe and a screw nut joint of a grouting pipe, and wrapping an orifice to be grouted;
and 4, during grouting, firstly, performing lower-section grouting through the grouting pipe, after the lower-section grouting is finished, performing upper-section grouting from a gap between the orifice pipe and the grouting pipe until the final hole standard is reached, and finishing the grouting.
The present invention is also characterized in that,
in the step 1, before the cement paste is initially set, the orifice pipe is lowered into the hole, the orifice pipe is fixed by a sitting grouting method, the setting time is not less than 24 hours, and the pouring height of the cement paste is 10 m.
In the step 1, the aperture phi of the orifice pipe is 127 mm; the orifice pipe is 20cm higher than the ground.
In step 3, the aperture phi of the grouting pipe is 48mm, and the grouting pipe is 50cm higher than the ground.
And 3, sleeving a rubber grout stop plug on the outer wall of the grouting pipe positioned at the lower part of the steel tray, wherein the rubber grout stop plug is tightly attached to the steel tray.
The inner diameter of the steel tray is 50mm, and the outer diameter of the steel tray is 100 mm; the rubber grout stop plug is a truncated cone, the diameter of a large opening is 100mm, the diameter of a small opening is 90mm, and the height is 100 mm.
In step 3, the diameter of the guide pipe is 20mm, and the distance between the bottom of the guide pipe and the steel tray is 5 m.
The invention has the beneficial effects that:
through sectional grouting, the filling compactness of the goaf can be obviously enhanced, the grouting uniformity is improved, the drilling utilization efficiency is improved, and the goaf treatment engineering quality is ensured.
Drawings
FIG. 1 is a schematic structural diagram of hole forming in an upward type sectional grouting process of a thick fourth-system deep-buried mining subsidence broken stratum according to the invention;
FIG. 2 is a schematic diagram of a lower stage grouting in an embodiment of the invention;
FIG. 3 is a schematic illustration of upper stage grouting in an embodiment of the invention.
In the figure, 1 is a fourth series unconsolidated formation, 2 is bedrock; 3. the method comprises the following steps of (1) a water-flowing fractured zone, 4. a caving zone, 5. a coal pillar, 6. a goaf, 7. a coal seam bottom plate, 8. a screw joint, 9. a grouting pipe, 10. a guide pipe, 11. a flange plate, 12. an orifice pipe, and 13.1: 1.5 cement paste, 14 steel trays, 15 rubber grout stop plugs, 16 perforated pipes, 17 pipe hoops, 18 pressure relief valves, 19 pressure gauges, 20 grouting pipes and 21 gaskets.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
The invention relates to an upstroke type sectional grouting process for a thick fourth-system deep-buried mining subsided broken stratum, wherein a pore-forming structure is shown in figure 1, and the upstroke type sectional grouting process is implemented according to the following steps:
step 1, forming holes, drilling holes with the aperture phi of 150mm, adopting slurry to protect walls in a fourth loose layer 1, drilling until the thickness of a stable bedrock is less than 5m, lowering a hole opening pipe 12 to a distance of 10m from the hole bottom, and pouring 1 into the hole bottom through the hole opening pipe: 1.5, cement paste 13, namely, before the cement paste is initially set, lowering the orifice pipe 12 to a position 5m below a stable bedrock, and fixing the orifice pipe 12 by adopting a sitting method, wherein the pipe fixing time is not less than 24 h;
the aperture phi of the orifice pipe is 127mm, and the orifice pipe is 20cm higher than the ground;
the pouring length of the cement paste 13 is 10 m;
step 2, after the grout setting is finished, carrying out first diameter changing, wherein the diameter of the diameter changing hole is phi 110mm, drilling by adopting clear water, continuing to drill to the bottom of a water flowing fractured zone 3, carrying out second diameter changing, wherein the diameter of the diameter changing hole is phi 91mm, and taking a rock core within a range of more than 20m of the bottom of a final hole;
step 3, after the hole is formed, rapidly putting down a grouting pipe 9, binding a guide pipe 10 on the outer wall of the grouting pipe 9, installing a steel tray 14 on the grouting pipe 9 corresponding to the second reducing position, sleeving a rubber grout stop plug 15 on the outer wall of the grouting pipe 9 positioned at the lower part of the steel tray 14, tightly attaching the rubber grout stop plug 15 to the steel tray 14, welding a perforated pipe 16 below the steel tray 14 to the coal seam bottom plate 7, and pouring 1 through the guide pipe 10 for 3-5 m on the upper part of the steel tray 14: 1.5, cleaning cement slurry 13, finally, welding an orifice pipe flange plate 11 and a grouting pipe nut joint 8, and wrapping an orifice to be grouted;
the aperture phi of the grouting pipe 9 is 48mm, and the grouting pipe 9 is 50cm higher than the ground; every two grouting pipes 9 are connected by a pipe hoop 17;
the diameter of the guide pipe 10 is 20mm, and the distance between the bottom of the guide pipe 10 and the steel tray 14 is 5 m;
the inner diameter of the steel tray 14 is 50mm, and the outer diameter is 100 mm;
the rubber grout stop plug 15 is a truncated cone, the diameter of a large opening is 100mm, the diameter of a small opening is 90mm, and the height is 100 mm;
and 4, during grouting, firstly, performing lower-section grouting through the grouting pipe 9, after the lower-section grouting is finished, performing upper-section grouting from a gap between the orifice pipe 12 and the grouting pipe 9 until the final hole standard is reached, and finishing the grouting.
Examples
In the goaf treatment project under a certain super-huge type highway bridge, the goaf is formed by fully mechanized mining, coal is mined for one layer, the roof management mode is free caving type, the average buried depth of the goaf is 274m, the average mining height is 2.5m, the average buried depth of a fourth series exceeds 100m, and a sand layer and two pebble layers are arranged on the lower part of a fourth series covering layer. Three zones in the goaf develop and the stratum is broken. The grouting drill holes are divided into three types, namely curtain holes, pier grouting holes and general grouting holes. The construction sequence is as follows: firstly, curtain holes, pier-rear grouting holes and finally general grouting holes; first, then, second. The method adopts a process of one-step pore forming and two-section upward grouting, and comprises the following specific implementation steps:
(1) drilling construction: the method comprises seven steps of fixing points, installing a drilling machine, drilling holes, pouring orifice pipes, forming holes, pouring grouting pipes and installing grouting joints;
firstly, fixing a point; performing point-by-point field lofting on a grouting drill hole by adopting measuring instruments such as an RTK (real time kinematic) instrument or a total station instrument according to engineering design hole site coordinates, wherein the actual position of the drill hole does not exceed the design position by 1.0m in principle;
installing a drilling machine; leveling a field, installing a drilling machine, leveling a frame and a machine body, preparing a drilling tool, and preparing equipment such as a sleeve, a drill bit, a drill rod and a rock core pipe;
drilling holes; drilling holes with the diameter of 150mm, adopting a slurry protection wall in the fourth loose layer 1, adopting a three-wing drill bit for drilling, then connecting a rock core pipe, increasing the rigidity of the drill bit, ensuring the verticality of the drilled hole, and drilling to the position 5m below the stable bedrock 2; with phi 127mm orifice pipe 12 down to apart from the hole bottom 10m, adopt full mouthful welding between the orifice pipe 12, adopt the level bar to measure during the welding, guarantee the straightness that hangs down between the orifice pipe, pour into 1 to the hole bottom through the pipeline: 1.5, cement paste 13 is poured with the pouring height of 10m, the lower part of the orifice pipe 12 is 10m away from the bottom of the hole before the cement paste is initially set, and the pipe is fixed by adopting a mortar sitting method (not less than 24 h);
hole forming; after the setting is finished, reducing to phi 110mm (primary reducing), drilling by adopting clear water to continue to the bottom of a water-flowing fractured zone 3, finally reducing to phi 91mm (secondary reducing), and finally taking a rock core at 20 m;
sixthly, pouring a grouting pipe; after hole forming, a grouting pipe 9 with the diameter of 48mm is put in, a guide pipe 10 is bound on the outer wall of the grouting pipe 9, the diameter of the guide pipe 10 is 20mm, a steel tray 14 is installed on the grouting pipe 9 corresponding to the secondary diameter changing position, a rubber grout stopping plug 15 is sleeved on the outer wall of the grouting pipe 9 positioned at the lower part of the steel tray 14, and the rubber grout stopping plug 15 is tightly attached to the steel tray 14; slip casting pipe 9 adopts ferrule 17 to connect, welds floral tube 16 below steel tray 14 to above coal seam floor 7, and 1 is poured into through the pipeline to steel tray 14 upper portion 5 m: 1.5, cement paste 13; the distance between the bottom of the guide pipe 10 and the steel tray 14 is 5 m;
seventhly, mounting a grouting connector; after the grouting pipe 9 is fed, welding the orifice pipe flange plate 11 and the grouting pipe 9 nut joint 8, checking and accepting the drilled hole, and wrapping the orifice to be grouted;
(2) grouting construction;
grouting at the lower section; as shown in fig. 2, during grouting, firstly, the lower section grouting is performed through the grouting pipe 9, and the grouting pipe 9 is connected with the grouting pipeline 20 by using a pipe hoop 17; the water-solid ratio is 1: 1.2, when the pressure gauge 19 reaches 2MPa, the pump capacity is less than 50L/min and exceeds 15min, grouting at the lower section of the hole is finished, and opening the pressure release valve 18;
secondly, grouting the upper section; as shown in fig. 3, after the lower section grouting is finished, the upper section grouting is carried out from the gap between the orifice pipe 12 and the grouting pipe 9, the upper section grouting is connected through the flange plates, the gasket 21 is clamped between the two flange plates, the good sealing is ensured, and the water-solid ratio is 1: 1, when the designed grouting end standard is reached, the grouting of the upper section of the hole is ended.
The grouting slurry is cement fly ash mortar, and the slurry proportion is as follows: pier curtain holes, cement: the mixing ratio of the fly ash is 2:8, and an accelerator which accounts for 3 to 5 percent of the weight of the cement is added; pier grouting holes, cement: the mixing ratio of the fly ash is 3: 7; general grouting hole, cement: the mixing ratio of the fly ash is 2: 8; the standard of grouting ending is that the grouting pressure reaches 2MPa, and the pump capacity is less than 50L/min and exceeds 15 min.
In the method, the goaf ascending type sectional grouting technology is adopted, and the perforated pipe is adopted from the position below the flange plate to the coal seam floor, so that the influence of hole collapse on lower section grouting can be effectively avoided, and the utilization efficiency of drilling is improved.
The three-wing drill bit is connected with the rock core pipe, so that the verticality of the drilled hole can be increased, and the orifice pipe can be smoothly lowered to the designed depth; by adopting a sitting slurry method, the sealing between the orifice pipe and the hole wall can be ensured to be good, and the loss of slurry from a soil-rock boundary during upper-section grouting can be avoided.
Because the thickness of the fourth series covering layer is larger, a three-wing drill bit is connected with a rock core pipe for drilling (the rigidity of the drill bit is increased), and the verticality of the drilled hole is ensured; full-mouth welding is adopted between the orifice pipes (screw thread connection can also be directly adopted), and a horizontal ruler is adopted for measurement during welding, so that the verticality between the orifice pipes is ensured; the drill hole is vertical, and the orifice pipe is vertical, so that the orifice pipe can be ensured to smoothly fall to the designed depth.
The flange plate and the grout stopping plug are adopted to clamp the grouting pipe at the secondary diameter-changing position and realize the segmentation, and cement grout is injected through the guide pipe to further strengthen the pipe fixing and the segmentation, so that the implementation effect is ensured.
The perforated pipe is arranged from the lower part of the flange plate to the bottom plate of the coal seam, so that the influence of hole collapse on lower section grouting can be effectively avoided, and the utilization efficiency of drilling is improved.
And finally, taking a core at the bottom of the hole by 20m, wherein the core is taken for the purposes of preventing rock powder from depositing to block a grouting channel, revealing a key stratum and evaluating the grouting effect.
Through sectional grouting, the filling compactness of the goaf can be obviously enhanced, the grouting uniformity is improved, the drilling utilization efficiency is improved, and the goaf treatment engineering quality is ensured.

Claims (5)

1. An upstroke type sectional grouting process for a thick fourth-system deep-buried mining and caving collapsed stratum is characterized by comprising the following steps:
step 1, forming holes, wherein the hole diameter of a drilled hole is phi 150mm, a slurry wall protection is adopted in a fourth loose layer, a three-wing drill bit is adopted for drilling and then connected with a rock core pipe, the rigidity of the drill bit is increased, the verticality of the drilled hole is ensured, the hole is drilled to be below 5m of stable bedrock, the phi 127mm hole pipe is lowered to be 10m away from the hole bottom, and 1 is poured into the hole bottom through the hole pipe: 1.5, cement paste is cleaned, the orifice pipe is lowered to be 5m below stable bedrock before the cement paste is initially set, the orifice pipe is fixed by adopting a sitting slurry method, and the pipe fixing time is not less than 24 h;
step 2, after the grout setting is finished, carrying out first diameter changing, wherein the diameter of the diameter changing hole is phi 110mm, drilling a bedrock section by using clean water, continuing to drill to the bottom of a water flowing fractured zone, carrying out second diameter changing, wherein the diameter of the diameter changing hole is phi 91mm, and taking a rock core within a range of 20m above the bottom of a final hole;
step 3, after the hole is formed, rapidly putting down a grouting pipe, binding a guide pipe on the outer wall of the grouting pipe, installing a steel tray on the grouting pipe corresponding to the second reducing position, welding a perforated pipe above a coal seam bottom plate below the steel tray, and pouring 1 through the guide pipe for 3-5 m on the upper part of the steel tray: 1.5, cleaning cement slurry, finally, welding a flange plate of an orifice pipe and a screw nut joint of a grouting pipe, and wrapping an orifice to be grouted;
the outer wall of the grouting pipe positioned at the lower part of the steel tray is sleeved with a rubber grout stopping plug, and the rubber grout stopping plug is tightly attached to the steel tray; the inner diameter of the steel tray is 50mm, and the outer diameter of the steel tray is 100 mm; the rubber grout stop plug is a truncated cone, the diameter of a large opening is 100mm, the diameter of a small opening is 90mm, and the height is 100 mm;
and 4, during grouting, firstly, performing lower-section grouting through the grouting pipe, after the lower-section grouting is finished, performing upper-section grouting from a gap between the orifice pipe and the grouting pipe until the final hole standard is reached, and finishing the grouting.
2. The upstroke type segmental grouting process for a thick fourth series deep-buried mining cavity collapsed crushed stratum according to claim 1, wherein in the step 1, the orifice pipe is lowered into the hole before the initial setting of the cement paste, the orifice pipe is fixed by a sitting grouting method, the setting time is not less than 24h, and the pouring height of the cement paste is 10 m.
3. The upstroke type sectional grouting process for a thick fourth series deep-buried mining cavity collapsed stratum according to claim 1, wherein in the step 1, the aperture phi of the orifice pipe is 127 mm; the orifice pipe is 20cm higher than the ground.
4. The upstroke type sectional grouting process for a thick fourth series deep-buried mining cavity collapsed stratum according to claim 1, wherein in the step 3, the aperture phi of the grouting pipe is 48mm, and the grouting pipe is 50cm higher than the ground.
5. The upstroke type segmental grouting process for a thick fourth series deep-buried mining caving fractured stratum according to claim 1, wherein in the step 3, the diameter of the guide pipe is 20mm, and the distance between the bottom of the guide pipe and the steel tray is 5 m.
CN201910058885.3A 2019-01-22 2019-01-22 Up-going type sectional grouting process for thick fourth-system deep-buried mining cave-in broken stratum Active CN109763483B (en)

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