CN113153375B - Construction method of soft foundation ultra-small clear distance tunnel primary support anti-drop support settlement-reducing support system - Google Patents
Construction method of soft foundation ultra-small clear distance tunnel primary support anti-drop support settlement-reducing support system Download PDFInfo
- Publication number
- CN113153375B CN113153375B CN202110376742.4A CN202110376742A CN113153375B CN 113153375 B CN113153375 B CN 113153375B CN 202110376742 A CN202110376742 A CN 202110376742A CN 113153375 B CN113153375 B CN 113153375B
- Authority
- CN
- China
- Prior art keywords
- steel
- support
- tunnel
- pipe
- arch
- 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 32
- 229910000831 Steel Inorganic materials 0.000 claims description 126
- 239000010959 steel Substances 0.000 claims description 126
- 230000008093 supporting effect Effects 0.000 claims description 16
- 238000009412 basement excavation Methods 0.000 claims description 5
- 239000011435 rock Substances 0.000 claims description 5
- 238000005553 drilling Methods 0.000 claims description 3
- 238000003466 welding Methods 0.000 claims description 3
- 238000000034 method Methods 0.000 description 10
- 238000002955 isolation Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- 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
- E21D11/14—Lining predominantly with metal
-
- 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
-
- 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
- E21D11/14—Lining predominantly with metal
- E21D11/18—Arch members ; Network made of arch members ; Ring elements; Polygon elements; Polygon elements inside arches
-
- 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
- E21D11/14—Lining predominantly with metal
- E21D11/18—Arch members ; Network made of arch members ; Ring elements; Polygon elements; Polygon elements inside arches
- E21D11/183—Supporting means for arch members, not provided for in E21D11/22
-
- 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)
- Mining & Mineral Resources (AREA)
- Architecture (AREA)
- Structural Engineering (AREA)
- Civil Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Lining And Supports For Tunnels (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
Abstract
The invention belongs to the technical field of tunnel construction, and particularly relates to a construction method of a soft foundation ultra-small clear distance tunnel primary support anti-drop support settlement support system.
Description
Technical Field
The invention belongs to the technical field of tunnel construction, and particularly relates to a construction method of a primary support anti-drop support settlement-reducing support system of a soft foundation ultra-small clear distance tunnel.
Background
Although various tunnel underground excavation construction methods exist at present, such as a full-section excavation method, a step excavation method, a circular excavation reserved core soil, a single-side-wall pit guiding method, a double-side-wall pit guiding method and the like, for ultra-small clear distance tunnels with limited urban space, a construction mode of multi-arch tunnels is generally adopted, but the construction cost of the multi-arch tunnels is high, and the construction process is complex. If the ultra-small clear distance tunnel is excavated and meets a soft foundation, the difficulty of tunnel construction can be further increased, one of the difficulties is that in the construction process, the mutual disturbance influence of the tunnels at two sides is obvious, so that the primary support of the tunnel is easy to deform, and serious or even collapse and other safety accidents occur.
Disclosure of Invention
The invention provides a construction method of a soft foundation ultra-small clear distance tunnel primary support anti-drop support settlement support system, aiming at solving the defects of the prior art.
The invention is realized by the following technical scheme:
the construction method of the soft foundation ultra-small clear distance tunnel primary support anti-drop support settlement support system comprises the following steps:
firstly, two rows of steel perforated pipes A are arranged at the middle rock wall positions of the left tunnel and the right tunnel, and the steel perforated pipes A are grouted; respectively drilling a row of steel perforated pipes B at the two sides of the left tunnel and the right tunnel, and grouting the steel perforated pipes B; respectively arranging two rows of steel perforated pipes C and steel pipes at the section positions of the left tunnel and the right tunnel, adopting the steel perforated pipes C at the parts above the vault of the tunnel, adopting the steel pipes at the parts below the vault of the tunnel, fixedly connecting the steel perforated pipes C and the steel pipes together, and grouting the steel perforated pipes C above the vault of the tunnel;
secondly, excavating a tunnel and following primary support, cutting off a steel pipe at the arch top of the tunnel to carry out arch top primary support construction, fixing a supporting device at the upper part of the cut-off steel pipe, and upwards supporting a steel arch frame of the primary support by the supporting device;
thirdly, when the steel arch centering of the primary support of the tunnel is constructed to two sides, fixedly connecting the steel perforated pipe A with the adjacent steel arch centering, and fixedly connecting the steel perforated pipe B with the adjacent steel arch centering;
and fourthly, cutting off the steel pipe in the tunnel after the primary support of the tunnel is closed, and connecting the top end of the cut steel pipe with the inverted arch.
As a preferable scheme:
in the step (I), the diameter of the steel perforated pipe C is smaller than that of the steel pipe, the steel perforated pipe C and the steel pipe are connected in a socket joint mode, and the depth of the steel perforated pipe C inserted into the steel pipe is not smaller than 300mm.
In the step (I), the steel perforated pipe C is a 108 steel perforated pipe, and the steel pipe is a 200 steel pipe.
In the step (two), the specific structure of the supporting device is as follows: including fixing two staple bolts on steel pipe upper portion, fixation nut on the staple bolt, a vertical screw rod of nut internal thread connection, a nut of bottom welding of screw rod, the top of screw rod is equipped with the top and holds in the palm, and the top holds in the palm and holds in the palm the top steel bow member.
In the step (two), the specific structure of the supporting device is as follows: the steel arch centering device comprises two hoops fixed on the upper part of a steel pipe, a support is fixedly connected to the hoops, a jack is fixed to the upper end of the support, and the jack props against an upper steel arch centering.
The upper part, the middle part and the bottom of the primary support of the tunnel are supported in the construction process, the steel perforated pipes which are arranged in a driving mode are grouting pipes and isolation piles and simultaneously play a role in supporting the steel arch of the tunnel, the three purposes of one pile and three purposes are achieved, meanwhile, the primary support of the tunnel is well protected in the whole process, a full-support system is built, the construction difficulty is greatly reduced through the construction method, and the construction cost is saved.
Drawings
FIG. 1 is a schematic view of the process of the present invention at step one.
FIG. 2 is a schematic view of the construction in step two of the present invention.
FIG. 3 is a schematic view of the construction in step four of the present invention.
Fig. 4 is a schematic structural diagram of a first supporting device in this embodiment.
Fig. 5 is a schematic structural diagram of a second supporting device in this embodiment.
In the figure, 1 steel floral tube A,2 steel floral tube B,3 left tunnels, 4 right tunnels, 5 steel floral tubes C,6 steel tubes, 7 hoops, 8 nuts, 9 screws, 10 jacking supports, 11 supports, 12 jacks and 13 steel arches.
Detailed Description
The following embodiments of the present invention are provided, and it should be noted that the present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention are within the protection scope of the present invention.
The invention comprises the following construction method comprising the following steps:
1. arranging steel perforated pipe
Two rows of steel perforated pipes A1 are arranged at the middle rock wall positions of the left tunnel and the right tunnel, the two rows of steel perforated pipes A1 are parallel along the length direction of the tunnels, and grouting reinforcement of the rock wall in the tunnels is realized by grouting the two rows of steel perforated pipes A1 while an isolation effect is achieved.
And respectively driving a row of steel perforated pipes B2 at the two sides of the left tunnel and the right tunnel, and grouting the steel perforated pipes B2 to form the isolation piles.
Two rows of steel perforated pipes C5 and steel pipes 6 are respectively arranged at the cross section positions of the left tunnel 3 and the right tunnel 4, and the steel perforated pipes C5 and the steel pipes 6 are combined together. The steel perforated pipe C5 is adopted in the part above the arch crown of the tunnel, the steel pipe 6 is adopted in the part below the arch crown, the diameter of the steel perforated pipe C5 is smaller than that of the steel pipe 6, for example, the steel perforated pipe C5 is 108 steel perforated pipes, the steel pipe 6 is 200 steel pipes, the selected steel pipe 6 needs to meet the requirements of slenderness ratio and bending stability, and the steel pipe 6 is used as an initial support vertical inner support in the later period. The steel perforated pipe C5 and the steel pipe 6 are fixedly connected together in various connection modes, in the embodiment, a socket connection mode is selected, and the depth of the steel perforated pipe C5 inserted into the steel pipe 6 is not less than 300mm. And (3) grouting the steel perforated pipe C5 above the arch top, and ensuring grouting pressure during grouting.
2. Primary support upper support
And (5) excavating the tunnel and following the primary support, and cutting off the steel pipe 6 at the vault so as to carry out vault primary support construction. During vault primary support construction, a support device is fixed on the upper portion of the steel pipe 6, and the support device is connected with the primary support and plays a role in supporting the upper portion of the primary support to serve as vertical support of the upper steel arch 13.
3. Primary support middle support
When the steel arch 13 of the primary support is constructed to two sides, the steel perforated pipe A1 is connected with the adjacent steel arch 13 through welding or a hoop 7, and the steel perforated pipe B2 is connected with the adjacent steel arch 13, so that the middle part of the primary support is supported.
Two preferred designs are described herein for the support device:
the first support structure is described as follows: including staple bolt 7, this embodiment staple bolt 7 is two, distributes from top to bottom. A nut 8 is fixed on the hoop 7, a vertical screw rod 9 is in threaded connection with the nut 8, the nut 8 is welded at the bottom end of the screw rod 9, and a jacking 10 is arranged at the top of the screw rod 9. When the device is used, the hoop 7 is fixed on the upper portion of the steel pipe 6, then the nut 8 is rotated by using a wrench, the screw 9 is rotated, the height of the screw 9 is adjusted until the jacking 10 supports the upper steel arch 13, the steel arch 13 is vertically supported, and the screw 9 stops rotating.
The second support structure is described as follows: including staple bolt 7, this embodiment staple bolt 7 is two, distributes from top to bottom. A bracket 11 is fixedly connected to the hoop 7, and a jack 12 is fixed at the upper end of the bracket 11. When the device is used, the hoop 7 is fixed on the upper portion of the steel pipe 6, then the jack 12 is started until the jack 12 props against the upper steel arch 13, and the device has a vertical supporting effect on the steel arch 13.
4. Primary support bottom support
And after the primary support is closed, cutting off the steel pipe 6 in the tunnel, and connecting the top end of the cut-off steel pipe 6 with the inverted arch to serve as a composite foundation, so that the settlement of the inverted arch is reduced, and the support of the lower part of the primary support is realized.
The invention realizes three purposes:
the steel perforated pipe A1 has three functions: 1. the function of a grouting pipe; 2. the middle rock wall is reinforced and has an isolation effect; 3. and the middle part of the primary support is supported.
The steel perforated pipe B2 has three functions: 1. the function of a grouting pipe; 2. the function of isolating piles is achieved; 3. and the middle part of the primary support is supported.
The steel perforated pipe C5 and the steel pipe 6 have three functions after combination: 1. the function of a grouting pipe; 2. supporting the primary support of the vault; 3. and (3) supporting the inverted arch.
The invention realizes the full support of the primary support of the tunnel, establishes a full support system, supports the steel arch 13 at the upper part of the primary support, the steel arch 13 at the middle part and the inverted arch in the whole construction process, and avoids the deformation and support falling of the primary support of the tunnel to the maximum extent, thereby forming a novel construction method of the support system for preventing the support falling and sinking of the primary support.
The above-described embodiment is only one of the preferred embodiments of the present invention, and general changes and substitutions by those skilled in the art within the technical scope of the present invention are included in the protection scope of the present invention.
Claims (5)
1. The construction method of the soft foundation ultra-small clear distance tunnel primary support anti-drop support settlement support system comprises the following steps:
firstly, two rows of steel perforated pipes A (1) are arranged at the middle rock wall positions of the left tunnel and the right tunnel, and the steel perforated pipes A (1) are grouted; respectively drilling a row of steel perforated pipes B (2) at the two sides of the left tunnel and the right tunnel, and grouting the steel perforated pipes B (2); respectively drilling two rows of steel perforated pipes C (5) and two rows of steel pipes (6) at the cross section positions of a left tunnel (3) and a right tunnel (4), adopting the steel perforated pipes C (5) at the part above the arch crown of the tunnel, adopting the steel pipes (6) at the part below the arch crown of the tunnel, fixedly connecting the steel perforated pipes C (5) and the steel pipes (6) together, and grouting the steel perforated pipes C (5) above the arch crown of the tunnel;
secondly, tunnel excavation is carried out and initial support is followed, arch crown construction is carried out by cutting off the steel pipe (6) at the arch crown of the tunnel, a supporting device is fixed at the upper part of the cut-off steel pipe (6), and the supporting device upwards supports a steel arch frame (13) of the initial support;
thirdly, when the steel arch centering (13) of the primary tunnel support is constructed to two sides, fixedly connecting the steel perforated pipe A (1) with the adjacent steel arch centering (13) and fixedly connecting the steel perforated pipe B (2) with the adjacent steel arch centering (13);
and fourthly, cutting off the steel pipe (6) in the tunnel after the primary support of the tunnel is closed, and connecting the top end of the cut steel pipe (6) with the inverted arch.
2. The soft foundation ultra-small clear distance tunnel primary support anti-drop support subsidence reducing support system construction method of claim 1, characterized in that: in the step (I), the diameter of the steel perforated pipe C (5) is smaller than that of the steel pipe (6), the steel perforated pipe C (5) and the steel pipe (6) are connected together in a socket-and-spigot manner, and the depth of the steel perforated pipe C (5) inserted into the steel pipe (6) is not smaller than 300mm.
3. The construction method of the primary support anti-drop support settlement support system of the soft foundation ultra-small clear distance tunnel according to claim 1, characterized in that: in the step (I), the steel perforated pipe C (5) adopts 108 steel perforated pipes, and the steel pipe (6) adopts 200 steel pipes.
4. The construction method of the primary support anti-drop support settlement support system of the soft foundation ultra-small clear distance tunnel according to claim 1, characterized in that: in the step (II), the specific structure of the supporting device is as follows: including fixing two staple bolts (7) on steel pipe (6) upper portion, fixation nut (8) on staple bolt (7), a vertical screw rod (9) of nut (8) internal thread connection, a bottom welding nut (8) of screw rod (9), the top of screw rod (9) is equipped with top support (10), and top support (10) hold in the palm top steel bow member (13).
5. The construction method of the primary support anti-drop support settlement support system of the soft foundation ultra-small clear distance tunnel according to claim 1, characterized in that: in the step (two), the specific structure of the supporting device is as follows: the steel arch support comprises two hoops (7) fixed on the upper portion of a steel pipe (6), a support (11) is fixedly connected to the hoops (7), a jack (12) is fixed to the upper end of the support (11), and the jack (12) abuts against an upper steel arch frame (13).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110376742.4A CN113153375B (en) | 2021-04-08 | 2021-04-08 | Construction method of soft foundation ultra-small clear distance tunnel primary support anti-drop support settlement-reducing support system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110376742.4A CN113153375B (en) | 2021-04-08 | 2021-04-08 | Construction method of soft foundation ultra-small clear distance tunnel primary support anti-drop support settlement-reducing support system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113153375A CN113153375A (en) | 2021-07-23 |
| CN113153375B true CN113153375B (en) | 2022-12-02 |
Family
ID=76889167
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110376742.4A Active CN113153375B (en) | 2021-04-08 | 2021-04-08 | Construction method of soft foundation ultra-small clear distance tunnel primary support anti-drop support settlement-reducing support system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113153375B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE202018102249U1 (en) * | 2017-09-07 | 2018-04-27 | Bag Bauartikel Gmbh | Reinforcement system for the concrete lining of the inner shell of a tunnel building |
| CN207513614U (en) * | 2017-11-08 | 2018-06-19 | 中铁十局集团有限公司 | Shallow tunnel subsurface excavation method advance support structure and combined type advanced tubule |
| 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 |
| CN110541721A (en) * | 2019-09-11 | 2019-12-06 | 中国建筑土木建设有限公司 | Support system and construction method for fully weathered surrounding rock tunnel in water-rich quicksand stratum |
| CN210888953U (en) * | 2019-10-22 | 2020-06-30 | 济南市市政工程设计研究院（集团）有限责任公司 | Tunnel pile and arch combined primary support system |
| CN112431599A (en) * | 2020-10-20 | 2021-03-02 | 中铁十九局集团第五工程有限公司 | Tunnel excavation method for upper soft and lower hard stratum |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018006558A1 (en) * | 2016-07-08 | 2018-01-11 | 山东大学 | Confined high-strength concrete support system applicable to underground tunnel |
| CN109779653B (en) * | 2019-01-22 | 2021-04-16 | 中铁隧道集团二处有限公司 | Construction method for crossing of soft rock large-section tunnel |
-
2021
- 2021-04-08 CN CN202110376742.4A patent/CN113153375B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE202018102249U1 (en) * | 2017-09-07 | 2018-04-27 | Bag Bauartikel Gmbh | Reinforcement system for the concrete lining of the inner shell of a tunnel building |
| CN207513614U (en) * | 2017-11-08 | 2018-06-19 | 中铁十局集团有限公司 | Shallow tunnel subsurface excavation method advance support structure and combined type advanced tubule |
| 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 |
| CN110541721A (en) * | 2019-09-11 | 2019-12-06 | 中国建筑土木建设有限公司 | Support system and construction method for fully weathered surrounding rock tunnel in water-rich quicksand stratum |
| CN210888953U (en) * | 2019-10-22 | 2020-06-30 | 济南市市政工程设计研究院（集团）有限责任公司 | Tunnel pile and arch combined primary support system |
| CN112431599A (en) * | 2020-10-20 | 2021-03-02 | 中铁十九局集团第五工程有限公司 | Tunnel excavation method for upper soft and lower hard stratum |
Non-Patent Citations (1)
| Title |
|---|
| 双洞隧道围岩稳定性分析及最小净距确定方法研究;宋蕾;《工程科技Ⅱ辑》;20190115;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113153375A (en) | 2021-07-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103603679B (en) | For arch crown steel frame and the method for tunnel construction of arch, supporting tunnel | |
| CN111502696A (en) | Dense-mesh type advanced support system of underground excavation tunnel and construction method | |
| CN103321659A (en) | Large-diameter tube curtain support underground excavation construction super-shallow burying large-section subway station structure and construction method | |
| CN102003187B (en) | Construction method of under cutting excavation supporting of of deeply buried soft-rock large tunnel | |
| CN112901208A (en) | Comprehensive construction method for shallow buried section of urban railway mining method tunnel | |
| CN111622268B (en) | Protection construction method based on large rigid box culvert penetrating under power pipe gallery | |
| CN107762529A (en) | Lateral Hole and tunnel main tunnel infall construction method based on gib system | |
| CN102305091A (en) | Support structure for hard rock large-section tunnel construction, and construction method for support structure | |
| CN113153355A (en) | Construction method for down-penetrating tunnel forepoling curtain | |
| CN110566236B (en) | Combined supporting device and supporting method for pipe shed and steel support | |
| CN112302686B (en) | Vertical jacking construction method for entering tunnel inclined shaft into main tunnel | |
| CN210068174U (en) | Large deformation section supporting structure of carbon slate tunnel | |
| CN110985066A (en) | Tunnel grouting support method and structure | |
| CN107780942B (en) | Novel prefabricated assembled pipe shed for pre-reinforcing soft soil tunnel and manufacturing process thereof | |
| CN113153375B (en) | Construction method of soft foundation ultra-small clear distance tunnel primary support anti-drop support settlement-reducing support system | |
| CN112302687B (en) | Support-changing and jacking construction method for entering main tunnel of tunnel inclined shaft | |
| CN113605951B (en) | Shallow tunnel supporting structure and construction method thereof | |
| CN112443331B (en) | Disturbance sensitive stratum ultra-small clear distance large section group-hole parallel subway tunnel construction method | |
| CN114607272A (en) | Construction method for passing existing water delivery tunnel under tunnel | |
| CN113944479A (en) | Unfavorable geological tunnel three-fork construction method | |
| CN112647978A (en) | Construction method for leading small pilot tunnel of soft rock large-deformation tunnel | |
| CN112282771A (en) | Rapid construction method for super-large-span highway tunnel | |
| CN213016381U (en) | Tunnel preliminary bracing and miniature stake integrated configuration | |
| CN212272228U (en) | Dense-net type advanced support system of underground excavation tunnel | |
| CN218759971U (en) | Weak surrounding rock section tunnel just props up hunch foot and subsides prevention and control structure |
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 |