CN115370371A - Tunnel ditch section construction method - Google Patents
Tunnel ditch section construction method Download PDFInfo
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- CN115370371A CN115370371A CN202210869361.4A CN202210869361A CN115370371A CN 115370371 A CN115370371 A CN 115370371A CN 202210869361 A CN202210869361 A CN 202210869361A CN 115370371 A CN115370371 A CN 115370371A
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- 238000010276 construction Methods 0.000 title claims abstract description 66
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 75
- 238000005553 drilling Methods 0.000 claims abstract description 54
- 238000011010 flushing procedure Methods 0.000 claims abstract description 43
- 238000000034 method Methods 0.000 claims abstract description 42
- 238000012360 testing method Methods 0.000 claims abstract description 41
- 239000011440 grout Substances 0.000 claims abstract description 20
- 238000003825 pressing Methods 0.000 claims abstract description 20
- 238000004873 anchoring Methods 0.000 claims abstract description 16
- 230000000694 effects Effects 0.000 claims abstract description 8
- 238000007689 inspection Methods 0.000 claims abstract description 7
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 5
- 239000010959 steel Substances 0.000 claims abstract description 5
- 239000004568 cement Substances 0.000 claims description 12
- 230000008569 process Effects 0.000 claims description 12
- 230000005641 tunneling Effects 0.000 claims description 7
- 230000035699 permeability Effects 0.000 claims description 6
- 238000004080 punching Methods 0.000 claims description 6
- 239000002002 slurry Substances 0.000 claims description 6
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 3
- 238000007569 slipcasting Methods 0.000 claims 1
- 239000011435 rock Substances 0.000 description 23
- 238000005406 washing Methods 0.000 description 11
- 239000003795 chemical substances by application Substances 0.000 description 4
- 238000007596 consolidation process Methods 0.000 description 4
- 230000002787 reinforcement Effects 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000009412 basement excavation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 235000019994 cava Nutrition 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
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- 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
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- 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
- E21D9/002—Injection methods characterised by the chemical composition used
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- 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
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- Mining & Mineral Resources (AREA)
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- Environmental & Geological Engineering (AREA)
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- Geochemistry & Mineralogy (AREA)
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- Chemical & Material Sciences (AREA)
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- General Chemical & Material Sciences (AREA)
- Piles And Underground Anchors (AREA)
Abstract
The application discloses a tunnel gully section construction method which comprises the steps of drilling a grouting hole according to the principle of sequential encryption after hole site lofting of the grouting hole is carried out on the earth surface of a gully section; selecting a drilling hole flushing mode and a crack flushing mode according to different geological conditions and field grouting tests to flush grouting holes and cracks in the holes; carrying out a water pressing test after the grouting holes are washed, selecting grouting holes with a preset proportion from the I-sequence grouting holes to carry out a single-point method water pressing test, and carrying out a simple water pressing test on the rest grouting holes; installing grouting anchor cables and anchoring, connecting the same row of grouting anchor cables by adopting W-shaped steel belts, installing grout stopping plugs, anchor piers and riggings after anchoring, and tensioning the grouting anchor cables through anchor cable tensioners; performing lag grouting by adopting a sectional grouting method, and finishing grouting after the preset grouting construction time is reached; and after grouting is finished, performing grouting effect inspection. The problem that the entry driving machine potential safety hazard is big when taking through the tunnel fault is solved to this application.
Description
Technical Field
The application relates to the technical field of civil engineering, in particular to a tunnel gully section construction method.
Background
A full face Tunnel Boring Machine (TBM) is a commonly used intelligent device in mechanized construction. The tunnel fault zone is likely to be encountered in the TBM tunneling process, and the tunnel fault zone is mostly generated at the position of a tunnel top serving as a gully. The inventor finds that the potential safety hazard is large when the TBM passes through the tunnel fault zone, the tunneling time is long, the cost is high, and even the TBM equipment is damaged and difficult to pass smoothly. Therefore, how to reduce the potential safety hazard of the tunneling construction of the TBM in the trench section of the tunnel is an urgent problem to be solved.
Disclosure of Invention
The main purpose of the application is to provide a tunnel trench section construction method, and the problem that how to reduce the potential safety hazard of tunneling construction of a TBM in a tunnel trench section needs to be solved urgently is solved.
In order to achieve the above object, a tunnel gully section construction method is provided according to the present application.
The construction method of the tunnel trench section comprises the following steps: s1: sequentially lofting hole sites of the grouting holes on the earth surface of the gully section, and drilling the grouting holes according to the hole sites according to the principle of sequential encryption; the construction is divided into two-sequence construction, wherein the ground surface of the trench punching section is the terrain surface above the tunnel; s2: selecting a corresponding drilling hole flushing mode according to different geological conditions and a field grouting test to flush a grouting hole, and selecting a corresponding crack flushing mode according to different geological conditions to flush a crack in the grouting hole; s3: carrying out a water pressing test in a first preset time period after the grouting holes are washed, wherein the grouting holes with preset proportion are selected from the I-sequence grouting holes in the second-sequence construction to carry out a single-point method water pressing test, and all the rest grouting holes except the grouting holes with the preset proportion are subjected to a simple water pressing test; s4: installing a grouting anchor cable and anchoring the grouting anchor cable, installing a grout stop plug, an anchor pier and a rigging after the anchoring time reaches a second preset time period, and tensioning the grouting anchor cable through an anchor cable tensioner; wherein, the same row of grouting anchor cables are connected by adopting W-shaped steel belts; s5: performing lag grouting by adopting a sectional grouting method, and finishing grouting after the preset grouting construction time is reached; s6: and after grouting is finished, performing grouting effect inspection.
Optionally, after tensioning the grouting anchor cable by the anchor cable tensioner, the method further includes: detecting the pre-tightening force of the grouting anchor cable; and if the pretightening force is reduced in a third preset time period, performing secondary tensioning on the grouting anchor cable with the reduced pretightening force.
Optionally, after drilling the grouting hole, the method further includes: detecting the grout holes according to drilling requirements, wherein the drilling requirements comprise: the axial deviation between the actual construction drilling axis and the preset drilling hole is less than 5 degrees, the deviation between the actual construction hole position of the grouting anchor cable and the lofting hole position corresponding to the grouting hole is less than or equal to 10cm, the drilling depth is greater than or equal to the preset drilling depth and is less than or equal to the preset drilling depth, and the length of the drilling depth is 100mm.
Optionally, the drilling mode of washing includes from the hole bottom to the hole outside open water wash, pressure wind washes, geomantic omen jointly washes, the crack mode of washing includes that pressure water washes, pressure wind washes, geomantic omen rotates and washes.
Optionally, the flushing water pressure during flushing the grouting holes and the cracks in the holes is 80% of the grouting pressure, and if the flushing water pressure is greater than 1MPa, the flushing water pressure is 1MPa; and the flushing air pressure when the grouting holes and the cracks in the holes are flushed is 50 percent of the grouting pressure, and if the flushing air pressure exceeds 0.5MPa, the flushing air pressure is 0.5MPa.
Optionally, the pressurized water pressure during the single-point method pressurized water test and the simple pressurized water test is 80% of the grouting pressure, and if the pressurized water pressure is greater than 1MPa, the pressurized water pressure is 1MPa; the time length of the simple pressurized water test is 20min, the pressurized water flow is measured and read every 5min, and the water permeability is calculated according to the last pressurized water flow value.
Optionally, in the process of the delayed grouting, the cement is 42.5MPa sulfate-resistant cement, and the cement slurry is selected from the following components: 1. 1: 1. 0.5:1 three water-cement ratio levels.
Optionally, the first preset time period is 24 hours, the second preset time period is 30min, and the third preset time period is 48 hours.
Optionally, in the construction process of the grouting anchor cable, if the pretightening force is less than 90% of the preset tension force, a new grouting anchor cable is repaired.
Optionally, the length of the segment in the segment grouting method is as follows: the first section is 3.0m, and the second section and below is 5.0m; and the preset grouting construction time is more than 7min and less than or equal to 8min.
Optionally, the grouting holes with the preset proportion are 20% of grouting holes.
Optionally, the grouting effect check includes: and measuring the wave velocity of the rock mass by using sound waves to perform consolidation grouting quality inspection, and comprehensively evaluating the consolidation grouting quality by combining a drilling water-pressurizing test, geophysical prospecting results before and after grouting, grouting construction data and drilling coring data.
According to the tunnel trench-punching segment construction method, firstly, hole site lofting of grouting holes is carried out on the surface of a trench-punching segment in a sequence mode, and then the grouting holes are drilled according to the hole sites in the sequence encryption principle; the construction is divided into two-sequence construction, wherein the earth surface of the gully section is the gully topographic surface above the tunnel; selecting a corresponding drilling hole flushing mode according to different geological conditions and a field grouting test to flush the grouting hole, and selecting a corresponding crack flushing mode according to different geological conditions to flush the crack in the grouting hole; carrying out a water pressing test in a first preset time period after the grouting holes are washed, wherein the grouting holes with preset proportion are selected from the I-sequence grouting holes in the second-sequence construction to carry out a single-point method water pressing test, and all the rest grouting holes except the grouting holes with the preset proportion are subjected to a simple water pressing test; after the pressurized water test is finished, installing a grouting anchor cable and anchoring the grouting anchor cable, installing a grout stop plug, an anchor pier and a rigging after the anchoring time reaches a second preset time period, and tensioning the grouting anchor cable through an anchor cable tensioner; wherein, the same row of grouting anchor cables are connected by adopting W-shaped steel belts; finally, performing lag grouting by adopting a sectional grouting method, and finishing grouting after the preset grouting construction time is reached; and after grouting is finished, performing grouting effect inspection. It can be seen that in the construction method of the embodiment of the application, when the tunnel trench-flushing section is encountered, the surrounding rock is reinforced by means of trench-flushing section surface grouting reinforcement, integrity of broken surrounding rock is enhanced, self-bearing capacity of the surrounding rock is improved, and loosening and collapse of the surrounding rock are inhibited, so that the problems that a TBM (tunnel boring machine) is damaged and buried in a tunneling process can be effectively prevented, construction potential safety hazards are reduced, and construction efficiency is improved. In addition, the grouting mode is an anchor cable grouting mode, and compared with an anchor rod grouting mode, the integrity of the surrounding rock can be enhanced. In addition, the concrete grouting construction process of the embodiment of the application has the advantages of ingenious design concept, easily controlled grouting quality and environment-friendly application.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, serve to provide a further understanding of the application and to enable other features, objects, and advantages of the application to be more apparent. The drawings and their description illustrate the embodiments of the invention and do not limit it. In the drawings:
fig. 1 is a flowchart of a tunnel gully section construction method according to an embodiment of the application;
FIG. 2 is a cross-sectional view of a tunnel trench segment according to an embodiment of the present application;
FIG. 3 is a schematic plan view of a grouting hole provided according to an embodiment of the present application;
FIGS. 4-5 are cross-sectional views of grout holes provided in accordance with embodiments of the present application;
fig. 6 is a schematic diagram of a grouting anchor cable during construction according to an embodiment of the present application.
In the figure, 1-the earth surface of a gully section, 2-grouting holes, 3-hole positions, 4-tunnels, 5-I-order grouting holes, 6-grouting anchor cables, 7-grout stop plugs, 8-anchor piers, 9-rigging, 10-hole top lines, 11-surrounding rocks, 12-axes, 13-II-order grouting holes, 14-grouting sections, 15-non-grouting sections, 16-anchoring agents, 17-grouting pumps and 18-grouting barrels.
Detailed Description
In order to make the technical solutions of the present application better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be used. Moreover, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
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 application will be described in detail below with reference to the embodiments with reference to the attached drawings.
Example 1:
a tunnel trench section construction method according to an embodiment of the present application will be specifically described with reference to fig. 1 to 6: as shown in fig. 1, the method comprises the following steps S1-S6: s1, sequentially lofting hole sites 3 of grouting holes 2 on a trench section ground surface 1, and drilling the grouting holes 2 according to the hole sites according to a sequential encryption principle; wherein, the two-sequence construction is divided between rows of grouting holes 2 and between holes of the same row of grouting holes 2, and the earth surface 1 of the gully section is the topographic surface above the tunnel 4; s2, selecting a corresponding drilling hole flushing mode according to different geological conditions and a field grouting test to flush the grouting hole, and selecting a corresponding crack flushing mode according to different geological conditions to flush the crack in the grouting hole; s3, carrying out a water pressing test in a first preset time period after the grouting holes are washed, wherein the grouting holes 2 with a preset proportion are selected from the grouting holes 5 of the I sequence in the second sequence construction to carry out a single-point method water pressing test, and all the rest grouting holes 2 except the grouting holes 2 with the preset proportion are subjected to a simple water pressing test; s4, installing a grouting anchor cable 6 and anchoring the grouting anchor cable, installing a grout stop plug 7, an anchor pier 8 and a rigging 9 after the anchoring time reaches a second preset time period, and tensioning the grouting anchor cable 6 through an anchor cable tensioner; wherein, the same row of grouting anchor cables 6 are connected by W-shaped steel belts; s5, performing lagging grouting by adopting a sectional grouting method, and finishing grouting after the preset grouting construction time is reached; and S6, after grouting is finished, performing grouting effect inspection.
For the trench section ground surface 1 in the step S1, a cross-sectional view of the tunnel trench section is provided, as shown in fig. 2, a hole top line 10 is a straight line corresponding to the inner top end of the tunnel 4, a trench is formed at a concave position above the hole top line 10, surrounding rocks 11 are arranged above the hole top line 10, and the surface of the surrounding rocks 11 is in a trench shape, that is, the trench section ground surface 1. In addition, the lofting of the hole 3 of the grouting hole 2 can be specifically carried out by adopting a GPS (global positioning system) measuring instrument or a total station. The GPS measuring instrument is a Global Positioning System (GPS) measuring instrument, and can perform accurate Positioning according to the GPS measuring instrument or a total station and perform lofting of the hole site 3 according to a designed lofting point. After the lofting of the hole site 3 is completed, the grouting hole 2 can be drilled. The injection hole 2 is drilled by a geological drilling machine, and the geological drilling machine can be a pneumatic rock drilling machine or a hydraulic rock drilling machine, such as a GY100 rock drilling machine. When drilling, the drilling is carried out downwards from the vertical roof line 10 of the trench surface, the depth of the grouting hole 2 is also set in advance, and the drilling is carried out according to the preset drilling depth. As shown in fig. 3, which is a schematic plan view of the holes 3 in the grouting holes 2, the dotted line in the middle is an axis 12 of the tunnel 4, the holes 3 are respectively distributed in the direction of the axis 12 and in the directions of both sides of the axis 12, and the distance between the holes 3 and the distance between rows in fig. 3 are schematic and can be adjusted according to actual requirements in practical application. In the second-order construction in the step S1, the grouting holes 2 are divided into I-order grouting holes 5 and II-order grouting holes 13, and the I-order grouting holes 5 and the II-order grouting holes 13 are respectively grouted according to the sequence. In addition, after drilling the grout hole 2, the grout hole 2 is detected according to the drilling requirements, which include: the axial deviation of the actual construction drilling axis and the preset drilling hole is less than 5 degrees, the deviation of the actual construction hole position 3 of the grouting anchor cable 6 and the lofted hole position 3 corresponding to the grouting hole 2 is less than or equal to 10cm, the drilling depth is greater than or equal to the preset drilling depth and is less than or equal to the preset drilling depth, and the elongation is 100mm. And if the drilling requirement is not met, drilling again after grouting is carried out. When the drilling hole is provided with caves, collapsed holes or fallen blocks and is difficult to drill, grouting treatment can be carried out firstly, and then drilling is carried out. As shown in fig. 4 and 5, both are sectional views of the grouting holes 2, and fig. 4 shows that the trench section is found after a part of the excavation, so that the grouting holes 2 above the tunnel 4 can only be drilled to the top of the tunnel 4, and fig. 5 shows that the grouting penetrates the tunnel 4 during grouting, that is, the grouting holes 2 are drilled to the lower side of the tunnel 4 for the part of the trench section which is not excavated in front. In addition, it should be noted that, as shown in fig. 4 and 5, the grouting hole 2 is divided into a grouting section 14 and a non-grouting section 15, only the grouting section 14 is grouted during grouting, the non-grouting section 15 is a section preset below the surface, the length of the non-grouting section 15 is determined according to an industry standard or geological characteristics, and the specific distance values in fig. 4 and 5 are schematic and can be adjusted according to actual requirements in practical application.
After the grouting hole 2 is drilled, the step S2 is carried out to wash the drilled hole (the grouting hole 2), the drilling hole washing mode in the step S2 comprises water washing from the bottom of the hole to the outside of the hole, pressure wind washing and wind-water combined washing, and the fracture washing mode comprises pressure water washing, pressure wind washing and wind-water alternate washing. Furthermore, the flushing water pressure during flushing the grouting holes 2 and the cracks in the holes is 80% of the grouting pressure, and if the flushing water pressure is greater than 1MPa, the flushing water pressure is 1MPa; the flushing air pressure when the grouting holes 2 and the cracks in the holes are flushed is 50% of the grouting pressure, and if the flushing air pressure exceeds 0.5MPa, the flushing air pressure is 0.5MPa. In the embodiment, the grouting pressure needs to be selected according to the compressive strength of the surrounding rock, and in addition, the selection of the numerical values of 80%, 1MPa, 50% and 0.5MPa can be adjusted in a small range according to actual requirements and industrial standards.
And (5) after the grouting hole 2 and the cracks in the hole are washed according to the washing mode of the step (S2), performing a pressurized water test in a step (S3). In the step S3, the first preset time period is 24 hours, namely a water pressing test is required within 24 hours after the flushing is finished, and if the water pressing test is not carried out within 24 hours, the grouting hole 2 and the cracks in the grouting hole are flushed before the water pressing test. In addition, in step S3, 20% of the first-order grouting holes 5 are selected for a single-point method water pressing test, and the remaining 80% of the first-order grouting holes 5 and all the second-order grouting holes 13 are subjected to a simple water pressing test. The grouting pressure of 80% is selected as the pressurized water pressure in the single-point method pressurized water test and the simple pressurized water test, and if the pressurized water pressure is greater than 1MPa, the pressurized water pressure is selected to be 1MPa; the simple water pressurizing test duration is 20min, the water pressurizing flow is measured every 5min, the water permeability is calculated according to the last water pressurizing flow value, and the water pressurizing test result is expressed by the water permeability. The specific water permeability is calculated by the following formula: q = Q/(p · L); wherein Q is the water permeability, Q is the pressurized water flow, p is the water pressure, and L is the test section length. In addition, the selection of the numerical values of 20%, 80%, 1MPa, 20min and 5min can be adjusted in a small range according to actual requirements and industrial standards.
After the water pressure test is completed, the step S4 is carried out in time, in the step S4, the grouting anchor cable 6 is anchored by using an anchoring agent 16 specifically, and the grout stop plug 7, the anchor pier 8 and the rigging 9 are installed after the anchoring time reaches a second preset time period, wherein the second preset time period is 30min, which means that the installation of the grout stop plug 7, the anchor pier 8 and the rigging 9 can be carried out only when the anchoring time at least reaches 30 min. In the installation of the grout stop plug 7, the anchor pier 8 and the rigging 9, the grouting anchor cable 6 is tensioned through the anchor cable tensioner, and after the grouting anchor cable 6 is tensioned through the anchor cable tensioner, the pre-tightening force of the grouting anchor cable 6 needs to be detected; if the pretightening force is reduced in a third preset time period, performing secondary tensioning on the grouting anchor cable 6 with the reduced pretightening force. Wherein the third preset period is 48h. And grouting by installing a grouting anchor cable 6, namely grouting in a subsequent anchor cable mode, wherein the anchor cable is selected instead of grouting by using an anchor rod in the embodiment of the application, so that the integrity of the surrounding rock can be improved by the anchor cable, the mechanical property of the surrounding rock is fundamentally improved, the displacement of the surrounding rock is effectively controlled, and the stability of the surrounding rock is promoted.
In step S5, the segment length in the segment grouting method is: the first section is 3.0m, the second section and below is 5.0m; the preset grouting construction time is more than 7min and less than or equal to 8min. The preset grouting construction time is determined by the following method: when grouting is started, the pressure reaches the design value as soon as possible, the pressure of the contact section and the hole section with high injection rate is gradually increased, the density of grout needs to be measured and recorded when the grout is converted and the grouting is finished in the grouting process, the measured value is reflected in the original grouting record, and through experimental analysis, the increase ratio of the diffusion radius of the grout is below 10% when the grouting construction time reaches more than 7min, so that the reasonable grouting time is finally determined to be 7-8 min by combining the uncontrollable performance of the site construction time, and the grouting can be finished when the reasonable grouting time meets the regulations. In the process of the lag grouting, the cement is 42.5MPa sulfate-resistant cement, and the cement slurry is selected from the following components: 1. 1: 1. 0.5:1 three water-cement ratio grades. In addition, in the grouting slurry preparation stage, feeding is carried out strictly according to the designed material proportion, the stirring is uniform, and when grouting operation is carried out, a filter screen is arranged at a slurry outlet to prevent the blocking of the grouting holes 2 caused by the caking of ingredients. Fig. 6 is a schematic diagram of a grouting anchor cable 6 during construction, and fig. 6 includes an anchoring agent 16, a grout stop plug 17, an anchor pier 8, a rigging 9, a grouting pump 17, and a grouting barrel 18, wherein the anchoring agent 16 and the grout stop plug 17 are all covered on the grouting anchor cable 6. During construction, the grouting slurry in the grouting barrel 18 is grouted into the grouting holes 2 through the grouting pump 17. In addition, for "42.5MPa, 2: 1. 1: 1. 0.5: 1' can be adjusted in a small range according to actual construction requirements and industry standards.
Furthermore, in the construction process of the grouting anchor cable 6, the pre-tightening force of the grouting anchor cable 6 needs to be detected, if the detected pre-tightening force is smaller than 90% of the preset pre-tightening force, it indicates that the quality of the anchor cable is in a problem, a new grouting anchor cable 6 needs to be timely repaired near the anchor cable with the problem, the pre-tightening force of the anchor cable needs to be detected regularly after the construction is completed, and the problem needs to be timely repaired after the problem is detected.
In step S6, the grouting effect check includes: and measuring the wave velocity of the rock mass by using sound waves to perform consolidation grouting quality inspection, and comprehensively evaluating the consolidation grouting quality by combining a drilling water-pressurizing test, geophysical prospecting results before and after grouting, grouting construction data and drilling coring data. And after the evaluation result meets the construction requirement, the reinforcement of the trench punching section of the tunnel is completed, and then the TBM can more safely tunnel.
Based on the above description, the beneficial effects of the embodiments of the present application are summarized as follows:
1. due to the fact that the geological condition of a tunnel trench flushing section is poor, the stability of surrounding rocks is poor, ground surface pre-grouting reinforcement is firstly carried out, the integrity and the stability of broken surrounding rocks can be enhanced, the self-supporting capacity of the surrounding rocks is improved, loosening and collapse of the surrounding rocks are restrained, the TBM machine is guaranteed to conduct tunneling smoothly, and the conditions that the TBM machine is buried or clamped are effectively prevented;
2. the pre-grouting reinforcement effect of the earth surface is stable and reliable, and the grouting quality is easy to control;
3. by adopting a grouting anchor cable advanced support mode, the labor intensity can be greatly reduced, the degree of mechanization is improved, the construction efficiency is improved, and the support cost is reduced; compared with an anchor rod grouting mode, the anchor cable grouting mode can better enhance the integrity of surrounding rock and improve the construction safety;
4. the construction scheme has the advantages of ingenious design concept, high construction efficiency, good safety, environment-friendly application and wide market prospect.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims (10)
1. A tunnel gully segment construction method is characterized by comprising the following steps:
s1: sequentially lofting hole sites of the grouting holes on the surface of the gully section, and drilling the grouting holes according to the hole sites according to the principle of sequential encryption; the construction is divided into two-sequence construction, wherein the ground surface of the trench punching section is the trench punching terrain surface above the tunnel;
s2: selecting a corresponding drilling hole flushing mode according to different geological conditions and a field grouting test to flush a grouting hole, and selecting a corresponding crack flushing mode according to different geological conditions to flush a crack in the grouting hole;
s3: carrying out a water pressing test in a first preset time period after the grouting holes are washed, wherein the grouting holes with preset proportion are selected from the I-sequence grouting holes in the second-sequence construction to carry out a single-point method water pressing test, and all the rest grouting holes except the grouting holes with the preset proportion are subjected to a simple water pressing test;
s4: installing a grouting anchor cable and anchoring the grouting anchor cable, installing a grout stop plug, an anchor pier and a rigging after the anchoring time reaches a second preset time period, and tensioning the grouting anchor cable through an anchor cable tensioner; wherein, the same row of grouting anchor cables are connected by adopting W-shaped steel belts;
s5: performing lagging grouting by adopting a sectional grouting method, and finishing grouting after the preset grouting construction time is reached;
s6: and after grouting is finished, performing grouting effect inspection.
2. The tunneling section construction method according to claim 1, wherein after tensioning the grouting anchor line by the anchor line tensioner, the method further comprises: detecting the pre-tightening force of the grouting anchor cable; and if the pretightening force is reduced in a third preset time period, performing secondary tensioning on the grouting anchor cable with the reduced pretightening force.
3. The method of constructing a tunnel trench section according to claim 1, wherein after drilling the grout hole, the method further comprises: detecting the grout holes according to drilling requirements, wherein the drilling requirements comprise: the axial deviation between the actual construction drilling axis and the preset drilling hole is less than 5 degrees, the deviation between the actual construction hole position of the grouting anchor cable and the lofting hole position corresponding to the grouting hole is less than or equal to 10cm, the drilling depth is greater than or equal to the preset drilling depth and is less than or equal to the preset drilling depth, and the length of the drilling depth is 100mm.
4. The method for constructing the tunnel trench section according to claim 1, wherein the drilling and flushing modes comprise open water flushing, pressure wind flushing and wind-water combined flushing from the bottom of the hole to the outside of the hole, and the crack flushing modes comprise pressure water flushing, pressure wind flushing and wind-water alternate flushing.
5. The method for constructing the tunnel trench section according to claim 4, wherein the flushing water pressure for flushing the grouting holes and the cracks in the holes is selected from 80% of the grouting pressure, and if the flushing water pressure is greater than 1MPa, the flushing water pressure is selected from 1MPa; and the flushing air pressure when the grouting holes and the cracks in the holes are flushed is 50 percent of the grouting pressure, and if the flushing air pressure exceeds 0.5MPa, the flushing air pressure is 0.5MPa.
6. The method for constructing the trench section of the tunnel according to claim 1, wherein the water pressure in the single-point method water pressure test and the simple water pressure test is selected to be 80% of the grouting pressure, and if the water pressure is greater than 1MPa, the water pressure is selected to be 1MPa; the time length of the simple pressurized water test is 20min, the pressurized water flow is measured and read every 5min, and the water permeability is calculated according to the last pressurized water flow value.
7. The method for constructing a tunnel trench section according to claim 1, wherein in the process of the post-grouting, the cement is 42.5MPa sulfate-resistant cement, and the cement slurry is selected from the group consisting of 2: 1. 1: 1. 0.5:1 three water-cement ratio levels.
8. The tunnel gully section construction method of claim 2, wherein the first preset time period is 24 hours, the second preset time period is 30min, and the third preset time period is 48 hours.
9. The tunnel gully section construction method according to claim 2, wherein in the grouting anchor cable construction process, if the pretightening force is less than 90% of the preset tension force, a new grouting anchor cable is additionally arranged.
10. The tunnel trench segment construction method according to claim 1, wherein the segment length in the segment slip casting method is: the first section is 3.0m, the second section and below is 5.0m; and the preset grouting construction time is more than 7min and less than or equal to 8min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210869361.4A CN115370371A (en) | 2022-07-22 | 2022-07-22 | Tunnel ditch section construction method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210869361.4A CN115370371A (en) | 2022-07-22 | 2022-07-22 | Tunnel ditch section construction method |
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| Publication Number | Publication Date |
|---|---|
| CN115370371A true CN115370371A (en) | 2022-11-22 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210869361.4A Pending CN115370371A (en) | 2022-07-22 | 2022-07-22 | Tunnel ditch section construction method |
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| Country | Link |
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| CN (1) | CN115370371A (en) |
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