Annular shield and core blasting step-by-step tunneling method in hard rock stratum vertical shaft

Abstract

The invention discloses an annular shield and core blasting step-by-step tunneling method in a hard rock stratum vertical shaft. The method comprises the following steps that S1, an annular pilot tunnel is excavated in a tunnel face of a hard rock stratum in the vertical shaft through an annular cutterhead shield tunneling machine; s2, after excavation of the annular pilot tunnel is completed, a telescopic assembly and a driving assembly of the annular cutterhead shield tunneling machine are closed; s3, a blast hole is formed in the tunnel face which is not excavated, and a cartridge is installed in the blast hole; s4, the telescopic assembly is started, the telescopic assembly drives the cutterhead assembly to move upwards, and the cutterhead assembly retreats to the tunnel face; s5, initiating the cartridge, and removing rock slag generated after the cartridge is blasted; and S6, the step S1 to the step S5 are repeated, and the next tunnel face is excavated till shaft excavation is completed. The method has the advantages that back break and underbreak are accurately controlled and eliminated, the number of blasting cartridges can be reduced, and cost is saved.

Description

Technical Field

[0001] The invention belongs to the technical field of vertical shaft shield tunneling, and in particular relates to a method for tunneling by an annular shield and core blasting in a hard rock formation vertical shaft. Background Art

[0002] my country's cities are developing rapidly, but in the process of decades of development, due to changes in development concepts at various stages, unreasonable urban planning, economic costs and population growth, urban space utilization and layout are unreasonable, as well as old and dilapidated renovation, urban development cannot meet people's needs, and urban renewal and transformation have become the future development trend. With the acceleration of urban renewal in my country, the problem of underground space utilization has become increasingly prominent. Major cities have built shaft garages to alleviate parking difficulties, underground storage pools to regulate flood disasters and recycle water resources, and shafts as underground energy storage and underground energy storage space, mountain tunnel ventilation shafts, etc. Shaft construction methods are divided into manual excavation construction, semi-mechanical excavation construction and mechanical excavation construction. Shield tunneling is widely used due to its advantages such as fast excavation speed, high safety and little impact on the surrounding environment.

[0003] Mechanized construction of large-diameter shafts has always been a difficult problem in the field of underground engineering. Currently, most construction methods use manually excavated shafts. After the shaft is built on the ground, it sinks as it is excavated. The construction speed is slow, and the shaft is prone to deflection, poor sinking, and the need to add sinking aids when sinking. In recent years, with the development of science and technology, some mechanized construction equipment has gradually emerged, but there are problems such as low mechanization and slow slag discharge speed that affect the construction progress. Especially for hard rock formations, a single drilling and blasting method or shield construction is usually used, which has problems such as low construction efficiency, safety of construction personnel, severe tool wear and frequent tool changes. It is impossible to comprehensively utilize the characteristics of shield tunneling, high safety, small impact on the surrounding environment, and high efficiency of drilling and blasting in hard rock excavation. Summary of the invention

[0004] The purpose of the present invention is to provide a method for step-by-step excavation of a ring shield and core blasting in a hard rock formation shaft according to the deficiencies of the above-mentioned prior art, which utilizes a ring-shaped cutterhead shield machine, which is composed of a cutterhead assembly, a telescopic assembly, a drive assembly and a shield, wherein the drive assembly is arranged in the shield, the telescopic assembly is installed on the drive assembly and connected to the cutterhead assembly, the telescopic assembly drives the cutterhead assembly to perform lifting and lowering movements, and the drive assembly drives the telescopic assembly to perform rotational movements. First, during the excavation of the hard rock shaft, the ring-shaped cutterhead shield forms a ring-shaped guide tunnel, which provides a pre-crack surface and increases the blasting free surface for the drilling and blasting excavation of a large-diameter hard rock shaft, and then the drilling and blasting method is used in the core hard rock face rock mass, which not only realizes precise control to eliminate over-excavation and under-excavation, but also reduces the number of blasting cartridges and saves costs.

[0005] The purpose of the present invention is achieved by the following technical solutions: A method for tunneling in a hard rock formation shaft by an annular shield and core blasting step by step, the tunneling method comprising the following steps: S1: Use an annular cutterhead shield machine to excavate an annular pilot tunnel on the tunnel face of the hard rock formation in the shaft; The annular cutterhead shield machine comprises a cutterhead assembly, a telescopic assembly, a drive assembly and a shield, wherein the drive assembly is arranged in the shield, and the telescopic assembly is mounted on the drive assembly and connected to the cutterhead assembly; the telescopic assembly and the drive assembly are started, the telescopic assembly drives the cutterhead assembly to move downward, and the drive assembly drives the telescopic assembly to rotate; S2: After the excavation of the annular guide tunnel is completed, the telescopic assembly and the driving assembly of the annular cutterhead shield machine are closed; S3: opening a blasthole on the unexcavated tunnel face and installing a charge in the blasthole; S4: starting the telescopic assembly, which drives the cutterhead assembly to move upward, so that the cutterhead assembly retreats to the tunnel face; S5: detonating the explosive roll and removing rock slag generated after the explosive roll is exploded; S6: Repeat steps S1 to S5 to excavate the next tunnel face until the excavation of the shaft is completed.

[0006] The driving assembly comprises a reaction frame, a planetary motor and a gear. A plurality of the planetary motors are arranged along the circumference of the reaction frame, and a gear is arranged on the planetary motor shaft of the planetary motor.

[0007] The reaction frame is composed of a fan-shaped support plate, a reaction plate, a radial rib plate and an arc-shaped rib plate. The reaction plate is annular, and a plurality of fan-shaped support plates are arranged along the circumference of the reaction plate. The radial rib plates and the arc-shaped rib plates are arranged along the radial direction and the arc direction of the fan-shaped support plate respectively.

[0008] The telescopic assembly includes a hydraulic cylinder, a base and a ring gear. The ring gear and the hydraulic cylinder are respectively arranged on the upper and lower sides of the base. The ring gear is meshed with the gear of the driving assembly. The hydraulic cylinders are arranged in multiple groups along the circumference of the base and installed in a protective telescopic tube. The base of the hydraulic cylinder is fixed on the base, and the telescopic rod is connected to the cutter disc assembly. A spiral slag discharge wall and a protective cover are sequentially arranged on the lower side of the base from the inside to the outside.

[0009] The cutter disc assembly includes an arc-shaped block cutter disc, a roller cutter and a scraper. The arc-shaped block cutter disc is provided with multiple ones along the circumferential direction, and a slag inlet is formed between adjacent arc-shaped block cutter discs. A group of scrapers is provided on each of the arc-shaped two sides of the arc-shaped block cutter disc, and a group of roller cutters is provided in the middle of the arc-shaped block cutter disc.

[0010] The advantages of the present invention are: (1) First, during the excavation of the hard rock shaft, the annular cutter shield forms an annular guide tunnel to provide a pre-crack surface and increase the blasting free surface for the drilling and blasting excavation of the large-diameter hard rock shaft. Then, the drilling and blasting method is used in the core hard rock face rock mass. This not only achieves precise control to eliminate over-excavation and under-excavation, but also reduces the number of blasting cartridges and saves costs. (2) Shield tunneling is highly safe, but there are problems with severe wear of cutters in hard rock formations and high maintenance costs. The drilling and blasting method is low-cost but less safe. Combining the advantages and disadvantages of the shield method and the drilling and blasting method, only annular cutters are used to form the pre-splitting surface of the shaft and increase the blasting free surface, which reduces the number of cutters and the length of time they are used, reduces cutter wear, and saves costs. (3) Using a ring-shaped cutterhead shield machine to construct a vertical shaft can form a temporary support around the shaft wall to ensure the safety of the shaft construction; (4) The spiral slag discharge wall can utilize the rotation of the spiral structure to discharge the slag from the annular guide tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the annular cutterhead shield machine of the present invention; Figure 2 for Figure 1 AA section view; Figure 3 for Figure 1 BB cross-section diagram; Figure 4 for Figure 1 CC profile of ; Figure 5 for Figure 1 DD profile diagram; Figure 6 for Figure 1 EE profile of Figure 7 It is a schematic diagram of the construction process of the present invention; Figure 8 for Figure 7 FF cross-section diagram in; Fig. 9 for Figure 7 GG profile in; like Figures 1 to 9 As shown, the marks in the figure represent respectively: 1. Annular cutterhead shield machine, 2. Hard rock formation, 3. Vertical shaft, 4. Blast hole, 5. Charge roll; 11. Cutter head assembly, 12. Telescopic assembly, 13. Driving assembly, 14. Shield; 111. arc block cutter disc, 112. roller cutter, 113. scraper, 114. slag inlet; 121. hydraulic cylinder, 122. telescopic rod, 123. protective telescopic tube, 124. base, 125. ring gear, 126. spiral slag discharge wall, 127. protective cover; 131. reaction frame, 132. planetary motor, 133. planetary motor shaft, 134. gear; 1311. Fan-shaped support plate, 1312. Reaction plate, 1313. Radial rib plate, 1314. Arc-shaped rib plate.

[0012] 21. Palm face, 22. Annular guide tunnel. DETAILED DESCRIPTION

[0013] The features of the present invention and other related features are further described in detail below through embodiments in conjunction with the accompanying drawings to facilitate understanding by those skilled in the art: Example: Figures 1 to 9 As shown, this embodiment specifically relates to a method for tunneling in a hard rock formation shaft by an annular shield and core blasting step by step, and the tunneling method mainly includes the following steps: S1: using an annular cutterhead shield machine 1 to excavate an annular guide tunnel 22 on the tunnel face 21 of the hard rock stratum 2 in the shaft 1.

[0014] Among them, Figures 1 to 6 As shown, the annular cutterhead shield machine 1 includes a cutterhead assembly 11, a telescopic assembly 12, a drive assembly 13 and a shield 14. The drive assembly 13 is arranged in the shield 14, and the telescopic assembly 12 is installed on the drive assembly 13 and connected to the cutterhead assembly 11.

[0015] The cutter disc assembly 11 includes an arc block cutter disc 111, a roller cutter 112 and a scraper 113. There are 6 arc block cutter discs 111 arranged along the circumferential direction. A slag inlet 114 is formed between adjacent arc block cutter discs 111. A group of scrapers 113 are respectively arranged on both sides of the arc direction of the arc block cutter disc 111. A group of roller cutters 112 is arranged in the middle of the arc block cutter disc 111. The roller cutters 112 and the scraper 113 are used for excavating the hard rock formation 2 to form slag, and the slag can enter the telescopic assembly 12 from the slag inlet 114.

[0016] The telescopic assembly 12 includes a hydraulic cylinder 121, a base 124 and a ring gear 125. The base 124 is annular. The ring gear 125 and the hydraulic cylinder 121 are respectively arranged on the upper side and the lower side of the base 124. Six groups of hydraulic cylinders 121 are arranged along the circumference of the base 124 and installed in the protective telescopic tube 123. Each group of hydraulic cylinders 121 includes two hydraulic cylinders 121. The two ends of the protective telescopic tube 123 are respectively connected to the arc block cutter disc 111 and the base 124 to protect the hydraulic cylinder 121. The base of the hydraulic cylinder 121 is fixed on the base 124, and the telescopic rod 122 is connected to the arc block cutter disc 111. The hydraulic cylinder 121 drives the cutter disc assembly 11 to move up and down through the telescopic rod 122. A spiral slag discharge wall 126 and a protective cover 127 are sequentially arranged on the lower side of the base 124 from the inside to the outside. The protective cover 127 plays a protective role. The spiral structure of the spiral slag discharge wall 126 facilitates the discharge of rock slag from the annular guide hole 22.

[0017] The driving assembly 13 includes a reaction frame 131, a planetary motor 132 and a gear 134. There are 6 planetary motors 132 arranged circumferentially along the reaction frame 131. A gear 134 is provided on the planetary motor shaft 133 of the planetary motor 132. The gear 134 of the driving assembly 13 is meshed with the ring gear 125 of the telescopic assembly 12. The planetary motor 132 drives the gear 134 to rotate to drive the ring gear 125 to rotate, thereby rotating the telescopic assembly 12, and then realizing the rotation of the cutter disc assembly 11. The reaction frame 131 is composed of a fan-shaped support plate 1311, a reaction plate 1312, radial ribs 1313 and arc-shaped ribs 1314. The reaction plate 131 is annular. There are 6 fan-shaped support plates 1311 arranged along the circumference of the reaction plate 1312, that is, 6 planetary motors 132 are respectively installed on 6 fan-shaped support plates 1311, and the radial ends of the fan-shaped support plate 1311 are respectively connected to the reaction plate 1312 and the shield 14. The radial ribs 1313 and the arc-shaped ribs 1314 are respectively arranged along the radial direction and arc direction of the fan-shaped support plate 1311, so as to strengthen the fan-shaped support plate 1311.

[0018] When the annular cutterhead shield machine 1 is located on the tunnel face 21, the telescopic rod 122 of the telescopic assembly 12 is in the minimum stroke state, the hydraulic cylinder 121 of the telescopic assembly 12 and the planetary motor 132 of the drive assembly 13 are started, the hydraulic cylinder 121 of the telescopic assembly 12 drives the cutterhead assembly 11 to move downward, and the planetary motor 132 of the drive assembly 13 drives the telescopic assembly 12 (cutterhead assembly 11) to rotate.

[0019] S2: After the excavation of the annular guide hole 22 is completed, the telescopic rod 122 of the telescopic assembly 12 is in the maximum stroke state, and the hydraulic cylinder 121 of the telescopic assembly 12 and the planetary motor 132 of the driving assembly 13 are turned off.

[0020] S3: A blast hole 4 is opened on the unexcavated tunnel face 21 , and a charge roll 5 is installed in the blast hole 4 .

[0021] The blast holes 4 are arranged along the circumferential direction and radial direction of the unexcavated tunnel face 21 .

[0022] S4: starting the hydraulic cylinder 121 of the telescopic assembly 12, which drives the cutterhead assembly 11 to move upward, so that the cutterhead assembly 11 retreats to the tunnel face 21. At this time, the telescopic rod 122 of the telescopic assembly 12 is in a minimum stroke state.

[0023] S5: Detonating the explosive roll 5 and removing the rock slag produced after the explosive roll 5 is blasted.

[0024] S6: Repeat steps S1 to S5 to excavate the next tunnel face 21 until the excavation of the shaft 3 is completed.

[0025] The beneficial effects of this embodiment are: (1) First, during the excavation of the hard rock shaft, the annular cutter shield forms an annular guide tunnel to provide a pre-crack surface and increase the blasting free surface for the drilling and blasting excavation of the large-diameter hard rock shaft. Then, the drilling and blasting method is used in the core hard rock face rock mass. This not only achieves precise control to eliminate over-excavation and under-excavation, but also reduces the number of blasting cartridges and saves costs. (2) Shield tunneling is highly safe, but there are problems with severe wear of cutters in hard rock formations and high maintenance costs. The drilling and blasting method is low-cost but less safe. Combining the advantages and disadvantages of the shield method and the drilling and blasting method, only annular cutters are used to form the pre-splitting surface of the shaft and increase the blasting free surface, which reduces the number of cutters and the length of time they are used, reduces cutter wear, and saves costs. (3) Using a ring-shaped cutterhead shield machine to construct a vertical shaft can form a temporary support around the shaft wall to ensure the safety of the shaft construction; (4) The spiral slag discharge wall can utilize the rotation of the spiral structure to discharge the slag from the annular guide tunnel.

[0026] Although the above embodiments have described in detail the concepts and embodiments of the present invention with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and changes can still be made to the present invention without departing from the scope of the claims, so they are not described one by one here.

Claims

1. A method for step-by-step excavation of a shaft in a hard rock formation by an annular shield and core blasting, characterized in that The excavation method comprises the following steps: S1: Use an annular cutterhead shield machine to excavate an annular pilot tunnel on the tunnel face of the hard rock formation in the shaft; The annular cutterhead shield machine comprises a cutterhead assembly, a telescopic assembly, a drive assembly and a shield, wherein the drive assembly is arranged in the shield, and the telescopic assembly is mounted on the drive assembly and connected to the cutterhead assembly; the telescopic assembly and the drive assembly are started, the telescopic assembly drives the cutterhead assembly to move downward, and the drive assembly drives the telescopic assembly to rotate; S2: After the excavation of the annular guide tunnel is completed, the telescopic assembly and the driving assembly of the annular cutterhead shield machine are closed; S3: opening a blasthole on the unexcavated tunnel face and installing a charge in the blasthole; S4: starting the telescopic assembly, which drives the cutterhead assembly to move upward, so that the cutterhead assembly retreats to the tunnel face; S5: detonating the explosive roll and removing rock slag generated after the explosive roll is exploded; S6: Repeat steps S1 to S5 to excavate the next tunnel face until the excavation of the shaft is completed.

2. A method for step-by-step excavation of a vertical shaft in a hard rock formation by an annular shield and core blasting according to claim 1, characterized in that The driving assembly comprises a reaction frame, a planetary motor and a gear. A plurality of the planetary motors are arranged along the circumference of the reaction frame, and a gear is arranged on the planetary motor shaft of the planetary motor.

3. A method for step-by-step excavation of a vertical shaft in a hard rock formation by an annular shield and core blasting according to claim 2, characterized in that The reaction frame is composed of a fan-shaped support plate, a reaction plate, a radial rib plate and an arc-shaped rib plate. The reaction plate is annular, and a plurality of fan-shaped support plates are arranged along the circumference of the reaction plate. The radial rib plates and the arc-shaped rib plates are arranged along the radial direction and the arc direction of the fan-shaped support plate respectively.

4. A method for step-by-step excavation of a vertical shaft in a hard rock formation by an annular shield and core blasting according to claim 2, characterized in that The telescopic assembly includes a hydraulic cylinder, a base and a ring gear. The ring gear and the hydraulic cylinder are respectively arranged on the upper and lower sides of the base. The ring gear is meshed with the gear of the driving assembly. The hydraulic cylinders are arranged in multiple groups along the circumference of the base and installed in a protective telescopic tube. The base of the hydraulic cylinder is fixed on the base, and the telescopic rod is connected to the cutter disc assembly. A spiral slag discharge wall and a protective cover are sequentially arranged on the lower side of the base from the inside to the outside.

5. The method for step-by-step excavation of a vertical shaft in a hard rock formation by an annular shield and core blasting according to claim 2, characterized in that The cutter disc assembly includes an arc-shaped block cutter disc, a roller cutter and a scraper. The arc-shaped block cutter disc is provided with multiple ones along the circumferential direction, and a slag inlet is formed between adjacent arc-shaped block cutter discs. A group of scrapers is provided on each of the arc-shaped two sides of the arc-shaped block cutter disc, and a group of roller cutters is provided in the middle of the arc-shaped block cutter disc.

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