Drilling blasting method for soft and hard interbedded surrounding rock tunnel

Abstract

The invention belongs to the technical field of engineering blasting, and provides a drilling blasting method for a soft and hard interbedded surrounding rock tunnel, which mainly comprises the following steps of: 1, determining the range of soft and hard interbedded surrounding rock of a tunnel face according to image data and geological exploration or rock drilling equipment while drilling parameters, and dividing a hard rock area and a soft rock area; 2, according to the range partition of the surrounding rock of the soft and hard interbedded layer of the tunnel face, the circulating footage, the cutting hole arrangement position and the explosive unit consumption of different rock stratum areas are determined, according to the different characteristics of soft rock and hard rock, the drill hole arrangement, the explosive loading amount and the detonating sequence are designed correspondingly, the design mode of one-time cutting is avoided, and the design efficiency is improved. The method can better adapt to complex geological conditions of soft and hard interbedded surrounding rock; large drilling spacing and continuous charging are adopted in the hard rock area, it is ensured that hard rock is fully crushed, and the excavation efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering blasting, and in particular relates to a drilling and blasting method for a tunnel with soft and hard interlayered surrounding rocks. Background Art

[0002] During the tunnel construction process, adverse geological conditions of passing through complex rock formations are often encountered. Interlayered soft and hard rock is a particularly common type of adverse geological condition. This rock mass has the characteristics of inhomogeneity, discontinuity and anisotropy, and is prone to interlayer peeling, fracture, and even overall instability and destruction.

[0003] At present, when designing blasting for tunnels surrounded by soft and hard interlayered rock, the blasting parameters are mainly selected based on manual experience, and often one design scheme is adopted for the entire tunnel. Since the influence of different rock strata joints on the blasting effect is not considered, the explosion energy is unevenly distributed, and the tunnel face is prone to over-excavation and under-excavation, which greatly increases the construction cost and affects the construction progress. Summary of the invention

[0004] In order to make up for the above-mentioned deficiencies, the present invention provides a drilling and blasting method for a tunnel with soft and hard interlayered surrounding rocks, so as to solve the related technical problems raised in the background technology.

[0005] The present invention is achieved in that:

[0006] A drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock mainly includes the following steps:

[0007] Step S1: Determine the range of the soft and hard interlayered surrounding rock of the tunnel face according to image data, geological exploration or drilling parameters of rock drilling equipment, and divide the hard rock area and the soft rock area;

[0008] Step S2: Determine the cycle footage, the location of the cut holes, and the unit consumption of explosives in different rock formations based on the range zoning of the soft and hard interlayer surrounding rocks at the tunnel face;

[0009] Step S3: sequentially design the slot holes, soft and hard rock joint surface blast holes, peripheral holes, and auxiliary holes, and determine the blasting parameters such as the position, spacing, row spacing, angle, depth, number of holes, and single hole charge, charge structure, etc. of each type of blast hole.

[0010] Step S4: Design the detonation network. According to the project characteristics and surrounding environment requirements, control the maximum single-shot charge within a safe range, and determine the detonation sequence and delay time difference.

[0011] Step S5: Perform drilling and blasting operations according to the aforementioned blasting design parameters to check the blasting effect.

[0012] Furthermore, in step S1, image data, advanced geological prediction or drilling parameters of rock drilling equipment can provide feedback on the occurrence information of different structural surfaces of the rock. The drilling parameters mainly include: rock properties, hardness and integrity.

[0013] Furthermore, in step S2, the slotting holes are arranged in the uniform rock mass in the middle and lower area of ​​the tunnel face in the hard rock area to ensure the slotting effect.

[0014] Furthermore, in step S2, the cycle footage range is 1.5 to 3.5 m; the cutouts are arranged in the hard rock area, and the charging coefficient is 0.8 to 0.9.

[0015] Furthermore, in step S2, the formulas for the unit consumption of explosives in the hard rock area and the soft rock area are used for calculation, wherein the unit consumption of explosives in the hard rock area is 1.2 to 2.0 kg / m3, and the unit consumption of explosives in the soft rock area is 0.4 to 0.8 kg / m3.

[0016] Furthermore, in step S2, the formula for the explosive consumption per unit in the hard rock area and the soft rock area is:

[0017] In the formula, k0=525 / p, p is the explosive force of the explosive; f is the Proctor coefficient of the rock; S is the area of ​​the tunnel face.

[0018] Furthermore, in step S2, the principle for selecting the unit consumption of explosives is to use a large unit consumption in hard rock areas and a small unit consumption in soft rock areas.

[0019] Furthermore, in step S3, the order of hole arrangement is: slot holes, soft and hard rock joint surface blast holes, peripheral holes and auxiliary holes. The hole arrangement principle is to arrange sparse holes in the hard rock area and dense holes in the soft rock area, and to reserve empty holes at intervals without explosives to ensure that the tunnel forms a flat contour surface.

[0020] Furthermore, in step S3, the spacing between the cut holes is 0.2-0.4 m, the spacing between the auxiliary holes in the hard rock area is 0.6-0.8 m, and the spacing between the peripheral holes is 0.4-0.6 m;

[0021] The spacing between auxiliary holes in the soft rock area is 0.8-1.0m, and the spacing between peripheral holes is 0.2-0.4m, and empty holes are reserved at intervals without explosives, so as to ensure that the tunnel forms a flat contour surface;

[0022] The charging structure of the groove eyes and auxiliary eyes is continuous charging, and the charging structure of the peripheral eyes is intermittent charging.

[0023] Furthermore, in step S4, the detonation network adopts an industrial electronic detonator detonation network, and the detonation sequence is extended from the middle to the outside in a circle, which is: the groove hole, the auxiliary hole, the soft and hard rock joint surface blast hole and the peripheral hole;

[0024] Multiple short-interval delays are set for blastholes in the same circle, and the delay time from the inside to the outside of each circle of blastholes is 50ms to control the blasting vibration effect.

[0025] The beneficial effects of the present invention are:

[0026] The present invention designs the drilling arrangement, charge amount and detonation sequence according to the different characteristics of soft rock and hard rock, avoiding the "one-size-fits-all" design method and being able to better adapt to the complex geological conditions of soft and hard interlayered surrounding rocks;

[0027] In the hard rock area, a larger drilling spacing and continuous charging are used to ensure that the hard rock is fully broken and improve the excavation efficiency. In the soft rock area, small-spaced drilling, spaced empty holes and segmented charging are used to reduce excessive damage to the soft rock and avoid landslides or instability of the surrounding rock. Through a reasonable detonation sequence and charging structure, the tunnel profile can be better controlled and over-excavation or under-excavation can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a schematic diagram of the blasting method flow of the present invention;

[0030] Figure 2 This is a schematic diagram of the division of the tunnel face in a tunnel with soft and hard interlayered surrounding rock;

[0031] Figure 3 A schematic diagram of the location of the cutout area;

[0032] Figure 4 This is a schematic diagram of blasthole arrangement at the tunnel face in soft and hard interlayered surrounding rock;

[0033] Figure 5 This is a schematic diagram of the blasting network delay at the tunnel face in soft and hard interlayered surrounding rock.

[0034] Explanation of the accompanying reference numerals: 1. Tunnel face; 2. Rock stratum joint surface; 3. Soft rock area; 4. Hard rock area; 5. Groove hole; 6. Joint surface blast hole; 7. Peripheral hole; 8. Auxiliary hole; 9. Empty hole. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0038] Example

[0039] Specific as Figure 1-5 As shown, a method for drilling and blasting excavation of a deep-water embedded caisson foundation pit 1 is provided, which mainly includes the following steps:

[0040] Step 1: Determine the range of the soft and hard interlayered surrounding rock of the tunnel face 1 based on image data, geological exploration or drilling parameters of rock drilling equipment, and divide it into hard rock area 4 and soft rock area 3.

[0041] Step 2: Based on the range zoning of the soft and hard interlayered surrounding rock of the tunnel face 1, determine the cycle footage, the layout position of the slot hole 5 and the unit consumption of explosives in different rock strata areas.

[0042] The cycle footage is generally 1.5 to 3.5 m; the slot hole 5 is arranged in the hard rock area 4, and the charge coefficient is 0.8 to 0.9. The explosive consumption of the hard rock area 4 and the soft rock area 3 is calculated according to formula (1), wherein the explosive consumption of the hard rock area 4 is generally designed to be 1.2 to 2.0 kg / m3, and the explosive consumption of the soft rock area 3 is generally designed to be 0.4 to 0.8 kg / m3.

[0043]

[0044] In the formula, k0=525 / p, p is the explosive force of the explosive; f is the Proctor coefficient of the rock; S is the area of ​​the tunnel face 1.

[0045] Step 3: Design the slot holes 5, soft and hard rock joint surface blast holes 6, peripheral holes 7, and auxiliary holes 8 in sequence, and determine the blasting parameters such as the position, spacing, row spacing, angle, depth, number of holes, single-hole charge, and charge structure of each type of blast hole.

[0046] Among them, the spacing between the slotted holes 5 is 0.2-0.4m; the spacing between the auxiliary holes 8 in the hard rock area 4 is 0.6-0.8m, and the spacing between the peripheral holes 7 is 0.4-0.6m; the spacing between the auxiliary holes 8 in the soft rock area 3 is 0.8-1.0m, and the spacing between the peripheral holes 7 is 0.2-0.4m, and the reserved empty holes 9 are not charged with explosives, so as to ensure that the tunnel forms a flat contour surface. The charging structure of the slotted holes 5 and the auxiliary holes 8 is continuous charging, and the charging structure of the peripheral holes 7 is intermittent charging.

[0047] Step 4: Design the detonation network. According to the project characteristics and surrounding environment requirements, control the maximum single-shot charge within a safe range and determine the detonation sequence and delay time difference.

[0048] The detonation sequence is: groove hole 5 → auxiliary hole 8 → peripheral hole 7, and the delay time of each circle of blast holes from the inside to the outside is 50ms.

[0049] Step 5: Carry out drilling and blasting operations according to the aforementioned blasting design parameters and check the blasting effect.

[0050] The image data, advanced geological prediction or drilling parameters of rock drilling equipment in step 1 can provide feedback on the occurrence information of different structural surfaces of the rock. The drilling parameters include the lithology, hardness, integrity, etc. of the rock.

[0051] The cutout holes 5 in step 2 can be set in various forms. The cutout holes 5 are arranged in the uniform rock mass in the middle and lower area of ​​the tunnel face in the hard rock area 4 to ensure the cutout effect.

[0052] The principle for selecting the charge unit consumption in step 2 is to use a large charge unit consumption in the hard rock area 4 and a small charge unit consumption in the soft rock area 3.

[0053] The hole arrangement sequence in step three is "groove hole 5 - soft and hard rock joint surface blasthole 6 - peripheral hole 7 - auxiliary hole 8". The hole arrangement principle is to arrange sparse holes in the hard rock area 4 and dense holes in the soft rock area 3 with reserved empty holes 9 at intervals without explosives to ensure that the tunnel forms a flat contour surface.

[0054] The detonation network in step 4 adopts an industrial electronic detonator detonation network, and the detonation sequence is extended from the middle to the outside in a circle, that is, the groove hole 5-auxiliary hole 8, the soft and hard rock joint surface blast hole 6-peripheral hole 7; the same circle of blast holes can also be set with multiple short interval extensions to control the blasting vibration effect.

[0055] The technical solution of the present invention is highly targeted and adaptable to complex geological conditions. According to the different characteristics of soft rock and hard rock, the drilling arrangement, charge amount and detonation sequence are designed respectively, avoiding the "one-size-fits-all" design method and being able to better adapt to the complex geological conditions of soft and hard interlayered surrounding rock. Through detailed geological survey and surrounding rock classification, the design is more accurate and the construction risk caused by unclear geological conditions is reduced;

[0056] The blasting effect is better. In the hard rock area 4, a larger drilling spacing and continuous charging are used to ensure that the hard rock is fully broken and the excavation efficiency is improved. In the soft rock area 3, small spacing drilling and segmented charging are used to reduce excessive damage to the soft rock and avoid landslides or surrounding rock instability. Through a reasonable detonation sequence and charging structure, the tunnel contour can be better controlled to reduce over-excavation or under-excavation.

[0057] Excellent economic efficiency. Precise blasting design can effectively control the tunnel profile, reduce over-break and under-break, and reduce the cost of concrete backfill and finishing. Optimizing blasting parameters according to the different characteristics of soft and hard rocks can speed up the excavation progress, shorten the construction period, and reduce construction costs. Reasonable charging structure and detonation sequence can reduce the amount of explosives and reduce material costs.

[0058] The advantages of this method are mainly reflected in its pertinence, high efficiency and economy. Through scientific design and strict construction management, it can effectively solve the problems in the excavation of soft and hard interlayered surrounding rock tunnels, improve construction efficiency, reduce costs and risks, and protect the environment and surrounding rock stability. This method is particularly suitable for tunnel projects with complex geological conditions and has wide promotion and application value.

[0059] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

1. A drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock, characterized in that: It mainly includes the following steps: Step S1: Determine the range of the soft and hard interlayered surrounding rock of the tunnel face according to image data, geological exploration or drilling parameters of rock drilling equipment, and divide the hard rock area and the soft rock area; Step S2: Determine the cycle footage, the location of the cut holes, and the unit consumption of explosives in different rock formations based on the range zoning of the soft and hard interlayer surrounding rocks at the tunnel face; Step S3: sequentially design the cut holes, soft and hard rock joint surface blast holes, peripheral holes, and auxiliary holes, and determine the blasting parameters such as the position, spacing, row spacing, angle, depth, number of holes, and single hole charge, charge structure, etc. of each type of blast hole; Step S4: Design the detonation network, control the maximum single-shot charge within a safe range according to the project characteristics and surrounding environment requirements, and determine the detonation sequence and delay time difference; Step S5: Perform drilling and blasting operations according to the aforementioned blasting design parameters to check the blasting effect.

2. The drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock according to claim 1, characterized in that: In step S1, image data, advanced geological prediction or drilling parameters of rock drilling equipment can feedback the occurrence information of different structural surfaces of rock. The drilling parameters mainly include: rock lithology, hardness and integrity.

3. The drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock according to claim 1, characterized in that: In the step S2, the cutting holes are arranged in the uniform rock mass in the middle and lower area of ​​the tunnel face in the hard rock area to ensure the cutting effect.

4. The drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock according to claim 3 is characterized in that: In step S2, the cycle footage range is 1.5 to 3.5 m; the cutouts are arranged in the hard rock area, and the charging coefficient is 0.8 to 0.

9.

5. The drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock according to claim 4, characterized in that: In step S2, the explosive unit consumption of the hard rock area and the soft rock area is calculated by the formula, wherein the explosive unit consumption of the hard rock area is 1.2-2.0 kg / m 3 The explosive consumption in soft rock area is 0.4~0.8kg / m 3 .

6. The drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock according to claim 5, characterized in that: In step S2, the formulas for explosive consumption in hard rock area and soft rock area are: In the formula, k0=525 / p, p is the explosive force of the explosive; f is the Proctor coefficient of the rock; S is the area of ​​the tunnel face.

7. The drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock according to claim 6, characterized in that: In step S2, the principle for selecting the unit consumption of the charge is to use a large unit consumption in the hard rock area and a small unit consumption in the soft rock area.

8. The drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock according to claim 1, characterized in that: In step S3, the hole arrangement sequence is: slot holes, soft and hard rock joint surface blast holes, peripheral holes and auxiliary holes. The hole arrangement principle is to arrange sparse holes in the hard rock area and dense holes in the soft rock area, and to reserve empty holes without explosives at intervals to ensure that the tunnel forms a flat contour surface.

9. The drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock according to claim 8, characterized in that: In step S3, the spacing between the slot holes is 0.2-0.4 m, the spacing between the auxiliary holes in the hard rock area is 0.6-0.8 m, and the spacing between the peripheral holes is 0.4-0.6 m; The spacing between auxiliary holes in the soft rock area is 0.8-1.0m, and the spacing between peripheral holes is 0.2-0.4m, and empty holes are reserved at intervals without explosives, so as to ensure that the tunnel forms a flat contour surface; The charging structure of the groove eyes and auxiliary eyes is continuous charging, and the charging structure of the peripheral eyes is intermittent charging.

10. The drilling and blasting method for a tunnel with soft and hard interlayered surrounding rock according to claim 1, characterized in that: In the step 4, the detonation network adopts the industrial electronic detonator detonation network, and the detonation sequence is extended from the middle to the outside, in order: the groove hole, the auxiliary hole, the soft and hard rock joint surface blast hole and the peripheral hole; Multiple short-interval delays are set for blastholes in the same circle, and the delay time from the inside to the outside of each circle of blastholes is 50ms to control the blasting vibration effect.

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