AU2021103706A4

AU2021103706A4 - Controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of open cut tunnel

Info

Publication number: AU2021103706A4
Application number: AU2021103706A
Authority: AU
Inventors: Chunfeng Meng; Jinshan SUN; Xin Zhang
Original assignee: Jianghan University; China Railway 18th Bureau Group Co Ltd; Wuhan Jiujiang Railway Passenger Dedicated Line Hubei Co Ltd
Current assignee: Jianghan University; China Railway 18th Bureau Group Co Ltd; Wuhan Jiujiang Railway Passenger Dedicated Line Hubei Co Ltd
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2021-09-09
Anticipated expiration: 2029-06-29

Abstract

Disclosed is a controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of an open cut tunnel. The method includes the following steps: (1) drilling charged blastholes and empty holes in a region I and a region II after a region III is subjected to presplitting blasting; (2) charging the charged blastholes by using a positive continuous structure, where cut holes can be charged in a manner of spacing from the charged blastholes; (3) tightly and firmly connecting detonator pin wires, guaranteeing good electrification, and covering with 0.5 m thick sandy soil; (4) covering a blasting body by using a steel plate with a thickness of 30 mm, and filling water above to submerge the steel plate for 0.5-1.0 m high; (5) evacuating equipment, staff, animals, and the like out of a safety distance, warning, detonating after safety is confirmed, re-checking and eliminating danger 15 minutes after blasting, and relieving the warming after confirming that there is no danger. The method has the beneficial effects that: thick mud and wet clay can effectively absorb blasting energy, reduce blasting vibration, and reduce noises. The blasting body is covered with the steel plate, and the boundary is pressed, so flying stones are effectively avoided, and the safety in a construction area, a residential area, and a plant is guaranteed. O- I 0 0 0 0 0 C]c'l i m' CID C: 0-1 J4 Q 0 0 o aq Lo O CD co -o C D C' , CID cn cc cv-n 00 0 0 0 MC o LO __ _

Description

O- I

0 0 0 0 0

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CONTROLLED BLASTING METHOD CAPABLE OF EFFECTIVELY AVOIDING FLYING STONES AND REDUCING BLASTING VIBRATION FOR SEGMENTED VERTICAL EXCAVATION OF OPEN CUT TUNNEL TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of blasting, and in particular, to a controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of an open cut tunnel.

BACKGROUND

[0002] Blasting, using explosives to destroy a structure, is very common in tunnel construction. In a lot of tunnel construction, open cut tunnel blasting is needed. The open cut tunnel blasting can accelerate the construction progress and improve the construction effect.

[0003] In the tunnel of Dalian Railway Junction Project, an open cut tunnel is 800 meters long, the blasting sites are very close to residential areas, and the construction red lines of individual sites are close to buildings, so a large number of flying stones are easily produced by blasting and excavating the open cut tunnel. Flying stones fly around to bring great inconvenience to protection work, and the flying stones cannot be controlled very well, so there are great potential safety hazards, nearby residents and factory workers often hinder the construction, and the construction progress goes very badly, which causes great economic loss to a construction unit.

SUMMARY

[0004] The objective of the present disclosure is to provide a controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of an open cut tunnel for solving the problems proposed in Background.

[0005] To achieve the above objective, the present disclosure provides the following technical solution:

[0006] A controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of an open cut tunnel includes the following steps:

(1) drilling charged blastholes and empty holes in a region I and a region II after a region III is subjected to presplitting blasting;

(2) charging the charged blastholes by using a positive continuous structure, where cut holes can be charged in a manner of spacing from the charged blastholes;

(3) tightly and firmly connecting detonator pin wires, guaranteeing good electrification, and covering with 0.5 m thick sandy soil;

(4) covering a blasting body by using a steel plate with a thickness of 30 mm, and filling water above to submerge the steel plate for 0.5-1.0 m high;

(5) evacuating equipment, staff, animals, and the like out of a safety distance, warning, detonating after safety is confirmed, re-checking and eliminating danger 15 minutes after blasting, and relieving the warming after confirming that there is no danger;

(6) performing blasting construction on the region II by the same method.

[0007] As a further solution of the present disclosure, a CD75 mm drill bit is selected and used for drilling in step (1), the blasthole distance is 1000 m, the resistance line is 1200 mm, the depth of cut holes is 4 m, the depth of auxiliary holes is 3.5 m, and four empty holes are drilled between two adjacent rows of charged blastholes.

[0008] As a much further solution of the present disclosure, (p70mm emulsified waterproof explosives and second delay detonators are selected and used; the delay between two adjacent segments is 1.2 to 1.4 s; stemming is filled for 1.0 m high by using wet clay, and the rest of the stemming is sealed by using thick mud; empty holes are not charged with explosives, but all filled with the thick mud.

[0009] As a much further solution of the present disclosure, the steel plate must press the boundary, overlaps for 300 to 500 mm, and is connected firmly by using bolts above M36.

[0010] As a much further solution of the present disclosure, in step (5), the safe distance of dodging shooting cannot be less than 200 m; shooting warning should be set up at every intersection; equipment, staff, animals, and the like are all evacuated out of a safety distance; operators all wear safety helmets.

[0011] The present disclosure has the following beneficial effects:

1. thick mud and wet clay can effectively absorb blasting energy, reduce blasting vibration, and reduce noises;

2. the blasting body is covered with the steel plate, and the boundary is pressed, so flying stones are effectively avoided, and the safety in a construction area, a residential area, and a plant is guaranteed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is an arrangement plan for open cut tunnel vertical-digging, blasting, and drilling of the present disclosure.

DETAILED DESCRIPTION

[0013] The technical solutions in the embodiments of the present disclosure will be clearly and completely described herein below with reference to the accompanying drawings in the embodiments of the present disclosure. It is apparent that the described embodiments are merely part rather than all of the embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present disclosure.

[0014] Please refer to FIG. 1, a controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of an open cut tunnel, including the following steps:

(3) tightly and firmly connecting detonator pin wires, guaranteeing good electrification, and covering with 0.5 m thick sandy soil to prevent damage, breakage, and the like in subsequent work of safety assurance;

(4) covering a blasting body by using a steel plate with a thickness of 30 mm, and filling water above to submerge the steel plate for 0.5-1.0 m high, which are used for absorbing energy, reducing blasting vibration velocity, and avoiding flying stones;

(5) evacuating equipment, staff, animals, and the like out of a safety distance, warning, detonating after safety is confirmed, re-checking and eliminating danger 15 minutes after blasting, and relieving the warming after confirming that there is no danger; implementing a system of chain shooting by a shooter, a monitor and a safety officer, where the safety officer is responsible for warning, the monitor is responsible for commanding, and the shooter gives a warning by using a loudspeaker and blowing a whistle after the monitor makes a safety patrol and gives a shooting order and then starts detonating after making sure the surrounding area is safe;

(6) performing blasting construction on the region II by the same method.

[0015] A 075 mm drill bit is selected and used for drilling in step (1), the blasthole distance is 1000 m, the resistance line is 1200 mm, the depth of cut holes is 4 m, the depth of auxiliary holes is 3.5 m, and 4 empty holes are drilled between two adjacent rows of charged blastholes.

[0016] 070 mm emulsified waterproof explosives and second delay detonators are selected and used; the delay between two adjacent segments is 1.2 to 1.4 s; stemming is filled for 1.0 m high by using wet clay, and the rest of the stemming is sealed by using thick mud; empty holes are not charged with explosives, but all filled with the thick mud, which are used for absorbing energy and reducing blasting vibration.

[0017] The steel plate must press the boundary, overlaps for 300 to 500 mm, and is connected firmly by using bolts above M36.

[0018] In step (5), the safe distance of dodging shooting cannot be less than 200 m; shooting warning should be set up at every intersection; equipment, staff, animals, and the like are all evacuated out of a safety distance; operators all wear safety helmets.

Table 1 Blasting parameter design table for vertical excavation region I of open cut tunnel Charge Amount Kg/hole kg

+ 1-4/ o 7 90 4.0 1000 4.0 28.0 1+2.2 1/2 I/II -7 0

8-14 . 7 90 3.5 1000 1200 3.0 21.0 1+1.9 3 II

15-21 7 90 3.5 1000 1200 3.0 21.0 1+1.9 4 IV

22-28 y 7 90 3.5 1000 1200 3.0 21.0 1+1.9 5 V .2

0t¶

29-35 - 7 90 3.5 1000 1200 3.0 21.0 1+1.9 6 VI

36-47 12 90 3.5 1000 1200 0+3.5

47 112

[0019] For those skilled in the art, it is obvious that the present disclosure is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the present disclosure. Therefore, from any point of view, the embodiments should be regarded as exemplary but not restrictive. The scope of the present disclosure is limited by the attached claims rather than the above description. Therefore, it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present disclosure. Any reference numeral in the claims shall not be regarded as limiting the claims involved.

[0020] In addition, it should be understood that although the description is described according to the embodiments, not every embodiment only contains an independent technical solution. This description of the description is only for the sake of clarity. Those skilled in the art should take the description as a whole, and the technical solutions in the various embodiments can also be properly combined to form other implementation manners that can be understood by those skilled in the art.

Claims

WHAT IS CLAIMED IS:

1. A controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of an open cut tunnel, comprising the following steps: a) drilling charged blastholes and empty holes in a region I and a region II after a region III is subjected to presplitting blasting; b) charging the charged blastholes by using a positive continuous structure, where cut holes can be charged in a manner of spacing from the charged blastholes; c) tightly and firmly connecting detonator pin wires, guaranteeing good electrification, and covering with 0.5 m thick sandy soil; d) covering a blasting body by using a steel plate with a thickness of 30 mm, and filling water above to submerge the steel plate for 0.5-1.0 m high; e) evacuating equipment, staff, animals, and the like out of a safety distance, warning, detonating after safety is confirmed, re-checking and eliminating danger 15 minutes after blasting, and relieving the warming after confirming that there is no danger; and f) performing blasting construction on the region II by the same method.

2. The controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of an open cut tunnel

according to claim 1, wherein a 0 75 mm drill bit is selected and used for drilling in

step (1), the blasthole distance is 1000 m, the resistance line is 1200 mm, the depth of cut holes is 4 m, the depth of auxiliary holes is 3.5 m, and four empty holes are drilled between two adjacent rows of charged blastholes.

3. The controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of an open cut tunnel according to claim 1, wherein 0 70 mm emulsified waterproof explosives and

second delay detonators are selected and used; the delay between two adjacent segments is 1.2 to 1.4 s; stemming is filled for 1.0 m high by using wet clay, and the rest of the stemming is sealed by using thick mud; empty holes are not charged with explosives, but all filled with the thick mud.

4. The controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of an open cut tunnel according to any one of claims 1 to 3, wherein the steel plate must press the boundary, overlaps for 300 to 500 mm, and is connected firmly by using bolts above M36.

5. The controlled blasting method capable of effectively avoiding flying stones and reducing blasting vibration for segmented vertical excavation of an open cut tunnel according to claim 4, wherein in step (5), the safe distance of dodging shooting cannot be less than 200 m; shooting warning should be set up at every intersection; equipment, staff, animals, and the like are all evacuated out of a safety distance; operators all wear safety helmets.