CN110700856B - Tunnel secondary lining steel bar protective layer control construction method - Google Patents
Tunnel secondary lining steel bar protective layer control construction method Download PDFInfo
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- CN110700856B CN110700856B CN201910852770.1A CN201910852770A CN110700856B CN 110700856 B CN110700856 B CN 110700856B CN 201910852770 A CN201910852770 A CN 201910852770A CN 110700856 B CN110700856 B CN 110700856B
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 114
- 239000010959 steel Substances 0.000 title claims abstract description 114
- 239000011241 protective layer Substances 0.000 title claims abstract description 37
- 238000010276 construction Methods 0.000 title claims abstract description 26
- 239000010410 layer Substances 0.000 claims abstract description 87
- 229910001294 Reinforcing steel Inorganic materials 0.000 claims abstract description 32
- 238000000034 method Methods 0.000 claims abstract description 16
- 238000009826 distribution Methods 0.000 claims abstract description 15
- 238000009434 installation Methods 0.000 claims abstract description 8
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- 239000004567 concrete Substances 0.000 abstract description 14
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
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Abstract
The invention discloses a tunnel secondary lining steel bar protective layer control construction method, and relates to the technical field of tunnel construction. One embodiment of the method comprises: positioning the steel bars: the method comprises the following steps that positioning ribs are symmetrically arranged from the center of an arch crown to two sides along the longitudinal direction and the circumferential direction of a tunnel, connecting positions of the positioning ribs and longitudinal distribution ribs and/or circumferential main ribs are marked on the positioning ribs, inverted arch reinforcing steel bars with first length are reserved at construction joints of inverted arch and arch walls, joints of adjacent longitudinal main ribs and/or circumferential main ribs are staggered by more than a first width, and the thickness of a concrete net protection layer is a first thickness; a steel bar installation step: and fixing the longitudinal distribution ribs and the annular main ribs at the connecting positions according to preset positions, then laying and fixing the distribution ribs, and finally laying the stirrups. The embodiment improves the installation quality of the two-lining steel bar and ensures the design requirement.
Description
Technical Field
The invention relates to the field of tunnel construction, in particular to a tunnel secondary lining steel bar protective layer control construction method.
Background
The secondary lining of the tunnel is a secondary lining of the tunnel, and is a reinforced concrete structure which is cast by adopting a mould or a secondary lining integral trolley on the inner side of a primary support in tunnel engineering construction. In contrast, secondary lining and primary support refer to inner lining constructed by concrete and other materials under the condition that the tunnel is subjected to primary support, so as to achieve the effects of reinforcing support, optimizing a route waterproof and drainage system, beautifying appearance, conveniently setting facilities such as communication, illumination, monitoring and the like, and adapt to the requirement of modern highway tunnel construction.
In the concrete structure, reinforced concrete is a composite material consisting of two different materials, namely reinforcing steel bars and concrete, and the good bonding property of the two materials is the basis for the joint work of the two materials. The reinforcing steel bar is exposed in the atmosphere or other media, and is easy to corrode and rust, so that the effective section of the reinforcing steel bar is reduced, and the stress of the structure is influenced. Therefore, from the angle of reinforcing steel bar bonding and anchoring and the requirement of durability, the concrete protective layer is required to ensure that the reinforcing steel bar does not generate corrosion which reduces the structural reliability within the designed service life of the member, ensure that the reinforcing steel bar and the surrounding concrete can work together, and ensure that the reinforcing steel bar fully exerts the required strength. Relevant specifications are established for the thickness of a concrete protection layer under different environments in the specification GB50010-2010 of concrete structure design.
However, in the practical process, the inventor finds that the positioning of the two-lining steel bar and the control of the protective layer still belong to the weak link of the tunnel quality control in the tunnel construction. The reason is that: firstly, the importance of a field constructor on a steel bar protection layer is not known in place, so that the steel bar protection layer is extremely large in thickness or insufficient in thickness, and the quality of a secondary lining is seriously influenced; secondly, the thickness of the protective layer is not reasonably adjusted according to different use environments, and reasonable countermeasures are not adopted for the reduction of the thickness of the protective layer caused by the vault crown descending; these are all key factors that contribute to the impairment of tunnel quality.
Disclosure of Invention
In view of this, the embodiment of the present invention provides a tunnel secondary lining steel bar protection layer control construction method, which can ensure that the durability of a tunnel meets the design life requirement, improve the installation quality of secondary lining steel bars, and ensure that the steel bar spacing, the layer distance and the protection layer thickness meet the design requirement.
In order to achieve the above object, according to an aspect of the embodiments of the present invention, there is provided a method for controlling construction of a protective layer of a reinforcing bar for a secondary lining of a tunnel, including:
positioning the steel bars:
the method comprises the following steps that positioning ribs are symmetrically arranged from the center of an arch crown to two sides along the longitudinal direction and the circumferential direction of a tunnel, the connecting positions of the positioning ribs and circumferential main ribs are marked, inverted arch reinforcing steel bars with first lengths are reserved at construction joints of inverted arch and arch walls, joints of adjacent circumferential main ribs are staggered by more than a first width, and the net protective layer thickness of the circumferential main ribs is a first thickness;
a steel bar installation step:
fixing the annular main reinforcements and the positioning reinforcements at the connecting positions according to preset positions, connecting the annular main reinforcements with joints of the inverted arch reinforcements, then laying and fixing longitudinal distribution reinforcements, and finally laying stirrups;
and (3) reinforcing the main reinforcement:
arranging supporting and reinforcing steel bars in the vault area of the tunnel, and fixing the annular main bars and the supporting and reinforcing steel bars;
the tunnel secondary lining can be provided with a plurality of layers of steel bar protection layers, and the space between the steel bar protection layers is determined by arranging L normal direction bars between the steel bar protection layers.
Optionally, the positioning ribs are meshed, the longitudinal distance is 1.5-3.5 m, and the circumferential distance is 2.0-4.0 m.
Optionally, a circumferential main rib is selected as a circumferential grounding steel bar at a fixed interval along the depth of the tunnel.
Optionally, the first length is determined according to the area of the bar joint in the same section being not more than 50% of the total area.
Optionally, the first width is 35d1, wherein d1 is the diameter of the circumferential main rib.
Optionally, the first thickness is 4-8 cm.
Optionally, the method further comprises: and arranging grounding steel bars, selecting a circumferential main bar to be welded and fixed with the grounding steel bars along the fixed interval of the tunnel depth, and enabling the steel bar joints exposed by the concrete net protective layer to form a straight line longitudinally and/or circumferentially.
Optionally, in the step of installing the reinforcing steel bars, two ends of the same annular main reinforcement are on the same section and are not inclined.
Optionally, the tunnel secondary lining is provided with two steel bar protection layers: after the first layer of steel bar protection layer is fixed, arranging normal bars at the connecting positions, wherein one ends of the normal bars are connected with the first layer of steel bars of the two lining steel bars, and the other ends of the normal bars are connected with the second layer of steel bars of the two lining steel bars; the thickness of the second layer main rib net protective layer is the second thickness.
Alternatively, the second thickness may be smaller than the first thickness, and not smaller than 3 cm.
Optionally, the normal bars are L-shaped bars, and the first right-angle edges of the L-shaped bars are fixedly connected with the longitudinal/circumferential distribution bars of the first layer of mesh reinforcement through stirrups; the second right-angle side forms a vertical angle with the plane of the tunnel, and the end point of the second right-angle side is connected with the second layer of steel bars; the normal direction muscle is used for guaranteeing the interval of first layer reinforcing bar protective layer and second layer reinforcing bar protective layer.
Optionally, the circumferential main ribs are connected with each other at the dome part by a sleeve.
Optionally, the circumferential main rib and the inverted arch reinforcing steel bar are connected by welding.
Optionally, if the welded connection is a single-side lap weld, the lap length is not less than 10d 2; if the welding connection is double-sided lap welding, the lap length is not less than 5d 2; wherein the width of the welding seam is not less than 0.8d2 and not less than 10 mm, the height of the welding seam is not less than 0.3d2 and not less than 4 mm, and d2 is the diameter of the inverted arch steel bar.
Optionally, the longitudinal distribution ribs are fixed by banding, and the overlapping length is not less than 35d3, wherein d3 is the diameter of the longitudinal distribution ribs.
Optionally, spacers are respectively arranged inside and outside the second layer of steel bars of the two lining steel bars and are fixedly connected with the steel bars, wherein the height of the spacer connected with the first layer of steel bars is the first thickness, and the height of the spacer connected with the second layer of steel bars is the second thickness.
Optionally, the distance between the cushion blocks is not more than 1 meter and/or the number of the cushion blocks per square meter is not less than 4, and the cushion blocks are arranged in a quincunx shape.
One embodiment of the above invention has the following advantages or benefits: because the technical means of controlling the construction of the second lining steel bars in the tunnel is adopted, the technical problem that the positioning of the second lining steel bars and the control of the protective layer are weak in tunnel quality is solved, and the technical effects of improving the installation quality of the second lining steel bars and ensuring the design requirements are further achieved.
Further effects of the above-mentioned non-conventional alternatives will be described below in connection with the embodiments.
Drawings
The drawings are included to provide a better understanding of the invention and are not to be construed as unduly limiting the invention. Wherein:
FIG. 1 is a schematic plan view of a steel bar protection layer according to the present invention;
fig. 2 is a schematic view of a longitudinal cross-sectional layout of a steel bar protection layer according to the present invention;
FIG. 3 is a schematic view of the main steps of a construction method according to an embodiment of the present invention;
FIG. 4 is a schematic illustration of a normal tendon fixation method according to an embodiment of the present invention;
wherein: n1-the hoop location muscle of first layer reinforcing bar protective layer, N2-the hoop location muscle of second layer reinforcing bar protective layer, N3-vertical positioning muscle, N4-normal direction muscle.
Detailed Description
Exemplary embodiments of the present invention are described below with reference to the accompanying drawings, in which various details of embodiments of the invention are included to assist understanding, and which are to be considered as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted in the following description for clarity and conciseness.
Fig. 1 is a schematic plan view of a steel bar protection layer according to the present invention, as shown in fig. 1: the plurality of annular positioning ribs N1 of the first layer of reinforcing steel bar protection layer are arranged along a preset interval, the preset interval is 1.5-3.5 meters, and in a preferred embodiment, the preset interval is 2.5 meters. The longitudinal positioning ribs N3 are vertically intersected with the circumferential positioning ribs N1 and are arranged along a preset distance, the preset distance is 2.0-4.0 meters, and in a preferred embodiment, the preset distance is 3.0 meters. And a normal rib N4 is arranged at the connecting position of the annular positioning rib N1 and the longitudinal positioning rib N3.
Fig. 2 is a schematic view of the arrangement of the longitudinal section of the steel bar protection layer according to the present invention, as shown in fig. 2: the hoop positioning rib N1 of the first layer of steel bar protection layer is connected with the hoop positioning rib N2 of the second layer of steel bar protection layer through a plurality of normal ribs N4, the distance between the two layers of steel bars is accurately controlled by the standard normal ribs, and the accuracy of the hoop main rib position is guaranteed. In a preferred embodiment, the net protector thickness of the circumferential positioning ribs N1 and N2 are both 5 cm.
Fig. 3 is a schematic diagram of main steps of a tunnel secondary lining steel bar protection layer control construction method according to an embodiment of the invention, as shown in fig. 3:
s101, a steel bar positioning step:
along the tunnel longitudinally and the hoop direction, from the vault center to both sides symmetrical arrangement location muscle, the location muscle can become netted, and the longitudinal separation is 1.5~3.5 meters, and the hoop interval is 2.0~4.0 meters, and preferably, the longitudinal separation is 2.5 meters, and the transverse separation is 3.0 meters.
The connecting position of the main rib and the longitudinal main rib and/or the annular main rib is marked on the positioning rib, red paint can be used for representing on the positioning rib, and the marked distance is the design distance of the main rib, generally 25cm, so that the distance of the main rib is ensured to meet the design requirement. And further, arranging normal ribs at the connecting positions, wherein one ends of the normal ribs are connected with the outer-layer steel bars of the two lining steel bars, and the other ends of the normal ribs are connected with the inner-layer steel bars of the two lining steel bars. The net length of the normal positioning rib is consistent with the actual thickness of the secondary lining concrete, the normal positioning rib is equivalent to an auxiliary line, the position of the two outer-layer lining steel bars is adjusted on the auxiliary line, and the position from the position of the two outer-layer lining steel bars to the end of the normal rib is the thickness of the protective layer.
That is to say, tunnel two lining reinforcing bar protective layer thickness adopts multichannel normal direction muscle to carry out positioning control, in order to improve the control effect, adopts balanced encryption normal direction muscle, ensures that normal direction muscle is indulged transversely and is laid the interval even.
The inverted arch reinforcing steel bar with the first length is reserved at the construction joint of the inverted arch and the arch wall, and the joints of the adjacent longitudinal main reinforcing steel bars and/or the circumferential main reinforcing steel bars are staggered by more than the first width. Wherein the first length may be determined in accordance with the area of the bar joint in the same section not being greater than 50% of the total area. The first width is 35d1, where d1 is the diameter of the circumferential main rib. Therefore, enough space is reserved for welding the reinforcing steel bars, and the welding quality is prevented from being influenced by too close space distance of the welded joint of the reinforcing steel bars.
In a preferred embodiment of the invention, two steel bar protection layers are arranged on the tunnel secondary lining, wherein the thickness of the first layer of annular main steel bar net protection layer is a first thickness, and the first thickness is 4-6 cm. Preferably, the first thickness is 5 cm. The thickness of the annular main rib net protective layer on the second layer is a second thickness which is not less than 3 cm, and the second thickness can be less than the first thickness. The steel bar joints exposed out of the main bar net protective layer form a straight line longitudinally and/or annularly.
The main reinforcement net protection layer is a concrete layer inside the second layer of steel bars and outside the first layer of steel bars and is used for protecting the second layer of steel bars and the first layer of steel bars. It will be appreciated by those skilled in the art that the thickness of the concrete cover layer should be adjusted to suit the particular circumstances. The thickness of the protective layer is not too large, the too large thickness of the protective layer can cause the too large width of the crack generated after the stress of the component, and the service performance of the component can be affected, for example, the decoration layer on the surface of the component is damaged, the too large width of the crack can cause people to be panic and uneasy, and the too large thickness of the protective layer can also cause economic waste. However, the thickness of the protective layer is not too small, and the protective strength of the steel bar is not enough due to the too small thickness of the protective layer, so that the bonding anchoring performance and the stress performance of the member are deteriorated due to the corrosion of the steel bar.
After the positioning ribs are arranged, the reinforcing steel bars at two ends of the two linings can be bound firstly, after the reinforcing steel bars at the ends are bound, horizontal lines are pulled from the two ends, the positions of the circumferential main reinforcing steel bars are marked, then the reinforcing steel bars at the middle part are constructed, and the crossing parts of the reinforcing steel bars are bound. And measuring and paying off are carried out again after the first layer of steel bar is bound, and the specific position of the second layer of main steel bar is determined.
As shown in fig. 4, in a preferred embodiment of the present invention, the normal bars are L-shaped bars, and the first right-angle side of the L-shaped bars is fixedly connected to the first layer of mesh reinforcement positioning bars by a stirrup; the second right-angle side forms a vertical angle with the plane of the tunnel, and the end point of the second right-angle side is connected with the second layer of steel bars; the normal direction muscle is used for guaranteeing the interval of first layer of reinforcing bar protective layer and second layer reinforcing bar protective layer. It will be understood by those skilled in the art that the thickness of the lines in fig. 4 do not represent actual rebar, and that the normal bars are thickened and darkened only to more clearly illustrate the invention.
In a preferred embodiment of the invention, the normal bars are straight reinforcing bars of the same length. One end of the normal direction rib is connected with the first layer of reinforcing mesh positioning rib, the other end of the normal direction rib is connected with the second layer of reinforcing mesh, and the normal direction rib and the plane of the tunnel form a vertical angle. The connection means may be welding.
In a preferred embodiment of the invention, both ends of the normal bar can be made into a hook shape, respectively hooked on the inner layer steel bar and the outer layer steel bar, and can be bound and fixed.
S102 represents a reinforcing bar installation step:
fixing the circumferential main reinforcement at the connecting position according to a preset position, fixing the joint of the circumferential main reinforcement and the inverted arch reinforcement, then laying and fixing the longitudinal distribution reinforcement, and finally laying the stirrups. The annular main ribs can be connected with the arch crown by a sleeve, so that the waterproof layer is prevented from being scalded and the joints are protected from being corroded.
Two ends of the same annular main rib are suitable to be on the same section and are not inclined. The hammer ball line can be hung from the vault, and a connecting line (namely the same mileage) is formed at two ends of the annular main rib, if the hammer ball line is intersected with the connecting line, the two ends of the annular main rib are on the same section and are not inclined.
The connection part of the annular main rib and the inverted arch reinforcing steel bar is welded. If the welding connection is single-side lap welding, the lap length of the steel bars is not less than 10d 2; if the welding connection is double-sided lap welding, the lap length of the steel bars is not less than 5d 2; wherein the width of the welding seam is not less than 0.8d2 and not less than 10 mm, the height of the welding seam is not less than 0.3d2 and not less than 4 mm, and d2 is the diameter of the steel bar. The welding quality and the firmness are ensured.
The longitudinal distribution ribs are fixed by banding, the lapping length is not less than 35d3, wherein d3 is the diameter of the longitudinal distribution ribs.
And respectively arranging cushion blocks inside and outside the second layer of steel bars of the two lining steel bars and fixedly connecting (such as binding and the like) the cushion blocks with the steel bars, wherein the height of the cushion block connected with the first layer of steel bars is a first thickness, and the height of the cushion block connected with the second layer of steel bars is a second thickness. Ensuring that the thickness of the concrete net protective layer is tightly controlled. Wherein, the distance between the cushion blocks can be set to be not more than 1 meter and/or the number of the cushion blocks per square meter is not less than 4, and the cushion blocks are arranged in a quincunx shape. And further controlling the accuracy of the thickness of the concrete protective layer.
The platform truck location is carried out after the cushion ligature is accomplished, and the back inspection layer cushion has damaged or drops after the location, and the discovery is damaged or drops and should in time change the benefit neat, and the platform truck template is pressed close to whether the inspection cushion is whole, and the discovery has the cushion that does not press close to the template to adjust the reinforcing bar, until whole qualified.
S103 represents a main bar reinforcement step:
and supporting and reinforcing steel bars are arranged in the vault area of the tunnel, and the main steel bars and the supporting and reinforcing steel bars are fixed annularly. The tunnel vault is usually the position with the largest bearing capacity, and the vault is easy to displace and subside over time, even leads to the condition such as crack, damage or collapse to appear. After the step of reinforcing the main ribs is carried out, vault settlement is slowed down, and the integral rigidity of the structure is obviously improved.
Further, before the construction of the tunnel secondary lining steel bar protection layer, a technical preparation step is also needed, and blanking and processing are carried out according to the requirements of design files and/or drawings: (1) determining parameters such as variety, grade, model, spacing, quantity and the like of the second lining reinforcing steel bar; (2) determining the specification and the model of the steel bars, the arrangement mode, the interval, the connection mode and the like of the steel bars; (3) the steel bar is straight and has no damage, and the surface has no crack, oil stain, granular or flaky old rust; (4) the connection mode of the steel bars requires that the welded joint and the connecting sleeve have no cracks; (5) checking the sizes of the center line, the elevation, the section and the like of the primary support section, determining the length of the contour line of the tunnel, and blanking according to the length; (6) checking the clearance of the primary support section of the tunnel to ensure the thickness of the lining; (7) and determining the connecting position according to the design requirement of the positions of the longitudinal distribution ribs and/or the circumferential main ribs.
Furthermore, after the tunnel secondary lining steel bars are installed, the quality inspection step is further included, parameters of related items are subjected to sampling inspection, and construction quality is further improved. The items of the spot check and the qualification standards thereof can be referred to table 1.
TABLE 1
In the process of constructing the secondary lining steel bars in the tunnel, quality measures, safety measures, cautions and the like are also formulated, and the method comprises the following steps:
(1) the training on the technology and the constructors is strengthened, and the quality consciousness of all the participating constructors is improved.
(2) The field technician enhances the control of the construction process, and checks that the following items must meet the design requirements:
steel bar lapping, welding length and welding quality;
specification, type, grade and number of steel bars;
the distance between the steel bars and the thickness of the protective layer.
(3) The training on the technology and the constructors is strengthened, and the safety consciousness of all the participating constructors is improved.
(4) And (4) formulating a safety construction emergency plan, and preparing emergency material storage in daily life.
(5) Constructors need to be trained and certified to post, and electricians and welders need to hold special worker work certificates.
(6) The welder must wear protective clothing. During construction, a welder should stand on a wood pad or other insulating pads. The welder must be grounded to ensure the safety of operators, and reliable insulation grounding is required for welding wires and welding clamp joints.
(7) When a large amount of welding is carried out, the welding transformer cannot be overloaded, the temperature rise of the transformer cannot exceed 60 ℃, and special attention needs to be paid to the temporary load rate regulation of the welding machine so as to avoid damage caused by excessive heating.
(8) Mechanical equipment used for straightening and cutting the reinforcing steel bars needs to be operated by a specially-assigned person.
(9) When the steel bar is welded, the waterproof board must be shielded by protective measures so as not to be damaged.
(10) The tunnel construction operation area must ensure enough illumination, and the area with larger unsafe factors should increase the illumination.
(11) All the reserved and pre-buried facilities are accurate in position and size.
(12) The multifunctional cloth hanging trolley is required to be pasted with a reflective mark and welded with handrail guardrails.
The above-described embodiments should not be construed as limiting the scope of the invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions can occur, depending on design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (6)
1. A tunnel secondary lining steel bar protective layer control construction method is characterized by comprising the following steps:
positioning the steel bars:
the method comprises the following steps that positioning ribs are symmetrically arranged from the center of an arch crown to two sides along the longitudinal direction and the circumferential direction of a tunnel, connecting positions of the positioning ribs with circumferential main ribs and longitudinal distribution ribs are marked, inverted arch reinforcing steel bars with first lengths are reserved at construction joints of inverted arch and arch walls, joints of adjacent circumferential main ribs are staggered by more than a first width, and the net protective layer thickness of the circumferential main ribs is a first thickness;
a steel bar installation step:
fixing the annular main reinforcements and the positioning reinforcements at the connecting positions according to preset positions, connecting the annular main reinforcements with joints of the inverted arch reinforcements, then laying and fixing longitudinal distribution reinforcements, and finally laying stirrups;
reinforcing the annular main reinforcement:
arranging supporting and reinforcing steel bars in the vault area of the tunnel, and fixing the annular main bars and the supporting and reinforcing steel bars;
a plurality of steel bar protection layers are lined in the tunnel II, normal steel bars are arranged among the steel bar protection layers for positioning control, and the space between the steel bar protection layers is determined;
the positioning ribs are meshed, the longitudinal distance is 1.5-3.5 m, and the circumferential distance is 2.0-4.0 m; the first length is determined according to the fact that the area of the steel bar joint in the same section is not more than 50% of the total area; the first width is 35d1, wherein d1 is the diameter of the circumferential main rib; the first thickness is 4-8 cm;
the tunnel is characterized by further comprising grounding steel bars, wherein a circumferential main bar is selected to be welded and fixed with the grounding steel bars at a fixed interval along the depth of the tunnel, and steel bar joints exposed out of a net protective layer of the circumferential main bar are longitudinally and/or circumferentially aligned;
the tunnel secondary lining is provided with two steel bar protection layers:
after the first layer of steel bar protection layer is fixed, arranging normal bars at the connecting positions, wherein one ends of the normal bars are connected with the first layer of steel bars of the two lining steel bars, and the other ends of the normal bars are connected with the second layer of steel bars of the two lining steel bars; the net protective layer thickness of the second layer of steel bars is a second thickness;
respectively arranging cushion blocks inside a second layer of steel bars of the second lining steel bars and outside the first layer of steel bars and fixedly connecting the cushion blocks with the steel bars, wherein the height of the cushion block connected with the first layer of steel bars is the first thickness, and the height of the cushion block connected with the second layer of steel bars is the second thickness; the distance between the cushion blocks is not more than 1 meter and/or the number of the cushion blocks per square meter is not less than 4, and the cushion blocks are arranged in a quincunx shape.
2. The method of claim 1, wherein for the rebar installation step, both ends of the same circumferential main bar are on the same section and are not inclined.
3. The method of claim 1, wherein the second thickness is less than the first thickness and is not less than 3 centimeters.
4. The method of claim 1, wherein the normal bars are L-shaped bars, and the first right-angle side of the L-shaped bars is fixedly connected with the positioning bars of the first layer of mesh reinforcement by stirrups; the second right-angle side forms a vertical angle with the plane of the tunnel, and the end point of the second right-angle side is connected with the second layer of steel bars; the normal direction muscle is used for guaranteeing the interval of first layer reinforcing bar protective layer and second layer reinforcing bar protective layer.
5. The method according to claim 1, wherein the circumferential main ribs are connected at the dome portion by a sleeve; the connection part of the annular main rib and the inverted arch steel bar is connected by welding; the longitudinal distribution ribs are bound and fixed.
6. The method of claim 5, wherein if the welded connection is a single lap weld, the lap length is not less than 10d 2; if the welding connection is double-sided lap welding, the lap length is not less than 5d 2; the width of the welding seam is not less than 0.8d2 and not less than 10 mm, the height of the welding seam is not less than 0.3d2 and not less than 4 mm, and d2 is the diameter of the inverted arch steel bar; the overlapping length of the banding fixation is not less than 35d3, wherein d3 is the diameter of the longitudinal distribution rib.
Priority Applications (1)
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| CN111456757B (en) * | 2020-04-30 | 2021-07-13 | 中铁隧道集团二处有限公司 | Construction method for preventing large-section tunnel lining reinforcing steel bars from collapsing |
| CN113027492B (en) * | 2021-03-31 | 2023-06-27 | 中铁十五局集团第一工程有限公司 | Reinforcement connecting method for rapid construction of tunnel secondary lining reinforcement |
| CN113236295A (en) * | 2021-04-25 | 2021-08-10 | 中铁二局第二工程有限公司 | Construction method of intensive tunnel embedded channel |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1068295A (en) * | 1996-08-27 | 1998-03-10 | Nippon Kokan Light Steel Kk | Concrete segment |
| JP3167937B2 (en) * | 1996-08-12 | 2001-05-21 | 株式会社ピー・エス | Construction method of shield lining segment and shield tunnel |
| CN1487151A (en) * | 2003-08-25 | 2004-04-07 | 中国科学院力学研究所 | Archimedes bridge with protecting shell |
| CN1563671A (en) * | 2004-03-19 | 2005-01-12 | 刘昌用 | Dormant digging and separating construction method for underground two layers and multilayer composite lining structure |
| CN104061004A (en) * | 2014-07-10 | 2014-09-24 | 招商局重庆交通科研设计院有限公司 | Steel bar construction for secondary lining of tunnel |
| CN106761838A (en) * | 2017-02-20 | 2017-05-31 | 长安大学 | Tunnel Second Lining bow member unit and its arch frame structure and erection method that are constituted |
-
2019
- 2019-09-10 CN CN201910852770.1A patent/CN110700856B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3167937B2 (en) * | 1996-08-12 | 2001-05-21 | 株式会社ピー・エス | Construction method of shield lining segment and shield tunnel |
| JPH1068295A (en) * | 1996-08-27 | 1998-03-10 | Nippon Kokan Light Steel Kk | Concrete segment |
| CN1487151A (en) * | 2003-08-25 | 2004-04-07 | 中国科学院力学研究所 | Archimedes bridge with protecting shell |
| CN1563671A (en) * | 2004-03-19 | 2005-01-12 | 刘昌用 | Dormant digging and separating construction method for underground two layers and multilayer composite lining structure |
| CN104061004A (en) * | 2014-07-10 | 2014-09-24 | 招商局重庆交通科研设计院有限公司 | Steel bar construction for secondary lining of tunnel |
| CN106761838A (en) * | 2017-02-20 | 2017-05-31 | 长安大学 | Tunnel Second Lining bow member unit and its arch frame structure and erection method that are constituted |
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