CN109339797B - Extremely-small-clear-distance tunnel exit shock absorption construction method - Google Patents
Extremely-small-clear-distance tunnel exit shock absorption construction method Download PDFInfo
- Publication number
- CN109339797B CN109339797B CN201811027172.2A CN201811027172A CN109339797B CN 109339797 B CN109339797 B CN 109339797B CN 201811027172 A CN201811027172 A CN 201811027172A CN 109339797 B CN109339797 B CN 109339797B
- Authority
- CN
- China
- Prior art keywords
- tunnel
- excavating
- hole
- rock pillar
- pilot
- 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.)
- Active
Links
- 238000010276 construction Methods 0.000 title claims abstract description 68
- 238000010521 absorption reaction Methods 0.000 title claims abstract description 11
- 230000035939 shock Effects 0.000 title claims abstract description 11
- 239000011435 rock Substances 0.000 claims abstract description 71
- 238000005422 blasting Methods 0.000 claims abstract description 68
- 238000000034 method Methods 0.000 claims abstract description 53
- 238000009412 basement excavation Methods 0.000 claims abstract description 31
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 12
- 238000000465 moulding Methods 0.000 claims abstract description 5
- 238000005520 cutting process Methods 0.000 claims description 7
- 238000013016 damping Methods 0.000 claims description 6
- 239000007788 liquid Substances 0.000 claims description 5
- 239000004568 cement Substances 0.000 claims description 4
- 239000002002 slurry Substances 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 10
- 230000002787 reinforcement Effects 0.000 description 5
- 238000005474 detonation Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000005553 drilling Methods 0.000 description 3
- 239000011440 grout Substances 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 239000002360 explosive Substances 0.000 description 2
- 230000000977 initiatory effect Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
-
- 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
- E21D11/003—Linings or provisions thereon, specially adapted for traffic tunnels, e.g. with built-in cleaning devices
-
- 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
- E21D11/04—Lining with building materials
- E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
- E21D11/105—Transport or application of concrete specially adapted for the lining of tunnels or galleries ; Backfilling the space between main building element and the surrounding rock, e.g. with concrete
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/001—Improving soil or rock, e.g. by freezing; Injections
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/006—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries by making use of blasting methods
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/14—Layout of tunnels or galleries; Constructional features of tunnels or galleries, not otherwise provided for, e.g. portals, day-light attenuation at tunnel openings
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Geochemistry & Mineralogy (AREA)
- Structural Engineering (AREA)
- Environmental & Geological Engineering (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Soil Sciences (AREA)
- Lining And Supports For Tunnels (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
Abstract
The invention discloses a small clear distance tunnel exit shock absorption construction method, which comprises the following steps: excavating a pilot tunnel, enabling the pilot tunnel to be out of the tunnel, grouting and reinforcing a middle rock pillar of the pilot tunnel, and constructing a secondary lining of a tunnel opening section of the pilot tunnel by adopting a jump-driving method; excavating a rear tunnel, excavating an advance pilot tunnel at the rear tunnel, constructing an advance pilot tunnel primary support, expanding and excavating one side, close to a middle rock pillar, of an upper step of the rear tunnel by matching a double-row slit pipe presplitting blasting method with a mechanical cold excavation method, constructing an upper step primary support, dismantling the advance pilot tunnel primary support, excavating a lower step section of the rear tunnel, constructing a lower section primary support, an inverted arch and a filling layer, and integrally molding a secondary lining of the rear tunnel; and repeating the second step until the hole-exiting construction of the hole is completed. The construction method reduces the damage of blasting vibration to the middle rock pillar and the concrete lining, and solves the problem that the blasting construction of the existing construction method is easy to damage the middle rock pillar and the tunnel lining.
Description
Technical Field
The invention relates to the technical field of tunnel construction, in particular to a construction method suitable for small-clear-distance and extremely-small-clear-distance tunnel exit shock absorption.
Background
In the prior art, due to the consideration of the requirement of route planning and the limitation of terrain, a traffic route sometimes inevitably adopts a small clear distance tunnel. Especially, at the position where the bridge and the tunnel are connected, the tunnel is mostly a branched tunnel, namely, the tunnel gradually transits from a separated tunnel with small clear distance and extremely small clear distance. In the section of the tunnel portal with extremely small clear distance, the existing tunnel blasting construction method has the following defects: (1) the blasting of the backward tunnel can damage the lining of the forward tunnel and the middle rock wall; (2) when the excavation footage is too small or mechanical excavation is adopted, the construction period is long, and the cost is increased; (3) the traditional multi-arch tunnel form is adopted, so that the excavating and supporting quantity is large, the construction procedures are multiple, the structural stress is complex, the construction period is long, and the construction cost is high.
Patent application No. CN201210036640.9 discloses a method for excavating a backward tunnel of a tunnel with a small clear distance. Firstly, drilling damping holes in rows along one side close to the intermediate wall, deviating 1-2m from one side far away from the intermediate wall for slitting blasting and slag removal; then blasting and slag removing are carried out on the periphery of the backward hole; and finally, grouting and reinforcing the medium rock wall. The method has limited damping effect of the damping holes, and the controlled blasting can not reduce the influence of backward hole excavation on the deformation of surrounding rock of the forward hole.
Patent application No. CN201710434558.4 discloses a blasting control construction method for ultra-small clear distance tunnel. Firstly, measuring and positioning, then firstly carrying out left tunnel construction, excavating an upper guide of the detonation left tunnel, excavating a lower guide of the detonation left tunnel, insisting on pre-splitting by blasting the lower guide of the left tunnel, and drilling a pre-splitting hole along the side of the middle rock pillar; and blasting excavation of upper and lower guide of the right hole is carried out, two rows of blast holes are drilled from bottom to top along an excavation line on one side close to the middle rock pillar, the blast holes are divided into inner pre-splitting holes and outer pre-splitting holes, the outer pre-splitting holes are divided into three sections, the inner pre-splitting holes are divided into five sections, each hole is filled with powder, the initiation sequence is consistent with the upper guide of the left hole, and finally excavation and initiation are finished. The method can reduce the damage of blasting vibration to the middle rock pillar to a certain extent, but the presplitting blasting of charging each hole causes certain damage to the middle rock pillar and the lining in a short distance, and the presplitting effect is limited.
Disclosure of Invention
The invention mainly aims to provide a damping construction method for the exit of a tunnel with a minimum clear distance, which at least solves the technical problem that the existing construction method is easy to damage a rock pillar and a tunnel lining when the tunnel with the minimum clear distance is constructed.
In order to achieve the aim, the invention provides a damping construction method for a tunnel with a minimum clear distance, which comprises the following steps:
s1, excavating a pilot tunnel to enable the pilot tunnel to be out of the tunnel, grouting and reinforcing a middle rock pillar of the pilot tunnel, and constructing a secondary lining of a tunnel opening section of the pilot tunnel by adopting a jump-driving method;
s2, excavating a back tunnel, excavating a front pilot tunnel at the back tunnel, constructing a front pilot tunnel primary support, excavating one side of an upper step of the back tunnel, which is close to a middle rock pillar, by matching a double-row slit pipe presplitting blasting method with a mechanical cold excavation method, excavating the rest part of the upper step of the back tunnel by adopting a controlled blasting method, constructing an upper step primary support, dismantling the front pilot tunnel primary support, excavating a lower step section of the back tunnel, constructing a lower section primary support, an inverted arch and a filling layer, and then integrally molding a secondary lining of the back tunnel;
and S3, repeating the step S2 until the hole-exiting construction of the backward hole is completed.
Further, in step S2, blasting and excavating the leading pilot tunnel at the back tunnel by using a multi-stage differential blasting method.
Furthermore, the number of the sections of the multi-section differential blasting mode is not less than 4, and the differential time is not less than 100 ms.
Further, in the step S2, a leading tunnel is excavated from a position where the thickness of the middle rock pillar is 0.3 to 0.5 times of the tunnel span, and the leading distance of the leading tunnel is 0.5 to 1.0 times of the tunnel span.
Further, in the step S2, the expanding excavation of the side, close to the middle pillar, of the upper step of the backward hole by using a double-row cutting and pipe presplitting blasting method in combination with a mechanical cold excavation method specifically includes: and expanding and excavating the upper step part of the backward hole on one side of the backward hole close to the middle rock pillar by adopting a double-row slit pipe presplitting blasting method, and expanding and excavating the rest part of the upper step of the backward hole on one side close to the middle rock pillar by adopting a mechanical cold excavation method when the backward hole is expanded and excavated to be close to the middle rock pillar.
Further, in the step S1, the grouting reinforcement of the middle rock pillar of the advanced hole specifically includes: and grouting and reinforcing the part of the middle rock pillar with the thickness less than 3.0m of the pilot hole by adopting a plurality of grouting guide pipes.
Furthermore, a plurality of grouting guide pipes are uniformly distributed along the annular direction of the pilot hole, and the whole grouting guide pipe is in a quincunx shape.
Furthermore, the grouting liquid filled in the grouting guide pipe is superfine single cement liquid, and the grouting pressure is 1-1.5 MPa.
By applying the technical scheme of the invention, the preceding hole is dug in a single direction, the problem of inconvenience in constructing the cliff at the outlet section is solved, the central rock pillar is grouted and reinforced after the preceding hole is dug out, secondary lining of the opening section of the preceding hole is constructed by adopting a jump driving method, deformation of surrounding rocks at the opening section is controlled, and the influence of blasting vibration on lining of the preceding hole in the construction process of the following hole is reduced; the backward tunnel is excavated by adopting an advanced pilot tunnel, the advanced pilot tunnel can effectively reduce the disturbance to the surrounding rock, so that the self bearing capacity of the backward tunnel can be fully exerted, meanwhile, a part of underground stress can be released in advance, and the later settlement convergence of the surrounding rock is effectively reduced; when the backward hole is excavated, a joint cutting pipe pre-splitting blasting method is adopted, so that pre-cracks are formed more effectively, the number of blast holes required by pre-splitting blasting is reduced, and the propagation of blasting seismic waves to the forward hole is blocked; and a mechanical cold excavation method is adopted at one side close to the middle rock pillar, so that the damage to the middle rock pillar is further reduced. The construction method can effectively reduce the damage of blasting vibration to the middle rock pillar and the concrete lining, shorten the construction period, save the construction cost and solve the technical problem that the middle rock pillar and the tunnel lining are easily damaged during blasting construction in the existing small-clearance or extremely-small-clearance tunnel construction method.
In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
fig. 1 shows a design drawing of a lining construction step sequence according to an embodiment of the present invention, wherein a left drawing is a schematic drawing of a pilot hole, and in the drawing: I. the first hole is arranged on the cross section of the step; II1, a left section of a lower step of the pilot tunnel; II2, a right section of a lower step of the pilot tunnel; the right diagram is a schematic diagram of a backward hole, wherein: III, leading the rear row of holes to the section of the pilot tunnel; IV1, a right section of an upper step of the backward hole; IV2, a left middle section of the upper step of the rear hole; IV3, cutting the left edge of the upper step of the backward hole; v1, a left section of a lower step of the rear tunnel; v2, lower step right section of rear row hole.
Fig. 2 is a schematic diagram illustrating a middle rock pillar reinforcement according to an embodiment of the present invention, wherein the left diagram is a schematic diagram of a leading hole, and the right diagram is a schematic diagram of a trailing hole.
Figure 3 shows a construction step diagram of one embodiment of the present invention.
Fig. 4 shows a rear-row hole leading-hole blast hole arrangement diagram according to an embodiment of the invention.
Fig. 5 shows a schematic diagram of excavation of a backward tunnel by adopting a double-row cutting pipe presplitting blasting and cold excavation method in combination according to an embodiment of the invention.
Fig. 6 shows a schematic view of a slit tube structure according to an embodiment of the present invention.
FIG. 7 shows a schematic of a slit tube charge of an embodiment of the present invention; wherein, figure (a) is a schematic cross-sectional view of a slit-tube charge and figure (b) is a schematic longitudinal view of the slit-tube charge.
Wherein the figures include the following reference numerals:
1. preliminary bracing on the step by the pilot tunnel; 2. preliminary bracing of a step under a tunnel; 21. firstly, a hole is inverted; 3. firstly, filling a hole; 4. firstly, secondary lining of a tunnel; 5. advanced pilot tunnel primary support; 6. carrying out preliminary bracing on the upper step of the backward tunnel; 7. performing primary support on a step under the backward tunnel; 71. a backward hole inverted arch; 8. a back hole filling layer; 9. secondary lining of the backward tunnel; 10. and (4) grouting a conduit.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail with reference to examples.
As described in the background art, the existing tunnel blasting construction method is adopted at the tunnel portal section of the small clear distance tunnel and the extremely small clear distance tunnel, and the problems of damage and damage to the lining of the preceding tunnel and the middle rock wall, long construction period, high manufacturing cost and the like caused by blasting of the following tunnel usually exist.
In an exemplary embodiment of the present application, a shock absorption construction method for a very small clear distance tunnel cave exit is provided, which includes the following steps:
s1, excavating a pilot tunnel to enable the pilot tunnel to be out of the tunnel, grouting and reinforcing a middle rock pillar of the pilot tunnel, and constructing a secondary lining of a tunnel opening section of the pilot tunnel by adopting a jump-driving method;
s2, excavating a back-row tunnel, excavating a front-row tunnel at the back-row tunnel, constructing a front-row tunnel primary support, expanding and excavating one side, close to a middle rock pillar, of an upper step of the back-row tunnel by matching a double-row slit pipe presplitting blasting method with a mechanical cold excavation method, expanding and excavating the rest part of the upper step of the back-row tunnel by adopting a controlled blasting method, constructing an upper-step primary support, dismantling the front-row tunnel primary support, excavating a lower step section of the back-row tunnel, constructing a lower-section primary support, an arch and a filling layer, and then integrally molding a secondary lining of the back-row tunnel;
and S3, repeating the step S2 until the hole-exiting construction of the rear hole is completed.
By adopting the construction method, the advanced hole is dug in a single direction, the problem that construction of the cliff at the outlet section is inconvenient is solved, the rock pillar is grouted and reinforced after the advanced hole is dug, secondary lining of the opening section of the advanced hole is constructed by adopting a jump driving method, deformation of surrounding rock at the opening section is controlled, and the influence of blasting vibration on lining of the advanced hole in the construction process of the advanced hole is reduced; the backward tunnel is excavated by adopting the advanced pilot tunnel, so that the distance between a blasting source and the lining of the forward tunnel is increased, and the blasting explosive quantity is reduced by more than 50% compared with that of an upper step excavation method, so that the disturbance to the surrounding rock can be effectively reduced, the self-bearing capacity of the surrounding rock can be fully exerted, a part of underground stress can be released in advance, and the later-stage settlement convergence of the surrounding rock is effectively reduced; when the backward hole is excavated, a joint cutting pipe pre-splitting blasting method is adopted, so that pre-cracks are formed more effectively, the number of blast holes required by pre-splitting blasting is reduced, and the propagation of blasting seismic waves to the forward hole is blocked; and a mechanical cold excavation method is adopted at one side close to the middle rock pillar, so that the damage to the middle rock pillar is further reduced. The construction method can effectively reduce the damage of blasting vibration to the middle rock pillar and the concrete lining, shorten the construction period, save the construction cost and solve the problem that the middle rock pillar and the tunnel lining are easily damaged during blasting construction in the existing small-clear-distance or extremely-small-clear-distance tunnel construction method.
In order to further reduce the influence on the pilot tunnel when the pilot tunnel is excavated, in the embodiment, a multi-section differential blasting mode is adopted to control blasting excavation of the pilot tunnel at the position of the rear tunnel. The method for blasting and excavating the advanced pilot tunnel can reduce the explosive using amount of each section, and effectively reduce the influence of blasting vibration on the advanced tunnel. In specific implementation, the number of the sections of the multi-section differential blasting mode is preferably not less than 4, and the differential time is preferably not less than 100 ms. Through verification, when the detonation time interval of each section is greater than or equal to 100ms, the seismic waves generated by each section of blasting cannot be obviously superposed, so that the vibration generated by the blasting can be better reduced, and the influence of the blasting on the pilot hole is further reduced.
In the section with larger clear distance, because the thickness of the middle rock pillar is larger, the construction mode of leading a tunnel is not needed, the conventional blasting mode can be adopted for construction, the larger damage to the leading tunnel can not be caused, and the construction progress can be properly improved by adopting the conventional blasting construction; when a section with a small clear distance is excavated, the requirements cannot be met by adopting the conventional construction method. Research results show that when the advanced pilot tunnel is excavated from the tunnel span with the thickness of the middle rock pillar being 0.3-0.5 times, and the advance distance of the advanced pilot tunnel is 0.5-1.0 times of the tunnel span, the blasting vibration can be effectively reduced, the influence of the excavation of the advanced pilot tunnel on the advanced tunnel is reduced, the safety of the tunnel structure is ensured, the temporary supporting amount of the advanced pilot tunnel can be reduced, and the construction period is shortened as much as possible. If the advance distance is too small, the function cannot be achieved; if the advance distance is too large, the temporary support amount of the advance pilot tunnel is increased.
In this embodiment, specifically, the side of the upper step of the tunnel close to the middle rock pillar after the expanding excavation by adopting the double-row slotted pipe presplitting blasting method and the mechanical cold excavation method is: the upper step part of the backward hole is excavated on one side of the backward hole close to the middle rock pillar by adopting a double-row slit pipe presplitting blasting method, so that the seismic wave can be effectively prevented from being transmitted to the forward hole; when expanding and digging to near the middle rock pillar, the mechanical cold digging method is adopted to expand and dig the rest part of the upper step of the tunnel close to one side of the middle rock pillar, so that the continuous blasting mode excavation is avoided, and the influence on the previous tunnel can be further reduced.
In this embodiment, the grouting reinforcement of the middle rock pillar of the preceding hole means: and a plurality of grouting guide pipes 10 are adopted to perform grouting reinforcement on the part of the leading hole with the thickness of the middle rock pillar less than 3.0 m. The grouting guide pipe 10 is adopted to reinforce the middle rock pillar of the preceding hole, so that the middle rock pillar can be effectively reinforced, and the damage to the preceding hole is reduced. Preferably, the plurality of grouting pipes 10 may be uniformly arranged along the circumferential direction of the pilot hole, and the plurality of grouting pipes 10 may be arranged in a quincunx shape as a whole. This maximizes the reinforcement effect of the middle pillar. Furthermore, the grouting liquid filled in the grouting guide pipe 10 is preferably ultra-fine single cement grout, and the grouting pressure is preferably controlled to be 1MPa to 1.5 MPa.
In the construction process, the blasting parameters, the excavation footage and the safety step are strictly controlled, and blasting vibration monitoring is carried out; and in the construction process, data such as surface settlement, tunnel deformation and steel frame internal stress are monitored on time, and the construction safety is ensured.
Classifying the small-clearance tunnels according to the recommended demarcation value of the JTG/T F60-2009 (JTG/T F60-2009) of the highway tunnel design construction rules, which is shown in the following table:
note: b-width of tunnel excavation section
The construction method can be suitable for the hole-exiting construction of the small-clear-distance tunnel in the seriously affected section.
The present invention will be further described with reference to specific examples, which should not be construed as limiting the scope of the invention.
Examples
An embodiment of a forked minimum clear distance tunnel exit shock absorption construction method. The construction method is adopted to construct the high-speed old foundation tunnel of the Xingzi city-around of Guizhou province, the total length of the tunnel is 393m, and the tunnel is a branched short tunnel. The tunnel line spacing exit segment is the minimum contour line clear distance of 0.6m, and then gradually separated into the separated tunnel with the minimum clear distance, the small clear distance and the entrance segment line spacing of about 35 m.
In the actual construction process, the construction method has obvious effect, effectively reduces the damage of the backward cave blasting to the rock pillar and the forward cave lining, and has good economic benefit. Referring to fig. 1 to 7, the construction process includes the following steps:
first, the first hole is excavated
(1.1) leading the advanced hole to go out in a single direction, and reinforcing the support parameters of the hole section;
(1.2) grouting and reinforcing the rock pillar in the pilot tunnel
In the process of excavating the pilot tunnel, grouting and reinforcing the middle rock pillar at the part with the thickness of 0.6-3.0 m, wherein the grouting guide pipes 10 with the diameter of 42mm and the thickness of 4mm are adopted for reinforcing the middle rock pillar, the circumferential distance of the grouting guide pipes 10 is 120cm, the longitudinal distance of the grouting guide pipes is 60cm, the whole body is arranged in a quincunx shape, the grout adopts 1:0.7 superfine cement single grout, and the grouting pressure is 1-1.5 MPa;
(1.3) jump drilling two linings with pilot holes
For the prior hole, the prior hole is penetrated in advance, primary supports (comprising an upper step primary support 1 of the prior hole and a lower step primary support 2 of the prior hole), an inverted arch 21 of the prior hole and a filling layer 3 of the prior hole are constructed, after the inverted arch of the hole outlet is finished, a secondary lining trolley is moved to the hole outlet, and a secondary lining 4 of the prior hole is constructed by adopting a jump driving method;
(II) excavating backward hole
(2.1) excavating a pilot tunnel in the backward tunnel, and then constructing a pilot tunnel primary support 5
When the thickness of the middle rock pillar is 5m, excavating a leading pilot tunnel for the backward tunnel, wherein the leading distance is more than 10 m; the advanced pilot tunnel adopts multi-section millisecond delay differential detonation, the number of the sections is not less than 4, the differential time is not less than 100ms, and an advanced pilot tunnel primary support 5 is constructed after the advanced pilot tunnel is excavated;
(2.2) adopting a double-row slit pipe presplitting blasting method and a mechanical cold digging method to cooperate with the expanding and digging of one side of the upper step close to the middle rock pillar
Referring to fig. 1, in the rock mass on the side close to the middle rock pillar, blasting excavation is adopted in the part IV1, presplitting blasting excavation is adopted in the part IV2, and mechanical cold excavation is adopted in the part IV 3; expanding and digging in a blasting mode at one side far away from the middle rock pillar; after the expanding excavation is finished, constructing a secondary hole upper step primary support 6;
(2.3) dismantling the preliminary support 5 of the pilot tunnel, excavating a lower step section of the backward tunnel, and then constructing a lower step preliminary support 7 of the backward tunnel, an inverted arch 71 of the backward tunnel and a filling layer 8 of the backward tunnel;
and (2.4) finally, integrally molding and then performing secondary lining 9 of the tunnel.
And (III) repeating the step (II) until the hole outlet construction of the back row of small clear distance tunnels is completed.
Aiming at the small clear distance tunnel exit shock absorption, a first-aid tunnel exit is adopted, the middle rock pillar is grouted and reinforced, and a second lining of the first-aid tunnel opening section is jumped; the backward hole adopts a leading hole to go out, and a double-row joint-cutting presplitting blasting method and a cold digging method are matched for expanding and digging; the invention can effectively reduce the damage of blasting vibration to the middle rock pillar and the concrete lining, shorten the construction period and save the construction cost.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. A shock absorption construction method for a tunnel with an extremely small clear distance is characterized by comprising the following steps:
s1, excavating a pilot tunnel to enable the pilot tunnel to be out of the tunnel, grouting and reinforcing a middle rock pillar of the pilot tunnel, and constructing a secondary lining of a tunnel opening section of the pilot tunnel by adopting a jump-driving method;
s2, excavating a back tunnel, excavating a front pilot tunnel at the back tunnel, constructing a front pilot tunnel primary support, excavating one side, close to a middle rock pillar, of an upper step of the back tunnel by adopting a double-row slit pipe presplitting blasting method and a mechanical cold excavation method, constructing an upper step primary support, dismantling the front pilot tunnel primary support, excavating a lower step section of the back tunnel, constructing a lower step primary support, an inverted arch and a filling layer, and integrally molding a secondary lining of the back tunnel;
and S3, repeating the step S2 until the hole-exiting construction of the backward hole is completed.
2. The vibration reduction construction method for the exit of the tunnel with the minimum clearance as claimed in claim 1, wherein in the step S2, the advanced pilot tunnel is excavated at the backward tunnel by controlled blasting in a multi-stage differential blasting manner.
3. The small-clearance tunnel cave-exiting shock-absorbing construction method according to claim 2, wherein the number of the multiple-stage differential blasting mode is not less than 4 stages, and the differential time is not less than 100 ms.
4. The minimum clear distance tunnel cave-exiting shock absorption construction method of claim 2, wherein in the step S2, a leading pilot tunnel is dug from the position where the thickness of the middle rock pillar is 0.3-0.5 times of the tunnel span, and the leading distance of the leading pilot tunnel is 0.5-1.0 times of the tunnel span.
5. The shock absorption construction method for the tunnel with the minimum clear distance as claimed in claim 1, wherein in the step S2, the step of enlarging and excavating the side of the upper step of the backward tunnel close to the middle rock pillar by using a double-row cutting pipe presplitting blasting method and a mechanical cold excavation method specifically comprises the steps of:
and expanding and excavating the upper step part of the backward hole on one side of the backward hole close to the middle rock pillar by adopting a double-row slit pipe presplitting blasting method, and expanding and excavating the rest part of the upper step of the backward hole on one side close to the middle rock pillar by adopting a mechanical cold excavation method when the backward hole is expanded and excavated to be close to the middle rock pillar.
6. The extremely-small-clear-distance tunnel cave-exiting shock-absorbing construction method according to claim 1, wherein in the step S1, the concrete step of grouting and reinforcing the middle rock pillar of the leading tunnel is: and grouting and reinforcing the part of the middle rock pillar with the thickness less than 3.0m of the pilot hole by adopting a plurality of grouting guide pipes.
7. The method for damping the vibration of the tunnel with the minimum clear distance as claimed in claim 6, wherein a plurality of grouting pipes are uniformly distributed along the circumferential direction of the pilot tunnel, and the grouting pipes are quincunx integrally.
8. The small clear distance tunnel cave-out shock absorption construction method according to claim 6, wherein the grouting liquid filled in the grouting guide pipe is ultra-fine cement single liquid slurry, and the grouting pressure is 1MPa to 1.5 MPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811027172.2A CN109339797B (en) | 2018-09-04 | 2018-09-04 | Extremely-small-clear-distance tunnel exit shock absorption construction method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811027172.2A CN109339797B (en) | 2018-09-04 | 2018-09-04 | Extremely-small-clear-distance tunnel exit shock absorption construction method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109339797A CN109339797A (en) | 2019-02-15 |
| CN109339797B true CN109339797B (en) | 2020-06-19 |
Family
ID=65292507
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811027172.2A Active CN109339797B (en) | 2018-09-04 | 2018-09-04 | Extremely-small-clear-distance tunnel exit shock absorption construction method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109339797B (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110307002B (en) * | 2019-05-09 | 2020-07-31 | 深圳市综合交通设计研究院有限公司 | Refined construction method for II-grade and III-grade surrounding rock ultra-small clear distance tunnel |
| CN110145315A (en) * | 2019-05-13 | 2019-08-20 | 中铁十六局集团第四工程有限公司 | A kind of driving method weakening city shallow tunnel concussion of blasting |
| CN110284900B (en) * | 2019-06-25 | 2024-07-05 | 深圳市综合交通设计研究院有限公司 | Broken stratum ultra-small clear distance city tunnel supporting structure and jump groove construction process thereof |
| CN111593734B (en) * | 2020-05-29 | 2021-10-26 | 中铁隧道局集团有限公司 | Shallow tunnel foundation pit enclosure construction method in upper-soft lower-hard stratum |
| CN112302661B (en) * | 2020-09-17 | 2022-09-27 | 浙江钱塘江水利建筑工程有限公司 | Long-distance small-section tunnel construction process |
| CN112964143B (en) * | 2021-03-24 | 2021-09-21 | 山东科技大学 | Three-time blasting method for hollow hole straight-hole cut |
| CN113236293B (en) * | 2021-03-30 | 2024-04-05 | 解长渊 | City trunk weak surrounding rock shallow-buried large-span small-clear-distance tunnel deformation control supporting method |
| CN113175328A (en) * | 2021-05-11 | 2021-07-27 | 蒲建莹 | Small-entrance large-section cavern excavation construction process |
| CN114046159B (en) * | 2022-01-13 | 2022-04-08 | 中铁五局集团第一工程有限责任公司 | Template part and construction method for excavating and lining tunnels in loess-rich stratum |
| CN114791246A (en) * | 2022-04-02 | 2022-07-26 | 中铁十六局集团路桥工程有限公司 | Blasting construction method for existing small-clear-distance close-connection tunnel |
| CN115263319A (en) * | 2022-07-06 | 2022-11-01 | 中铁一局集团(广州)建设工程有限公司 | Steep-dip bedding limestone tunnel out-of-tunnel construction method |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100757202B1 (en) * | 2006-12-12 | 2007-09-07 | 윤석렬 | Center Wall of Two Arch Tunnel |
| CN102536252A (en) * | 2012-02-17 | 2012-07-04 | 中国建筑第六工程局有限公司 | Method for digging backward hole of tunnel with quite small clear distance |
| CN202707073U (en) * | 2012-08-10 | 2013-01-30 | 浙江省交通规划设计研究院 | Arch tunnel structure |
| CN102966360A (en) * | 2012-11-26 | 2013-03-13 | 中铁四局集团第二工程有限公司 | Method for reinforcing rock walls in neighborhood tunnel |
| KR20140055477A (en) * | 2012-10-31 | 2014-05-09 | 한국과학기술원 | Proximity tunnel construction method and system using free surface |
| CN104405402A (en) * | 2014-10-13 | 2015-03-11 | 中铁二院重庆勘察设计研究院有限责任公司 | Symmetric middle separation wall construction method for hidden type middle wall multi-arch tunnel |
| CN205477660U (en) * | 2016-02-02 | 2016-08-17 | 中铁十九局集团轨道交通工程有限公司 | Little clean apart from tunnel in rock pillar reinforcerment system |
| CN108533272A (en) * | 2018-03-30 | 2018-09-14 | 贵州省公路工程集团有限公司 | A kind of minimum clear-distance tunnel goes out cavity construction method |
-
2018
- 2018-09-04 CN CN201811027172.2A patent/CN109339797B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100757202B1 (en) * | 2006-12-12 | 2007-09-07 | 윤석렬 | Center Wall of Two Arch Tunnel |
| CN102536252A (en) * | 2012-02-17 | 2012-07-04 | 中国建筑第六工程局有限公司 | Method for digging backward hole of tunnel with quite small clear distance |
| CN202707073U (en) * | 2012-08-10 | 2013-01-30 | 浙江省交通规划设计研究院 | Arch tunnel structure |
| KR20140055477A (en) * | 2012-10-31 | 2014-05-09 | 한국과학기술원 | Proximity tunnel construction method and system using free surface |
| CN102966360A (en) * | 2012-11-26 | 2013-03-13 | 中铁四局集团第二工程有限公司 | Method for reinforcing rock walls in neighborhood tunnel |
| CN104405402A (en) * | 2014-10-13 | 2015-03-11 | 中铁二院重庆勘察设计研究院有限责任公司 | Symmetric middle separation wall construction method for hidden type middle wall multi-arch tunnel |
| CN205477660U (en) * | 2016-02-02 | 2016-08-17 | 中铁十九局集团轨道交通工程有限公司 | Little clean apart from tunnel in rock pillar reinforcerment system |
| CN108533272A (en) * | 2018-03-30 | 2018-09-14 | 贵州省公路工程集团有限公司 | A kind of minimum clear-distance tunnel goes out cavity construction method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109339797A (en) | 2019-02-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109339797B (en) | Extremely-small-clear-distance tunnel exit shock absorption construction method | |
| CN108533272B (en) | Exit construction method for tunnel with extremely small clear distance | |
| CN110132084B (en) | Tunnel over-under-excavation control method | |
| CN109209392B (en) | Full-ring excavation method suitable for IV-V-grade surrounding rock of large-section tunnel | |
| CN109209391A (en) | Tiny step excavation method suitable for IV-V grade of country rock of large cross-section tunnel | |
| KR101148331B1 (en) | Excavation method for pre-nailed tunneling | |
| CN110307002B (en) | Refined construction method for II-grade and III-grade surrounding rock ultra-small clear distance tunnel | |
| CN112013733B (en) | Blast hole arrangement blasting method for dealing with complex surrounding rock conditions | |
| CN107060773B (en) | A kind of underground chamber drilling and blasting method damping excavation method of static(al) explosion presplitting shock insulation | |
| CN108915694B (en) | Construction method for tunnel lower-layer step full-section protective-layer-free extrusion blasting and road repairing and access protection | |
| CN111023930B (en) | Tunnel step excavation method | |
| CN219176328U (en) | Gradient vibration reduction structure for ultra-small clear distance tunnel | |
| CN108590667B (en) | Tunnel excavation and primary support method based on regional surrounding rock fracture evolution analysis | |
| CN103195454A (en) | Method for supporting filling roadway or chamber | |
| CN109184704A (en) | A kind of small-clear-distance tunnel excavation and middle folder rock reinforcement technique | |
| CN113605903B (en) | Quick, simple and easy-to-operate new excavation and lining method for tunnel or arch base chamber of special anchorage | |
| CN110566236A (en) | Pipe shed and steel support combined supporting device and supporting method | |
| CN116658178B (en) | Ultra-small clear distance tunnel subsection differential blasting vibration reduction and isolation construction method | |
| JP5382432B2 (en) | Excavation method of adjacent twin tunnel | |
| CN105909262A (en) | Subsurface tunnel driving method | |
| CN108222976A (en) | Diversion tunnel pole weak surrounding rock section constructing method | |
| CN112504041A (en) | Method for reducing tunnel blasting excavation vibration speed in urban sensitive environment | |
| CN107014263A (en) | The eccentric powder charge joint-cutting pipe and roadway construction method constructed applied to tunnelling | |
| CN112964143B (en) | Three-time blasting method for hollow hole straight-hole cut | |
| CN210622819U (en) | Pipe shed and steel support combined supporting device |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |