CN115324623A - Advanced supporting method for deep broken rock mass roadway of metal ore - Google Patents
Advanced supporting method for deep broken rock mass roadway of metal ore Download PDFInfo
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
- E21D20/003—Machines for drilling anchor holes and setting anchor bolts
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
- E21D11/107—Reinforcing elements therefor; Holders for the reinforcing elements
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
- E21D20/02—Setting anchoring-bolts with provisions for grouting
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D21/00—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
- E21D21/0026—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection characterised by constructional features of the bolts
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Abstract
The invention discloses a method for supporting a deep broken rock mass roadway in a metal mine in advance, which comprises the steps of firstly determining roadway self-stabilization time, self-stabilization span and tunneling footage, and if the self-stabilization time of a rock mass is not enough to complete supporting operation circulation, firstly executing the following step 2~7, and then circularly executing the step 1~7; if the supporting process can be completed within the self-stabilization time, circularly executing the step 1~6; step 1: tunneling, and step 2: metal mesh and sprayed concrete, and step 3: erecting a prefabricated steel bar net rack, and step 4: fixing the prestressed anchor rod and the double ribs, and step 5: spraying concrete, and step 6: installing a fixed anchor cable at the bottom of the hole, and step 7: and (5) grouting an anchor rod in advance. The invention provides a pre-supporting method based on rock self-stabilization time, self-stabilization span and full coupling of a supporting body and surrounding rocks, which improves the supporting quality, supporting efficiency and safety of a metal mine deep broken roadway and provides technical support for safe and efficient construction of the metal mine deep roadway support.
Description
Technical Field
The invention relates to the technical field of deep broken rock mass support, in particular to a method for advanced support of a deep broken rock mass roadway of a metal mine.
Background
Along with the increase of the mining depth of the ore deposit, the stratum penetrated by the deep mining roadway is complex and changeable and is mostly under special conditions of high well depth, high ground stress, high ground temperature, strong mining and the like. Particularly, extremely weak broken rock masses such as faults, broken zones and the like which are penetrated by deep roadways of metal mines have the characteristics of high stress, low rock mass strength, muddy contact and extremely poor integrity. At present, a pipe shed type or steel arch support design method mainly based on a shallow part experience method and an engineering comparison method is still adopted for support design for crossing complex broken strata, so that a tunneling roadway is seriously collapsed, the self-stabilization time is short, the safety is poor, and support construction is very difficult.
The existing supporting design aiming at the roadway crossing complex broken strata is fixed, the balance between self-stabilization time and construction efficiency is not considered, the process design is unreasonable, the construction efficiency is low, and the economical efficiency is poor; the existing supporting structure cannot be completely coupled with surrounding rocks of the roadway, the supporting effect is poor, and the safety is low; the existing hole bottom anchoring type anchor cable is low in anchoring force, poor in durability, unrelated in supporting structures, and poor in integrity and supporting quality.
Disclosure of Invention
The invention aims to solve the technical problem of providing a forward support method based on rock self-stabilization time, self-stabilization span and full coupling of a support body and surrounding rocks, improving the support quality, the support efficiency and the safety of deep broken roadways of metal mines and providing technical support for safe and efficient construction of deep roadway supports of metal mines.
The technical scheme of the invention is as follows:
a method for advanced supporting of deep broken rock mass roadway of metal ore is characterized in that:
firstly, carrying out engineering exploration to grade the quality of a rock mass, and determining roadway self-stabilization time, self-stabilization span and tunneling footage, wherein if the self-stabilization time of the rock mass is not enough to complete the supporting operation cycle, the advance supporting operation needs to be carried out before the roadway is tunneled, firstly, the following steps 2-7 are carried out, and then, the steps 1-7 are carried out in a cycle manner; if the mine construction efficiency is high and the supporting process can be completed within the self-stabilizing time, circularly executing the steps 1-6;
step 1: tunnelling
Adopting a drilling and blasting method for tunneling, wherein the tunneling footage is not more than the self-stabilizing span;
and 2, step: metal net and sprayed concrete
After the drilling and blasting tunneling is finished, immediately erecting a metal net and spraying concrete;
and 3, step 3: erecting prefabricated reinforced bar net rack
Installing a reinforcing steel bar net rack designed according to the shape and size of the section of the roadway, the quality of surrounding rocks and ground pressure conditions on the surface of the surrounding rocks of the roadway after the concrete is sprayed; the structure of the reinforcing steel bar net rack adopts a grid structure;
and 4, step 4: fixing of prestressed anchor rod and double reinforcing bars
Fixing the reinforcing steel bar net rack on the surrounding rock by adopting the prestressed anchor rods and the double ribs, and reinforcing the reinforcing steel bar net rack, the prestressed anchor rods, the double ribs and the crushed surrounding rock to form an integral structure;
and 5: sprayed concrete
The prefabricated steel bar net rack, the prestressed anchor rods and the double bars erected in the step 3 are reinforced by sprayed concrete, so that the roadway support strength is increased, the roadway surrounding rock is sealed, and the corrosion resistance is improved;
step 6: anchor cable fixed at bottom of mounting hole
In order to avoid deformation of the roadway surrounding rock after reinforcing and supporting, an anchor cable is fixed at the bottom of the mounting hole, so that the reinforced supporting structure is further improved, and the stability of the supporting structure is enhanced;
and 7: advanced grouting anchor rod
The length of the advanced grouting anchor rod is determined according to the tunneling footage, the length of the advanced grouting anchor rod is at least 1.5 times of the tunneling footage, the advanced grouting anchor rod is installed to form an angle of 15-20 degrees with the surface of surrounding rock of the roadway, and the distance between the anchor rods is not more than 30cm.
Preferably, in the step 1, the size of the metal mesh grid is not more than 50mm × 50mm, and the diameter of the metal mesh steel bar is not less than 6mm; the strength of the sprayed concrete is not lower than C20, and the thickness of the sprayed concrete is not less than 20mm.
Preferably, in step 2, the rebar grid consists of a main bar and a stirrup, wherein the diameter of the main bar is not less than 20mm, and the diameter of the stirrup is not less than 10mm.
Preferably, in step 3, the prestress provided by the prestressed anchor is not less than 8t; the double ribs are installed to be attached to the wall of the roadway as tightly as possible; the double-rib strips are arranged along the tunneling direction of the roadway, the diameter of each double-rib strip is not less than 6mm, the length of each double-rib strip is consistent with the tunneling footage of the roadway, and the double-rib strips are manufactured by spot welding.
Preferably, in the step 4, if water seepage occurs in a certain section or the deformation is larger than 100mm, steel fiber containing 2-3% of the weight of the material is used for spraying concrete to increase the strength of the spraying layer, so that a coupling supporting effect is achieved, and the reinforced supporting structure and the surrounding rock of the roadway are deformed in a coordinated manner; the strength grade of the sprayed concrete is not lower than C20.
Preferably, in step 5, the length of the anchor cable is not less than 6m, the bottom of the hole is fixed by adopting an inverted wedge structure, the anchor is anchored by injecting cement slurry, and the water cement ratio of the cement slurry is not less than 0.4: and 1, adopting an anchor pushing device to increase the prestress, wherein the prestress is not less than 15t.
Preferably, in step 6, the grouting bolt structure is a conical hollow steel pipe with the diameter of 40mm, holes with the diameter of 2mm are drilled at the end part of the grouting bolt structure, and the hole distance is not more than 5cm.
The method for determining the self-stabilizing time, the self-stabilizing span and the tunneling footage of the roadway comprises the following steps: and (4) evaluating the quality of the rock mass according to the engineering investigation result and a rock mass geomechanics (RMR) classification table, determining the self-stabilizing time and the maximum self-stabilizing span of the roadway according to the evaluation result, and making the tunneling footage not larger than the maximum self-stabilizing span.
Compared with the prior art, the invention has the following economic effects:
firstly, the advance support is time-consuming, the advance support step is omitted on the premise of ensuring safety, and the construction efficiency is greatly improved. The invention determines the tunneling footage and the self-stabilization time by RMR classification, and if the subsequent supporting procedure cannot be completed in the current self-stabilization time, the roadway tunneling cannot be carried out in advance, and advanced supporting is required. If the mine construction efficiency is high (the number of mine workers, mechanical equipment and the section size are determined), the supporting process can be completed within the self-stabilizing time, the direct tunneling can be realized, and the advance support is omitted.
Secondly, the supporting structure and the surrounding rock of the roadway can be coupled with each other by optimally combining the supporting structure, so that the self-supporting capability of the surrounding rock and the supporting capability of the anchor rod can be utilized to the greatest extent, the integral rigidity of the surrounding rock is improved, the deformation resistance of the surrounding rock is enhanced, the integrity of the surrounding rock is enhanced, the supporting quality, the supporting efficiency and the safety of the metal mine deep crushing roadway are improved, and the technical guarantee is provided for the safe and efficient construction of the metal mine deep roadway support.
Thirdly, unlike the U-shaped steel bracket generally used in the prior art, the present invention uses the bracket processed by the steel bars as a net frame and sprays concrete. The drilling and blasting tunneling section is usually irregular, and the method has the advantages that: the net rack is easy to adjust the form to adapt to the ultra-short excavation of the roadway, the coupling degree of the supporting structure and the surrounding rock is improved, the integrity of the supporting structure is enhanced, and the supporting quality is improved.
Fourthly, different from the hole bottom fixing mode generally adopted in the prior art, the invention adopts a full-length anchoring grouting mode, and the method has the advantages that: the anchor power is high, and the anchor rope is corrosion-resistant to improve the durability, can additionally play slip casting reinforcing action to the peripheral country rock of anchor rope simultaneously.
Fifthly, the pre-stressed anchor rods and the double-rib strips are adopted to fix the prefabricated reinforcing steel bar net rack, so that the supporting structures of all rows are connected with each other, and the integrity and the stability of the supporting structures are further improved.
Drawings
Fig. 1 is a sectional view (vertical roadway orientation) of the roadway support according to the embodiment of the present invention.
Figure 2 is a cross-sectional view (along the course of a roadway) of a roadway support of an embodiment of the present invention.
In the figure, 1, anchor cables, 2, anchor rods, 3, grouting anchor rods, 4, concrete, 5 and a steel bar net rack.
Detailed Description
The present invention is further illustrated by the following examples.
Example one
A certain underground metal mine-1070 m horizontal roadway is positioned in a soft broken rock body, and roadway surrounding rocks mainly comprise green curtain stones and marble rocks, have the characteristics of low rock body strength, water-argillization and extremely poor integrity, and aim at solving the problem that the tunneling and supporting construction of the-1070 m roadway is influenced by a constructional zone.
The rock mass of the support area is broken, the quality of the rock mass is evaluated according to an engineering investigation result and a rock mass geomechanics (RMR) classification table, the roadway self-stabilization time and the maximum self-stabilization span are determined according to a grading result, and the tunneling footage is not larger than the maximum self-stabilization span.
According to the RMR rock mass quality score of less than 20, the rock mass is a V-grade rock mass, the maximum self-stability span is 1m, and the tunneling footage is determined to be 1m according to the table 1, but the self-stability time is only 30min, so that the rock mass needs to be supported in advance before drilling, blasting and excavating.
TABLE 1 rock mass quality evaluation and engineering characteristics based on RMR Total score
| Value of credit | 100～81 | 80～61 | 60～41 | 40～21 | ＜20 | ||
| Rock mass grading | I | II | III | IV | V | ||
| Description of rock mass | Is very good | Good taste | Medium and high grade | Difference (D) | Is very poor | ||
| Mean self-stabilization time | 15m span 20 | 10m span | 1 | 5m span | 1 week | 2.5m span 10h | Span of 1m for 30min |
The following steps are carried out with reference to fig. 1 and 2.
Step 1: tunnelling
And (4) tunneling by adopting a drilling and blasting method, wherein the tunneling footage is 1m.
Step 2: metal net and sprayed concrete support
The diamond galvanized metal net is adopted, the mesh degree is 50 x 50mm, and the metal net with the metal net reinforcing steel bar diameter of 7mm is arranged to be attached to the roadway wall as tightly as possible, so that the effect of the metal net is exerted to the maximum extent. The overlapping length of the two metal nets is 100mm, so that the whole roadway anchor net support is integrated, and concrete is sprayed on the side wall, the top plate and the gangue pile of the roadway primarily, the strength of the sprayed concrete is C20, and the thickness of the sprayed concrete is 50mm, so that temporary support is performed.
And step 3: erecting prefabricated steel bar net rack
The size of the tunneling section of the designed roadway is as follows: 3.0 × 3.0m; the single length of the reinforcing steel bar net rack 5 is 2.1m, and the width is 0.3m. The side of the reinforcing bar is welded with reinforcing bar legs, and the length of the legs is 0.2m. The tunnel girth is about 8m (detach the bottom plate), adopts four reinforcing bar rack 5 to erect the tunnel country rock surface after installing the shotcrete, and 5 lap joints of every reinforcing bar rack are tied firmly with the iron wire, and the lap joint is 0.5 ~ 1m, and reinforcing bar rack 5 row spacing 400mm (steel support central line distance), and every reinforcing bar rack 5 of group must not leave the space with the country rock back of the body is real.
The steel bar net rack 5 is composed of a main bar and stirrups, wherein the diameter of the main bar is 20mm, and the diameter of the stirrups is 10mm. When the ground stress is increased, the ribs are added on the basis of the existing net rack so as to strengthen the structural strength of the net rack. The concrete structure of the steel bar net rack 5 is as follows: the four main ribs arranged in parallel form a main body with a rectangular cross section, and the four main ribs are connected together through a plurality of stirrups.
And 4, step 4: fixing of prestressed anchor rod and double reinforcing bars
After the reinforcing steel bar net rack 5 is erected, the prestressed anchor rod and the double ribs are adopted to fix the reinforcing steel bar net rack to the surrounding rock, a drill bit with the diameter of phi 32mm is adopted in a drilling anchor rod hole, the hole depth is 2.3m, and the exposed length of the anchor rod 2 is not more than 150mm. When drilling, the hole is perpendicular to the rock wall of the roadway, and the axial included angle between two side holes is 85 degrees; the included angle of the arch crown side hole in the axial direction is 75 degrees, the included angle of the arch crown center hole in the radial direction is 70 degrees, and the included angle of the bottom anchor eye is 75 degrees. The prestressed anchor rods adopt resin anchor rods, and the row spacing is 800mm multiplied by 800mm; diameter: 20mm, length: 2200mm. When the double ribs are installed, the double ribs must be installed from one end to the other end in sequence, and when the anchor rod 2 is subjected to pre-tightening force, the nut must be tightened to achieve the pre-stress of more than 8t; the double ribs between the sub-supporting are mutually connected, the fixing effect of the pre-stressed anchor rod and the double ribs on the pre-fabricated reinforcing steel bar net rack 5 is exerted to the maximum extent, and the pre-fabricated reinforcing steel bar net rack 5, the pre-stressed anchor rod, the double ribs and the broken surrounding rock are reinforced to form an integral structure.
The double-rib is installed to be tightly attached to the wall of the roadway as much as possible, the fixing effect of the pre-stressed anchor rod and the double-rib on the prefabricated steel bar net rack 5 is exerted to the maximum extent, the pre-stressed anchor rod is preferably a resin anchoring type anchor rod, and the length of the pre-stressed anchor rod is determined according to the damage depth of the surrounding rock of the roadway; the double ribs are arranged along the tunneling direction of the roadway, the diameter of the double ribs is 6mm, the length of the double ribs is consistent with the tunneling footage of the roadway, and spot welding is adopted.
And 5: sprayed concrete
The concrete 4 with the spraying strength of C25 and the thickness of 50mm reinforces the prefabricated steel bar net rack, the prestressed anchor rod and the double-rib strip erected in the previous step, so that the supporting strength of the roadway can be increased, the surrounding rock of the roadway can be sealed, and the corrosion resistance can be improved.
If water seepage occurs in a certain section or the deformation is larger than 100mm, the steel fiber containing 2-3% of the weight of the material is used for spraying concrete to increase the strength of the spraying layer, so that the coupling supporting effect is achieved, and the reinforced supporting structure and the surrounding rock of the roadway deform in a coordinated manner.
Step 6: anchor cable fixed at bottom of mounting hole
Drilling anchor rope hole adopts phi 28 mm's drill bit, and the hole depth 7m adopts the fixed water injection mud anchor rope in hole bottom, and the water injection mud anchor, anchor rope 1 length are not less than 6m, and the fixed inverted wedge structure that adopts in hole bottom, water injection mud anchor, grout water cement ratio 0.4:1, tensioning the anchor cable 1 by using an anchor cable tensioning device to enable the prestress to reach more than 15t.
And 7: advanced grouting anchor rod
The length of the advanced grouting anchor rod 3 is 3200mm according to a roadway driving footage, the angle between the installation of the advanced grouting anchor rod 3 and the surface of roadway surrounding rock is 15 degrees, the distance between anchor rods is 150mm, the lap joint length is 1m, and the row spacing is 2m. The grouting anchor rod 3 is a conical hollow steel pipe with the diameter of 42mm, holes with the diameter of 2mm are drilled at the end part of the grouting anchor rod, and the hole distance is 50mm; the grouting material is determined according to the properties of the surrounding rock.
The operation is repeated in such a way and circulated.
Example two
A horizontal tunnel of a certain underground metal mine-960 m is positioned in a soft and broken rock body, the lithology mainly comprises yellow iron serigonized granite broken rock and serigonized granite, the rock is hard, the broken structure in the zone is relatively developed, the local rock in the near main section alteration zone is relatively broken, the alteration is relatively strong, the fracture is relatively developed, and the rock core is relatively broken.
The rock mass of the support area is broken, the quality of the rock mass is evaluated according to an engineering investigation result and a rock mass geomechanics (RMR) classification table, the roadway self-stabilization time and the maximum self-stabilization span are determined according to a grading result, and the tunneling footage is not larger than the maximum self-stabilization span.
According to the RMR rock mass quality score of 30, the rock mass is an IV-grade rock mass, the maximum self-stability span is 2.5m, and the self-stability time is about 10h as shown in the table 1, so that the tunneling footage is determined to be 2m, the mechanization degree of the mine is high, and the supporting process can be completed within the self-stability time, so that the steps 1 to 6 in the first embodiment are circularly executed.
The rock mass geomechanical (RMR) classification table of the invention is shown in Table 2.
TABLE 2 rock mass geomechanics (RMR) classification table
When classifying, according to the measured data of various parameters, respectively grading according to the standard; then adding the scoring values of various parameters to obtain a rock mass total mass RMR value; then correcting the data according to the joint classification; finally, the rock mass is graded by the corrected RMR value.
Claims (8)
1. A method for advanced supporting of deep broken rock mass roadway of metal ore is characterized in that:
firstly, engineering exploration is carried out to grade the quality of rock masses, and the self-stabilization time, self-stabilization span and tunneling footage of a roadway are determined, if the self-stabilization time of the rock masses is not enough to complete the cycle of supporting operation, advance supporting operation needs to be carried out before tunneling of the roadway, the following step 2~7 is firstly carried out, and then step 1~7 is circularly carried out; if the mine construction efficiency is high and the supporting process can be completed within the self-stabilization time, circularly executing the step 1~6;
step 1: tunnelling
Tunneling by adopting a drilling and blasting method, wherein the tunneling footage is not more than the self-stabilizing span;
step 2: metal net and sprayed concrete
After the drilling and blasting tunneling is finished, immediately erecting a metal net and spraying concrete;
and step 3: erecting prefabricated steel bar net rack
Installing a reinforcing steel bar net rack designed according to the shape and size of the section of the roadway, the quality of surrounding rocks and ground pressure conditions on the surface of the surrounding rocks of the roadway after the concrete is sprayed; the structure of the reinforcing steel bar net rack adopts a grid structure;
and 4, step 4: fixing of prestressed anchor rod and double reinforcing bars
Fixing the reinforcing steel bar net rack on the surrounding rock by adopting the prestressed anchor rods and the double ribs, and reinforcing the reinforcing steel bar net rack, the prestressed anchor rods, the double ribs and the crushed surrounding rock to form an integral structure;
and 5: sprayed concrete
The prefabricated steel bar net rack, the prestressed anchor rods and the double bars erected in the step 3 are reinforced by sprayed concrete, so that the roadway support strength is increased, the roadway surrounding rock is sealed, and the corrosion resistance is improved;
step 6: anchor cable fixed at bottom of mounting hole
In order to avoid deformation of the roadway surrounding rock after reinforcing and supporting, the anchor cable fixed at the bottom of the hole is installed, so that the reinforced supporting structure is further improved, and the stability of the supporting structure is enhanced;
and 7: advanced grouting anchor rod
The method comprises the steps of determining the length of an advanced grouting anchor rod according to a roadway tunneling footage, wherein the length of the advanced grouting anchor rod is at least 1.5 times of the roadway tunneling footage, the advanced grouting anchor rod is arranged to form an angle of 15-20 degrees with the surface of roadway surrounding rock, and the distance between anchor rods is not more than 30cm.
2. The method for the advance support of the deep fractured rock mass roadway of the metal mine according to claim 1, wherein: in the step 1, the size of the metal mesh grid is not more than 50mm multiplied by 50mm, and the diameter of the metal mesh steel bar is not less than 6mm; the strength of the sprayed concrete is not lower than C20, and the thickness of the sprayed concrete is not less than 20mm.
3. The method for the advance support of the deep fractured rock mass roadway of the metal mine according to claim 1, wherein: in step 2, the steel bar net rack is composed of main bars and stirrups, wherein the diameter of the main bars is not less than 20mm, and the diameter of the stirrups is not less than 10mm.
4. The method for the advance support of the deep fractured rock mass roadway of the metal mine according to claim 1, wherein: in the step 3, the prestress provided by the prestressed anchor rod is not less than 8t; the double ribs are installed to be attached to the wall of the roadway as tightly as possible; the double ribs are arranged along the tunneling direction of the roadway, the diameter of each double rib is not less than 6mm, the length of each double rib is consistent with the tunneling footage of the roadway, and the double ribs are manufactured by spot welding.
5. The method for the advance support of the deep fractured rock mass roadway of the metal mine according to claim 1, wherein: in step 4, if water seepage occurs in a certain section or deformation is larger than 100mm, steel fiber containing 2-3% of material weight is used for spraying concrete to increase the strength of the spraying layer, so that a coupling supporting effect is achieved, and the reinforced supporting structure and surrounding rocks of the roadway are deformed in a coordinated manner; the strength grade of the sprayed concrete is not lower than C20.
6. The method for the advance support of the deep fractured rock mass roadway of the metal mine according to claim 1, wherein: in the step 5, the length of the anchor cable is not less than 6m, the bottom of the hole is fixedly provided with an inverted wedge structure, the anchor is anchored by cement slurry, and the water cement ratio of the cement slurry is not less than 0.4: and 1, adopting an anchor pushing device to increase the prestress, wherein the prestress is not less than 15t.
7. The method for the advance support of the deep fractured rock mass roadway of the metal mine according to claim 1, wherein: in step 6, the grouting anchor rod structure is a conical hollow steel pipe, the diameter of the grouting anchor rod structure is 40mm, holes with the diameter of 2mm are drilled at the end part of the grouting anchor rod structure, and the hole distance is not more than 5cm.
8. The method for forepoling a deep fractured rock mass roadway of a metal mine according to any one of claims 1 to 7, wherein the method for determining the self-stabilization time, self-stabilization span and tunneling footage of the roadway is as follows: and (4) evaluating the quality of the rock mass according to the engineering investigation result and a rock mass geomechanics (RMR) classification table, determining the self-stabilizing time and the maximum self-stabilizing span of the roadway according to the evaluation result, and making the tunneling footage not larger than the maximum self-stabilizing span.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211140079.9A CN115324623A (en) | 2022-09-19 | 2022-09-19 | Advanced supporting method for deep broken rock mass roadway of metal ore |
Applications Claiming Priority (1)
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| CN202211140079.9A CN115324623A (en) | 2022-09-19 | 2022-09-19 | Advanced supporting method for deep broken rock mass roadway of metal ore |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116658219A (en) * | 2023-08-02 | 2023-08-29 | 阳泉市广凯机械制造有限公司 | Anchor cable prestress control device and application method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116658219A (en) * | 2023-08-02 | 2023-08-29 | 阳泉市广凯机械制造有限公司 | Anchor cable prestress control device and application method |
| CN116658219B (en) * | 2023-08-02 | 2023-10-13 | 阳泉市广凯机械制造有限公司 | Anchor cable prestress control device and application method |
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