CN114719698B - Ultra-long lower step blasting construction method based on blasting refinement analysis - Google Patents
Ultra-long lower step blasting construction method based on blasting refinement analysis Download PDFInfo
- Publication number
- CN114719698B CN114719698B CN202210521477.9A CN202210521477A CN114719698B CN 114719698 B CN114719698 B CN 114719698B CN 202210521477 A CN202210521477 A CN 202210521477A CN 114719698 B CN114719698 B CN 114719698B
- Authority
- CN
- China
- Prior art keywords
- blasting
- holes
- auxiliary
- group
- hole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000005422 blasting Methods 0.000 title claims abstract description 64
- 238000010276 construction Methods 0.000 title claims abstract description 19
- 239000002360 explosive Substances 0.000 claims abstract description 31
- 230000002093 peripheral effect Effects 0.000 claims abstract description 27
- 239000011435 rock Substances 0.000 claims abstract description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 13
- 238000000034 method Methods 0.000 claims abstract description 8
- 238000009412 basement excavation Methods 0.000 claims description 6
- 125000004122 cyclic group Chemical group 0.000 claims description 5
- 238000005474 detonation Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 11
- 238000004880 explosion Methods 0.000 abstract description 11
- 230000005641 tunneling Effects 0.000 abstract description 5
- 239000002699 waste material Substances 0.000 abstract description 3
- 239000003814 drug Substances 0.000 abstract 1
- 229940079593 drug Drugs 0.000 abstract 1
- 239000000428 dust Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000000889 atomisation Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000001804 emulsifying effect Effects 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/006—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries by making use of blasting methods
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
- F42D1/08—Tamping methods; Methods for loading boreholes with explosives; Apparatus therefor
- F42D1/10—Feeding explosives in granular or slurry form; Feeding explosives by pneumatic or hydraulic pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D3/00—Particular applications of blasting techniques
- F42D3/04—Particular applications of blasting techniques for rock blasting
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Drilling And Exploitation, And Mining Machines And Methods (AREA)
Abstract
The application discloses an ultralong lower step blasting construction method based on blasting refinement analysis, which comprises the steps of firstly calculating and designing the number of blastholes according to a traditional empirical formula; then optimally designing the structure and the drug loading of the tunneling blast hole, wherein the optimized design comprises intermittent placement of an emulsified explosive package and a spacing water bag of blasting Kong Yandan, and plugging the hole opening by stemming; the design loading capacity is obtained based on the strength of the rock and the grade of the surrounding rock, and on the basis of the design loading capacity, the loading capacity of the blastholes gradually approaching to the surrounding rock from inside to outside along the central line of the tunnel is gradually reduced, so that the blasting stress of the blastholes forms a cutting effect and the overall blasting effect is not influenced; and finally, calculating the optimal charge of each blasthole, and blasting according to the sequence of auxiliary holes and peripheral holes. The method provided by the application can accurately determine the position of the explosion hole and the loading capacity thereof, so that the explosion is more accurate, the explosion quality meets the requirement, the construction efficiency is improved, the construction quality is ensured, and meanwhile, the economic waste is effectively avoided.
Description
Technical Field
The application relates to the technical field of tunnel engineering, in particular to an ultra-long lower step blasting construction method based on blasting refinement analysis.
Background
In recent years, along with the rapid development of basic traffic construction in China, tunnel engineering in railway and highway construction is also increasing. In the construction process of blasting excavation, the tunnel often does not meet the requirements due to the fact that the selected blasting position or blasting process and the like are not met, deviation occurs during blasting, the construction progress is seriously affected, and meanwhile, serious economic waste is caused due to low aperture utilization rate.
The ultra-long lower step means that the length of one blasting tunneling of the lower step is relatively long and is generally 3m when the lower step is excavated, and the length of the blasting tunneling of the ultra-long lower step exceeds 6m. When the current ultra-long downstairs tunnel is blasted, the explosive loading quantity is either charged according to the uniform quantity or is simply adjusted based on experience, so that the amount of the blasted ultra-undermining is huge.
Disclosure of Invention
Aiming at the defects of the prior art, the application aims to provide an ultralong lower step blasting construction method based on blasting refinement analysis, so as to solve the problems in the prior art.
In order to achieve the above purpose, the application adopts the following technical scheme:
an ultra-long lower step blasting construction method based on blasting refinement analysis comprises the following steps:
determining the arrangement position of the blast holes: taking left lower pilot pit excavation blasting as an example, calculating and designing the number of blastholes according to a traditional empirical formula, wherein the blastholes comprise auxiliary holes and peripheral holes positioned at the outer sides of the auxiliary holes;
optimizing the charging structure of the blast hole: a plurality of explosive bags are arranged in the blast hole at intervals, a water bag is arranged between every two adjacent explosive bags, and the orifice of the blast hole is plugged by stemming; the explosion energy is transmitted to surrounding rock through water to generate a water wedge effect almost without loss, so that the rock is broken, the atomization dust fall effect is achieved, and the explosive consumption is saved. Preferably, the stemming is columnar in shape, and the outer diameter of the stemming is matched with the inner diameter of the blasthole. The explosive package is an emulsified explosive package.
Design explosive loading of blast hole: the method is characterized in that the design loading capacity is obtained based on the strength of rock and the grade of surrounding rock, and on the basis of the design loading capacity, the loading capacity of a blast hole gradually approaching to the surrounding rock is gradually reduced from inside to outside along the central line of a tunnel, so that the blasting stress of the blast hole forms a cutting effect and the whole blasting effect is not influenced.
And (3) detonating: blasting is performed in the order of auxiliary holes and peripheral holes.
Furthermore, smooth blasting is adopted for blasting, the cyclic excavation length is 6m, the blasting footage is 3m, and each cycle of blasting is performed twice.
Further, the auxiliary holes comprise three groups of auxiliary holes from top to bottom, namely an A group of auxiliary holes, a B group of auxiliary holes and a C group of auxiliary holes in sequence; the peripheral holes comprise a group D peripheral hole positioned at the upper part and a group E peripheral hole positioned at the bottom side; the detonation sequence of the blast holes is as follows: auxiliary holes of group A, auxiliary holes of group B, auxiliary holes of group C, peripheral holes of group D and peripheral holes of group E.
Further, the designed charge capacity of the auxiliary hole and the final charge capacity are respectively recorded as Q auxiliary and Q auxiliary ', wherein Q auxiliary' =Q auxiliary/2+0.02X, wherein X is the distance of the auxiliary hole relative to the central line of the tunnel, and the unit is m;
the design charge and the final charge of the peripheral holes are respectively recorded as qweek, qweek' =qweek/2+0.01x, wherein X is the distance of the peripheral holes relative to the tunnel centerline, and the unit is m.
Compared with the prior art, the application has the following beneficial effects:
the overlong lower step blasting construction method based on blasting fine analysis provided by the application can accurately determine the position of the blasting hole and the loading capacity of the blasting hole, so that the blasting is more accurate, the blasting quality meets the requirements, the construction efficiency is improved, the construction quality is ensured, and meanwhile, the economic waste is effectively avoided.
Drawings
FIG. 1 is a position of a tunnelling blast hole;
FIG. 2 is a schematic diagram of the explosive loading structure in a blast hole;
reference numerals: A. b, C the group is auxiliary holes, D, E the group is peripheral holes, 1-emulsion explosive package, 2-water bag and 3-stemming.
Detailed Description
The present application will be described in detail with reference to the accompanying drawings.
The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
An ultra-long lower step blasting construction method based on blasting refinement analysis comprises the following steps:
the tunnel blasting adopts smooth blasting, the cyclic excavation length is 6m, the blasting footage is 3m, and every cyclic blasting is carried out twice. To ensure the blasting effect, the blast hole depth in the actual engineering is determined to be 3.2 m/min.
The blastholes comprise auxiliary holes and peripheral holes positioned outside the auxiliary holes, and referring to fig. 1, the blastholes A, B, C are auxiliary holes, the D, E are peripheral holes, and the detonation sequence is as follows: a→b→c→d→e.
Taking left lower pilot pit excavation blasting as an example, the number of blastholes, explosive amount per cycle and single-hole explosive amount at the left lower pilot pit are calculated and designed according to a traditional empirical formula. The specific method comprises the following steps:
number of blastholes:
N＝(K·S·η·m)/(α·G) (1)
wherein: n is the number of blastholes;
k-specific explosive consumption;
s-excavated cross-sectional area, upper left pilot pit about 25.26m 2 ；
η -blasthole utilization, i.e. loading coefficient, is taken η=0.9;
m-length of each pack, m;
g-mass per pack kg.
The average charging coefficient of the alpha-blasting holes is 0.6 to 0.72 when the diameter of the explosive package is 32 mm;
N＝(K·S·η·m)/(α·G)
＝(0.67·25.26·0.9·0.3)/(0.6·0.15)
50.77 =51 (pieces).
Dose per cycle:
Q＝qv＝qSLη (2)
wherein: the eta-blasthole utilization rate is generally 0.8-0.95, and the design takes 0.90;
Q＝qSLη
＝0.89×25.26×3.2×0.90
≈64.7464kg，
64.75kg was designed and obtained.
Depth of each type of hole:
auxiliary hole L auxiliary = 3.2m
Peripheral hole lburn = 3.2m
Light explosion hole:
w light= (10-20) d=42-85 cm, W light=60 cm is taken in the design,
pitch of holes: the light is expressed by an empirical formula a= (0.6-0.8) W, a=36-48 cm,
the design takes a peripheral holes=55 cm and a auxiliary holes=80-85 cm
Single hole loading rate:
q＝QEV (3)
wherein: q-charge concentration, kg/m
Q-consumption per unit volume, g/m 3
E, the spacing of peripheral holes, m;
v-minimum resistance line, m.
Linear charge density according to empirical values: the auxiliary holes q were 0.38kg/m, and the peripheral holes q were 0.20kg/m. (q varies with pore size and rock firmness factor)
Qassist=ql assist=0.38×3.2≡1.216kg, 1.22kg is taken.
Qweek=ql week=0.20×3.2≡0.640kg, 0.64kg is taken.
On the basis of the design of the loading quantity, the structure of a tunneling blasting loading hole is optimally designed, and referring to fig. 2, an emulsifying explosive package 1 and a water bag 2 in the blasting hole are intermittently placed, and the hole opening is plugged by columnar stemming 3. Because of the incompressibility of the shock wave of the energy propagating in the water to the water, the explosion energy is almost not lost in the surrounding rock through the water, and meanwhile, the water wedge effect generated by the water under the expansion effect of the explosion gas is beneficial to the rock breaking, the water in the explosion hole can play a role in atomizing and dust falling, the pollution of dust to the environment is greatly reduced, the explosive consumption is saved, and the method is economical and efficient.
The optimal design reduces the explosive consumption by about half:
q assist 2 =qminor/2≡0.608kg. (4)
Week Q 2 Q weeks/2≡0.320kg. (5)
On the basis of the design of the explosive loading quantity, the optimal design is carried out on the explosive loading quantity of the tunneling blasting explosive loading hole, the explosive loading quantity can be gradually reduced by gradually approaching to the auxiliary hole at the surrounding rock from inside to outside, and the blasting stress of the explosive loading hole can form a cutting effect without affecting the overall blasting effect. And calculating according to a formula to obtain the optimal loading of each blast hole.
Optimally designing, and obtaining the final explosive with the following dosage:
group a wells: q (Q) A =q assist 2 +a A X，a A ＝0.02 (6)
Group B wells: q (Q) B =q assist 2 +a B X，a B ＝0.02 (7)
Group C wells: q (Q) C =q assist 2 +a C X，a C ＝0.02 (8)
Group D wells: q (Q) D =q weeks 2 +a D X，a D ＝0.01 (9)
Group E wells: q (Q) E =q weeks 2 +a E X，a E ＝0.01 (10)
Wherein: a, a i -the reduction coefficient of the charge hole of group i, kg/m, i is a, B, C, D, E;
x-distance of blasthole relative to tunnel center line (left lower pilot pit takes negative value), m.
The calculation formula of the loading capacity is obtained by fitting on the basis of multiple trial explosions by considering the thickness of the overlying rock mass of the explosion on the basis of single-hole explosion calculation capacity.
In this example, a total of 39 blastholes are actually formed. Of these, 22 auxiliary holes (6 in group A, 7 in group B, 9 in group C) and 17 peripheral holes (6 in group D, 11 in group E).
The total amount of the explosive per cycle is reduced by more than half compared with the original design amount, the blasting is accurate, and the blasting quality meets the requirement.
Therefore, the method provided by the application is easy to construct, strong in realizability, wide in application range, economical and reasonable.
Claims (3)
1. An ultra-long lower step blasting construction method based on blasting refinement analysis is characterized by comprising the following steps of: the method comprises the following steps:
determining the arrangement position of the blast holes: firstly, calculating and designing the number of blast holes according to a traditional empirical formula, wherein the blast holes comprise auxiliary holes and peripheral holes positioned at the outer sides of the auxiliary holes;
optimizing the charging structure of the blast hole: a plurality of explosive bags are arranged in the blast hole at intervals, a water bag is arranged between every two adjacent explosive bags, and the orifice of the blast hole is plugged by stemming;
design explosive loading of blast hole: firstly, obtaining a design loading capacity based on the strength of rock and the grade of surrounding rock, and gradually reducing the loading capacity of a blast hole which is gradually close to the surrounding rock from inside to outside along the central line of a tunnel on the basis of the design loading capacity;
and (3) detonating: blasting according to the sequence of auxiliary holes and peripheral holes;
the auxiliary holes comprise three groups of auxiliary holes from top to bottom, namely an A group of auxiliary holes, a B group of auxiliary holes and a C group of auxiliary holes in sequence; the peripheral holes comprise a group D peripheral hole positioned at the upper part and a group E peripheral hole positioned at the bottom side; the detonation sequence of the blast holes is as follows: auxiliary holes of group A, auxiliary holes of group B, auxiliary holes of group C, peripheral holes of group D and peripheral holes of group E;
the design charge and the final explosive charge of the auxiliary hole are respectively recorded as Q auxiliary and Q auxiliary ', wherein Q auxiliary' =Q auxiliary/2+0.02X, wherein X is the distance between the auxiliary hole and the central line of the tunnel, and the unit is m;
the design charge and the final explosive charge of the peripheral holes are respectively recorded as qweek and qweek ', qweek' =qweek/2+0.01x, wherein X is the distance between the peripheral holes and the central line of the tunnel, and the unit is m;
the blasting adopts smooth blasting, the cyclic excavation length is 6m, the blasting footage is 3m, and every cyclic blasting is carried out twice.
2. The ultra-long lower step blasting construction method based on blasting refinement analysis according to claim 1, wherein: the stemming is columnar in shape, and the outer diameter of the stemming is matched with the inner diameter of the blasting hole.
3. The ultra-long lower step blasting construction method based on blasting refinement analysis according to claim 1, wherein: the explosive package is an emulsified explosive package.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210521477.9A CN114719698B (en) | 2022-05-13 | 2022-05-13 | Ultra-long lower step blasting construction method based on blasting refinement analysis |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210521477.9A CN114719698B (en) | 2022-05-13 | 2022-05-13 | Ultra-long lower step blasting construction method based on blasting refinement analysis |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114719698A CN114719698A (en) | 2022-07-08 |
| CN114719698B true CN114719698B (en) | 2023-11-03 |
Family
ID=82230687
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210521477.9A Active CN114719698B (en) | 2022-05-13 | 2022-05-13 | Ultra-long lower step blasting construction method based on blasting refinement analysis |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114719698B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115342696B (en) * | 2022-09-06 | 2023-09-29 | 南昌大学 | Rock foundation excavation forming construction method |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103344154A (en) * | 2013-07-05 | 2013-10-09 | 武汉科技大学 | Carbonaceous schist tunnel blasting method and construction method |
| CN205748141U (en) * | 2016-06-21 | 2016-11-30 | 中国水利水电第五工程局有限公司 | A kind of Tunnel Blasting charge constitution |
| CN107289827A (en) * | 2017-08-11 | 2017-10-24 | 中铁四局集团有限公司 | Double-side wedge cut tunneling blasting method for extra-large section tunnel |
| CN108061491A (en) * | 2017-12-12 | 2018-05-22 | 中交公局第二工程有限公司 | A kind of Pile Diameter is the bridge cylinder pile foundation blasting method of 1.4-1.6m |
| CN108489350A (en) * | 2018-03-23 | 2018-09-04 | 中铁四局集团有限公司 | Smooth blasting construction method for rapid tunneling of upper step of grade-III surrounding rock tunnel |
| CN109839043A (en) * | 2019-03-15 | 2019-06-04 | 广西大学 | A kind of presplit blasting shock-dampening method |
| CN111912307A (en) * | 2020-07-23 | 2020-11-10 | 中交上海航道局有限公司 | Blasting excavation method of V-level surrounding rock large-section granite tunnel |
| CN111928746A (en) * | 2020-06-09 | 2020-11-13 | 甘肃路桥建设集团有限公司 | Energy-concerving and environment-protective digital detonator water pressure blasting loaded constitution in tunnel |
| CL2021000735A1 (en) * | 2020-03-24 | 2021-09-10 | Indurad Gmbh | Method and device to control hole filling and inspection |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106014428B (en) * | 2016-07-06 | 2018-08-07 | 中国电建集团华东勘测设计研究院有限公司 | TBM passes through the country rock preprocess method with strong rockburst risk detour hole section |
-
2022
- 2022-05-13 CN CN202210521477.9A patent/CN114719698B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103344154A (en) * | 2013-07-05 | 2013-10-09 | 武汉科技大学 | Carbonaceous schist tunnel blasting method and construction method |
| CN205748141U (en) * | 2016-06-21 | 2016-11-30 | 中国水利水电第五工程局有限公司 | A kind of Tunnel Blasting charge constitution |
| CN107289827A (en) * | 2017-08-11 | 2017-10-24 | 中铁四局集团有限公司 | Double-side wedge cut tunneling blasting method for extra-large section tunnel |
| CN108061491A (en) * | 2017-12-12 | 2018-05-22 | 中交公局第二工程有限公司 | A kind of Pile Diameter is the bridge cylinder pile foundation blasting method of 1.4-1.6m |
| CN108489350A (en) * | 2018-03-23 | 2018-09-04 | 中铁四局集团有限公司 | Smooth blasting construction method for rapid tunneling of upper step of grade-III surrounding rock tunnel |
| CN109839043A (en) * | 2019-03-15 | 2019-06-04 | 广西大学 | A kind of presplit blasting shock-dampening method |
| CL2021000735A1 (en) * | 2020-03-24 | 2021-09-10 | Indurad Gmbh | Method and device to control hole filling and inspection |
| CN111928746A (en) * | 2020-06-09 | 2020-11-13 | 甘肃路桥建设集团有限公司 | Energy-concerving and environment-protective digital detonator water pressure blasting loaded constitution in tunnel |
| CN111912307A (en) * | 2020-07-23 | 2020-11-10 | 中交上海航道局有限公司 | Blasting excavation method of V-level surrounding rock large-section granite tunnel |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114719698A (en) | 2022-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113390308B (en) | Composite cut blasting structure and cut method thereof | |
| CN102878876B (en) | Mine roadway advancing and undermining method and main blasting parameters | |
| CN114719698B (en) | Ultra-long lower step blasting construction method based on blasting refinement analysis | |
| CN208588280U (en) | A kind of fixed Cutting Excavation Blasting cloth pore structure of opencut | |
| CN112880499B (en) | Smooth blasting method for tunnel weak surrounding rock | |
| CN105222660B (en) | A kind of High-geotemperature tunnel cooling presplit blasting method | |
| CN110645855B (en) | Dust suppression blasting method for medium-length hole of strip mine | |
| CN101419040A (en) | Deep hole blasting method in large aperture composite undermine | |
| CN108412495A (en) | A kind of excavating plant bench blasting method | |
| CN104990471B (en) | Extremely short-range blasting construction vibration absorbing method and vibration absorbing and energy gathering lancing cartridge | |
| CN112943262A (en) | Karst landform tunnel energy-gathering water pressure smooth blasting structure and method | |
| CN113465461A (en) | Large-section tunnel blasting hole-reducing layout method | |
| CN113959283A (en) | Blasting construction method for large-section tunnel | |
| CN111412802B (en) | Precise blasting method for protecting ultra-small clear distance middle clamped rock column of tunnel | |
| CN105275435B (en) | A kind of method of accurate delay presplit blasting enhanced gas extraction coal-bed gas | |
| CN209623525U (en) | The steel for shot structure of roadway development blasting | |
| CN110500926A (en) | A kind of deep hole blasting spaced loading method | |
| CN114111479B (en) | Tunnel blasting auxiliary hole arrangement method | |
| CN108759597A (en) | A kind of blasthole pulse infusion shot firing method | |
| CN102980453B (en) | Water injection drilling and blasting method for unloading stress of structural strong rock burst area of horizontal structural surface | |
| CN204881365U (en) | Utmost point closely blasting construction damping gathers ability joint -cutting cartridge bag | |
| CN110196002B (en) | Safe and efficient blasting construction method for vertical shaft wall beam nest | |
| CN101769152A (en) | Safe and rapid tunneling process for high-outburst mine coal roadway | |
| CN207936861U (en) | A kind of excavating plant bench blasting pore structure | |
| CN112880506A (en) | Construction method for mine bench blasting |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |