CN104457465B - A kind of deep-lying tunnel Blasting Excavation effect control method - Google Patents

Abstract

The invention discloses a kind of deep-lying tunnel Blasting Excavation effect control method, including: step 1, determine the principal stress level and direction for the treatment of tunnel excavation face before Blasting Excavation; Step 2, is treating laying big gun hole and design explosive payload on tunnel excavation face according to the hole blasting design scheme being core Con trolling index with explosive quantity in a sound; Step 3, increases by a circle in the former keyhole section laid and points to the cone cut hole of former slotting section hollow hole of centre, and outmost turns breaking hole is used as cushion hole; Step 4, based on excavation detonate design to cone cut hole outside other big gun holes detonate networking; Step 5, adopts millisecond detonating method to detonate. The present invention can control explosive load simultaneously and deep rock mass strain energy transient state discharges the excavation disturbance brought out, thus realizing the active of deep rock mass damage and rock burst is controlled, can be widely applied to the Blasting Excavation of the field deep-buried underground engineerings such as Hydraulic and Hydro-Power Engineering, traffic, mine and deep blasting excavation disturbance controls.

Description

A kind of deep-lying tunnel Blasting Excavation effect control method

Technical field

The invention belongs to Geotechnical Engineering field, particularly relate to a kind of deep-lying tunnel Blasting Excavation effect control method.

Background technology

Buried Rock Damage district is bred by Blasting Excavation disturbance and impact of developing is great, and the Blasting Excavation effect such as the vibration of country rock and damage is also the geological problem being frequently encountered by Underground Engineering Blasting, is the rock catastrophic rupture that brings out of a kind of mankind's activity. It is applied to heavy construction from blasting technique, especially the buried rock excavation of high-mountain gorge areas, can greatly improve construction speed, and be substantially reduced construction cost. But the engineering project disaster caused by Blasting Excavation effect also produces therewith. Blasting Excavation effect is primarily referred to as and is caused vibration of base rock, strain of rock mass energy high speed pay-out by explosion, thus the rock convergence measure caused the even phenomenon of rock burst. The damage of rock mass and rock burst generally have hysteresis quality and autgmentability, and hysteresis quality refers to that rock burst often lags behind Blasting Excavation process; Autgmentability refers to after damaging a period of time, and previous damage zone can to the characteristic retaining the extension of rock mass deep. These characteristics show, Blasting Excavation disturbance is in the propagation excavated in country rock and adjoining rock stability is had material impact. Therefore, excavation disturbance is carried out by deep-lying tunnel Blasting Excavation process actively, suitable control be weaken one of effective means of blasting damage such as rock convergence measure.

Increase along with Southwestern China area high-mountain gorge areas engineering, Blasting Excavation causes deep rock mass crustal stress redistribution, rock mass is internal will produce local elastic plastics characteristic concentration phenomenon, the energy gathered causes rock cranny to produce and extension, or even the motion of geological interval layer, thus cause the release of stress wave or elastic wave and fast propagation brings out Rock Damage even rock burst in rock mass around. Traditional Blasting Excavation disturbance control method does not consider the clamping action that when deep rock mass slotting section is detonated, high-ground stress is powerful, slotting instantankeous strain can discharge acutely, its shock wave when propagating to rock mass deep may to excavation area outside reservation rock mass cause damage, and tradition presplit blasting construction technology does not generally adopt Pre-splitting Blasting Technique under high-ground stress, its network needs to be optimized further.

Summary of the invention

It is an object of the invention to provide a kind of deep-lying tunnel Blasting Excavation effect control method suitable in deep underground engineering.

The index weighing Blasting Excavation effect is a lot, and characterizes country rock excavation disturbance effect at the commonly used Peak Particle Velocity of engineering field. In blasting rock-broken process, strain energy transient state release in rock mass, stress transient state unloads. The unloading disturbance that in each section of big gun hole initiation process, the release of the crustal stress transient state in excavation face produces outwards is propagated with elastic wave velocity, and Peak Particle Velocity PPV is:

$\mathrm{PPV}=K{\left(\frac{Q^n}{R}\right)}^{\mathrm{\α}}---\left(1\right)$

In formula (1):

N is that Cartridge shape coefficient, China and the former Soviet Union generally take 1/3, and more American-European countries generally take 1/2;

Q is maximum single blow blasting charge;

R be the quick-fried heart from;

K, �� are the empirical coefficient relevant with geological conditions, explosion type.

Be can be seen that by formula (1), Peak Particle Velocity PPV is directly proportional to maximum single blow blasting charge Q and K, ��, therefore, it can reduce Peak Particle Velocity PPV by reduction maximum single blow blasting charge Q and adjustment explosion type, thus controlled blasting excavation effects.

For reaching above-mentioned purpose, the present invention adopts the following technical scheme that:

A kind of deep-lying tunnel Blasting Excavation effect control method, including step:

Step 1, determines the principal stress level and direction for the treatment of tunnel excavation face before Blasting Excavation;

Step 2, based on principal stress level and the direction for the treatment of tunnel excavation face, treating laying big gun hole and design explosive payload on tunnel excavation face according to the hole blasting design scheme being core Con trolling index with explosive quantity in a sound, the big gun hole laid includes keyhole, breaking hole and photoface exploision hole;

Step 3, in the former keyhole section laid, increase by a circle point to the cone cut hole of former slotting section hollow hole of centre, and outmost turns breaking hole is used as cushion hole, former keyhole explosive payload and cone cut hole explosive payload are the 1/2��2/3 of keyhole design explosive payload, cushion hole explosive payload designs the 1/3��1/2 of explosive payload for breaking hole, and other hole charges and network structure are all consistent with former hole blasting design scheme;

Step 4, treating to hole on tunneling face, powder charge, is linked to be cone cut hole section by cone cut hole, based on excavation detonate design to cone cut hole outside other big gun holes detonate networking;

Step 5, adopts millisecond detonating method to detonate by keyhole, cushion hole, breaking hole, photoface exploision hole order.

Principal stress level and the direction for the treatment of tunnel excavation face in step 1 are to determine according to geology survey data or numerical computations.

The present invention can control explosive load simultaneously and deep rock mass strain energy transient state discharges the excavation disturbance brought out, thus realizing the active of deep rock mass damage and rock burst is controlled. Based on traditional quick-fried steel for shot, by slotting section segmentation and change explosive payload, thus reducing first paragraph slotting list to ring area and explosive quantity in a sound, make the strain energy release will not be excessive; And protect reservation rock mass further by cushioning presplitting, thus realize deep rock mass Blasting Excavation disturbance is controlled.

Compared with traditional Blasting Excavation effect control method, there is advantages below and beneficial effect in the present invention:

(1) based on controlling the Blasting Excavation disturbance that explosive load is brought out, by by slotting area segmentation, the list to reduce first paragraph slotting rings area and explosive quantity, makes strain energy release be controlled;

(2) the outmost turns breaking hole originally tunneling design is used as cushion hole after forming free face by slotting, carries out pre-ceasma and detonates, and protection retains rock mass further;

(3) can be widely applied to the Blasting Excavation of the field deep-buried underground engineerings such as Hydraulic and Hydro-Power Engineering, traffic, mine and deep blasting excavation disturbance controls.

Accompanying drawing explanation

Fig. 1 is steel for shot on certain deep-lying tunnel face and the cross-sectional schematic diagram of networking that detonates, wherein, figure (a) is conventional steel for shot and the cross-sectional schematic diagram of networking that detonates, and figure (b) is the steel for shot after optimization of the present invention and the cross-sectional schematic diagram of networking that detonates;

Fig. 2 is that on certain deep-lying tunnel face, keyhole arranges schematic diagram, and wherein, figure (a) is that conventional keyhole arranges schematic diagram, schemes the keyhole after (b) optimizes for the present invention and arranges schematic diagram;

Fig. 3 is conventional steel for shot and the networking drawing in side sectional elevation that detonates on certain circular deep-lying tunnel face;

Fig. 4 is for optimizing steel for shot and the networking drawing in side sectional elevation that detonates on certain circular deep-lying tunnel face;

Fig. 5 is steel for shot conventional on certain gateway opening shape deep-lying tunnel face and the networking drawing in side sectional elevation that detonates;

Fig. 6 is for optimizing steel for shot and the networking drawing in side sectional elevation that detonates on certain gateway opening shape deep-lying tunnel face.

In figure, 1-hollow hole of centre, 2-cone cut hole section.

Detailed description of the invention

When the inventive method is applied to deep rock mass excavation for conventional blast method, keyhole initiation process energy discharges acutely, it is likely to the rock mass that retains beyond excavation border is caused the deficiency of damage, by to the segmentation of slotting position and change undermining type, to reduce first paragraph slotting list sound area, and protect reservation rock mass further by a circle cushion hole, finally adopt photoface exploision again, thus reaching weakening on the basis of keyhole strain energy release speed, the purpose of disturbance is brought out during controlled blasting excavation, active to realize deep rock mass is excavated the blasting effect such as rock convergence measure and vibration of base rock controls.

Describe the present invention in detail below in conjunction with detailed description of the invention, specifically comprise the following steps that

Step one, determines the size and Orientation of maximum principal stress and the minimum principal stress treating tunnel excavation face before Blasting Excavation.

Treat that the maximum principal stress of tunnel excavation face and the size and Orientation of minimum principal stress are determined according to geology survey data or numerical computations. See Fig. 1, horizontal initial field stress ��₁For treating the maximum principal stress of tunnel excavation face, vertical initial field stress ��₃For treating the minimum principal stress of tunnel excavation face.

Step 2, size and Orientation based on the maximum principal stress and minimum principal stress for the treatment of tunnel excavation face, laying big gun hole and design explosive payload on tunnel excavation face is being treated according to the hole blasting design scheme being core Con trolling index with explosive quantity in a sound, in the former slotting section laid, increase by a circle point to the cone cut hole of former slotting section hollow hole of centre (1), it is simple to keyhole segmentation; And outmost turns breaking hole is used as cushion hole.

Cone cut hole explosive payload designs the 1/2 2/3 of explosive payload for keyhole, and former keyhole explosive payload designs the 1/2 2/3 of explosive payload for keyhole; Cushion hole explosive payload designs the 1/3 1/2 of explosive payload for breaking hole; Other hole charges and network structure are all consistent with former hole blasting design scheme. Boring powder charge on tunnel excavation face is being treated according to design cloth hole.

In this step, it is primarily based on conventional hole blasting design method on deep-lying tunnel face, lays big gun hole, see that Fig. 1 (a) and Fig. 2 (a), MS3 are the former keyhole section laid, MS5, MS7, MS9 are the former breaking hole section laid, and MS11 is the former photoface exploision hole laid. The present invention is optimized based on former cloth hole, namely, in former keyhole section MS3, increase by a circle point to the cone cut hole MS1 of MS3 hollow hole of centre (1), and with outmost turns breaking hole section MS9 for cushion hole, see Fig. 1 (b) and Fig. 2 (b).

Step 3, treats tunnel excavation face big gun hole and carries out, according to excavation design of detonating, networking of detonating.

Particularly as follows: a newly-increased circle cone cut hole is linked to be cone cut hole section (2), it is divided into two sections by keyhole section, increases millisecond detonating hop count so that former keyhole section list rings area and diminishes; And outmost turns breaking hole is used as cushion hole.

The line of centres in above-mentioned big gun hole is not limited to straight line, it is also possible to for camber line or broken line.

Step 4, adopts millisecond detonating method to detonate by keyhole, cushion hole, breaking hole, photoface exploision hole order.

See Fig. 1 (a), conventionally from inside to outside detonate successively, namely detonate successively according to MS3, MS5, MS7, MS9, MS11 order; After adopting the present invention to optimize, add cone cut hole section MS1, and using outmost turns breaking hole (i.e. MS9 in Fig. 1 (a)) as cushion hole, firing order is first keyhole section (MS1, MS3 in Fig. 1 (b)), cushion hole (MS5 in Fig. 1 (b)) again, then breaking hole (MS7, MS8, MS9 in Fig. 1 (b)), last photoface exploision hole (MS11 in Fig. 1 (b)).

Below in conjunction with drawings and Examples, the inventive method is described further.

Embodiment 1

Certain unlimited massif excavates a buried circular tunnel, tunnel face radius r=2.5m, the horizontal initial field stress �� of this face₁For maximum principal stress, vertical initial field stress ��₃For minimum principal stress, full-face blast excavation molding. Straight hole slotting is adopted in the middle part of face, by inner outward, excavation face is sequentially arranged 1 circle keyhole MS3,3 circle breaking hole MS5��MS9,1 circle periphery bright finish blast hole MS11, above-mentioned keyhole, breaking hole, photoface exploision hole the routine networking method that detonates be: big gun hole is connected into circle and obtains MS3, MS5, MS7, MS9, MS11 totally 5 millisecond detonating sections, as shown in Figure 1.

If detonating by above-mentioned networking, slotting section detonate area and explosive quantity in a sound excessive, strain energy release is violent, can cause the strong vibration of rock mass and damage, damage may be caused to retaining outside MS11 millisecond detonating section in Fig. 3 rock mass, be unfavorable for the adjoining rock stability of excavation hole section.

The present embodiment then adopts following optimization to detonate networking method:

Seeing Fig. 4, increase by a circle cone cut hole MS1, make keyhole divide two circle explosions, see the MS1 section of detonating and the MS3 section of detonating in Fig. 4 in slotting section MS3, powder charge measures the 2/3 of former slotting design powder charge. Former breaking hole MS9 section is used as Buffer control section, namely changes the explosion type of outmost turns breaking hole, and powder charge measures the 1/3 of former breaking hole. Then according to keyhole, cushion hole, breaking hole, photoface exploision hole order detonate. So by controlling slotting section first time single sound area and explosive quantity in a sound, the violent release of strain energy can be reduced, especially the rock vibration caused and damage development are not transmitted to retain in rock mass, and utilize buffering presplitting to control the propagation of energy further, reach the purpose of controlled blasting vibration simultaneously and deep rock mass blasting effect.

Embodiment 2

See Fig. 5, certain unlimited massif excavates a buried Arch cross-section tunnel, tunnel face radius r=2.5m, horizontal initial field stress ��₁For maximum principal stress, vertical initial field stress is ��₃For minimum principal stress, full-face blast excavation molding. According to the hole blasting design scheme face being core Con trolling index with explosive quantity in a sound being arranged, keyhole MS3, breaking hole MS5��MS13 and periphery bright finish blast hole MS15��17, above-mentioned keyhole, breaking hole, the periphery bright finish blast hole routine networking method that detonates is: big gun hole to be connected into totally 8 the millisecond detonating sections of MS3, MS5, MS7, MS9, MS11, MS13, MS15, MS17 as shown in Figure 5.

If detonating by above-mentioned networking, slotting section detonate area and explosive quantity in a sound excessive, strain energy release is violent, can cause the strong vibration of rock mass and damage, it is possible to can cause damage to retaining outside MS15, MS17 section in Fig. 5 rock mass. It is unfavorable for the adjoining rock stability of excavation hole section.

The present embodiment then adopts following optimization to detonate networking method:

Seeing Fig. 6, increase by a circle cone cut hole MS1, make keyhole divide two circle explosions in slotting section, the MS1 section of detonating and the MS3 section of detonating in Fig. 6, powder charge measures the 2/3 of former slotting design powder charge. Former breaking hole MS13 section is used as buffering presplit blasting hole section, namely changes outmost turns breaking hole explosion type, and powder charge measures the 1/3 of former breaking hole. And detonate according to the order of Fig. 4, namely by keyhole, the order cushioning pre-ceasma, breaking hole, light blast hole. So detonate area by controlling slotting section first time, the violent release of strain energy can be reduced, especially the rock vibration caused and damage development are not transmitted to retain in rock mass, and utilize buffering presplitting to control the propagation of energy further, reach the purpose of controlled blasting vibration simultaneously and deep rock mass blasting effect.

The composite can be widely applied to the active of the deep-lying tunnel in the fields such as mine under large ground pressure, water conservancy and hydropower, traffic excavation or deep mining process borehole blasting excavation effects control, for controlling rock vibration and damaging even rock burst there is good effect.

Claims (2)

1. a deep-lying tunnel Blasting Excavation effect control method, it is characterised in that include step:

Step 1, determines the principal stress level and direction for the treatment of tunnel excavation face before Blasting Excavation;

Step 2, based on principal stress level and the direction for the treatment of tunnel excavation face, treating laying big gun hole and design explosive payload on tunnel excavation face according to the hole blasting design scheme being core Con trolling index with explosive quantity in a sound, the big gun hole laid includes keyhole, breaking hole and photoface exploision hole;

Step 3, in the former keyhole section laid, increase by a circle point to the cone cut hole of former slotting section hollow hole of centre, and outmost turns breaking hole is used as cushion hole, former keyhole explosive payload and cone cut hole explosive payload are the 1/2 ~ 2/3 of keyhole design explosive payload, cushion hole explosive payload designs the 1/3 ~ 1/2 of explosive payload for breaking hole, and other hole charges and network structure are all consistent with former hole blasting design scheme;

Step 4, treating to hole on tunneling face, powder charge, is linked to be cone cut hole section by cone cut hole, based on excavation detonate design to cone cut hole outside other big gun holes detonate networking;

Step 5, adopts millisecond detonating method to detonate by keyhole, cushion hole, breaking hole, photoface exploision hole order.

2. deep-lying tunnel Blasting Excavation effect control method as claimed in claim 1, it is characterised in that:

Principal stress level and the direction for the treatment of tunnel excavation face in step 1 are to determine according to geology survey data or numerical computations.