CN112196582B - Method for controlling severe deformation of strong-earthquake deep-buried soft rock stratum tunnel - Google Patents
Method for controlling severe deformation of strong-earthquake deep-buried soft rock stratum tunnel Download PDFInfo
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- CN112196582B CN112196582B CN202011103853.XA CN202011103853A CN112196582B CN 112196582 B CN112196582 B CN 112196582B CN 202011103853 A CN202011103853 A CN 202011103853A CN 112196582 B CN112196582 B CN 112196582B
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/003—Linings or provisions thereon, specially adapted for traffic tunnels, e.g. with built-in cleaning devices
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
- E21D11/107—Reinforcing elements therefor; Holders for the reinforcing elements
Abstract
The invention relates to the field of tunnel construction technology, in particular to a method for controlling severe deformation of a strong-earthquake deep-buried soft rock stratum tunnel. The deformation control method adopts a step method for construction in excavation, and an advance support is firstly made before the excavation of an upper step, so that the relative stability of surrounding rocks during the excavation of the tunnel section is guaranteed. After the upper step is excavated, immediately constructing a first layer of support of the upper step, and lagging behind by 3-5 m to synchronously construct a temporary inverted arch and form a ring with the first layer of support of the upper step; the distance between the lower step belt and the inverted arch excavation lagging face is not more than 35m, the lower step belt and the inverted arch first layer support are implemented together, and the lower step belt and the inverted arch first layer support are quickly connected into a ring shape, so that the deformation of surrounding rock tends to be stable as soon as possible. And after the first layer of support of the inverted arch of the lower step is finished and the primary support sprayed concrete reaches a certain strength, immediately constructing a second layer of support of the lower step and the inverted arch, determining whether to construct a second support of the upper step in an annular mode again according to the measurement information, and adopting a reinforcement deformation control measure.
Description
Technical Field
The invention relates to the field of tunnel construction technology, in particular to a method for controlling severe deformation of a strong-earthquake deep-buried soft rock stratum tunnel.
Background
Underground projects such as tunnels pass through soft rock fragmentation zones with complex ground stress states. After the tunnel is excavated, plastic deformation occurs due to stress release, large deformation (more than or equal to 500 mm) easily occurs, and the tunnel is characterized by large deformation amount, high deformation speed, long duration, large-area extrusion and intrusion limit of surrounding rock, severe cracking or damage of a support, even collapse accidents caused by instability, and high treatment difficulty. After an earthquake, a weak stratum is in an extremely complex stress adjustment stage through strong vibration, so that the phenomena of support structure damage, repeated replacement of an arch center and the like caused by large deformation of a weak surrounding rock tunnel under the condition of strong vibration are avoided, the stress state of the surrounding rock is effectively improved, the stability of the tunnel support structure is maintained, the use safety and reliability of a permanent structure are guaranteed, and the method is a problem to be solved in the construction of underground engineering such as railway tunnels and the like at present.
Disclosure of Invention
The invention aims to provide a method for controlling severe large deformation of a strong earthquake deeply-buried soft rock stratum tunnel, which can well control large deformation of the tunnel.
The embodiment of the invention is realized by the following steps:
a method for controlling severe major deformation of a strong earthquake deeply-buried soft rock stratum tunnel is characterized in that excavation construction is carried out on each tunnel section after advance support; the excavation construction comprises the following steps:
s1: excavating an upper step by a step method and installing a first layer of steel frame of the upper step;
s2: installing meshes and spraying concrete;
s3: constructing an upper step anchor rod;
s4: sealing construction of the upper step and the temporary inverted arch of the upper step;
s5: excavating a lower step and an inverted arch and completing the first-layer support of the inverted arch;
s6: constructing a second layer of support construction of the lower step and the inverted arch, and immediately constructing a second liner of the inverted arch and filling the inverted arch after the second layer of support construction is finished;
s7: if the maximum accumulated deformation is greater than 50% of the first reserved deformation or the absolute maximum deformation of section scanning is greater than 200mm, and the deformation rate is greater than 2mm/d, immediately constructing a second layer of support of the upper step;
if the maximum accumulated deformation is greater than 50% of the first reserved deformation or the absolute maximum deformation of section scanning is greater than 200mm, and the deformation rate is less than 2mm/d, the second layer of support of the upper step is not carried out;
after a first steel frame layer of the upper step is constructed on the upper step, a net sheet and a sprayed concrete layer are installed, if the deformation speed is more than 20mm/d and the primary support is cracked and falls, immediately constructing an anchor rod of the upper step and a second steel frame layer of the upper step and spraying the concrete layer;
s8: when the convergence rate of the surrounding rock is less than or equal to 0.6mm/d and the sinking rate of the arch part is less than or equal to 0.3mm/d, constructing a second lining.
Further, the circulating footage of the upper step excavation is not more than 1.2m; and the circulating footage of the inverted arch excavation is less than 3m.
And further, excavating by adopting a two-step method, wherein the height of an upper step is 7-8 m, the height of a lower step is 4m, the excavation depth of an inverted arch is not more than 3.5m, the length of the upper step is 15-20 m, and the length of the lower step is 15m. .
Further, the distance between the primary support closed loop and the tunnel face is less than 35m.
Further, the first layer of steel frame of the upper step is made of H200 section steel; and a plurality of arches of the first layer of steel frame of the upper step are connected through section steel.
Furthermore, the arch frame locking foot of the first layer steel frame of the upper step adopts a 2 phi 76 steel pipe with the length of 6m; and the arch frame bottom cushion channel steel is arranged at the corner of the side wall of the upper step.
Further, the mesh is a double-layer mesh; the sprayed concrete is C30 early high-strength fiber concrete.
And further, after the net sheets are installed and the concrete layer is sprayed, if water seepage occurs in the holes or the deformation rate of the surrounding rock reaches 20mm/d, radial grouting is performed on the surrounding rock.
Further, radial grouting adopts a phi 42mm steel perforated pipe for grouting to reinforce the surrounding rock; the length of a single steel flower tube is 5m, and the ring X longitudinal distance is 1.0m X1.2 m; pure cement single-liquid slurry or cement-water glass double-liquid slurry is adopted as the slurry; the water-cement ratio of the single slurry is 0.6-1.1; when the single-liquid slurry can not block water, the double-liquid slurry is used for supplement.
Further, the anchor rods comprise an arch anchor rod, an arch anchor rod and a side wall anchor rod; the length of the arch anchor rod is 6m; the length of each of the arch anchor rod and the side wall anchor rod is 8m-10m.
Further, the arch anchor rod is a hollow anchor rod; the arch anchor rod and the side wall anchor rod are both mortar anchor rods; the ring x longitudinal distance of the anchor rod is 0.8m x 1.2m. Further, the distance between the anchor rod construction position and the tunnel face and the working face is within 1 time of the hole diameter or within 15m.
Further, the cross-sectional shape of the tunnel is circular.
Further, before each tunnel section is excavated, the large deformation level and the corresponding reserved deformation of the tunnel section need to be determined.
Further, a first reserved deformation amount is arranged between the surrounding rock and the first layer of support; and a second reserved deformation is arranged between the first layer of support and the second layer of support.
Further, in step S8, if the convergence rate of the surrounding rock is greater than 0.6mm/d and the subsidence rate of the arch is greater than 0.3mm/d, the surrounding rock is radially grouted until the convergence rate of the surrounding rock is less than or equal to 0.6mm/d or the subsidence rate of the arch is less than or equal to 0.3mm/d.
The invention has the beneficial effects that:
and (4) making advanced supports before each tunnel section of the high-ground-stress soft rock tunnel is excavated. During excavation, the surrounding rock of the tunnel section is relatively stable. The excavation of the upper step and the first layer of steel frame of the upper step are implemented together, so that the situation that the surrounding rock is not supported due to overlong excavation of the upper step to cause large deformation of the surrounding rock is avoided. The inverted arch excavation and the inverted arch first-layer support are implemented together, so that the inverted arch first-layer support and the upper step first-layer support are quickly connected into a ring shape, better support is achieved, and large deformation is avoided. Meanwhile, after the upper step is supported for the first time, if the upper step is unstable, a second steel frame layer of the upper step can be constructed, so that the upper step is more stable.
Drawings
Fig. 1 is a step sequence diagram of the method for controlling severe deformation of the strong seismic deep-buried soft rock stratum tunnel.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Example (b):
underground projects such as tunnels pass through soft rock fragmentation zone sections with complex ground stress states. After the tunnel is excavated, plastic deformation occurs due to stress release, large deformation (more than or equal to 500 mm) is easy to occur, and the tunnel is characterized by large deformation amount, high deformation speed, long duration, large-area extrusion and invasion limit of surrounding rock, severe cracking or damage of a support, even collapse accident caused by instability, and high treatment difficulty. The tunnel of the prior art is revealed to be geological carbon phyllite, extremely low in strength (less than 5 MPa), anhydrous, about 650m in tunnel burial depth and about 15MPa in maximum principal stress. The section of the tunnel is circular, the excavation height is 14m, and the excavation area is 154m2.
Referring to fig. 1, the embodiment provides a method for controlling severe and major deformation of a strong-seismic deep-buried soft rock stratum tunnel, and excavation is performed after each tunnel section is subjected to advance support. Before advance support, construction preparation is needed. The work content of the construction preparation comprises large deformation grade determination, technical bottom crossing, tunnel face measurement and paying-off, operation rack feeding and the like.
The severe large deformation section is often large in structural stress, the rock mass is broken, the stability of the tunnel face is poor, and particularly, the stability is worse when the rock mass is influenced by underground water in sections such as faults, broken zones, fold core parts, rock stratum interfaces and the like. Therefore, the advance support measures can well consolidate the stratum stability of the excavated part in advance and ensure the normal operation of excavation.
The advance support usually adopts a small advance conduit, an extremely broken tunnel section or a broken water-containing tunnel section, and when the tunnel face stability is poor, a medium pipe shed can be adopted. Construction is carried out after advance support through the following steps:
s1: and excavating an upper step by a step method and constructing a first layer steel frame of the upper step. The conventional tunnel is shallow in buried depth, the ground stress is mainly in the vertical direction, and a horseshoe-shaped or oval section is usually adopted. In the extrusion type large-deformation tunnel, the stress around the tunnel is mainly structural stress, and the stress in the horizontal direction is usually greater than or equal to vertical stress, so that a near-circular section design is adopted, an inverted arch is deepened to resist the deformation force around the tunnel, and the structural stress is relatively uniform. In this embodiment, the cross-sectional shape of the tunnel is circular or nearly circular.
The 'quick sealing' is a basic principle of large deformation control, and in order to shorten the distance between an inverted arch and a face, the excavation construction method is simplified on the premise of ensuring the stability of the face through advance support, the construction is carried out by adopting a large-section step method, and the large-scale tool operation such as a three-arm rock drilling trolley, an arch frame installing machine, an anchor rod trolley and the like can be met only by adopting large-section excavation. The large-scale frock can be worked and can be made the operating efficiency higher, and better assurance supporting construction can "seal fast". If a large-sized tool is not adopted, the construction efficiency is low, and the sealing is slow.
Adopting a two-step method to excavate, wherein the height of an upper step is 7-8 m, the height of a lower step is 4m, the excavation depth of an inverted arch is not more than 3.5m, the length of the upper step is 15-20 m, and the length of the lower step is 15m.
And after the upper step is excavated, immediately constructing a first layer of steel frame of the upper step on the upper step. In order to better guarantee the stability of the surrounding rock and avoid large deformation of the surrounding rock, the circulating footage of the upper step excavation is not more than 1.2m. In practice, the distance between two adjacent arches is about 0.6m, and the circulating footage of the upper step excavation is not more than 2 arches. And (4) performing primary support on the upper steps when 2 arch frames at most are excavated on the upper steps. The first support of the upper step comprises a first steel frame layer of the upper step, net piece installation, a sprayed concrete layer and an anchor rod installation of the upper step. H200 steel is preferably selected as the first layer of steel frame of the upper step. The profile steel has good mechanical property, high strength and strong torsion resistance, and has good supporting effect when used as an arch frame. Meanwhile, considering that the force borne by the first steel frame layer of the upper step is large, the section steel with the large H200 grade is selected as the section steel, and the force borne by the section steel is larger.
The first layer of steel frame of the upper step is reserved with deformation according to the design for enlarging and processing, and the rack is assisted with jacking equipment or installed by adopting an arch installing trolley. The reserved deformation amount of serious large deformation is more than 50cm, the section with water holes is preferably more than 60cm, and the adjustment is carried out according to the test section and the subsequent construction monitoring data.
S2: installing the meshes and spraying a concrete layer. C30 early high-strength fiber concrete is selected as the sprayed concrete, and wet spraying operation is carried out by a manipulator. The net sheets are double-layer and are firmly welded with the steel frame. The stress performance of the net sheet is ensured.
S3: and (5) constructing an anchor rod. The long anchor rod or the long and short combined anchor rod can be adopted for severe deformation, the short anchor rod is generally 4m, the resin anchoring agent anchor rod can be adopted, the anchor rod is timely constructed after excavation, the bench hand pneumatic drill is adopted for drilling, manual installation is adopted, and initial deformation is controlled. The long anchor rod is generally 6-10 m. Wherein the arch part is 6m, and the arch part is 8-10 m from the waist to the side wall. The anchor rod of 6-10 m is a long anchor rod which can penetrate through the plastic ring, so that the stabilizing effect is better. The anchor rod can be hollow anchor rod, and the collapsed hole and lock hole section can be self-advancing anchor rod. The long anchor rod is drilled by an anchor rod trolley or a three-arm rock drilling trolley. All anchor rods should be radially constructed as much as possible or be perpendicular to the main structural surface of the rock body, so that the supporting effect of the anchor rods is ensured. In practice, the arch 90 degree range adopts 4m long combined hollow anchor rods, the arch waist to side wall adopts 10m long hollow anchor rods, the inverted arch adopts 5m long hollow anchor rods, and the distance between the anchor rods is 0.8 multiplied by 1.2m (ring multiplied by longitudinal).
Because the working space of the tunnel face is limited, the construction is difficult, and the construction is carried out every time of circular excavation, the working procedure conversion is frequent, and the construction efficiency is low. Therefore, the upper step anchor rod is applied within the range of 1 time of the hole diameter or 15m on the tunnel face by comprehensively considering the operation space, the construction efficiency and the proper release of deformation. The distance between the construction position of the long anchor rod and the tunnel face is 5-15 m. When the deformation rate is high, the upper step anchor rod can be constructed by excavating 5m. Construction can be organized in principle with operating conditions. The long anchor rods of the double-line tunnel are arranged after the installation and the net spraying of the arch frames on the upper step or the middle step.
The hollow anchor rod grouting should be carried out in time after the anchor rod is inserted into the drilled hole, and quick-setting cement slurry is preferably adopted as the grouting material.
The long anchor rod should strengthen the backing plate system, except backing plate and nut, should add the packing ring etc. additionally, prevent that the backing plate from drawing and splitting, installation backing plate and fastening nut should go on after the intensity of mortar body reaches 10MPa, backing plate size 200mm.
S4: and (5) sealing the upper step and the temporary inverted arch. I18I-steel is adopted, arranged corresponding to the main arch frame, and sprayed with concrete for covering. The upper step and the temporary inverted arch are closed to form a ring, and the support stability of the upper step is ensured. Meanwhile, the operation of the tunnel face is convenient, and the temporary inverted arch closed support of the upper step can be delayed by 3-5 m from the tunnel face.
S5: and excavating the lower step and the inverted arch, and constructing a first layer support of the lower step and a first layer support of the inverted arch simultaneously so as to seal the first layer support of the upper step and the first layer support of the inverted arch into a ring. And after the first supporting of the upper step is finished, the lower step excavation and the inverted arch excavation can be carried out. The first layer of support of the lower step is constructed along with excavation. The lower step first-layer support and the upper step first-layer support jointly form an upper step first-layer support. The first layer of inverted arch support is constructed along with excavation, so that inverted arch excavation is guaranteed to be supported, and the first layer of inverted arch support and the first upper step support are guaranteed to be immediately sealed and looped after inverted arch excavation. The distance between a closed loop formed by the first-layer support of the inverted arch and the first-time support of the upper step and the tunnel face is less than 35m, so that the support effect is ensured as far as possible. The anchor rod at the bottom of the tunnel can be manufactured along with digging, the construction at the bottom of the tunnel can be performed at first 6m, 9m or 12m, then the construction is performed in a unified mode, and when the bearing capacity at the bottom of the tunnel is insufficient or water seeps from the bottom of the tunnel, the bottom of the tunnel can be reinforced through grouting with the flower steel pipes. The circulating footage of the inverted arch excavation is less than 3m, and the 'quick sealing' can be ensured.
S6: and (5) constructing the lower step and the second layer of inverted arch support, and immediately constructing the second liner of the inverted arch and filling the inverted arch after the second layer of support construction is finished. After the lower step and the inverted arch are excavated and supported simultaneously, the hole slag is filled back to meet the requirements of traffic and construction of an anchor rod of the upper step, the hole slag is cleaned after an anchor rod operation area, and a trestle is used for constructing an inverted arch second lining and filling.
S7: and according to the monitoring and section scanning results, if the maximum accumulated deformation is greater than 50% of the first reserved deformation or the absolute maximum deformation of the section scanning is greater than 200mm, the deformation rate is greater than 2mm/d. At this time, the deformation rate does not tend to be stable, and the second-layer support of the upper step is constructed immediately.
The second floor steelframe of upper step can support jointly with the first floor steelframe of upper step, and the bearing that double-deck bow member supported jointly is stronger, struts more firmly, and more effectual control is out of shape greatly.
And if the maximum accumulated deformation is greater than 50% of the first reserved deformation or the absolute maximum deformation of the section scanning is greater than 200mm, the deformation rate is less than 2mm/d. At this time, the deformation rate tends to be stable, and the second-layer support of the upper step can be omitted.
And after the upper step is constructed with the first steel frame layer and the net sheets and the sprayed concrete layer, if the deformation speed is more than 20mm/d and the primary support is cracked and falls, immediately constructing the anchor rod and the second steel frame layer of the upper step and spraying the concrete layer. The steel frame on the second layer of the upper step is constructed in time and supported in time, so that the first layer of the steel frame on the upper step is prevented from being damaged, and the large deformation is also prevented.
S8: when the convergence rate of the surrounding rock is less than or equal to 0.6mm/d or the sinking rate of the arch part is less than or equal to 0.3mm/d, constructing a second lining.
In the embodiment, a plurality of arch frames of the first layer of steel frames of the upper step are connected through section steel. The shaped steel is connected with a plurality of arches, so that all the arches are mutually supported, the arches are more stable, and the supporting effect is better.
In this embodiment, the arch locking leg of the first steel frame layer of the upper step is a steel pipe with the length of 2 phi 76 m. The arch frame locking leg is longer and better fixes the arch frame. Meanwhile, the steel pipe used by the arch frame locking leg is thick, and the stress is better. And the channel steel is cushioned at the corner of the side wall of the upper step, so that the lower end of the arch truss applies downward pressing force to the channel steel. The force applied to the surrounding rock by the whole arch frame is more dispersed, and the arch frame is prevented from sinking.
In this embodiment, after the mesh is installed on the upper step and the concrete layer is sprayed, if water seepage occurs in the hole or the deformation rate of the surrounding rock reaches 20mm/d, the surrounding rock is extremely unstable. In order to better control the deformation of the surrounding rock, the upper step is subjected to radial grouting in time, and then the surrounding rock is stabilized. The radial grouting adopts phi 42mm steel perforated pipes to perform grouting to reinforce surrounding rocks, the length of a single pipe is 5m, the distance is 1.0 multiplied by 1.2m (ring multiplied by longitudinal), the grout adopts pure cement single-fluid grout or cement-water glass double-fluid grout, and the water-cement ratio of the single-fluid grout is 0.6-1.1; when the single-liquid slurry has poor water plugging effect, the double-liquid slurry is used for supplement.
In this embodiment, the reserved deformation of each tunnel section needs to be determined before excavation, so that the size of the excavated hole diameter can be conveniently determined. A first reserved deformation is arranged between the first layer of steel frames and the surrounding rock. For severe large deformations, the total reserved deformation is 60cm (75 cm in the presence of water), and the first reserved deformation is 40cm. And a second reserved deformation is arranged between the first layer support and the second layer support. The second reserved deflection is 20cm. When the deformation that first layer steelframe produced reached 20cm, the second floor steelframe supported once more for it is more firm to strut.
After the second supporting is finished, if the total reserved deformation is less than 50% or the absolute value of section scanning is less than 300mm and the deformation rate tends to be stable, the secondary lining can be constructed; if the deformation speed is unstable and is more than 2mm/d, radial grouting is adopted to consolidate the surrounding rock or the anchor rod is adopted for reinforcement, and secondary lining is not carried out until the stability is reached.
And (4) making advanced supports before each tunnel section of the high-ground-stress soft rock tunnel is excavated. During excavation, the surrounding rock of the tunnel section is relatively stable. The excavation of the upper step and the first layer of steel frame of the upper step are implemented together, so that the situation that the surrounding rock is not supported due to overlong excavation of the upper step to cause large deformation of the surrounding rock is avoided. Inverted arch excavation and inverted arch first floor are strutted and are implemented together for the first floor of inverted arch is strutted and is strutted the high-speed joint one-tenth ring-type with the first floor of upper ledge, and better support makes the country rock deformation tend to stability as soon as possible. Meanwhile, after the upper step is supported for the first time, if the upper step is unstable, a second steel frame layer of the upper step can be constructed, so that the whole supporting system is more stable.
In the step S8, if the convergence rate of the surrounding rock is greater than 0.6mm/d and the subsidence rate of the arch part is greater than 0.3mm/d, radial grouting is carried out on the surrounding rock until the convergence rate of the surrounding rock is less than or equal to 0.6mm/d or the subsidence rate of the arch part is less than or equal to 0.3mm/d.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (14)
1. A method for controlling severe major deformation of a strong earthquake deeply-buried soft rock stratum tunnel is characterized by comprising the following steps: excavating construction is carried out on each tunnel section after advanced support; the excavation construction comprises the following steps:
s1: excavating an upper step by a step method and installing a first layer of steel frame of the upper step;
s2: installing meshes and spraying concrete;
s3: constructing an upper step anchor rod;
s4: sealing the upper step and the temporary inverted arch of the upper step;
s5: excavating a lower step and an inverted arch and completing the first-layer support of the inverted arch;
s6: constructing a second layer of support construction of the lower step and the inverted arch, and immediately constructing a second liner of the inverted arch and filling the inverted arch after the second layer of support construction is finished;
s7: if the maximum accumulated deformation is greater than 50% of the first reserved deformation or the absolute maximum deformation of section scanning is greater than 200mm, and the deformation rate is greater than 2mm/d, immediately constructing a second layer of support of the upper step;
if the maximum accumulated deformation is greater than 50% of the first reserved deformation or the absolute maximum deformation of section scanning is greater than 200mm, and the deformation rate is less than 2mm/d, the second layer of support of the upper step is not performed;
after the first layer of steel frame of the upper step is provided with the net piece and the sprayed concrete layer, if the deformation speed is more than 20mm/d and the primary support is cracked and falls, immediately constructing an anchor rod of the upper step and a second layer of steel frame of the upper step and spraying the concrete layer;
s8: when the convergence rate of the surrounding rock is less than or equal to 0.6mm/d or the sinking rate of the arch part is less than or equal to 0.3mm/d, constructing a second lining;
the first layer of steel frame of the upper step adopts H200 steel; a plurality of arch frames of the first layer of steel frames of the upper step are connected through section steel;
the arch frame locking leg of the first layer of steel frame of the upper step is a steel pipe with the length of 6m and the diameter of 2 phi 76 mm; and the arch frame bottom cushion channel steel is arranged at the corner of the side wall of the upper step.
2. The method for controlling the severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 1, which is characterized in that: the circulating footage of the upper step excavation is not more than 1.2m; and the circulating footage of the inverted arch excavation is less than 3m.
3. The method for controlling severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 1, which is characterized by comprising the following steps of: and (3) excavating by adopting a two-step method, wherein the height of an upper step is 7-8 m, the height of a lower step is 4m, the excavating depth of an inverted arch is not more than 3.5m, the length of the upper step is 15-20 m, and the length of the lower step is 15m.
4. The method for controlling the severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 3, which is characterized in that: the distance between the primary support closed loop and the tunnel face is less than 35m.
5. The method for controlling severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 1, which is characterized by comprising the following steps of: the meshes are double-layer meshes; the sprayed concrete is C30 early high-strength fiber concrete.
6. The method for controlling the severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 1, which is characterized in that: after the upper step is provided with the net piece and the concrete layer is sprayed, if water seepage or surrounding rock deformation rate in the hole reaches 20mm/d, radial grouting is carried out on the upper step.
7. The method for controlling the severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 6, which is characterized in that: radial grouting adopts phi 42mm steel perforated pipes for grouting to reinforce surrounding rocks; the length of a single steel flower tube is 5m, and the ring X longitudinal distance is 1.0m X1.2 m; pure cement single-liquid slurry or cement-water glass double-liquid slurry is adopted as the slurry; the water-cement ratio of the single slurry is 0.6-1.1; when the single-liquid slurry can not block water, the double-liquid slurry is used for supplement.
8. The method for controlling severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 1, which is characterized by comprising the following steps of: the anchor rods comprise arch anchor rods, arch waist anchor rods and side wall anchor rods; the length of the arch anchor rod is 6m; the length of each of the arch anchor rod and the side wall anchor rod is 8m-10m.
9. The method for controlling severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 8, is characterized in that: the arch anchor rod is a hollow anchor rod; the arch anchor rod and the side wall anchor rod are both mortar anchor rods; the ring x longitudinal distance of the anchor rod is 0.8m x 1.2m.
10. The method for controlling the severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 8, which is characterized in that: the distance between the construction position of the anchor rod and the tunnel face and the working face is within 1 time of the hole diameter or within 15m.
11. The method for controlling severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 1, which is characterized by comprising the following steps of: the cross-sectional shape of the tunnel is circular.
12. The method for controlling severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 1, which is characterized by comprising the following steps of: the large deformation grade and the corresponding reserved deformation of each tunnel section need to be determined before excavation.
13. The method for controlling severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 1, which is characterized by comprising the following steps of: a first reserved deformation is arranged between the surrounding rock and the first layer of support; and a second reserved deformation is arranged between the first layer support and the second layer support.
14. The method for controlling the severe deformation of the strong seismic deep-buried soft rock stratum tunnel according to claim 1, which is characterized in that: in step S8, if the convergence rate is greater than 0.6mm/d and the arch sinking rate is greater than 0.3mm/d, radial grouting is carried out on the surrounding rock until the convergence rate of the surrounding rock is less than or equal to 0.6mm/d or the arch sinking rate is less than or equal to 0.3mm/d.
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| CN113236296B (en) * | 2021-04-25 | 2023-08-18 | 中铁二局第二工程有限公司 | Arch leg rock mass preservation method for subway station arch cover method construction |
| CN113137235B (en) * | 2021-04-30 | 2023-01-31 | 中铁十六局集团第二工程有限公司 | Construction method of high-ground-stress soft rock extrusion large-deformation tunnel |
| CN113279814B (en) * | 2021-06-21 | 2023-04-18 | 中铁十二局集团有限公司 | Inverted arch dismantling and replacing construction method for bottom bulging section of high-speed rail tunnel |
| CN114183172A (en) * | 2021-11-22 | 2022-03-15 | 中铁十六局集团第三工程有限公司 | Large-deformation tunnel construction method based on safety step |
| CN114352358B (en) * | 2021-12-28 | 2022-12-02 | 中南大学 | Dynamic grading control method and system for large deformation of high-ground-stress deep-buried soft rock tunnel |
| CN114320317A (en) * | 2022-01-21 | 2022-04-12 | 中交四航局第一工程有限公司 | Construction method for weak surrounding rock section of short-step super-large section tunnel |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107725058A (en) * | 2017-09-05 | 2018-02-23 | 长安大学 | The large deformation control method of chlorite schist stratum list hole Three-Lane Highway Tunnel |
| CN108412519A (en) * | 2018-05-21 | 2018-08-17 | 中铁二局集团有限公司 | The slight large deformation single-track tunnel suspension device of highlands soft rock and construction method |
| CN110130948A (en) * | 2019-06-19 | 2019-08-16 | 中铁十九局集团第六工程有限公司 | A kind of two steps band inverted arch quick closure tunnel support structure and its construction method |
| CN111335923A (en) * | 2020-05-19 | 2020-06-26 | 中铁五局集团第一工程有限责任公司 | Construction method for large deformation of soft rock of tunnel with unfavorable geology |
| CN111594182A (en) * | 2020-05-14 | 2020-08-28 | 北京交通大学 | Large deformation control method for large buried depth soft rock tunnel |
-
2020
- 2020-10-15 CN CN202011103853.XA patent/CN112196582B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107725058A (en) * | 2017-09-05 | 2018-02-23 | 长安大学 | The large deformation control method of chlorite schist stratum list hole Three-Lane Highway Tunnel |
| CN108412519A (en) * | 2018-05-21 | 2018-08-17 | 中铁二局集团有限公司 | The slight large deformation single-track tunnel suspension device of highlands soft rock and construction method |
| CN110130948A (en) * | 2019-06-19 | 2019-08-16 | 中铁十九局集团第六工程有限公司 | A kind of two steps band inverted arch quick closure tunnel support structure and its construction method |
| CN111594182A (en) * | 2020-05-14 | 2020-08-28 | 北京交通大学 | Large deformation control method for large buried depth soft rock tunnel |
| CN111335923A (en) * | 2020-05-19 | 2020-06-26 | 中铁五局集团第一工程有限责任公司 | Construction method for large deformation of soft rock of tunnel with unfavorable geology |
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