CN109736843B - Reverse waterproof method for assembling and pouring two linings of small template - Google Patents
Reverse waterproof method for assembling and pouring two linings of small template Download PDFInfo
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- CN109736843B CN109736843B CN201910049724.8A CN201910049724A CN109736843B CN 109736843 B CN109736843 B CN 109736843B CN 201910049724 A CN201910049724 A CN 201910049724A CN 109736843 B CN109736843 B CN 109736843B
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Abstract
The invention relates to a reverse waterproof method for assembling and pouring a secondary lining by a small template, belonging to the technical field of tunnel construction; after lagging behind the upper section of the top right pilot tunnel and the upper section of the top left pilot tunnel by a certain distance, excavating the lower end surface of the top right pilot tunnel and the lower section of the top left pilot tunnel; excavating an upper section of the middle right pilot tunnel, an upper section of the middle left pilot tunnel, a lower end surface of the middle right pilot tunnel and a lower section of the middle left pilot tunnel; and excavating the upper section of the bottom right pilot tunnel, the upper section of the bottom left pilot tunnel, the lower section of the bottom right pilot tunnel and the lower section of the bottom left pilot tunnel by using a step method, wherein the left side and the right side are crossed. The waterproof difficult problem of construction face kneck about solving for the construction progress improves secondary lining's quality, guarantees the safe quick construction of cross access and even station main tunnel.
Description
Technical Field
The invention relates to the technical field of tunnel construction, in particular to a reverse waterproof method for assembling and pouring a secondary lining by a small template.
Background
The underground excavation tunnel of striding greatly of narrow and small place construction is the common problem in city subway station construction, receives the place condition restriction, often utilizes the cross passage to transfer into main tunnel and be under construction during subway station construction. Therefore, safe and rapid construction of the transverse passage has important significance for saving the construction period of the subway station. After the transverse channel is excavated, primary support and pouring lining are generally required to maintain the stability of surrounding rocks. During actual construction, due to the consideration of construction period and excavation risk management, the secondary lining may need to be poured in sections and then sealed to form a ring, the integrity is poor, the phenomena of water seepage and water leakage are often caused at the interface parts of the upper construction surface and the lower construction surface, and particularly in areas with abundant underground water, the engineering quality is seriously influenced.
Disclosure of Invention
The invention aims to provide a reverse waterproof method for assembling and pouring a secondary lining by a small template, which has the advantages of simple structure, reasonable design and convenient use, and aims to overcome the difficult problem of waterproofing at the joints of the upper construction surface and the lower construction surface, accelerate the construction progress, improve the quality of the secondary lining and ensure the safe and rapid construction of a transverse channel and even a main tunnel of a vehicle station.
In order to achieve the purpose, the invention adopts the technical scheme that: the construction method comprises the following steps:
1. constructing a small grouting guide pipe on the side wall phi 42 of the tunnel by using a steel frame erected in the previous cycle; excavating an upper section of the top right pilot tunnel and an upper section of the top left pilot tunnel by using a CD method; spraying a closed palm surface; constructing primary support and temporary support at the periphery of the guide pit of the upper section of the right guide pit at the top, namely initially spraying 4CM thick concrete, laying a steel bar mesh, erecting a steel frame and an I20a temporary steel frame, and arranging a foot locking anchor rod and a positioning steel bar; after setting a system anchor rod, re-spraying concrete to the designed thickness; after lagging behind the upper section of the top right pilot tunnel and the upper section of the top left pilot tunnel by a certain distance, excavating the lower end surface of the top right pilot tunnel and the lower section of the top left pilot tunnel;
2. after arch excavation supporting and forming for 20 m, performing waterproof system treatment and secondary pouring operation on the upper section of the top right pilot tunnel and the upper section of the top left pilot tunnel;
3. excavating an upper section of a middle right pilot tunnel, an upper section of a middle left pilot tunnel, a lower end face of the middle right pilot tunnel and a lower section of the middle left pilot tunnel by using a step method, performing left-right cross operation, staggering front and back of two-lining pouring operation, performing two-lining waterproof, reinforcing steel bar and pouring operation on a middle side wall on one side when the construction length is more than 15m, and performing two-lining pouring operation on a middle side wall on the other side when the previous pouring strength reaches 70%;
4. excavating an upper section of a right guide pit at the bottom, an upper section of a left guide pit at the bottom, a lower section of the right guide pit at the bottom and a lower section of the left guide pit at the bottom by using a step method, constructing left and right sides in a crossed manner, constructing a bottom arch part two-lining pouring operation when the construction length is more than 10m, then performing two-lining waterproof, reinforcing steel bar and pouring operation of a side wall at the bottom of one side, and staggering the two-lining pouring operation front and back, namely performing the two-lining pouring operation of the side wall at the bottom of the other side when the current pouring strength reaches 70%.
Further, in the step 2, the secondary lining concrete is poured for 20 meters at one time, and after the strength reaches 70%, excavation is carried out on one side of the lower part of the pouring section.
Furthermore, the pouring of the middle side wall in the step 3 is controlled within the range of 5 meters, and the pouring of the rest side walls is controlled within the range of 15 meters.
Furthermore, the pouring in the step 3 and the step 4 adopts an integral pouring mode and a sequential construction method, and the pouring length is controlled within a range of 10 meters.
Furthermore, in the excavation process of the steps 1 to 4, when a joint of the two linings of concrete is encountered, weak blasting excavation of the middle groove is firstly carried out, and the side wall adopts the construction processes of weak blasting, carbon dioxide cracking and cold cracking, so that the protection of the grouted rubble is enhanced, and the influence of blasting on the completed two linings is completely avoided.
After adopting the structure, the invention has the beneficial effects that: the reverse waterproof method for assembling and pouring the secondary lining by the small template solves the problem of water prevention at the interface between the upper construction surface and the lower construction surface, accelerates the construction progress, improves the quality of the secondary lining, and ensures safe and rapid construction of a transverse channel and even a main tunnel of a vehicle station.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic cross-sectional view of the present invention.
FIG. 2 is a construction elevation of the upper section of the top right pilot tunnel and the upper section of the top left pilot tunnel according to the present invention.
FIG. 3 is a construction plan view of the upper section of the top right pilot tunnel and the upper section of the top left pilot tunnel according to the present invention.
FIG. 4 is a construction elevation view of the upper section of the middle right pilot tunnel and the upper section of the middle left pilot tunnel in the present invention.
FIG. 5 is a construction plan view of the upper section of the middle right pilot tunnel and the upper section of the middle left pilot tunnel according to the present invention.
FIG. 6 is a construction elevation of the upper section of the right pilot tunnel at the bottom and the upper section of the left pilot tunnel at the bottom according to the present invention.
FIG. 7 is a construction plan view of the upper section of the right pilot tunnel at the bottom and the upper section of the left pilot tunnel at the bottom according to the present invention.
FIG. 8 is a view showing the construction of the joint of the reinforcing bars and the waterproofing treatment in the construction joint according to the present invention.
FIG. 9 is a view showing a construction procedure for treating a construction joint in which concrete is not poured tightly according to the present invention.
Description of reference numerals:
the top right pilot tunnel upper section 1, the top right pilot tunnel lower end face 1-1, the top left pilot tunnel upper section 2, the top left pilot tunnel lower section 2-1, the middle right pilot tunnel upper section 3, the middle right pilot tunnel lower end face 3-1, the middle left pilot tunnel upper section 4, the middle left pilot tunnel lower section 4-1, the bottom right pilot tunnel upper section 5, the bottom right pilot tunnel lower section 5-1, the bottom left pilot tunnel upper section 6, the bottom left pilot tunnel lower section 6-1, the top arch 7, the middle side wall 8, the bottom side wall 9, the bottom arch 10, the lining template 11, the grouted rubble 12, the waterproof board 13, the steel plate 14, and the windable grouting pipe 15.
Detailed Description
The invention will be further described with reference to the accompanying drawings.
Referring to fig. 1 to 9, the present embodiment is applied to the construction of a cross channel of a # 2 wind shelter station of a # 2 line waterway observation station of a Guiyang rail transit. The 2# wind pavilion of the water viewing station is positioned in a civil house area on the left side of a left tunnel between-YDK 36+300 sections of the water viewing station, the central line of a transverse channel intersects with a route at a distance ZDK36+136.287, and the transverse channel is connected with a main tunnel and is orthogonal to the main tunnel. The clearance size in the No. 2 wind pavilion shaft is 6.6 x 15m, and the shaft depth is 32.998 m; the length of the transverse channel is 51.03m, the excavation width is =12.26 is 18.293m, the ground layer where the vertical shaft is located sequentially comprises a concrete ground, artificial miscellaneous fill, red clay and three-stacked lower system Anshun group dolomite from top to bottom, and the well body is mainly located in the dolomite; the top arch of the transverse channel has the buried depth of 14.7-16.5m and the thickness of the vault bedrock of 0.3-4.2 m.
The construction method of the embodiment is as follows:
1. constructing a small grouting guide pipe on the side wall phi 42 of the tunnel by using a steel frame erected in the previous cycle; excavating an upper section 1 of a top right pilot tunnel and an upper section 2 of a top left pilot tunnel by using a CD method; spraying a closed palm surface; constructing primary support and temporary support at the periphery of the guide pit of the upper section of the right guide pit at the top, namely initially spraying 4CM thick concrete, laying a steel bar mesh, erecting a steel frame and an I20a temporary steel frame, and arranging a foot locking anchor rod and a positioning steel bar; after setting a system anchor rod, re-spraying concrete to the designed thickness; after lagging behind the upper section 1 of the top right pilot tunnel and the upper section 2 of the top left pilot tunnel by a certain distance, excavating a lower end surface 1-1 of the top right pilot tunnel and a lower section 2-1 of the top left pilot tunnel;
2. after arch excavation supporting and forming for 20 m, installing an arch secondary lining multifunctional assembly trolley, and pouring concrete of the top arch part 7 by designing a small template assembly scheme;
3. excavating an upper cross section 3 of a middle right pilot pit, an upper cross section 4 of a middle left pilot pit, a lower end surface 3-1 of the middle right pilot pit and a lower cross section 4-1 of the middle left pilot pit by using a step method, performing left-right cross operation, staggering front and back of two-lining pouring operation, performing two-lining waterproof, reinforcing steel bar and pouring operation on the middle side wall 8 on one side when the construction length is more than 15m, and performing two-lining pouring operation on the middle side wall 8 on the other side when the previous pouring strength reaches 70%;
4. excavating an upper section 5 of a right guide pit at the bottom, an upper section 6 of a left guide pit at the bottom, a lower section 5-1 of the right guide pit at the bottom and a lower section 6-1 of the left guide pit at the bottom by using a step method, performing crossed construction on the left side and the right side, performing two-lining pouring operation on a bottom arch part 10 when the construction length is more than 10m, performing two-lining waterproof, reinforcing steel bar and pouring operation on a side wall 9 at the bottom at one side, and staggering the two-lining pouring operation front and back, namely performing two-lining pouring operation on the side wall 9 at the bottom at the other side when the current pouring strength reaches 70%.
Further, in the step 2, the secondary lining concrete is poured for 20 meters at one time, and after the strength reaches 70%, excavation is carried out on one side of the lower part of the pouring section.
Furthermore, the pouring of the middle side wall 8 in the step 3 is controlled within the range of 5 meters, and the pouring of the rest side walls is controlled within the range of 15 meters.
Furthermore, the pouring in the step 3 and the step 4 adopts an integral pouring mode and a sequential construction method, and the pouring length is controlled within a range of 10 meters.
Furthermore, in the excavation process of the steps 1 to 4, when a joint of the two linings of concrete is encountered, weak blasting excavation of the middle groove is firstly carried out, and the side wall adopts the construction processes of weak blasting, carbon dioxide cracking and cold cracking, so that the protection of the grouted rubble is enhanced, and the influence of blasting on the completed two linings is completely avoided.
Further, the construction joints of the top arch part 7, the middle side wall 8, the bottom side wall 9 and the bottom arch part 10 need to be subjected to steel bar joint and waterproof treatment, and the process is as follows: the concrete pouring method comprises the steps of reserving reinforcing steel bars before concrete pouring of the top arch portion 7, paving a template 11 at the bottom and the side face, grouting rubbles 12 to a foundation rock face below the template 11, completing protection and reinforcement of the grouted rubbles 12 before pouring of a middle side wall 8 (hanging a net and spraying concrete when necessary), connecting upper reinforcing steel bars and lower reinforcing steel bars through connectors, protecting waterproof boards 13 from being damaged due to filling of fine sand, setting steel plates above the grouted rubbles 12 to be 10% of inclination angles, enabling a formed secondary lining to be low outside and high inside and facilitating prevention of groundwater backflow.
Furthermore, the construction joint waterstop at the construction joints of the top arch part 7, the middle side wall 8, the bottom side wall 9 and the bottom arch part 10 is pre-embedded and can wind the grouting pipe 15, the process of backfilling cement grout is adopted, the grouting pipes are transversely and longitudinally arranged, and pouring surfaces are led out from two ends of each grouting pipe, so that the aim of compacting the integral connection position is fulfilled.
In the concrete embodiment, the wall thickness of the phi 42 grouting small guide pipe is 4.0mm, L =3.5m, the circumferential distance is 0.35m, the longitudinal distance is 1.5m, the external insertion angle is 5-7 degrees, the lap joint length of the small guide pipe is not less than 1m, the stratum is reinforced by grouting, the excavation footage of each earthwork excavation is 0.5m, bottom excavation construction is strictly forbidden during excavation, the earthwork excavation is carried out layer by layer from top to bottom, the underexcavated part is treated after the earthwork excavation is finished, and concrete with the thickness of 40mm is initially sprayed. Steel frame: i25b steel frames were installed all around with a pitch of 0.5 m/pin. System anchor rod: the arch part adopts a phi 32 grouting steel floral tube, the external insertion angle is 60 degrees, the longitudinal distance between rings is 1.0 x 1.0m, the arch part is arranged in a quincunx shape, L =3.5m, the wall thickness is 3mm, a grouting hole is drilled at the front part, the aperture is 6-8 mm, the hole distance is 20cm, a grout stopping section not less than 30cm is reserved at the tail part, and the grouting parameters of the phi 32 grouting steel floral tube are handled by referring to the grouting parameters of the leading small duct; the side wall adopts a phi 22 mortar anchor rod, and L =4.5 m; anchor rod spacing: 1.0 x 1.0m (circles x vertical), quincunx arrangement. Reinforcing mesh: phi 8 steel bars form 20 × 20cm grids which are arranged in a full ring; the reinforcing mesh should be welded firmly with the tail end of the anchor rod.
After adopting above-mentioned structure, this embodiment beneficial effect does:
after the transverse channel is excavated, the prior art carries out secondary lining after the construction of the station and the interval tunnel is completed. However, in the actual construction process, the excavation risk of each excavation step is possibly large, the construction period is short, when the secondary lining is poured in a segmented and time-sharing mode, corresponding waterproof measures are too simple, and the problems of water leakage and water leakage at the interface of the upper construction surface and the lower construction surface cannot be solved well.
The above description is only for the purpose of illustrating the technical solutions of the present invention and not for the purpose of limiting the same, and other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention should be covered within the scope of the claims of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims (1)
1. A reverse waterproof method for assembling and pouring a second lining by a small template is characterized by comprising the following steps: the construction method comprises the following steps:
(1) constructing a small grouting guide pipe on the side wall phi 42 of the tunnel by using the steel frame erected in the previous cycle; excavating an upper section of the top right pilot tunnel and an upper section of the top left pilot tunnel by using a CD method; spraying a closed palm surface; constructing primary support and temporary support at the periphery of the guide pit of the upper section of the right guide pit at the top, namely initially spraying 4CM thick concrete, laying a steel bar mesh, erecting a steel frame and an I20a temporary steel frame, and arranging a foot locking anchor rod and a positioning steel bar; after setting a system anchor rod, re-spraying concrete to the designed thickness; after lagging behind the upper section of the top right pilot pit and the upper section of the top left pilot pit by a certain distance, excavating the lower end face of the top right pilot pit and the lower section of the top left pilot pit, in the excavating process, when meeting the joint of the two linings of concrete, firstly performing weak blasting excavation of a middle groove, and adopting the construction process of weak blasting, carbon dioxide presplitting and cold opening on a side wall to strengthen the protection of the grouted rubble and completely avoid the influence of blasting on the completed two linings;
(2) after arch excavation supporting and forming is carried out for 20 meters, waterproof system treatment and secondary pouring operation of the upper section of the right pilot tunnel at the top and the upper section of the left pilot tunnel at the top are carried out, secondary lining concrete is poured for 20 meters at one time, after the strength reaches 70%, excavation of one side of the lower part of a pouring section is carried out, in the excavation process, when the joint of the secondary lining concrete is met, weak blasting excavation of a middle groove is carried out firstly, and the side wall adopts the construction processes of weak blasting, carbon dioxide presplitting and cold opening, so that the protection of grouted rubble stones is enhanced, and the influence of blasting on the completed secondary lining is completely avoided;
(3) excavating the upper section of the middle right pilot tunnel, the upper section of the middle left pilot tunnel, the lower end surface of the middle right pilot tunnel and the lower section of the middle left pilot tunnel by using a step method, controlling the pouring of the middle side wall within the range of 5 meters, controlling the pouring of the other side walls within 15m, performing left-right cross operation, staggering the front and back of the second lining pouring operation, performing the second lining waterproof, reinforcing steel bar and pouring operation of the middle side wall on one side when the construction length is more than 15m, and after the previous pouring strength reaches 70%, performing secondary lining pouring operation of the side wall at the middle part of the other side, wherein the pouring adopts an integral pouring mode and a sequential construction method, the pouring length is controlled within 10 meters, and when a joint of secondary lining concrete is encountered in the excavation process, weak blasting excavation of the middle groove is firstly carried out, and the side wall adopts the construction processes of weak blasting, carbon dioxide presplitting and cold cracking, so that the protection of the grouted rubble is enhanced, and the influence of blasting on the finished secondary lining is completely avoided;
(4) excavating the upper section of the bottom right pilot tunnel, the upper section of the bottom left pilot tunnel, the lower section of the bottom right pilot tunnel and the lower section of the bottom left pilot tunnel by using a step method, performing crossed construction on the left side and the right side, performing secondary lining pouring operation on the arch part of the bottom when the construction length is more than 10m, then carrying out two-lining waterproof, reinforcing steel bar and pouring operation of the side wall at the bottom of the single side, wherein the two-lining pouring operation is staggered from front to back, namely, after the current casting strength reaches 70%, the two-lining casting operation of the bottom side wall at the other side is carried out, the casting adopts an integral casting mode, the construction process is carried out by a sequential method, the casting length is controlled within 10 meters, when the joint of the two-lining concrete is encountered in the excavation process, weak blasting excavation of the middle groove is firstly carried out, and the side wall adopts the construction processes of weak blasting, carbon dioxide presplitting and cold cracking, so that the protection of the grouted rubble is enhanced, and the influence of blasting on the finished secondary lining is completely avoided.
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| CN201910049724.8A CN109736843B (en) | 2019-01-18 | 2019-01-18 | Reverse waterproof method for assembling and pouring two linings of small template |
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| CN109736843B true CN109736843B (en) | 2020-06-19 |
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| CN110593893B (en) * | 2019-11-01 | 2024-04-12 | 中建八局轨道交通建设有限公司 | Main body structure construction method and system at intersection of main tunnel and construction transverse channel |
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| 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 |
| CN101067374A (en) * | 2007-02-13 | 2007-11-07 | 铁道第二勘察设计院 | Single-hole double-layer overlapping tunnel structure and construction method thereof |
| CN104806251B (en) * | 2015-04-27 | 2017-05-17 | 北京市轨道交通建设管理有限公司 | Subsidiary inverted excavation construction method for urban subway station under complex environment |
| CN108005660A (en) * | 2017-11-16 | 2018-05-08 | 党文华 | A kind of Optimization of Expressway Tunnel Construction method |
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