CN108195242B

CN108195242B - Rock blasting method

Info

Publication number: CN108195242B
Application number: CN201810167576.5A
Authority: CN
Inventors: 刘月江
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-02-28
Filing date: 2018-02-28
Publication date: 2020-03-10
Anticipated expiration: 2038-02-28
Also published as: CN108195242A

Abstract

The invention provides a rock blasting method, which comprises the following steps: 1) detecting rock strength parameters, 2) exploding a position, 3), drilling, 4), charging, 5), exploding hole blockage, 6), connecting network lines, 7), warning, 8) and blasting. According to the scheme, the main acting force direction of rock blasting is changed according to the rock blasting principle and the rock breaking mechanism, so that the rock blasting mechanism is changed. High-pressure gas energy generated by explosive combustion is promoted to work at the bottom, and flying rocks generated by rock blasting are avoided. The rock blasting is not limited by the blasting environment and is more widely applied to various engineering constructions.

Description

Rock blasting method

Technical Field

The invention relates to a rock blasting technology, in particular to a rock blasting method.

Background

Rock is a relatively hard and brittle substance with a lower tensile strength and lower shear strength than compressive strength. The rock is deformable to a small extent and to a certain extent can be broken. Therefore, the explosive can be broken when being exploded in the rock hole, and the explosive can only be deformed when being exploded in the lead hole, which is the essential difference of the object types to be exploded.

With the rapid development of social economy, rock blasting becomes a major engineering project in town construction, hydraulic and electric engineering construction and various road engineering construction. The technical research of rock blasting is more and more emphasized by the scientific and technological community and becomes a professional subject. The technical theory and the actual operation technology of rock blasting are developed greatly, and good results are obtained. However, it cannot satisfy blasting construction in various complex environments and blasting in various special requirements. Blasting theory has not been a substantial breakthrough for decades and is misleading in miszones. The rock blasting principle also lingers in the processes that the blasting high-pressure gas expansion force is dominant and the gas shock wave and the tension wave are dominant. There is no clear theoretical criterion, so the rock blasting technology can not be improved in a breakthrough way. In theoretical research on a blasting state model of rock blasting, the method still remains in a funnel blasting model. However, the funnel blasting is an initial blasting form, and is a blasting effect model for carrying out single-hole shallow pot blasting in the center of large-area rock, and the crushing amount of the funnel blasting is small. In order to improve the blasting efficiency, blasting workers adopt lateral face-to-empty face single-hole blasting, multi-hole side mountain blasting and multi-hole step plane group blasting, and the blasting is developed from shallow hole blasting to deep hole blasting. The blasting mode is changed, the blasting efficiency is improved, meanwhile, the blasting effect model is also changed, and funnel blasting is not adopted in the actual blasting production process of the engineering, so that the single funnel blasting model selected for rock blasting theoretical simulation analysis has one-sidedness and limitation, and the correct theoretical criterion cannot be obtained. Therefore, the rock blasting principle analysis is to start from the physical properties of rock species, comprehensively research by a plurality of rock crushing modes and a plurality of rock blasting types, screen by an exclusion method and a comparison method to obtain a correct theoretical criterion, and enable the rock blasting theory to better serve rock blasting construction.

1. Artificial splitting stone

When the stone has a lateral face, people utilize the physical properties of low tensile strength, low shear strength and small deformable amount of the stone. Drilling a hole in the stone, then plugging a steel cone with moderate taper, continuously applying pressure on the steel cone to enable the stone to form linear tension, and when the tensile strength of the rock reaches the limit, extending the tensile strength to the limit shear strength of the rock to enable the rock to crack. It can be seen that the main acting force of the artificial rock splitting is that the extrusion force of the steel cone acting in the rock hole generates linear tension on the rock.

2. Breaking of expanding agent

The expansion agent rock is broken, namely the expansion agent expands in rock holes to generate radial thrust on rock hole walls so as to form tangential tension and shearing force to crack the rock. This is a static effect, breaking the rock in the complete absence of shock and tension waves.

3. Blasting with explosives

Explosive detonation is the detonation of an explosive that burns to produce a large amount of gas. In the deep hole blasting and the shallow hole blasting in the conventional rock blasting, the stack length of the explosive sticks loaded with the explosive sticks accounts for more than sixty percent of the hole depth, the explosive is detonated by a detonator to be used as ignition combustion, and then a short combustion process is bound to exist from a combustion source to complete combustion until the energy peak value is reached. The explosive is burnt in the relatively closed blasting hole volume, and the gas pressure of the explosive gas reaches the energy peak value from low to high. It can be seen that there is no gas shock wave present and attenuation by the gas shock wave into a tensile wave in this process. The high-pressure gas is stored in the fixed container, no impact is formed in the space without operation, and only expansion tension to the wall surface of the container exists. When high-pressure gas generates radial expansion thrust to the hole wall in the blast hole, tangential tension is formed successively. Rock cracking occurs when the tangential tension is greater than the rock tensile resistance. When the rock cracks to a certain degree, the tensile force generated by the radial expansion thrust on the rock body can be converted into the shearing force, and meanwhile, the high-pressure gas is wedged into the cracks to form the extrusion force to expand the cracks so as to completely break the rock. When the rock is cracked, high-pressure gas attacks the fracture impact interface rock mass to form a wave, namely a shock wave, the shock wave penetrates through the rock mass and the soil layer to be transmitted on the surface layer of the ground, and the shock wave is attenuated into a stress wave to form an earthquake effect. It can be seen that the main force of rock blasting is the expansive thrust of the high pressure gas.

Analysis of the direction of travel of the forces of rock blasting

1. Explosive

The explosive is instantaneously combusted to generate high-pressure gas to form detonation. Because the burning speed of the explosive is far faster than the speed of generating gas dispersion, the gas is compressed mutually by itself in the instantaneous burning process, and high-pressure gas mass is formed when the explosive is completely burnt and then released in a spherical shape to all directions. Slamming at interface objects to form an explosion.

2. Direction of action of rock blasting

The energy release of high-pressure gas generated by explosion of the explosive in the air and the dispersion of the high-pressure gas are all released and dispersed in a spherical shape in all directions, but the rock blasting has obvious difference. The bottom of the blast hole is an absolute firm surface and is only a stress field of high-pressure gas and a supporting point of high-pressure gas tension. Therefore, the rock mass at the bottom of the blast hole cannot generate a relatively long-distance split crack. There is only a range of clast zones, which is rock stress: the reason why the rock is damaged when it is deformed to a certain extent under load is known. Therefore, the energy of the high-pressure gas generated by explosion is released in the direction of the explosion hole opening in a semispherical shape with the bottom of the explosion hole as a cross section. The acting force of rock blasting includes the expansion radial thrust of high-pressure gas and the thrust of high-pressure gas energy moving towards the blasting orifice in a hemispherical mode.

Mechanism analysis of rock blasting

1. Funnel blasting

The funnel blasting shape is a blasting effect shape generated by single-hole blasting in the center of a large area rock, no free face exists around the lateral direction of a funnel blasting hole, and the only free face is a free ground. The minimum resisting line only has the distance from the stress point of the blast rock wall to the free ground. When the acting force of high-pressure gas generated by explosion acts, the radial expansion thrust acting on the wall surface of the explosion hole and the vertical thrust of the energy release operation of the high-pressure gas combine to form an oblique resultant force; when the starting point of the minimum resistance line of the rock body is cracked, the high-pressure gas is wedged into the crack to form extrusion force, and the crack is expanded to completely crack the rock body. When the high-pressure gas is wedged into a rock body crack, the energy of the high-pressure gas continues to work, the split rock blocks are thrown to the free ground, the rock blocks are possibly mutually laid in the process of throwing the rock blocks, and the rock blocks form shearing force under the thrust action of the expansion gas to continue to be cracked. The rock pieces have the opportunity to collide with each other and break during the process of being thrown. The more explosive consumed, the more gas produced and the higher the gas pressure in the fixed volume. The faster the flight speed of the thrown rock mass, the greater the mutual impact force of the rock mass and the higher the breaking rate. The explosive dosage is proportional to the breakage rate to a certain extent.

2. Multiple hole group plane blasting

The porous group blasting is a large-scale blasting mode, and hundreds of blasting positions can be simultaneously detonated. When the high-pressure gas energy of each explosion position acts simultaneously, the simultaneous upward thrust on the rock mass can be generated in each adjacent explosion hole, and tangential tension is formed at the bottom of the explosion hole to ensure that the rock mass is tangentially fractured; when the high-pressure gas energy simultaneously generates radial thrust in each blast hole, thrust separated towards two sides is generated by taking the connecting line of each adjacent blast hole as the center, and the thrust applied to the connecting line forms extrusion force for the opposite penetration of the connecting line, so that the rock body is radially fractured on the connecting line or the fracture of the connecting line is resisted at least in the rock body.

The blasting effect of the porous group and the blasting effect of the funnel have great effect change. The multi-hole group blasting can generate a radial and tangential resultant force when the explosives explode at the same time in each blast hole. Therefore, the blasting efficiency is greatly improved, and the blasting of the porous group can not form the funnel blasting effect. The degree of rock fragmentation is related to the amount of explosive consumed, and to the transverse and longitudinal density of the blastholes.

Cause of explosive fly-stones

1. Too much explosive loading in the blast hole

The explosive quantity of the explosive hole is too much, the superposition strength of the explosive cartridge in the explosive hole can be increased, and the distance between the explosive and the explosive hole opening is synchronously shortened. When the explosive is burnt into high-pressure expansion gas, the plug is easy to be punched out, so that the expansion acting force of the high-pressure gas is close to the blast hole opening, and the rock mass at the blast hole opening is broken first and flies out, namely the flyrock with the farthest flying distance. Secondly, the explosive amount is too much, the gas amount generated after the explosive burns is increased, the gas pressure is increased, and the breaking rate of the rock is synchronously increased. The force of throwing the stone is increased, the speed is accelerated, the flying distance of the broken stone is increased, and the detonation of the scattered stones is formed.

2. Unscientific location of detonation

The detonation position is the position where the detonator is arranged in the explosive region in the blasting hole. If the detonator is arranged at the center of the explosive section for detonation, the explosive can be combusted towards two poles from top to bottom, the pressure of the detonation gas is increased from the combustion source section to each section, and finally the energy peak value is reached. Thus, two energy peak points are formed in the same blast hole, and two main blast areas are formed. At the moment, the lower section explosion area is not considered, when explosive in the upper section explosion area is completely combusted to enable explosive gas to reach an energy peak value, the plug is easily punched out, and when the plug is punched out, the energy of high-pressure gas forms radial expansion thrust and upward gas energy operation thrust on the hole wall surface close to the explosion hole opening, so that the rock mass at the explosion hole opening is broken and flies out. This is the main reason why rock blasting cannot fully control flyrock. The arrangement method of the detonator and the explosive has poor blasting effect, and because the acting force of the blasting gas is dispersed, when the expansion thrust of the blasting gas at the bottom of the blasting hole is less than the resistance force of the rock mass, the rock mass cannot be completely fractured to form gaps so that the high-pressure gas can be dispersed and decompressed in time, so that the high-pressure gas can form transient continuous load pressure on the rock mass at the bottom of the blasting hole, and the rock mass at the bottom of the blasting hole forms a fragment area in a certain range under the load action. Therefore, the blast hole opening section is broken and scattered, the rock mass in the middle of the blast hole cannot be completely broken or the breaking effect is poor, and the bottom of the blast hole becomes a small-range fragment area. This rock burst state is one of the block burst states in rock burst. The detonator lengthens the explosive stack to a length that is one third of the upper two thirds of the bottom of the blast hole. The closed blasting state disappears, but blasting flyrock still appears. The rock blasting flyrock is completely controlled, and a more scientific blasting technology needs to be researched.

Disclosure of Invention

The invention strictly controls the depth of the blast hole according to the reason of the flyrock generated by the rock blasting, and simultaneously installs the detonator on the top of the explosive.

In order to achieve the purpose, the technical scheme provided by the invention is as follows: a rock blasting method comprises the following steps:

1) detecting the parameters of the compressive strength of the rock,

2) explosion position releasing points, and explosion position parameters are calculated as follows: the maximum block of the rock is w, the blasting hole and cannon pitch is a, the row pitch of the blasting holes is d, the depth of the blasting holes is h, and the nonlinear fracture parameter is v; then:

；

3) drilling, wherein the shallowest depth h of a blast hole cannot be less than 2m, and the distance from the top end of the explosive to a blast hole opening after the explosive is installed cannot be less than 1.8 m;

4) and charging, wherein charging parameters are calculated as: the single-hole explosive quantity is f, the hole bursting depth is h, and the parameter v is v, v = 0.2333; then: f = hvf = kg; description of f = hv, f = kg, where v =0.2333, h = m, i.e. the depth of the blast hole h is given in meters, h is the depth, m is given in meters, i.e. h = m, the explosive dosage f is given in kilograms, i.e. f = kg, and the charge length does not exceed one third of the depth of the blast hole; the blast hole with the diameter of 40mm is calculated according to f = hv;

5) the blasting hole is blocked, the priming detonator is arranged at the top end of the explosive superposition length in the direction of the blasting hole, and the explosive can not be arranged after the detonator is arranged; the space from the initiation point to the explosion orifice is tightly filled with fine sand, and the explosive plays a role of initial sealing when the explosive starts to burn;

6) the network circuit is connected, and electric detonators are connected in series to form a network connection, so that all explosion positions are detonated simultaneously to form resultant force;

7) the periphery is cleaned, the boulder blasting firstly cleans the enclosing soil and the broken small enclosing stones on one side of the boulder to reduce the resistance of the boulder, so that the boulder is smoothly cracked from the bottom first to release the energy of high-pressure gas in time; preventing high-pressure gas from rushing out of the blast hole opening to burst a blast hole opening rock mass to form flying stones;

8) warning and starting the cannon.

Drawings

FIG. 1 is a schematic diagram of a layered interval of a blast hole of the present invention.

Detailed Description

The invention is further explained below, and the technical key points of the invention are as follows:

1. strictly controlling the depth of the blast hole

According to the reason that rock blasting generates flyrock, strictly controlling the depth of a blast hole is an important link of non-flyrock blasting, because the distance length from a blast hole opening to the top end of an explosive is too short, the acting force of high-pressure gas generated by blasting is close to the blast hole opening, the rock mass at the blast hole opening can be firstly blasted, and the blasted rock mass is propelled to fly into the air by the expansion thrust of the high-pressure gas. According to the blasting experience, the shallowest depth h of the blast hole cannot be less than 2m, and the distance from the top end of the explosive to the opening of the blast hole after the explosive is installed cannot be less than 1.8 m. Therefore, for the blast holes which cannot reach more than 2m due to special reasons during the drilling process, the blast holes are not required to be blasted any more, so as to control the occurrence of flying stones.

2. Strictly controlling explosive amount

In the flying-stone-free blasting technology, the strict control of the explosive dosage of a single hole is key. Due to the fact that the stacking length of the explosive filled in the blast hole is too long, the distance from the top end of the explosive to the opening of the blast hole is shortened successively, and flying stones can be caused. Secondly, the explosive is discharged too much, the more the generated gas is, the higher the explosion gas pressure is, and the higher the breaking rate of the rock is. The force for throwing the crushed stone is increased, and the distance for throwing the crushed stone is long, so a large amount of flying stones can be formed. The flying stone for controlling blasting adopts a weak loosening blasting scheme and a porous less-explosive method. The largest block of rock blasting is controlled by shortening the distance between blastholes. The method comprises the following steps of maximum block w, hole blasting distance a, hole blasting row distance d, hole blasting depth h and nonlinear fracture parameters v.

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The calculation of the explosive dosage is controlled, and the diameter of a blast hole is 40mm, the diameter of a cartridge is 37mm, and no coupling charge is taken as an example. The explosive loading of a single explosion hole is empirically 0.7kg of explosive is loaded in an explosion hole with a depth of 3 m. Single-hole dosage f, hole blasting depth h and parameter v.

f=hv f=kg v=0.2333

The stacked charging length of the explosive cartridges for flying stone-free blasting is not more than one third of the depth of the blast hole.

3. Core technology of flyrock-free blasting

In the case of buildings or other facilities adjacent to the periphery of the blast area, the flying stone-free blasting is required to be adopted to control the flying stones, and the blasting seismic effect is also required to be controlled. Therefore, the shallow hole blasting mode is suitable for the flying stone-free blasting, and the deep hole blasting consumes more explosive, has large explosive power and strong earthquake effect. Most importantly, the deep hole blasting damage range is large, and when a building is 3-5 m away from an explosion area, the deep hole blasting can directly damage the foundation of the building or other facilities. The flying-stone-free blasting is a principle of breaking rock by using expansion thrust of high-pressure gas generated by blasting. The running direction of the acting force is changed, so that the high-pressure gas generated by explosion can work under the ground, and the rock mass starts to crack from the bottom layer to influence the cracking of the free ground. When the rock mass generates tangential fracture and radial fracture on the bottom layer, high-pressure gas is dispersed in the fracture, so that the energy of the high-pressure gas is greatly reduced, and the throwing force of the high-pressure gas on the fractured rock is reduced. So that the whole cracked rock in the explosion area is thrown out of the free ground by 300-600 mm and falls on the original place.

The flying-stone-free blasting is to change the running direction of high-pressure gas energy by changing the position of the blasting. The priming detonator is arranged at the top end of the explosive, and when the explosive starts to burn, the sandy soil filling at the upper end of the explosive plays a role in sealing the initial burning of the explosive. The initial explosive combustion section forms higher air pressure, prevents the gas combusted by the lower explosive from rushing upwards and enables the gas combusted by the lower explosive to rush downwards, so that the initial explosive combustion section becomes a self-sealing area, the more the explosive burns downwards, the more the gas generated by the combustion of the explosive is extruded, and the higher the gas pressure is. The process from initial combustion to complete combustion of the explosive forms several distinct compartments (as shown in fig. 1); the energy peak of the detonation gas is concentrated to the bottom of the explosion hole. The high-pressure gas energy is submerged to do work, the running thrust of the high-pressure gas is controlled to impact the blasting orifice, and the blasting orifice is broken into stones and flies out to form flyrock. The blasting effect of the flyrock-free blasting is as follows: the hard stone has almost no chipping rate, most of the hard stone is broken according to the perforation connecting line, and the few hard stone is broken at the minimum resistance line of the rock body, namely nonlinear breakage. The large rock blocks can be dug and transported only by being reduced by a gun platform machine. The second hard and soft stones can be broken during the process of blasting and being thrown at the blasting interface and can be directly dug and transported. The second hard stone and soft stone blasting adopts a flying stone-free blasting technology, and the flying stones can be prevented from happening.

The blasting method comprises the following steps:

(1) the priming detonator is required to be arranged at the top end of the explosive superposition length in the direction of the blasting orifice, and the explosive cannot be arranged after the detonator is arranged.

(2) The explosive dosage is strictly controlled, the blasting is carried out according to a weak loosening blasting scheme, and the single-hole explosive loading cannot exceed one half of the conventional blasting. Blastholes of 40mm diameter were calculated as f = hv.

(3) The explosive installation stacking length cannot exceed one third of the depth h of the blast hole.

(4) The depth of the blast hole with the diameter of 40mm is 3m in principle, the shallowest depth can not be less than 2m, and the blast hole with the depth of less than 2m can not be detonated when being discarded.

(5) Before the explosive is installed, a marker post with a length mark is used for detecting the bottom of an explosion hole, whether the explosion hole falls into a stone block for grounding or not is judged, if grounding exists, a steel skewer is used for punching through the explosion hole, and the original drilling depth is basically reached.

(6) The packing depth of each roll of explosive is verified, whether the packing depth is consistent with the length of the explosive roll or not, and the explosive is prevented from being stranded in a blast hole when the explosive is installed.

(7) The space from the initiation point to the explosion orifice is tightly filled with fine sand, and the explosive plays the role of initial sealing when the explosive starts to burn.

(8) The electric detonators are connected in series through a network, so that explosion positions are simultaneously detonated to form resultant force, and the explosion effect is guaranteed.

(9) The boulder blasting is to remove surrounding soil and broken small boulders on one side of the boulder to reduce the resistance of the boulder, so that the boulder is smoothly cracked from the bottom and the energy of high-pressure gas is released in time. Prevent high-pressure gas from rushing out to the blast hole opening to burst the rock mass of the blast hole opening to form flying stones.

Example (b):

the project name is as follows: and XX road east-side yielding foundation earth-rock engineering.

An owner unit: XX City construction investment company.

A construction unit: XX City town construction engineering Co

Actually completing the amount of stone blasting engineering: 53 ten thousand cubic meters.

Geological conditions: the surface layer of the mountain is provided with a layer of surface soil, and main stone areas are occasionally provided with limestone hard stones, coal gangue hard stones and sandstone soft hard stones.

Blasting construction environment: the east is XX high-rise residential area, the mountain top is basically level with the top of the high-rise building, and the horizontal distance between the building seat and the nearest explosion area is 5 meters. A civil residential area is arranged on a south slope, one civil structure critical house and a plurality of brick-wood structure houses are arranged 8 meters away from the nearest explosion area, two civil structure critical houses are arranged in parallel at a position 6 meters away from the west explosion area for raising pigs, a temporary shelter area for immigration is arranged at a position of 100 meters, and a primary school with more than one thousand students is arranged at a position of 130 meters. A gas station is arranged 10 meters away from the explosion area in the north, the XX street is 40 meters away from the explosion area, the XX city leads to the main path in the directions of the XX village and the XX city, people flow continuously, and traffic flow is like pouring. In such a complex blasting construction environment, a construction unit adopts the technology of the scheme to blast and finish the rock blasting of more than 50 ten thousand cubic meters. The flying stone protective net and other coverings are not adopted, a road is not sealed, no flying stone is injured by one person, and a piece of glass or a piece of tile of a peripheral house is not damaged.

Summary of the invention

The rock blasting is carried out by adopting a flying-rock-free blasting technology, and the blasting safety distance of 300m (from the blasting safety regulation) can be shortened to 5 m. Therefore, the blasting technology of the scheme can completely replace expensive expansive agent rock crushing. The blasting production cost is greatly reduced, and the construction progress is greatly improved. The flyrock-free blasting technology concentrates the energy peak value of the high-pressure gas generated by blasting to the bottom of the blast hole, so that the high-pressure gas generated by blasting can work by submerging. The blasting technology of the scheme is applied to conventional blasting, the occurrence of the closed blasting phenomenon can be avoided, and meanwhile, flying stones are controlled, so that the blasting efficiency is improved and the safety is ensured.

Claims

1. A method of rock blasting, characterized by: it comprises the following steps:

1) detecting the parameters of the compressive strength of the rock,

2) explosion position releasing points, and explosion position parameters are calculated as follows: the maximum block of the rock is w, the blasting distance of the blast holes is A, the row spacing of the blast holes is d, the depth of the blast holes is h, and the nonlinear fracture parameter is v; then:

；

4) and charging, wherein charging parameters are calculated as: the single-hole explosive quantity is f, the hole bursting depth is h, and the parameter v is v, v = 0.2333; then: f = hv; wherein the unit of the single-hole dosage f is kg, the unit of the blast hole depth h is meter, and the charge length is not more than one third of the blast hole depth;

8) warning and starting the cannon.