CN116537221A - Highway tunnel portal section collapse sliding body slope protection reinforcing structure and construction method - Google Patents
Highway tunnel portal section collapse sliding body slope protection reinforcing structure and construction method Download PDFInfo
- Publication number
- CN116537221A CN116537221A CN202210089109.1A CN202210089109A CN116537221A CN 116537221 A CN116537221 A CN 116537221A CN 202210089109 A CN202210089109 A CN 202210089109A CN 116537221 A CN116537221 A CN 116537221A
- Authority
- CN
- China
- Prior art keywords
- tunnel
- slope
- open cut
- cut tunnel
- wall
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003014 reinforcing effect Effects 0.000 title claims abstract description 14
- 238000010276 construction Methods 0.000 title claims description 36
- 239000011435 rock Substances 0.000 claims abstract description 34
- 238000004873 anchoring Methods 0.000 claims abstract description 21
- 239000007921 spray Substances 0.000 claims abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 44
- 229910000831 Steel Inorganic materials 0.000 claims description 33
- 239000010959 steel Substances 0.000 claims description 33
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 30
- 239000002689 soil Substances 0.000 claims description 21
- 239000004567 concrete Substances 0.000 claims description 20
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 16
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 16
- 238000009412 basement excavation Methods 0.000 claims description 16
- 239000004571 lime Substances 0.000 claims description 16
- 239000004746 geotextile Substances 0.000 claims description 15
- 229910052742 iron Inorganic materials 0.000 claims description 15
- 239000004927 clay Substances 0.000 claims description 12
- 239000004570 mortar (masonry) Substances 0.000 claims description 11
- 238000005507 spraying Methods 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 9
- 238000011065 in-situ storage Methods 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 8
- 239000011150 reinforced concrete Substances 0.000 claims description 8
- 244000025254 Cannabis sativa Species 0.000 claims description 7
- 238000009825 accumulation Methods 0.000 claims description 7
- 238000009792 diffusion process Methods 0.000 claims description 7
- 238000009423 ventilation Methods 0.000 claims description 6
- 239000002956 ash Substances 0.000 claims description 5
- 238000010009 beating Methods 0.000 claims description 5
- 239000004744 fabric Substances 0.000 claims description 5
- 239000010881 fly ash Substances 0.000 claims description 5
- 230000002787 reinforcement Effects 0.000 claims description 5
- 238000009941 weaving Methods 0.000 claims description 4
- 235000012766 Cannabis sativa ssp. sativa var. sativa Nutrition 0.000 claims description 3
- 235000012765 Cannabis sativa ssp. sativa var. spontanea Nutrition 0.000 claims description 3
- 239000010426 asphalt Substances 0.000 claims description 3
- 235000009120 camo Nutrition 0.000 claims description 3
- 235000005607 chanvre indien Nutrition 0.000 claims description 3
- 238000005520 cutting process Methods 0.000 claims description 3
- 239000006261 foam material Substances 0.000 claims description 3
- 239000011487 hemp Substances 0.000 claims description 3
- 230000000149 penetrating effect Effects 0.000 claims description 3
- 238000005266 casting Methods 0.000 claims description 2
- 230000007704 transition Effects 0.000 claims description 2
- 238000009966 trimming Methods 0.000 claims description 2
- 238000009736 wetting Methods 0.000 claims description 2
- 238000005728 strengthening Methods 0.000 claims 1
- 239000004575 stone Substances 0.000 abstract description 4
- 230000008859 change Effects 0.000 abstract description 2
- 230000001681 protective effect Effects 0.000 abstract description 2
- 230000007613 environmental effect Effects 0.000 abstract 1
- 238000005516 engineering process Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 5
- 229910001294 Reinforcing steel Inorganic materials 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 230000005484 gravity Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 2
- 238000006253 efflorescence Methods 0.000 description 2
- 239000011087 paperboard Substances 0.000 description 2
- 206010037844 rash Diseases 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 239000011378 shotcrete Substances 0.000 description 2
- 241000196324 Embryophyta Species 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000001012 protector Effects 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000008234 soft water Substances 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/20—Securing of slopes or inclines
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
- E01F7/00—Devices affording protection against snow, sand drifts, side-wind effects, snowslides, avalanches or falling rocks; Anti-dazzle arrangements ; Sight-screens for roads, e.g. to mask accident site
- E01F7/04—Devices affording protection against snowslides, avalanches or falling rocks, e.g. avalanche preventing structures, galleries
- E01F7/045—Devices specially adapted for protecting against falling rocks, e.g. galleries, nets, rock traps
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/20—Securing of slopes or inclines
- E02D17/202—Securing of slopes or inclines with flexible securing means
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/20—Securing of slopes or inclines
- E02D17/207—Securing of slopes or inclines with means incorporating sheet piles or piles
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/02—Retaining or protecting walls
- E02D29/0258—Retaining or protecting walls characterised by constructional features
- E02D29/0275—Retaining or protecting walls characterised by constructional features cast in situ
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/02—Improving by compacting
- E02D3/10—Improving by compacting by watering, draining, de-aerating or blasting, e.g. by installing sand or wick drains
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/74—Means for anchoring structural elements or bulkheads
-
- 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
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A10/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE at coastal zones; at river basins
- Y02A10/23—Dune restoration or creation; Cliff stabilisation
Abstract
The invention provides a slope protection reinforcing structure of a road tunnel portal section collapse sliding body, which comprises a tunnel, a ladder-shaped anchoring frame beam arranged on at least one side of the tunnel, a lower retaining wall, an end part anti-sliding pile and a long open hole, wherein the lower retaining wall is arranged on the lower retaining wall; the ladder-shaped anchoring frame beams comprise multi-stage frame beams distributed along a side slope in a ladder-shaped manner, self-advancing anchor rods are arranged at the intersections of the frame grids of the frame beams and anchored on a mountain rock layer, net-hanging grass-planting protection is arranged in the frame grids, and net-hanging spray tamping protection is arranged at the gradual change section between the tunnel upward slope and the multi-stage frame beams; the lower retaining wall is arranged at the slope toe of the slope and is inclined towards the slope; the end part anti-skid piles are arranged at the end parts of the holes; the long open cut tunnel comprises a first-stage open cut tunnel, a second-stage open cut tunnel and a third-stage open cut tunnel. The protective structure is designed aiming at the landslide of the collapse slide body, and a series of technical problems such as loose collapse slide body, bias voltage, high slope, operation crash stone, greening and environmental protection are effectively solved.
Description
Technical Field
The invention relates to the field of tunnel construction, in particular to a slope protection reinforcing structure of a collapse sliding body of a tunnel portal section of a highway and a construction method.
Background
Aiming at the situation that highway tunnel construction passes through mountain areas with relief, mountain and longitudinal and transverse mountains and mountains, the tunnel portal is often high and steep in pitch and broken in slope due to limitation of line conditions. Whether the tunnel portal section is safe and stable plays an extremely critical role in the whole tunnel construction process. The tunnel portal section excavation has larger disturbance to the undisturbed side slope, so that the safety of the construction process is influenced, and the damage to the operation of a later tunnel is also caused.
The conventional technology is to brush and protect the slope of the tunnel opening according to a certain stable slope rate or adopt a method of lengthening open cut tunnel. The conventional tunnel portal section collapse sliding body bias slope protection mainly improves the supporting strength by means of increasing the model of a steel frame, adding grouting anchor rods for anchoring, increasing the thickness of lining supporting and the like, so that the sliding of the slope and the deformation of the lining in the excavation process are reduced; or the side of the side slope buried is provided with a gravity retaining wall, a back pressure backfill and other measures.
The traditional construction technology is simpler, the biasing force of the slope collapse body is balanced by improving the strength of the supporting structure or backfilling the baffle body and other measures, the conventional treatment technology cannot eliminate the biasing force of the collapse body slope, the conventional treatment technology slides at any time along with the prolonging of the operation period time, the structure of the opening section is damaged, the achieved protection effect is not ideal, the traditional technology has long construction period and high manufacturing cost.
Summarizing, the existing highway tunnel portal section collapse sliding body slope protection construction method mainly has the following defects:
(1) Aiming at the protection of the side elevation slope of the tunnel portal section, the conventional treatment measures are to brush the slope on the tunnel portal side or the side slope according to a certain stable slope rate, then to spray anchors for protection, and to perform retaining wall protection on the slope toe. Conventional treatment measures often dig greatly, damage to undisturbed vegetation on the slope is larger, and if the geological stability of the slope of the opening section is worse, engineering landslide is easily induced if cautious treatment is not carried out, so that the construction cost is increased, the construction period is delayed, even serious safety accidents are caused, and casualties are caused.
(2) Because most of highway tunnel construction in southwest area is located between high steep mountain, the entrance to a cave section faces the threat that the mountain weathers and falls the stone. The conventional treatment measures are to install a passive protection net on the end gate wall, and the protection capability of the passive protection net is very limited for mountain areas frequently suffered from geological disasters, especially for the falling rocks weathered by high-steep rock bodies, the passive protection net is extremely easily damaged seriously, and has short protection length, and although the passive protection net can resist partial small falling rocks, the passive protection net still has great operation safety hidden trouble for the mountain areas frequently suffered from geological disasters.
Therefore, how to design a protective structure of a biasing tunnel portal section which can safely and stably pass through the giant and thick collapse sliding body and is reasonably stressed is extremely important.
Disclosure of Invention
The invention aims at overcoming the defects of the prior art, and provides a slope protection reinforcing structure of a collapsed sliding body of a tunnel portal section of a highway.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a highway tunnel portal section collapse sliding body slope protection reinforcing structure comprises a tunnel, a ladder-shaped anchoring frame beam arranged on at least one side of the tunnel, a lower retaining wall, an end part slide-resistant pile and a long open hole;
the stepped anchoring frame beams comprise multistage frame beams distributed in a stepped manner along a side slope, self-advancing anchor rods are arranged at the intersection points of the frame grids of the frame beams and anchored to a mountain rock layer, net-hanging grass planting protection is arranged in the frame grids, net-hanging spray tamping protection is arranged at the gradual transition section between the upward slope of the tunnel and the multistage frame beams, and side slope water discharge holes penetrating into the lower portion of the rock surface are formed in the stepped anchoring frames at equal intervals;
the lower retaining wall is arranged at the slope toe of the slope and is inclined towards the slope, the bottom of the retaining wall is provided with a toe, the bottom of the retaining wall is buried underground, the top of the retaining wall is horizontal, and a plurality of rows of retaining wall water drainage holes with slopes are arranged on the retaining wall;
the end anti-skid piles are arranged at the end parts of the holes and comprise long piles and short piles, the long piles are arranged close to the tunnels, and retaining plates are arranged between the long piles and the short piles;
the long open cut tunnel comprises a first-level open cut tunnel, a second-level open cut tunnel and a third-level open cut tunnel, the first-level open cut tunnel is connected with a tunnel, the second-level open cut tunnel is connected with the end of a bridge, the third-level open cut tunnel is arranged on the bridge and is connected with the end of the second-level open cut tunnel, a collapse object diffusion accumulation area is arranged at the top of the second-level open cut tunnel, a ventilation window is arranged on the third-level open cut tunnel, an expansion joint is arranged between the first-level open cut tunnel and the second-level open cut tunnel, and a deformation joint is arranged between the second-level open cut tunnel and the third-level open cut tunnel.
Before the side slope excavation construction, a wire netting is woven on a round steel frame bar frame by galvanized iron wires in a construction area, after the side slope excavation is finished, the position of a net hanging anchor rod is set according to design, the self-advancing anchor rod is beaten into rock and exposed, anchoring mortar is poured, an anchoring head is supported, prefabricated wire netting is paved and hung, a cushion block is arranged between the wire netting and a rock surface, and a certain gap is kept between the wire netting and the rock surface.
The two frame strips positioned on the diagonal line are bound on the anchor rod, and the other two frame strips are bound with each other.
And 5-10% of lime soil doped with ash is backfilled at the toe part of the wall and below the water discharge hole of the retaining wall, impermeable geotextile is paved on the surface of lime soil at the back of the wall, a soft permeable pipe with phi 90-120mm is longitudinally distributed at the position close to the water discharge hole, the lime wall at the back of the wall is backfilled with a permeable material 50cm below the wall top, and clay is backfilled and tamped within a range 50cm below the wall top.
Basically, the end part anti-slip pile is formed by casting C30 reinforced concrete in situ, the bottom of a hole is paved with M7.5 mortar to be 10cm thick, the concrete protection layer of the steel bars is not less than 8cm, the longitudinal steel bar spacing marks are all distances between the heavy centers of the steel bars, when the number of the steel bar bundles is multiple, the steel bars in the steel bar bundles are tightly attached, and each 1-2M of the steel bar bundles are spot-welded into a bundle.
Based on the above, the basement of the long open cut tunnel is of a C30 impervious lining structure, and a vault part of the long open cut tunnel is paved with a double-layer geotextile buffer layer, a waterproof layer, a fly ash filling layer and a clay waterproof layer from inside to outside in sequence.
A highway tunnel portal section collapse slide slope protection construction method comprises the following steps:
step 1), step-by-step excavation is adopted from top to bottom on a wall body at one side of a tunnel, and square clearing and supporting are carried out at the same time; the slope surface after the collapse sliding body is cleared adopts a frame beam structure, and the frame lattice intersection points adopt self-advancing anchor rods for anchoring; specifically, before the collapse sliding body is treated and protected, firstly, weaving an iron wire net on a round steel frame bar frame by using galvanized iron wires, after slope excavation and trimming, laying out a net hanging anchor rod position according to design, beating the anchor rod while exposing a rock surface, pouring M30 anchoring mortar, depending on an anchor rod head, paving and binding a prefabricated iron wire net, and simultaneously beating ribs and supporting the steel wire net under the net by using a cushion block to keep a gap between the net and the rock surface; two frame strips in the diagonal direction are bound on the anchor rod, and the other two frame strips are bound with each other; binding the two frame strips with galvanized iron wires at intervals; the iron wire net should be added with anchor rods for fixation at the special concave position, the middle part of the frame lattice adopts a net hanging and spraying grass planting protection, the gradient section side slope between the upward slope of the tunnel and the frame beam adopts a net hanging and spraying concrete protection, C20 spraying concrete is adopted, the rock surface is sprayed with water for wetting before C20 concrete is sprayed, and C20 concrete is sprayed from top to bottom in time before the net sheet is rusted; the side slope water discharge holes are formed by adopting PVC pipes and are arranged on the slope at equal intervals, the rear ends of the side slope water discharge holes are arranged deep into the rock face, the rear parts of the side slope water discharge holes are wrapped by water seepage geotextiles, expansion joints are arranged at intervals, and asphalt hemp battles are used for filling;
step 2), arranging an inclined retaining wall structure at the slope toe, wherein the retaining wall is arranged at the slope toe, the wall height is 8-10 m, the base of the retaining wall is buried 2-3 m below the slope toe, and the wall body material is cast-in-situ C20 concrete; the top of the retaining wall is horizontal, the width of the toe of the retaining wall is 0.6-0.8 m, the height of the toe of the retaining wall is 0.8-1.0 m, the base slope ratio is 0.1:1, the face slope ratio is 1:0.25, and the back slope ratio is 1:0.25; backfilling 8% lime soil doped with ash at the toe part and below the water discharge hole, paving impermeable geotextile on the surface of lime soil at the back of the wall, longitudinally arranging a soft permeable pipe at the position close to the water discharge hole, backfilling the lime soil at the back of the wall to 50cm below the top of the wall by adopting a permeable material, and backfilling and tamping clay within the range of 50cm below the top of the wall; the cutting retaining wall is provided with water discharge holes at a position 30-50 cm higher than the roadbed design line, 2-4 rows of water discharge holes are arranged at equal intervals, the water discharge holes are formed by PVC pipes, the camber gradient is 5-10%, circular holes are formed in the end parts of the PVC pipes in a circumferential direction, and the PVC pipes are wrapped by water seepage geotextiles;
step 3) arranging square anti-slide piles at the end parts of the side slopes and configuring a retaining plate structure, implementing the anti-slide piles after the side slopes at the tops of the anti-slide piles are excavated, arranging 2 pile types of the anti-slide piles at the end parts of the opening sections, wherein the length of the short piles is 20M, the length of the long piles is 1, the length of the long piles is 24M, the retaining plate is arranged in front of the piles, the pile bodies of the anti-slide piles are cast in situ by adopting C30 reinforced concrete, the bottoms of the holes are paved by M7.5 mortar, and the concrete protection layer of the reinforced concrete is not less than 8cm; after the construction of the anti-slide pile is completed, when the strength of the pile body reaches 80%, excavating a slope body in front of the pile, removing a locking opening in front of the pile, and constructing a front facing wall of the pile; the main reinforcements of the slide-resistant pile are connected in a sleeve manner, and the area percentage of the longitudinal tension reinforcement joints in the same connecting section is not more than 50%;
step 4), setting a long open cut tunnel buffer structure after slope protection is stable, wherein the long open cut tunnel buffer structure is arranged at the joint of a bridge tunnel, takes the original open cut tunnel as a first-stage open cut tunnel, is positioned right below a cliff of a mountain at the top of the tunnel, and is a C30 impervious lining structure; a foam material buffer layer is arranged between the newly added arch and the first-stage open cut tunnel; the secondary open cut tunnel is connected with the end part of the bridge, a tunnel end wall structure is arranged at the end part, a collapse object diffusion accumulation area is arranged at the top of the tunnel, the lining structure is consistent with the primary open cut tunnel, and expansion joints are arranged between the primary open cut tunnel and the secondary open cut tunnel; the third-level open cut tunnel is arranged on the bridge and connected with the second-level open cut tunnel, and a ventilation window is arranged on a straight wall of the third-level open cut tunnel;
step 5), paving the arch crown parts of the first-level, second-level and third-level open cut tunnels sequentially from inside to outside into a double-layer geotechnical cloth buffer layer, a waterproof layer, a fly ash filling and clay water-resisting layer.
Compared with the prior art, the invention has outstanding substantive characteristics and remarkable progress, and particularly, the invention mainly solves the following problems and achieves corresponding effects:
under the geological environment of the collapse sliding body and the high side slope, firstly, steel wire meshes are used for enclosing, then, top-down hierarchical excavation is adopted, frame beams and self-advancing long anchor rods are arranged, so that the collapse sliding body sliding slope before, during and after construction can be effectively avoided, and the characteristics of the side slope without an outward-inclined structural surface, the whole bias of the side slope and rock breaking in the local range of the collapse sliding body can be dealt with;
the inclined retaining wall support is arranged at the lower part of the side slope, so that the problem of bias under the high side slope can be further solved;
the end parts of the opening sections are still in an unstable state after the opening sections are clear and the retaining wall is supported, and in order to avoid collapse in the construction process of the end parts of the tunnel opening sections, square anti-slip piles are arranged at the end parts of the roadbed sides of the tunnel opening sections and a retaining plate structure is arranged;
the three-stage long open cut tunnel is arranged, so that the safety of a tunnel can be protected, the damage to a road caused by falling of weathered rock is reduced, the traffic safety is guaranteed, meanwhile, the buffer structure is arranged at the top end of the three-stage open cut tunnel, the open cut tunnel can be protected, and the collapse object diffusion area is arranged at the second-stage open cut tunnel, so that collapse objects with considerable capacity can be accommodated.
Drawings
FIG. 1 is a longitudinal section view of a highway tunnel portal segment collapse slide slope protection reinforcing structure according to the present invention.
FIG. 2 is a cross-sectional view of the highway tunnel portal segment slump body slope protection reinforcing structure of the present invention.
FIG. 3 is a construction flow chart of the highway tunnel portal segment collapse slide slope protection reinforcing structure of the invention.
Fig. 4 is a sectional view of the retaining wall of the present invention.
Fig. 5 is a schematic view of the construction structure of the three-stage long open cut tunnel of the present invention.
In the figure: 1. a frame beam; 2. self-advancing anchor rod; 3. prefabricating an iron wire net; 4. hanging concrete; 5. a retaining wall; 6. retaining wall drain holes; 7. an anti-slide pile; 8. a soil retaining plate; 9. a long open cut tunnel; 10. a double-layer geotextile buffer structure; 11. light backfill; 12. a clay water-blocking layer; 13. tamping clay water sealing layer; 14. breaking gravel; 15. a soft water permeable pipe; 16. impermeable geotextile; 17. lime soil; 18. primary and secondary open cut tunnels; 19. three-stage open cut tunnel; 20. a sloughing material diffusion accumulation region; 21. a headwall top drain trench; 22. and a ventilation window.
Detailed Description
The technical scheme of the invention is further described in detail through the following specific embodiments.
The explanation of the implementation scheme is carried out by taking the Emein high-speed large-rock tunnel project as a support:
the large rock tunnel project is a 7km ultralong expressway tunnel and is located in Han Yuan county of Atlantic city in Sichuan province. The geological data of the large-rock tunnel show that the inlet end of the tunnel is a huge-thickness collapse sliding body and mainly comprises loose gravelly soil, the square quantity is huge, and the situation that the left side is weak and the right side is huge is presented. The left hole opening and the right hole opening are positioned in the middle of the covering layer, are about 20m away from the ground, and are used for preventing the tunnel from penetrating through the huge thick covering layer, generating open collapse roof and ensuring the smooth tunnel entering, and providing a reasonable construction site for constructing the long and large tunnel. The large rock tunnel project proposes that the inlet end collapse integrated is subjected to clearing treatment firstly, but the left cover layer is completely cleared after the clearing treatment, and the bias accumulation body with the side slope height of about 80m is formed after the right side is cleared.
After re-demonstration, the opening section is proposed to be cleared in stages, the upper part of the side elevation slope formed after clearing is protected by adopting frame beams, deep hole anchor rods for anchoring and net hanging for concrete spraying, the lower part corner protector is of an inclined retaining wall structure, the end part is of an anti-slide pile matched retaining plate structure, and the side slope is applied to a long open hole buffer structure, an end wall protection structure and a light backfill covering structure after being stabilized.
The concrete construction is as follows:
as shown in fig. 1-5, step 1) adopting stepped excavation from top to bottom on a wall body at one side of a tunnel, and supporting while excavating a square; the slope surface after the collapse sliding body is cleared adopts a frame beam 1 structure, and the frame lattice intersection points adopt self-advancing anchor rods 2 for anchoring; specifically, a common galvanized iron wire with phi 2.2 is firstly used for weaving a 200cm multiplied by 200cm iron wire net on a round steel frame with phi 8. When the side slope is excavated and trimmed, the positions of the net-hanging anchor rods are set according to the design, the anchor rods are beaten, the rock faces are exposed for 10cm, M30 anchoring mortar is poured, the anchor rod heads are supported, phi 22 prefabricated wire netting 3 is paved and hung, meanwhile, ribs are beaten and supported under the net by cushion blocks, and a 5cm gap is kept between the net and the rock faces. Two frame strips in the diagonal direction are bound on the anchor rod, and the other two frame strips are bound with each other. And binding the two frame strips with galvanized iron wires with phi of 2.6 every 50cm at the joint of the two frame strips, wherein each binding is not less than 5 circles. The wire should remain smooth and anchor rods should be added in special depressions.
The gradient section side slope between the tunnel upward slope and the frame beam is supported by adopting a sprayed concrete hanging net 4, the sprayed concrete is adopted, the thickness is 10cm, water is sprayed to wet the rock surface before spraying the C20 concrete, so that a slurry layer is prevented from being shelled and falling off, and the C20 concrete is sprayed from top to bottom in time before the net sheet is rusted.
The drain holes are arranged at equal intervals of 2m multiplied by 2m by adopting PVC pipes with diameter of 10cm, penetrate into the rock face for 5cm, and are wrapped by water seepage geotextile at the rear part of the drain pipe. Before spraying, the mouth of the PVC pipe at the outlet of the water discharge hole is sealed by paper board or plastic cloth, etc. so as to prevent the water discharge hole from being blocked by mortar, and after the spraying is finished, the paper board or plastic cloth, etc. is removed to facilitate water discharge. Every 10m is provided with an expansion joint, the width of the joint is 2cm, and the joint is filled with asphalt hemp batting.
Step 2), arranging an inclined retaining wall structure at the slope toe, wherein the retaining wall 5 is arranged at the slope toe, the wall height is 8-10 m, the base of the retaining wall is buried 2-3 m below the slope toe, and the wall body material is cast-in-situ C20 concrete; the top of the retaining wall is horizontal, the width of the toe of the retaining wall is 0.6-0.8 m, the height of the toe of the retaining wall is 0.8-1.0 m, the base slope ratio is 0.1:1, the face slope ratio is 1:0.25, and the back slope ratio is 1:0.25; backfilling lime soil 17 doped with 8% ash at the toe part and below the retaining wall water discharge hole 6, paving impermeable geotextile 16 on the surface of the lime soil doped at the back part of the wall, longitudinally arranging a phi 100mm soft permeable pipe 15 near the water discharge hole, backfilling the lime soil doped at the back part of the wall to 50cm below the top of the wall by adopting water permeable materials such as crushed gravel 14 or sand gravel, and the like, and tamping a clay water sealing layer 13 within 50cm below the top of the wall. The cutting retaining wall is provided with water discharge holes at a position 50cm higher than the roadbed design line, 2-4 rows are arranged in total, the distance is 2.0m, the water discharge holes adopt phi 100mm PVC pipes, the camber gradient is 5%, phi 10mm round holes are circumferentially arranged at the end part of the phi 100mm PVC pipe within 10cm, and the water discharge holes are wrapped by water seepage geotextiles;
step 3) the end part is still in a instable state after the opening section is clear and the retaining wall is supported, in order to avoid collapse in the construction process of the opening section end part, a square anti-slide pile 7 is arranged at the right end part of the roadbed and a retaining plate 8 structure is configured, and the construction sequence of the pile end anti-slide piles is as follows: pile top slope excavation, anti-slide pile implementation, pile front slope excavation, soil body excavation within the range of a soil retaining plate, soil retaining plate hanging and sand gravel backfilling after the soil retaining plate hanging. 4 detection steel pipes are buried in each pile in the diagonal direction and used for ultrasonic detection of the pile body, and the ultrasonic detection steel pipes are fixed on the inner side of the stirrups.
Specifically, 2 pile types are arranged on the anti-slide piles at the end parts of the hole sections, the pile sections are 1.75mX2.5 m, the pile center-to-center distance is 5.0m, and the length of the anchoring section is 9.14m. Wherein the pile length of the I type pile is 20m, the total pile length of the II type pile is 24m, the total pile length is 1, a soil retaining plate is arranged in front of the pile, the plate length is 4.98m, and the width is 0.5m. All adopt square hole digging pile machines, and the orifice is provided with a locking notch which is 1m higher.
The pile body of the sliding-collapse anti-sliding pile adopts C30 reinforced concrete for cast-in-situ, the bottom of the hole is paved with M7.5 mortar to be 10cm thick, and the reinforced concrete protection layer is not smaller than 8cm. The distance between longitudinal steel bars is marked as the distance between the heavy centers of the steel bars, and when the number of the steel bar bundles is multiple, the distance between the gravity centers of the steel bar bundles is the distance between the gravity centers of the steel bar bundles, the steel bars in the steel bar bundles should be closely attached, and each 1-2 m of the steel bar bundles are spot-welded into a bundle. After the construction of the anti-slide pile is completed, when the strength of the pile body reaches 80%, the pile body can be excavated by the slope body before the pile, the locking notch before the pile is removed, and the front facing wall of the pile is constructed. The main reinforcements of the slide-resistant pile are connected in a sleeve mode, the reinforcing steel joints are staggered according to the specification, the length of the connecting section of the reinforcing steel sleeve connecting joint is 35d, and the area percentage of the longitudinal tension reinforcing steel joints in the same connecting section is not more than 50%.
Step 4), setting a long open cut tunnel 9 buffer structure after slope protection is stable, wherein the long open cut tunnel buffer structure is arranged at the joint of a bridge tunnel, takes the original open cut tunnel as a first-stage open cut tunnel, and is a C30 impervious lining structure with the length of 10m and the thickness of 60cm and positioned right below a cliff of a mountain body at the top of the tunnel; a foam material buffer layer is arranged between the newly added arch and the first-stage open cut tunnel; the secondary open cut tunnel is connected with the end part of the bridge, a tunnel end wall structure is arranged at the end part, a collapse object diffusion accumulation area 20 is arranged at the top of the tunnel, an end wall top drainage groove 21 is arranged for the end wall, the lining structure is consistent with that of the primary open cut tunnel, expansion joints are arranged between the primary open cut tunnel and the secondary open cut tunnel, the structural length is arranged according to the actual distance from the end part of the bridge, and the primary open cut tunnel and the secondary open cut tunnel 18 are shown in the figure; the third-stage open cut tunnel 19 is arranged on the bridge and connected with the second-stage open cut tunnel, and ventilation windows 22 with the longitudinal distance of 1.5m are arranged on the third-stage open cut tunnel straight wall to weaken the light and shade change at the tunnel opening and the lateral influence of crosswind in the mountain ditch on the traveling crane.
The technical problem that long open cut tunnel buffer structure mainly solves is at the abrupt standing of tunnel portal mountain slope, receives under the geological condition that rock efflorescence crack developed, prevents that the efflorescence stone from breaking away from the mountain body and falling, smashes the tunnel open cut tunnel, protects tunnel portal and the safety of vehicle that traveles.
Step 5), paving the arch crown parts of the primary, secondary and tertiary open cut tunnels sequentially from inside to outside, wherein the double-layer geotechnical cloth buffer layer 10, the waterproof layer, the light backfill 11 such as fly ash and the like and the clay waterproof layer 12 are arranged. The long open hole buffer structure is arranged at a tunnel opening section with poor highway tunnel geological conditions, can effectively protect the safety of the open hole of the tunnel and reduce the damage of falling weathered block stones to the open hole.
The method and the device are mainly used for researching poor geology of the high slope and the loose collapse sliding body of the tunnel portal section. The scheme is provided with a stepped excavation mode, the upper frame beam is anchored by a self-advancing long anchor rod, the lower part of the side slope is supported by an inclined retaining wall, the end part of the side slope is supported by square anti-slide piles and retaining plates, vine plants are planted on the side slope, the green environment-friendly idea is implemented, a multistage buffering long open cut tunnel structure is arranged at the joint of the middle section of a hole and a bridge, and a series of technical problems such as loose collapse sliding bodies, bias voltages, high side slopes, greening environment protection, operation falling rocks and the like are effectively solved. The construction key technology is advanced and reliable, engineering measures are strong in pertinence, construction parties are cheap to operate, engineering construction quality and construction safety are effectively guaranteed, construction progress is accelerated, higher economic benefits are created, and the poor geological construction treatment level of tunnel portal sections is greatly improved.
Finally, it should be noted that the above-mentioned embodiments are only for illustrating the technical scheme of the present invention and are not limiting; while the invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that: modifications may be made to the specific embodiments of the present invention or equivalents may be substituted for part of the technical features thereof; without departing from the spirit of the invention, it is intended to cover the scope of the invention as claimed.
Claims (7)
1. A highway tunnel portal section sliding body side slope protection additional strengthening that collapses, its characterized in that: the tunnel comprises a tunnel, a ladder-shaped anchoring frame beam arranged on at least one side of the tunnel, a lower retaining wall, an end part slide-resistant pile and a long open hole;
the stepped anchoring frame beams comprise multistage frame beams distributed in a stepped manner along a side slope, self-advancing anchor rods are arranged at the intersection points of the frame grids of the frame beams and anchored to a mountain rock layer, net-hanging grass planting protection is arranged in the frame grids, net-hanging spray tamping protection is arranged at the gradual transition section between the upward slope of the tunnel and the multistage frame beams, and side slope water discharge holes penetrating into the lower portion of the rock surface are formed in the stepped anchoring frames at equal intervals;
the lower retaining wall is arranged at the slope toe of the slope and is inclined towards the slope, the bottom of the retaining wall is provided with a toe, the bottom of the retaining wall is buried underground, the top of the retaining wall is horizontal, and a plurality of rows of retaining wall water drainage holes with slopes are arranged on the retaining wall;
the end anti-skid piles are arranged at the end parts of the holes and comprise long piles and short piles, the long piles are arranged close to the tunnels, and retaining plates are arranged between the long piles and the short piles;
the long open cut tunnel comprises a first-level open cut tunnel, a second-level open cut tunnel and a third-level open cut tunnel, the first-level open cut tunnel is connected with a tunnel, the second-level open cut tunnel is connected with the end of a bridge, the third-level open cut tunnel is arranged on the bridge and is connected with the end of the second-level open cut tunnel, a collapse object diffusion accumulation area is arranged at the top of the second-level open cut tunnel, a ventilation window is arranged on the third-level open cut tunnel, an expansion joint is arranged between the first-level open cut tunnel and the second-level open cut tunnel, and a deformation joint is arranged between the second-level open cut tunnel and the third-level open cut tunnel.
2. The highway tunnel portal segment slump body slope protection reinforcing structure according to claim 1, wherein: before the side slope excavation construction, weaving wire netting on a round steel frame by using galvanized wire in a construction area, after the side slope excavation is finished, laying out and hanging net anchor rod positions according to design, beating the self-advancing anchor rod to enter rocks and expose, filling anchoring mortar, depending on an anchoring head, paving and hanging prefabricated wire netting, and enabling the wire netting and the rock surface to keep a certain gap by using a cushion block between the wire netting and the rock surface.
3. The highway tunnel portal segment slump body slope protection reinforcing structure according to claim 2, wherein: two frame strips positioned at the diagonal line are bound on the anchor rod, and the other two frame strips are bound with each other.
4. A highway tunnel portal segment slump body slope protection reinforcing structure according to claim 3, wherein: backfilling lime soil doped with 5-10% of ash at the toe of the wall and below the water discharge hole of the retaining wall, paving anti-seepage geotextile on the surface of lime soil at the back of the wall, longitudinally arranging soft permeable pipes with phi 90-120mm close to the water discharge hole, backfilling the lime wall at the back of the wall to 50cm below the wall top by adopting permeable materials, and backfilling and tamping clay within the range of 50cm below the wall top.
5. The highway tunnel portal segment slump body slope protection reinforcing structure according to claim 4, wherein: the end part anti-slip pile is formed by casting C30 reinforced concrete in situ, the bottom of a hole is paved with M7.5 mortar, the thickness of a concrete protection layer of the steel bar is not less than 8cm, the distance between longitudinal steel bar spacing marks are the distance between the heavy centers of the steel bars, when a plurality of steel bar bundles are adopted, the steel bars in the steel bar bundles are tightly attached, and each 1-2M of the steel bar bundles are spot welded into a bundle.
6. The highway tunnel portal segment slump body slope protection reinforcing structure according to claim 5, wherein: the basement of the long open cut tunnel is of a C30 impervious lining structure, and a vault part of the long open cut tunnel is paved with a double-layer geotextile buffer layer, a waterproof layer, a fly ash filling layer and a clay waterproof layer from inside to outside in sequence.
7. A highway tunnel portal section collapse sliding body slope protection construction method is characterized in that: the method comprises the following steps:
step 1), step-by-step excavation is adopted from top to bottom on a wall body at one side of a tunnel, and square clearing and supporting are carried out at the same time; the slope surface after the collapse sliding body is cleared adopts a frame beam structure, and the frame lattice intersection points adopt self-advancing anchor rods for anchoring; specifically, before the collapse sliding body is treated and protected, firstly, weaving an iron wire net on a round steel frame bar frame by using galvanized iron wires, after slope excavation and trimming, laying out a net hanging anchor rod position according to design, beating the anchor rod while exposing a rock surface, pouring M30 anchoring mortar, depending on an anchor rod head, paving and binding a prefabricated iron wire net, and simultaneously beating ribs and supporting the steel wire net under the net by using a cushion block to keep a gap between the net and the rock surface; two frame strips in the diagonal direction are bound on the anchor rod, and the other two frame strips are bound with each other; binding the two frame strips with galvanized iron wires at intervals; the iron wire net should be added with anchor rods for fixation at the special concave position, the middle part of the frame lattice adopts a net hanging and spraying grass planting protection, the gradient section side slope between the upward slope of the tunnel and the frame beam adopts a net hanging and spraying concrete protection, C20 spraying concrete is adopted, the rock surface is sprayed with water for wetting before C20 concrete is sprayed, and C20 concrete is sprayed from top to bottom in time before the net sheet is rusted; the side slope water discharge holes are formed by adopting PVC pipes and are arranged on the slope at equal intervals, the rear ends of the side slope water discharge holes are arranged deep into the rock face, the rear parts of the side slope water discharge holes are wrapped by water seepage geotextiles, expansion joints are arranged at intervals, and asphalt hemp battles are used for filling;
step 2), arranging an inclined retaining wall structure at the slope toe, wherein the retaining wall is arranged at the slope toe, the wall height is 8-10 m, the base of the retaining wall is buried 2-3 m below the slope toe, and the wall body material is cast-in-situ C20 concrete; the top of the retaining wall is horizontal, the width of the toe of the retaining wall is 0.6-0.8 m, the height of the toe of the retaining wall is 0.8-1.0 m, the base slope ratio is 0.1:1, the face slope ratio is 1:0.25, and the back slope ratio is 1:0.25; backfilling 8% lime soil doped with ash at the toe part and below the water discharge hole, paving impermeable geotextile on the surface of lime soil at the back of the wall, longitudinally arranging a soft permeable pipe at the position close to the water discharge hole, backfilling the lime soil at the back of the wall to 50cm below the top of the wall by adopting a permeable material, and backfilling and tamping clay within the range of 50cm below the top of the wall; the cutting retaining wall is provided with water discharge holes at a position 30-50 cm higher than the roadbed design line, 2-4 rows of water discharge holes are arranged at equal intervals, the water discharge holes are formed by PVC pipes, the camber gradient is 5-10%, circular holes are formed in the end parts of the PVC pipes in a circumferential direction, and the PVC pipes are wrapped by water seepage geotextiles;
step 3) arranging square anti-slide piles at the end parts of the side slopes and configuring a retaining plate structure, implementing the anti-slide piles after the side slopes at the tops of the anti-slide piles are excavated, arranging 2 pile types of the anti-slide piles at the end parts of the opening sections, wherein the length of the short piles is 20M, the length of the long piles is 1, the length of the long piles is 24M, the retaining plate is arranged in front of the piles, the pile bodies of the anti-slide piles are cast in situ by adopting C30 reinforced concrete, the bottoms of the holes are paved by M7.5 mortar, and the concrete protection layer of the reinforced concrete is not less than 8cm; after the construction of the anti-slide pile is completed, when the strength of the pile body reaches 80%, excavating a slope body in front of the pile, removing a locking opening in front of the pile, and constructing a front facing wall of the pile; the main reinforcements of the slide-resistant pile are connected in a sleeve manner, and the area percentage of the longitudinal tension reinforcement joints in the same connecting section is not more than 50%;
step 4), setting a long open cut tunnel buffer structure after slope protection is stable, wherein the long open cut tunnel buffer structure is arranged at the joint of a bridge tunnel, takes the original open cut tunnel as a first-stage open cut tunnel, is positioned right below a cliff of a mountain at the top of the tunnel, and is a C30 impervious lining structure; a foam material buffer layer is arranged between the newly added arch and the first-stage open cut tunnel; the secondary open cut tunnel is connected with the end part of the bridge, a tunnel end wall structure is arranged at the end part, a collapse object diffusion accumulation area is arranged at the top of the tunnel, the lining structure is consistent with the primary open cut tunnel, and expansion joints are arranged between the primary open cut tunnel and the secondary open cut tunnel; the third-level open cut tunnel is arranged on the bridge and connected with the second-level open cut tunnel, and a ventilation window is arranged on a straight wall of the third-level open cut tunnel;
step 5), paving the arch crown parts of the first-level, second-level and third-level open cut tunnels sequentially from inside to outside into a double-layer geotechnical cloth buffer layer, a waterproof layer, a fly ash filling and clay water-resisting layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210089109.1A CN116537221A (en) | 2022-01-26 | 2022-01-26 | Highway tunnel portal section collapse sliding body slope protection reinforcing structure and construction method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210089109.1A CN116537221A (en) | 2022-01-26 | 2022-01-26 | Highway tunnel portal section collapse sliding body slope protection reinforcing structure and construction method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116537221A true CN116537221A (en) | 2023-08-04 |
Family
ID=87444070
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210089109.1A Pending CN116537221A (en) | 2022-01-26 | 2022-01-26 | Highway tunnel portal section collapse sliding body slope protection reinforcing structure and construction method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116537221A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117052421A (en) * | 2023-10-13 | 2023-11-14 | 湖南省通盛工程有限公司 | Tunnel portal supporting structure in deep slippage and large bias state and construction method |
-
2022
- 2022-01-26 CN CN202210089109.1A patent/CN116537221A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117052421A (en) * | 2023-10-13 | 2023-11-14 | 湖南省通盛工程有限公司 | Tunnel portal supporting structure in deep slippage and large bias state and construction method |
| CN117052421B (en) * | 2023-10-13 | 2024-01-09 | 湖南省通盛工程有限公司 | Tunnel portal supporting structure in deep slippage and large bias state and construction method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103410159B (en) | Expansive soil cut slope support structure and construction method thereof | |
| CN106013191A (en) | Environmental-friendly grass concrete highway slope protection structure and construction method thereof | |
| CN110042716B (en) | Widening construction method for high-fill roadbed with foamed light soil | |
| CN205999903U (en) | Environment-friendly type grass planting Concrete Highway protective slope structure | |
| Holtz et al. | Stabilization of soil slopes | |
| CN111549799A (en) | Comprehensive control system applied to gravel soil slope | |
| CN109930613A (en) | A kind of construction method and structure of the roadbed slope drainage system that seeps water | |
| CN111322087A (en) | Construction method for soft soil highway tunnel entrance semi-open semi-hidden tunnel in mountainous area | |
| CN210002425U (en) | structure of seepage roadbed side slope drainage system | |
| CN209568379U (en) | A kind of road prevention structure for blocking falling rocks | |
| CN112983461B (en) | Construction method for biasing tunnel portal in slope integrated | |
| CN116537221A (en) | Highway tunnel portal section collapse sliding body slope protection reinforcing structure and construction method | |
| CN217462179U (en) | Semi-bright and semi-dark tunnel protection structure | |
| CN113550336B (en) | Construction method of loose formation region railway deep cutting adjacent to existing building | |
| CN212026135U (en) | Slope protection structure of waterfront footpath | |
| CN213173779U (en) | Cutting slope protection structure | |
| CN216920384U (en) | Highway tunnel entrance to a cave section landslide body side slope protection additional strengthening that collapses | |
| CN106436725A (en) | Construction method of road cutting stereoscopic protection structure achieving high polymer grouting reinforcement and water prevention | |
| CN112411584A (en) | Anti-slide pile and greening strip combined grout rubble highway slope protection structure | |
| CN117052421B (en) | Tunnel portal supporting structure in deep slippage and large bias state and construction method | |
| CN217026767U (en) | Existing culvert structure is striden on open cut tunnel | |
| CN217480236U (en) | Pile-plate type retaining wall suitable for high slope | |
| CN116220729B (en) | Shallow-buried bias multi-arch tunnel non-flush tunnel portal structure and construction method thereof | |
| CN218374011U (en) | Easy-to-collapse roadbed construction wall structure | |
| CN210341522U (en) | Highway abrupt slope roadbed in rainy season area |
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 |