CN116558383A - Tunnel rock burst prevention and control method and system - Google Patents
Tunnel rock burst prevention and control method and system Download PDFInfo
- Publication number
- CN116558383A CN116558383A CN202310493201.9A CN202310493201A CN116558383A CN 116558383 A CN116558383 A CN 116558383A CN 202310493201 A CN202310493201 A CN 202310493201A CN 116558383 A CN116558383 A CN 116558383A
- Authority
- CN
- China
- Prior art keywords
- tunnel
- kerf
- slits
- kerfs
- cutting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000011435 rock Substances 0.000 title claims abstract description 162
- 238000000034 method Methods 0.000 title claims abstract description 54
- 230000002265 prevention Effects 0.000 title claims description 32
- 238000005520 cutting process Methods 0.000 claims abstract description 84
- 239000000945 filler Substances 0.000 claims description 21
- 230000008569 process Effects 0.000 claims description 10
- 210000001624 hip Anatomy 0.000 claims description 8
- 238000004381 surface treatment Methods 0.000 claims description 3
- 230000005641 tunneling Effects 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 15
- 230000008093 supporting effect Effects 0.000 abstract description 13
- 238000006073 displacement reaction Methods 0.000 abstract description 4
- 229910000831 Steel Inorganic materials 0.000 description 39
- 239000010959 steel Substances 0.000 description 39
- 238000005422 blasting Methods 0.000 description 14
- 238000010276 construction Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 5
- 238000005336 cracking Methods 0.000 description 4
- 238000005553 drilling Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 238000009412 basement excavation Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 238000009826 distribution Methods 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 230000002706 hydrostatic effect Effects 0.000 description 2
- 230000005764 inhibitory process Effects 0.000 description 2
- 238000005065 mining Methods 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000004323 axial length Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009933 burial Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000011378 shotcrete Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 208000008918 voyeurism Diseases 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D5/00—Safety arrangements
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D3/00—Particular applications of blasting techniques
- F42D3/04—Particular applications of blasting techniques for rock blasting
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
Abstract
The invention provides a method and a system for preventing and controlling tunnel rock burst, and relates to the technical field of geotechnical engineering; determining the size of the kerf according to the number of kerfs and the ground stress of the tunnel; and controlling the cutting equipment to cut on the inner wall of the tunnel along the axial direction of the tunnel to form the kerfs according to the size, the position and the number of the kerfs. The surrounding rock around the tunnel is cut by using the mechanized cutting equipment, so that the surrounding rock is quickly and timely cut, the generated vibration is small, and the inside of the surrounding rock is not damaged; the kerf enables the rock which is originally deformed and is mutually extruded to generate rock burst to obtain a displacement space, the surrounding rock can close the kerf after the surrounding rock is released or most of the stress is released, the surrounding rock on two sides of the kerf generates mutual supporting force to form a complete and closed self-supporting layer, and a good tangential pressure relief effect is generated.
Description
Technical Field
The invention relates to the technical field of geotechnical engineering, in particular to a tunnel rock burst prevention and control method and system.
Background
The deep-buried hard-rock tunnel is widely distributed in the fields of water conservancy and hydropower, traffic, mining engineering, nuclear waste disposal and the like. Under high ground stress, hard and brittle rock masses typically develop a rock burst by rapidly releasing strain energy through brittle fracture. The rock burst brings a plurality of adverse factors to roadway construction, support, later maintenance and the like in deep hard rock mining, can also cause casualties, equipment damage and construction period delay, and provides a great challenge for safe and efficient construction of deep hard rock tunnels and galleries. In order to ensure the construction safety and smoothness, active prevention and control measures are adopted to reduce the occurrence probability and the rock burst intensity level of the rock burst in the deep-buried tunnel to the rock burst section, so that the construction safety of the rock burst section is ensured.
At present, according to different mechanisms, active rock burst prevention and control measures are mainly divided into three basic types: 1) Increasing radial supporting stress of the tunnel; the common methods are shotcrete and laying of prestressed anchors. 2) Improving the mechanical properties of surrounding rock; the common methods are to strictly control the blasting dosage, soften surrounding rock by water injection, lay anchor rods, grouting the surrounding rock and the like. 3) The tangential stress distribution state is improved; the common method is surrounding rock medium-deep hole blasting and shallow hole blasting pressure relief.
Among the above methods, the more common method is blasting pressure relief, but blasting pressure relief still has some defects. For example, after single-cycle blasting is carried out into a ruler, quick pressure relief is needed to inhibit surrounding rock from plate cracking, a blasting method is adopted to form a pressure relief seam, a row of blast holes are needed to be arranged in a tunnel, the drilling engineering quantity is large, time is relatively long, and the timeliness requirement of pressure relief is difficult to meet; in addition, during blasting, although the aim of pressure relief is achieved, dynamic load damage is caused to surrounding rock, so that the strength of the surrounding rock is weakened, the rock mass self-resistance to rock burst is reduced, and the rock burst prevention and control are not facilitated.
Disclosure of Invention
The invention aims to solve the problems that the existing blasting is poor in pressure relief timeliness, the strength of surrounding rock can be weakened, the rock mass self-resistance capability of rock burst is reduced, and the rock burst prevention and control are not facilitated.
In order to solve the problems, in one aspect, the present invention provides a method for preventing and controlling rock burst of a tunnel, comprising:
determining positions and the number of kerfs arranged on the inner wall of the tunnel according to the arc length of the arch of the tunnel;
determining the size of the kerf according to the number of the kerfs and the ground stress of the tunnel;
and controlling a cutting device to cut on the inner wall of the tunnel along the axial direction of the tunnel to form the kerfs according to the size, the position and the number of the kerfs.
Optionally, the determining the positions and the number of the slits arranged on the inner wall of the tunnel according to the arc length of the arch of the tunnel comprises:
setting the distance between two adjacent slits according to the arc length of the tunnel arch;
and determining the number and the positions of the slits according to the intervals among the slits and the arc length.
Optionally, determining the size of the kerf according to the number of kerfs and the ground stress of the tunnel includes:
analyzing the strain generated by surrounding rocks of the tunnel according to the relation between the ground stress and the stress strain of the tunnel;
determining the width of the kerf according to the strain and the distance between two adjacent kerfs;
and determining the length and the depth of the kerf according to the length of the single-cycle footage of the tunnel.
Optionally, determining the width of the kerf according to the strain and the spacing between two adjacent kerfs comprises:
a is less than or equal to epsilon delta L, wherein a is the width of the kerf, epsilon is the strain, and delta L is the spacing between the kerfs.
Optionally, the determining the length and depth of the kerf according to the length of the single-cycle footage of the tunnel comprises:
g is less than or equal to L2, wherein g is the length of the cutting seam, and L2 is the length of the single-cycle footage of the tunnel;
b is more than or equal to 0.5m and less than or equal to 2m, wherein b is the depth of the cutting seam.
Optionally, controlling the cutting device to cut the slits on the inner wall of the tunnel along the axial direction of the tunnel according to the size, the position and the number of the slits comprises:
and controlling the cutting equipment to cut and form the kerfs on the inner wall of the tunnel along the axial direction of the tunnel according to the set cutting sequence of the kerfs and the yield of the kerfs according to the size, the position and the number of the kerfs.
Optionally, the cutting sequence of the kerf comprises:
when the number of the slits is even, alternately cutting the waists on the left and right sides of the tunnel, and forming a plurality of slits which are bilaterally symmetrical with the center line of the tunnel on the tunneling surface of the tunnel;
when the number of the slits is an odd number, firstly cutting a slit on the vault of the tunnel, and then alternately cutting the arches on the left side and the right side of the tunnel.
Optionally, the slit comprises a yield comprising:
the length direction of the kerf is parallel to the hole axis of the tunnel, the dip angle of the kerf changes along with the position of the kerf, and the dip direction of the kerf is perpendicular to the digging interface of the tunnel at the position of the kerf.
Optionally, after the cutting equipment is controlled to cut on the inner wall of the tunnel along the axial direction of the tunnel to form the kerf according to the size, the position and the number of the kerfs, the tunnel rock burst prevention and control method further comprises:
and controlling the cutting equipment to process the kerf at the kerf opening so as to enlarge the width of the kerf opening of the kerf.
Optionally, after the size of the kerf is determined according to the number of kerfs and the ground stress of the tunnel, the tunnel rock burst prevention and control method further comprises:
and selecting a filler of the kerf according to the size of the kerf, wherein the filler is used for being placed in the kerf, and the rigidity of the filler is larger than the rigidity of rock around the tunnel.
Optionally, before the fixing the filler in each of the slits, the tunnel rock burst prevention and control method further includes:
a surface treatment device is controlled to treat the surface of the filler to increase the surface friction coefficient of the filler.
In another aspect, the present invention further provides a tunnel rock burst prevention and control system, including:
the analysis module is used for determining the positions and the number of the kerfs arranged on the inner wall of the tunnel according to the arc length of the arch of the tunnel; the device is also used for determining the size of the kerf according to the number of the kerfs and the ground stress of the tunnel;
the control module is used for controlling cutting equipment to cut on the inner wall of the tunnel along the axial direction of the tunnel to form the kerfs according to the size, the position and the number of the kerfs;
the cutting device is used for cutting the rock to construct the kerf.
Compared with the prior art, the invention has the following beneficial effects:
according to the tunnel rock burst prevention and control method and system provided by the invention, the number and the positions of the cutting slits are obtained through analysis according to the arc length of the arch of the tunnel, and further, the proper size of the cutting slits is determined according to the ground stress of the tunnel, so that rock burst generated by mutual extrusion after original deformation can obtain a displacement space, after the surrounding rock is released or most of ground stress is released, the surrounding rock can close the cutting slits, the surrounding rock on two sides of the cutting slits generates mutual supporting force to form a complete and closed self-supporting layer, a good tangential pressure relief effect is generated, the stability of the surrounding rock is enhanced, the surrounding rock around the tunnel is prevented from being cut by using mechanical cutting equipment, the generated vibration is small in time, and the inside of the surrounding rock is not damaged.
Drawings
FIG. 1 shows a schematic flow chart of a tunnel rock burst prevention and control method in an embodiment of the invention;
FIG. 2 shows a schematic cross-sectional view of a tunnel perpendicular to a tunnel axis in an embodiment of the invention;
FIG. 3 shows a schematic view of a tunnel cross-section kerf location in an embodiment of the present invention;
FIG. 4 shows a uniaxial loading stress strain curve of a tunnel surrounding rock in an embodiment of the invention;
FIG. 5 shows a schematic view of the surface of a steel sheet with a surface rolled pattern in an embodiment of the invention;
fig. 6 shows a schematic view of an arch-shaped load bearing area in an embodiment of the invention.
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
It is noted that the terms "first," "second," and the like in the description and claims of the invention and in the foregoing figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein.
In the description of the present specification, the descriptions of the terms "embodiment," "one embodiment," and the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or embodiment is included in at least one embodiment or illustrated embodiment of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same examples or implementations. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or implementations.
The tunnel excavation is similar to taking out the rock pillar from the bottom depths, and after the rock pillar is taken out, the supporting effect of the rock pillar to the peripheral rock of tunnel originally disappears, and when the radial stress of tunnel reduces, tangential stress increases, and tangential stress increases and is the main reason that causes surrounding rock plate to crack, and then the rock burst takes place, and tangential stress can not only reduce, otherwise the surrounding rock is difficult to stabilize.
Fig. 1 shows a schematic flow chart of a tunnel rock burst prevention and control method in an embodiment of the invention, which includes:
s1: determining positions and the number of kerfs arranged on the inner wall of the tunnel according to the arc length of the arch of the tunnel;
specifically, facing the tunnel face, as shown in fig. 2 and 3, numbering the slits from the left arch (arch to arch range) of the tunnel, wherein the first slit at the left arch is denoted as 1# slit, and the slit on the right arch at the symmetrical position of the tunnel center line is denoted as 2# slit; then in a clockwise direction, the slits adjacent to the slits # 1 are marked as slits # 3, the slits on the right side arch at the symmetrical positions of slits # 3 are marked as slits # 5, and so on until the last slit is numbered. The arc length from the 1# kerf to the arch springing is L1,0< L1< L, wherein L is the arc length of the arch waist at one side of the tunnel, and the distance between every two adjacent kerfs is equal and is delta L; the joint cutting distance delta L is larger than the joint cutting depth b and smaller than 2 times of the joint cutting length g, the total arc length of the tunnel can be calculated according to the arc length of the arch, and then the number and the positions of the joint cutting can be obtained according to the arc length L1 from the joint cutting to the arch springing and the joint cutting distance delta L.
In the embodiment, a certain railway tunnel is taken as a lancing pressure relief object, the maximum main stress of the railway tunnel is in the horizontal direction, the burial depth is 2000m, the vertical ground stress and the horizontal ground stress are both similar to be 50MPa, the side pressure coefficient is close to 1, and the schematic cross section of the tunnel perpendicular to the direction of the tunnel axis is shown in fig. 2. The arc line from the arch foot to the vault is a arch waist, which is divided into the left side and the right side, L=15m respectively, and the total length is 30m. For the present tunnel, the number of slits may be set to 5.
S2: determining the size of the kerf according to the number of the kerfs and the ground stress of the tunnel;
specifically, after the tunnel completes single-cycle blasting, surrounding rocks are destroyed, radial stress is reduced, and under the action of gravity and ground stress generated by the influence of environmental factors, the shear stress of surrounding rocks around the tunnel is increased, so that the instability of the tunnel is increased, and the possibility of rock blasting is increased when the pressure release treatment is not carried out on the tunnel. The surrounding rock is deformed due to the ground stress, the deformation is mutually gathered to generate extrusion, rock burst is generated when energy is accumulated to a certain extent, and the kerf enables rock which is originally deformed and mutually extruded to generate rock burst to obtain a displacement space, so that the dimension of the kerf needs to be calculated, the surrounding rock at the kerf can close the kerf after the surrounding rock is released or most of ground stress is released, the surrounding rock at two sides of the kerf can also generate mutual supporting force to form a complete and closed self-supporting layer, and a better tangential pressure relief effect is generated.
S3: and controlling a cutting device to cut on the inner wall of the tunnel along the axial direction of the tunnel to form the kerfs according to the size, the position and the number of the kerfs.
Specifically, after the tunnel completes single-cycle blasting and risk is removed, lancing and pressure relief are performed immediately, and lancing and pressure relief are performed in a short time by adopting mechanized cutter equipment. The annular crack is prevented from being generated excessively in the stress adjustment process of the surrounding rock due to the fact that the kerf time is too late. If the condition is met, the advanced hydraulic support can be adopted for supporting.
In this embodiment, according to the arc length of the tunnel arch, the number and the position of the slits are obtained by analysis, and further according to the ground stress of the tunnel, the appropriate size of the slits is determined, so that the slits can enable rocks which should be mutually extruded to generate rock burst after original deformation to obtain a displacement space, and after the surrounding rocks are released or most of the ground stress is released, the surrounding rocks at two sides of the slits can be closed to generate mutual supporting force, so that a complete and closed self-supporting layer is formed, a good tangential pressure relief effect is generated, stability of the surrounding rocks is enhanced, rock burst is avoided, the surrounding rocks around the tunnel are cut rapidly and timely by using mechanized cutting equipment, generated vibration is small, and damage to the inside of the surrounding rocks is avoided.
In one embodiment of the present invention, the determining the positions and the number of slits provided on the inner wall of the tunnel according to the arc length of the arch of the tunnel includes:
setting the distance between two adjacent slits according to the arc length of the tunnel arch;
and determining the number and the positions of the slits according to the intervals among the slits and the arc length.
Specifically, firstly, setting a reasonable interval and number according to the arc length of the arch, wherein the number of the slits is n, when the arch length of the arch is longer, the interval between two slits can be properly increased or the number of the slits can be increased, in order to ensure the uniformity of the slit distribution, the interval between two adjacent slits is basically kept consistent, but sometimes the condition of the tunnel rock wall is special, for example, the cutting is difficult or the cutting position is provided with cracks, and the position of the original slits can be finely adjusted, so that the cutting work is smoothly carried out. Illustratively, for some railway tunnel in southwest, the arc length from 1# kerf to the footing is l1=5m; and the right side of the tunnel is arched to cut a No. 2 kerf, and the No. 2 kerf and the No. 1 kerf are symmetrical about the central line of the tunnel. The pitch between every two adjacent slits is equal and Δl=5m. Other slits and numbers are shown in fig. 3.
In one embodiment of the present invention, the determining the size of the kerf according to the number of kerfs and the ground stress of the tunnel comprises:
analyzing the strain generated by surrounding rocks of the tunnel according to the relation between the ground stress and the stress strain of the tunnel;
specifically, assuming that the deep-buried tunnel is under a hydrostatic pressure state, both vertical and horizontal ground stresses are σmpa. According to Ji Erxi solution, the tangential stress of the periphery of the tunnel is maximally 2σMPa. And obtaining the strain epsilon generated by the surrounding rock when the stress is 2 sigma MPa from the stress strain curve of the surrounding rock uniaxial loading process. Illustratively, assuming that the deep buried tunnel is under hydrostatic pressure, the vertical and horizontal ground stresses are both 50MPa. According to Ji Erxi solution, the tangential stress at the periphery of the tunnel is 100MPa at most. Fig. 4 is a stress-strain curve of a uniaxial loading process of a surrounding rock, wherein the abscissa represents strain and the ordinate represents stress. From fig. 4, it is obtained that the strain generated by the surrounding rock becomes epsilon=0.15% when the stress is 100MPa.
Determining the width of the kerf according to the strain and the distance between two adjacent kerfs;
and determining the length and the depth of the kerf according to the length of the single-cycle footage of the tunnel.
Specifically, as shown in fig. 3, the slit is rectangular in a tunnel cross-sectional view. The slit dimensions mainly include width a (tangential length), depth b (radial length) and length g (axial length). In practice, the magnitude of the width a may be estimated using the following method.
In this embodiment, the determining the width of the kerf according to the strain and the spacing between two adjacent kerfs includes:
a is less than or equal to epsilon delta L, wherein a is the width of the kerf, epsilon is the strain, and delta L is the spacing between the kerfs.
Specifically, when the distance between two adjacent slits is Δl, then all of the surrounding rock in the range of Δl/2 on one side of the slit and the surrounding rock in the range of Δl/2 on the other side of the slit are relieved, and the required slit width is a=εΔl. After the kerf is relieved, the kerf is closed in the automatic adjustment process of the stress of the surrounding rock, and the surrounding rock within the depth range of the kerf still bears partial pressure. In practical applications, a=εΔL may be first taken.
Illustratively, when the distance between two adjacent slits is Δl=5m, then the surrounding rock in the range of Δl/2 on one side of the slit and the surrounding rock in the range of Δl/2 on the other side of the slit are all relieved, and the required slit width is a=εΔl=7.5 mm. Thus, after the kerf is depressurized, the surrounding rock in the kerf range still bears partial pressure. Likewise, the number n of slits cannot be too large, otherwise, the slits are difficult to be closed, and the number n of slits is set to be 5, so that the constraint condition is met:
in this embodiment, the determining the length and depth of the kerf according to the length of the single-cycle footage of the tunnel includes:
g is less than or equal to L2, wherein g is the length of the cutting seam, and L2 is the length of the single-cycle footage of the tunnel;
b is more than or equal to 0.5m and less than or equal to 2m, wherein b is the depth of the kerf.
Specifically, the lancing depth is b, and the range suggested by b is 0.5 m-2 m. If the thickness of the arch bearing structure is too small, the radial thickness of the arch bearing structure is thinner, and better bearing effect is difficult to play; if the pressure is too large, construction is difficult, and the timeliness requirement of joint cutting pressure relief is difficult to ensure. In addition, the lancing mode suggests to adopt a large-scale cutter with higher efficiency for mechanical cutting. The length g of the cutting seam is smaller than or equal to the length of the drilling and blasting method construction circulating footage. Typically the length of a single circulation feed is 3m. In addition, the kerf distance DeltaL is larger than the kerf depth b and smaller than 2 times of kerf length g, in the range, after the kerf is filled with the steel plate, the range of acting force generated by the steel plate on the rock is overlapped, and the integrity and supporting effect of the surrounding rock can be increased. In addition, the slit pitch Δl should not be too small, otherwise the amount of work required for cutting the slit and filling material is increased, and the time taken is increased.
In one embodiment of the invention, the controlling the cutting device to cut the slits on the inner wall of the tunnel along the axial direction of the tunnel according to the size, the position and the number of the slits comprises:
and controlling the cutting equipment to cut the slits on the inner wall of the tunnel along the axial direction of the tunnel according to the set cutting sequence of the slits and the yield of the slits according to the size of the slits. The slit shape includes trend, inclination and tendency. Vibration and surrounding rock internal stress change possibly caused by cutting are reduced to the minimum in the cutting process, the left and right deformation of the surrounding rock can be guaranteed to be basically consistent, more stress change caused by inconsistent left and right deformation is avoided, and instability of the surrounding rock is not aggravated.
In this embodiment, the cutting sequence of the kerf includes:
when the number of the slits is even, alternately cutting the waists on the left and right sides of the tunnel, and forming a plurality of slits which are bilaterally symmetrical with the center line of the tunnel on the tunneling surface of the tunnel;
when the number of the slits is an odd number, firstly cutting a slit on the vault of the tunnel, and then alternately cutting the arches on the left side and the right side of the tunnel.
For example, when five slits are cut, the sequence of firstly cutting the vault and then cutting the arch waist is carried out, and each slit is cut at the left arch waist, the slits are cut at corresponding positions of the right arch waist symmetrical to the central line of the tunnel at once. Therefore, due to the uniform deformation of the surrounding rock, the uniformity of stress release is ensured, the local stress concentration is restrained, the damage of the surrounding rock is reduced, the integrity of the surrounding rock is improved, and the method is not suitable for cutting all the seams of one side arch before cutting the seams of the other side arch. For example, in fig. 3, the time sequence of lancing is: 5# slit >1# slit >2# slit >3# slit >4# slit.
In this embodiment, the slit shape comprises:
the length direction of the kerf is parallel to the hole axis of the tunnel, the dip angle of the kerf changes along with the position of the kerf, and the dip direction of the kerf is perpendicular to the digging interface of the tunnel at the position of the kerf.
Specifically, each kerf runs parallel to the hole axis; the cutting angle changes along with the cutting position, for example, the cutting is vertical to the horizontal plane in a vault, the cutting angle is 90 degrees, and other cutting is vertical to the excavation interface of the position; the lancing tendency is all pointed by surrounding rock to the tunnel direction.
In one embodiment of the invention, after the cutting equipment is controlled to cut on the inner wall of the tunnel along the axial direction of the tunnel to form the kerf according to the size, the position and the number of the kerfs, the tunnel rock burst prevention and control method further comprises:
and controlling the cutting equipment to process the kerf at the kerf opening so as to enlarge the width of the kerf opening of the kerf.
Specifically, the joint seam is positioned at the intersection position of the joint seam and the excavation interface, and the joint seam is a rectangular joint seam before treatment. When the pressure relief deformation of the surrounding rock is completed, the stress concentration is most likely to occur at the joint cutting opening. In order to suppress stress concentration at the slit, it is subjected to a further dicing process. The cutting purpose is to cut the corners at two sides of the rectangular seam, convert the rectangular seam into a trapezoid seam, and reduce stress concentration. The width of the bottom of the trapezoid opening is c mm, the width of the top of the trapezoid opening is a mm, the depth of the trapezoid opening is d mm, c is not excessively large, and d is smaller than the lancing depth b within 100 mm. Illustratively, the width c=100 mm of the bottom of the trapezoidal orifice, the depth d=100 mm, c should not be too great, and it is recommended to be within 100 mm. The trapezoid slit formed after the slitting treatment is shown in figure 3.
In one embodiment of the invention, after the size of the kerf is determined according to the number of kerfs and the ground stress of the tunnel, the tunnel rock burst prevention and control method further includes:
and selecting a filler of the kerf according to the size of the kerf, wherein the filler is placed in the kerf.
Specifically, in order to increase the integrity of the surrounding rock in the lancing area, the lancing needs to be filled in time after the lancing is completed. The choice of filler is critical, such filler having a high tensile strength and a stiffness greater than the stiffness of the rock surrounding the tunnel. In general, a steel sheet with a thickness of e mm can meet this requirement, e >1mm. The surface treatment equipment is controlled to treat the surface of the filler, and rolling pattern treatment can be carried out on the surface of the steel plate so as to increase the surface friction coefficient of the filler, so that the end surface friction effect of the steel plate can be better exerted, and the tensile strength of surrounding rock is increased.
The condition to be satisfied by a can thus be further defined as: e is smaller than a and smaller than epsilon delta L, wherein e is the thickness of the filler, and the thickness of the steel plate used for filling the kerf is smaller than the width of the kerf, so that the requirements that a mm is larger than e and smaller than 1mm are met; the width of the steel plate is equal to the depth of the cutting seam; the length f of the steel plate is slightly smaller than the length L2 of the single-cycle footage. In addition, the larger the kerf length g is, the larger the length of the fillable steel plate is, the better the surrounding rock integrity in the action range of the steel plate is, and the better the supporting effect is. Sometimes, for convenience of filling, a small steel plate can be adopted, but the total length of the steel plate is still f, and the length of the steel plate can be less than 1m, so that the supporting effect of the steel plate on surrounding rock can be weakened.
Illustratively, the steel plate thickness is taken as e=2mm. In order to increase the surface friction coefficient of the steel plate, the surface of the steel plate is required to be provided with double-sided rolling patterns (see figure 5), the pattern protrusions are controlled within 0.5mm, the end face friction effect of the steel plate can be better exerted, and the tensile strength of surrounding rock is increased. The thickness of the steel plate filled with the kerfs is smaller than the width of the kerfs, and 1mm < e < a=7.5 mm is satisfied; the width of the steel plate is equal to the depth of the kerf minus d is 900mm; the length f=2900 mm of the steel plate is slightly smaller than the distance l2=3000 mm of single-cycle footage. Sometimes, for convenience of filling, small steel plates can be adopted, and the length of the steel plates is less than 1m, but the supporting effect of the steel plates on surrounding rocks is weakened.
The method for controlling the tunnel rock burst comprises the steps of selecting a filling material of the kerf according to the size of the kerf, wherein after the filling material is placed in the kerf, the method further comprises the following steps:
the filler is fixed in each of the slits.
Specifically, the filling time is selected, after cutting is completed, the width of the kerf is smaller and smaller in the surrounding rock pressure relief process, if filling is too late, the kerf is closed, and filling is difficult to complete. It is suggested that the steel plate is filled immediately after the cutting is completed. For some kerfs, the inclination angle is larger, and the steel plate slides downwards under the action of gravity after being filled, such as vault kerfs and the like. For such a slit, when the steel plate is filled, the filler is fixed in the slit, for example, a cementing agent which is quickly coagulated, such as 502, is smeared on the surface of the steel plate, so as to help the quick adhesion between the steel plate and the surface of the slit, prevent the steel plate from automatically falling off and injure workers by smashing.
In order to verify the implementation effect of the prevention and control method, a stress box can be buried in surrounding rocks around the tunnel before pressure relief lancing, the stress change before and after surrounding rock pressure relief is measured in real time, and the pressure relief effect is tested.
The pressure relief method can also form an arch bearing structure with the thickness of b in the surrounding rock in the kerf range, provide larger radial supporting stress for the inner surrounding rock, reduce the generation of cracking surfaces of the inner plate of the surrounding rock and increase the strength of the surrounding rock. The plate crack inhibition effect can be detected and compared through drilling coring or by adopting a drilling peeping instrument.
Ideally, the steel plate filled in the kerf can generate larger friction force after being pressed; if the kerf is too wide, after the pressure relief of the surrounding rock is completed, the kerf surface is not fully contacted and is extruded, and the friction effect of the steel plate is difficult to fully exert. And a steel plate drawing test method can be adopted to test whether the kerf width is proper, and the kerf parameters are further optimized or the steel plate matched with the kerf width after deformation is selected according to the result.
For the tunnel rock burst prevention and control method and system provided by the invention, firstly, the method adopts a mechanical cutting mode to construct the kerf, explosive is not used for blasting, the damage to the internal stress and stability of surrounding rock is reduced, the rock burst process of the surrounding rock is not aggravated, and the mechanical cutting speed is higher.
And secondly, the method can achieve better tangential pressure relief effect, obviously reduce tangential stress of surrounding rocks near the periphery of the tunnel, transfer the tangential stress to the depths of the surrounding rocks, and greatly reduce the energy released by rock burst.
The method can then also improve the mechanical properties of the surrounding rock. The steel plate is filled in the cutting joint, and as the rigidity of the steel plate is larger than the rigidity of the rock, the radial friction effect shown in figure 6 can be generated after the steel plate is pressed, which is equivalent to providing radial stress, the longer steel plate is filled in surrounding rock, the integration degree of the surrounding rock can be improved, the integrity of the surrounding rock is increased, an arch bearing area is formed around the tunnel, larger radial supporting stress is provided for deep surrounding rock, the occurrence of surrounding rock plate cracking and rock burst is restrained, and the tensile strength and stability of the surrounding rock can be effectively improved.
In conclusion, the method simultaneously obtains various effects of radial stress relief, improvement of surrounding rock mechanical properties, exertion of surrounding rock self-supporting function, inhibition of deep surrounding rock plate cracking and the like, and belongs to a comprehensive rock burst active prevention and control method.
In another embodiment of the present invention, there is also provided a tunnel rock burst prevention and control system, including:
the analysis module is used for determining the positions and the number of the kerfs arranged on the inner wall of the tunnel according to the arc length of the arch of the tunnel; the device is also used for determining the size of the kerf according to the number of the kerfs and the ground stress of the tunnel;
the control module is used for controlling cutting equipment to cut on the inner wall of the tunnel along the axial direction of the tunnel to form the kerfs according to the size, the position and the number of the kerfs;
the cutting device is used for cutting the rock to construct the kerf.
The tunnel rock burst prevention and control system in the embodiment of the invention has similar technical effects to the tunnel rock burst prevention and control method, and is not described in detail herein.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be assessed accordingly to that of the appended claims.
Claims (12)
1. The tunnel rock burst prevention and control method is characterized by comprising the following steps of:
determining positions and the number of kerfs arranged on the inner wall of the tunnel according to the arc length of the arch of the tunnel;
determining the size of the kerf according to the number of the kerfs and the ground stress of the tunnel;
and controlling a cutting device to cut on the inner wall of the tunnel along the axial direction of the tunnel to form the kerfs according to the size, the position and the number of the kerfs.
2. The tunnel rock burst prevention and control method according to claim 1, wherein the determining the positions and the number of slits provided on the inner wall of the tunnel according to the arc length of the arch of the tunnel comprises:
setting the distance between two adjacent slits according to the arc length of the tunnel arch;
and determining the number and the positions of the slits according to the intervals among the slits and the arc length.
3. The tunnel rock burst prevention and control method according to claim 2, wherein said determining the dimensions of the slits according to the number of slits and the ground stress of the tunnel comprises:
analyzing the strain generated by surrounding rocks of the tunnel according to the relation between the ground stress and the stress strain of the tunnel;
determining the width of the kerf according to the strain and the distance between two adjacent kerfs;
and determining the length and the depth of the kerf according to the length of the single-cycle footage of the tunnel.
4. A tunnel rock burst prevention and control method according to claim 3, wherein said determining the width of said slits in accordance with said strain and the spacing between adjacent two of said slits comprises:
a is less than or equal to epsilon delta L, wherein a is the width of the kerf, epsilon is the strain, and delta L is the spacing between the kerfs.
5. A tunnel rock burst prevention and control method according to claim 3, wherein said determining the length and depth of the kerf from the length of the single-cycle footage of the tunnel comprises:
g is less than or equal to L2, wherein g is the length of the cutting seam, and L2 is the length of the single-cycle footage of the tunnel;
b is more than or equal to 0.5m and less than or equal to 2m, wherein b is the depth of the cutting seam.
6. The tunnel rock burst prevention and control method according to claim 1, wherein controlling a cutting device to cut the slits on the inner wall of the tunnel in the tunnel axial direction according to the size, the position and the number of the slits includes:
and controlling the cutting equipment to cut and form the kerfs on the inner wall of the tunnel along the axial direction of the tunnel according to the set cutting sequence of the kerfs and the yield of the kerfs according to the size, the position and the number of the kerfs.
7. The tunnel rock burst prevention and control method according to claim 6, wherein the cutting sequence of the slits comprises:
when the number of the slits is even, alternately cutting the waists on the left and right sides of the tunnel, and forming a plurality of slits which are bilaterally symmetrical with the center line of the tunnel on the tunneling surface of the tunnel;
when the number of the slits is an odd number, firstly cutting a slit on the vault of the tunnel, and then alternately cutting the arches on the left side and the right side of the tunnel.
8. The tunnel rock burst prevention and control method according to claim 6, wherein the slitting shape comprises:
the length direction of the kerf is parallel to the hole axis of the tunnel, the dip angle of the kerf changes along with the position of the kerf, and the dip direction of the kerf is perpendicular to the digging interface of the tunnel at the position of the kerf.
9. The method for controlling rock burst of a tunnel according to any one of claims 1 to 8, wherein the controlling the cutting device to cut the inner wall of the tunnel in the axial direction of the tunnel to form the slits according to the size, the position and the number of the slits further comprises:
and controlling the cutting equipment to process the kerf at the kerf opening so as to enlarge the width of the kerf opening of the kerf.
10. The method for controlling rock burst in a tunnel according to any one of claims 1 to 8, wherein after determining the dimensions of the slits according to the number of slits and the ground stress of the tunnel, further comprising:
and selecting a filler of the kerf according to the size of the kerf, wherein the filler is used for being placed in the kerf, and the rigidity of the filler is larger than the rigidity of rock around the tunnel.
11. The tunnel rock burst prevention and control method of claim 10 wherein said securing said filler in each of said slits further comprises:
a surface treatment device is controlled to treat the surface of the filler to increase the surface friction coefficient of the filler.
12. The utility model provides a tunnel rock burst prevention and control system which characterized in that includes:
the analysis module is used for determining the positions and the number of the kerfs arranged on the inner wall of the tunnel according to the arc length of the arch of the tunnel; the device is also used for determining the size of the kerf according to the number of the kerfs and the ground stress of the tunnel;
the control module is used for controlling cutting equipment to cut on the inner wall of the tunnel along the axial direction of the tunnel to form the kerfs according to the size, the position and the number of the kerfs;
the cutting device is used for cutting the rock to construct the kerf.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310493201.9A CN116558383A (en) | 2023-04-28 | 2023-04-28 | Tunnel rock burst prevention and control method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310493201.9A CN116558383A (en) | 2023-04-28 | 2023-04-28 | Tunnel rock burst prevention and control method and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116558383A true CN116558383A (en) | 2023-08-08 |
Family
ID=87494016
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310493201.9A Pending CN116558383A (en) | 2023-04-28 | 2023-04-28 | Tunnel rock burst prevention and control method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116558383A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116973549A (en) * | 2023-09-20 | 2023-10-31 | 中铁四局集团有限公司 | Rock burst prediction method and system |
-
2023
- 2023-04-28 CN CN202310493201.9A patent/CN116558383A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116973549A (en) * | 2023-09-20 | 2023-10-31 | 中铁四局集团有限公司 | Rock burst prediction method and system |
| CN116973549B (en) * | 2023-09-20 | 2024-01-30 | 中铁四局集团有限公司 | Rock burst prediction method and system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112196596B (en) | Grouting anchor rod cable combination beam for advanced support of deep broken surrounding rock and support method | |
| Jin et al. | An in-tunnel grouting protection method for excavating twin tunnels beneath an existing tunnel | |
| CN104763432B (en) | A kind of method that high stress tunnel country rock release controls large deformation | |
| Xie et al. | Stability analysis of integral load-bearing structure of surrounding rock of gob-side entry retention with flexible concrete formwork | |
| CN110985058A (en) | Grouting reinforcement method for fault fracture zone of coal face | |
| CN110344861B (en) | Rapid construction method and structure of rock stratum ultra-large span underground engineering | |
| CN116558383A (en) | Tunnel rock burst prevention and control method and system | |
| CN109930609A (en) | A kind of campshed composite supporting construction and its construction method for upper-soft lower-hard ground | |
| CN105971630A (en) | Method for controlling caving of roof of short distance coal bed roadway | |
| CN110541710B (en) | V-level high-risk geological surrounding rock tunnel mechanized construction method | |
| CN109958454B (en) | Stope tunnel floor heave control system and control method thereof | |
| CN114086991A (en) | Supporting method for extremely-broken oversized-section roadway with high-altitude frozen soil layer | |
| CN116537784B (en) | Stabilization method for small coal pillar gob-side entry driving | |
| CN111577355A (en) | Extra-soft rock stratum tunnel interval secondary arch frame long anchor cable locking foot composite construction method | |
| CN208441868U (en) | A kind of liner structure of tunnel rock burst hole section | |
| CN114000896B (en) | Composite grouting reinforcement method for deep-section fracture surrounding rock | |
| CN115788533A (en) | Close-distance coal seam group strong dynamic pressure roadway cooperative control method | |
| CN212612517U (en) | Micro steel pipe pile composite supporting structure for deep foundation pit in limited space | |
| CN114165268A (en) | Grading coordination and reinforcement method for coal roadway tunneling broken surrounding rock | |
| Broms | Design and construction of anchored and strutted sheet pile walls in soft clay | |
| CN209855807U (en) | Mining roadway floor heave control system | |
| CN111379580A (en) | Tunnel primary support protection construction method | |
| CN112012769A (en) | Semi-rigid and semi-flexible anti-impact tunnel surrounding rock supporting structure under seismic belt and construction method thereof | |
| CN219412632U (en) | Layout structure for supporting rock pillar formed by simultaneous excavation of two adjacent projects | |
| CN109989404B (en) | Cement mixing pile wall foundation pit reinforcing construction method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |