CN111287216A - Cast-in-place utility tunnel structure movement joint - Google Patents
Cast-in-place utility tunnel structure movement joint Download PDFInfo
- Publication number
- CN111287216A CN111287216A CN202010255529.3A CN202010255529A CN111287216A CN 111287216 A CN111287216 A CN 111287216A CN 202010255529 A CN202010255529 A CN 202010255529A CN 111287216 A CN111287216 A CN 111287216A
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- Prior art keywords
- joint
- deformation joint
- rubber
- concrete
- steel
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- 229920001971 elastomer Polymers 0.000 claims abstract description 51
- 239000004567 concrete Substances 0.000 claims abstract description 41
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 37
- 239000010959 steel Substances 0.000 claims abstract description 37
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 33
- 239000010410 layer Substances 0.000 claims abstract description 15
- 239000010426 asphalt Substances 0.000 claims abstract description 14
- 239000011241 protective layer Substances 0.000 claims abstract description 14
- 239000000853 adhesive Substances 0.000 claims abstract description 13
- 239000002131 composite material Substances 0.000 claims abstract description 13
- 239000004570 mortar (masonry) Substances 0.000 claims abstract description 13
- 239000000463 material Substances 0.000 claims abstract description 12
- 239000004519 grease Substances 0.000 claims abstract description 8
- 229920006327 polystyrene foam Polymers 0.000 claims abstract description 8
- 239000004587 polysulfide sealant Substances 0.000 claims abstract description 8
- 239000004575 stone Substances 0.000 claims description 6
- 229910001335 Galvanized steel Inorganic materials 0.000 claims description 4
- 239000008397 galvanized steel Substances 0.000 claims description 4
- 229920001084 poly(chloroprene) Polymers 0.000 claims description 4
- 238000009434 installation Methods 0.000 claims description 3
- 229910000746 Structural steel Inorganic materials 0.000 claims 1
- 238000012423 maintenance Methods 0.000 description 5
- 238000010276 construction Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 238000009435 building construction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229920001021 polysulfide Polymers 0.000 description 1
- 239000005077 polysulfide Substances 0.000 description 1
- 150000008117 polysulfides Polymers 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 239000000565 sealant Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000004078 waterproofing Methods 0.000 description 1
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/10—Tunnels or galleries specially adapted to house conduits, e.g. oil pipe-lines, sewer pipes ; Making conduits in situ, e.g. of concrete ; Casings, i.e. manhole shafts, access or inspection chambers or coverings of boreholes or narrow wells
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/16—Arrangement or construction of joints in foundation structures
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- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Lining And Supports For Tunnels (AREA)
Abstract
The invention discloses a deformation joint of a cast-in-place comprehensive pipe gallery structure, which comprises a concrete box body, wherein a back-attached rubber waterstop is arranged on the concrete box body and is arranged along a pocket ring at the periphery of the concrete box body; a middle embedded type steel-edged rubber water stop is arranged at the deformation joint of the concrete box body and is fixed with a tie steel wire through a deformation joint positioning steel bar; a polystyrene foam plate is arranged in the deformation joint, and the inner wall of the joint is sealed by adopting a double-grease polysulfide sealant; the composite self-adhesive rubber asphalt waterproof roll is covered outside the structural joint, a fine aggregate concrete protective layer is arranged outside the composite self-adhesive rubber asphalt waterproof roll, and waterproof mortar is arranged outside the fine aggregate concrete protective layer to finish the whole structural deformation joint. The invention protects layer by layer in the form of 'inner 2 and outer 3' by arranging a back-pasting rubber water stop, a double-grease polysulfide sealant, a composite self-adhesive rubber asphalt waterproof coiled material, a poured concrete protective layer and a waterproof mortar plastering surface.
Description
Technical Field
The invention relates to a deformation joint of a cast-in-place comprehensive pipe gallery structure, and belongs to the technical field of building construction.
Background
At present, the underground pipe gallery is tried to be used in every place of China, and along with the entering of the engineering of the pipe gallery into the use stage, some early construction problems of the pipe gallery are gradually exposed in the maintenance process of an operation unit, wherein the main problems are that the deformation joint of the pipe gallery seeps water and the water leakage phenomenon is serious.
The main reasons for this are as follows:
firstly, the lap joint seam of the coiled material has the hidden trouble of water leakage, the coiled material cannot be completely adhered for water prevention, and the coiled material is very easy to hollowly under the action of external force or temperature difference;
secondly, the inner and outer water stops are torn due to the uneven structure settlement or deformation, which causes the water leakage of the deformation joint and the expansion joint
And thirdly, due to reasons such as load disturbance, internal and external temperature difference and the like, a gap appears at one side of the waterstop at the deformation joint and the settlement joint caused by structural deformation, shrinkage and the like, so that a water seepage channel is formed, and water leakage at the deformation joint is caused.
Disclosure of Invention
The invention aims to provide a deformation joint of a cast-in-place comprehensive pipe gallery structure, which solves the problems of water seepage and water leakage of the deformation joint caused by uneven settlement, poor construction quality, stress strain and the like in the prior art and overcomes the technical difficulties of high water leakage maintenance cost, difficult maintenance and repeated maintenance of the existing deformation joint.
The invention is realized by the following steps:
a cast-in-place comprehensive pipe gallery structure deformation joint comprises a concrete box body positioned on a bottom plate, a side wall and a top plate, wherein a back-attached rubber waterstop is arranged on the concrete box body and is arranged along a pocket ring around the concrete box body; a middle-buried steel-edge rubber water stop crossing the deformation joint is arranged at the deformation joint of the concrete box body, and the middle-buried rubber water stop is fixed with a tie steel wire through a deformation joint positioning steel bar; a polystyrene foam plate is arranged in the deformation joint, and the inner wall of the joint is sealed by adopting a double-grease polysulfide sealant; the composite self-adhesive rubber asphalt waterproof roll is covered outside the structural joint, a fine aggregate concrete protective layer is arranged outside the composite self-adhesive rubber asphalt waterproof roll, and waterproof mortar plastering is arranged outside the fine aggregate concrete protective layer to form the structural deformation joint integrally.
Furthermore, the buried steel-edged rubber waterstop is made of chloroprene rubber material, and the galvanized steel edge is suitable for the temperature of minus 35-60 ℃.
Further, when the back-pasted rubber water stop is positioned in the outer wall of the plate structure, the outer sides of the two steel belts are higher than the middle rubber water stop to form U-shaped installation.
Further, the composite self-adhesive rubber asphalt waterproof coiled material is covered on the whole periphery of the outer side of the outer wall of the plate for two times according to the thickness of 4mm per channel; the fine stone concrete protective layer is formed by pouring C20 fine stone concrete with the thickness of 80mm, and the waterproof mortar surface is formed by a concrete surface with the thickness of 20mm and 1: 2.5, the waterproof mortar realizes two waterproof layers in the structural joint and three waterproof layers outside the structural joint.
Furthermore, the buried steel edge rubber waterstop is fixedly connected with the deformation joint positioning steel bars before concrete pouring, steel edge mounting holes on two sides of the buried steel edge rubber waterstop are used for bundling and positioning the buried steel edge rubber waterstop and the structural main bars by the aid of the tie steel wires.
Compared with the prior art, the middle embedded steel edge rubber waterstop is arranged in the middle of the deformation joint, the rubber is chloroprene rubber and galvanized steel edges, the applicable temperature is-35-60 ℃, and the structure can be effectively controlled in a crack development state when differential settlement is overlarge by fixing the positioning steel bars and the bonding steel wires to form regular cracks, so that the later-stage treatment and maintenance are facilitated, and the differential settlement resistance is effectively increased; set up the polystyrene foam board, can effectively cushion the deformation that structure both ends structure produced because of the expend with heat and contract with cold of temperature change to enable in the movement joint not have the space, can't produce the infiltration passageway. Through setting up back of body and pasting formula rubber waterstop, the sealed glue of double grease polysulfide sealant, compound self-adhesion rubber asphalt waterproofing membrane and pouring concrete protective layer, waterproof mortar plastering "2 outside 3" forms protect layer by layer, and the at utmost is waterproof, satisfies the interior waterproof requirement of structural design year, promotes the development of new era utility tunnel.
Drawings
FIG. 1 is a schematic cross-sectional view of a unitary structural seam of the present invention;
FIG. 2 is a sectional view A-A of FIG. 1, showing a substantial portion of the deformation joint of the top plate structure;
FIG. 3 is a sectional view taken along line B-B of FIG. 1, showing a substantial portion of the deformation joint of the sidewall construction;
FIG. 4 is a cross-sectional view taken at C-C of FIG. 1, showing a substantial portion of the deformation joint of the base plate structure;
fig. 5 is a schematic view of a deformation joint-positioning reinforcing bar structure.
Description of reference numerals: the concrete is characterized by comprising the following steps of 1-deformation joint positioning steel bars, 2-tie steel wires, 3-back-attached rubber water stops, 4-middle embedded steel edge rubber water stops, 5-bis-ester polysulfide sealant, 6-polystyrene foam plates, 7-concrete boxes, 8-composite self-adhesive rubber asphalt waterproof coiled materials, 9-fine stone concrete protective layers, 10-waterproof mortar plastering, 11-plain concrete cushion layers, 12-main ribs, 13-longitudinally distributed steel bars and 14-inner walls of pipe gallery structures.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples.
As shown in fig. 1-5: the deformation joint comprises a bottom plate structure deformation joint (shown in figure 4), a side wall structure deformation joint (shown in figure 3) and a top plate structure deformation joint (shown in figure 2), wherein the structure deformation joints comprise a concrete box body 7, deformation joint positioning steel bars 1 (shown in figure 5), a tie steel wire 2, a back-attached rubber water stop belt 3, a middle-embedded steel edge rubber water stop belt 4, a polystyrene foam plate 6, a double-grease polysulfide sealing paste sealant 5, a composite self-adhesive rubber asphalt waterproof coiled material 8, a fine aggregate concrete protective layer 9, a waterproof mortar plastering surface 10, a plain concrete cushion layer 11, a structure main rib 12, a longitudinal distribution steel bar 13, a pipe gallery structure inner wall 14 and the like. The middle-buried steel-edged rubber waterstop 4 is made of chloroprene rubber and galvanized steel edges, and the applicable temperature is-35-60 ℃. The buried rubber water stop 4 is fixed with the tie steel wire 2 through the deformation joint positioning steel bar 1, after concrete is poured, the polystyrene foam plate 6 is arranged in the deformation joint, and the inner wall of the joint is sealed by the double-grease polysulfide sealant 5. A back-attached rubber water stop 3 is arranged in the concrete of the outer wall of the plate. The outer part of the structural joint is integrally covered with 84mm double composite self-adhesive rubber asphalt waterproof coiled materials, a C20 fine aggregate concrete protective layer 9 is arranged outside the coiled materials, and a waterproof mortar plastering 10 is arranged outside the fine aggregate concrete protective layer 9 to form a structural deformation joint integrally;
in the implementation process, the middle-buried steel-edge rubber water stop 4 is fixed in the deformation joint positioning steel bar 1 before concrete is poured, steel-edge mounting holes are formed in two sides of the middle-buried steel-edge rubber water stop 4, and the middle-buried steel-edge rubber water stop 4 and the structural main steel bar 12 are bound and positioned by the tying steel wire 2; when the back-pasted rubber water stop 3 is positioned in the outer wall of the plate structure, the outer sides of the two steel belts are higher than the middle rubber water stop to form U-shaped installation; and a polystyrene foam plate 6 is arranged in the structural deformation joint, and a double-grease polysulfide sealant 5 is constructed on the inner wall of the plate.
Covering two 4mm composite self-adhesive rubber asphalt waterproof rolls 8 around the outer side of the outer wall of the plate, and pouring a 80mm thick C20 fine aggregate concrete protective layer 9 which is 1 mm thick by 20 mm: 2.5 plastering 10 with waterproof mortar to realize two waterproof layers in the structural joint and three waterproof layers outside the structural joint.
Of course, the above is only a specific application example of the present invention, and other embodiments of the present invention are also within the scope of the present invention.
Claims (5)
1. The utility model provides a cast-in-place utility tunnel structure movement joint which characterized in that: the concrete box body (7) is positioned on the bottom plate, the side wall and the top plate, a back-attached rubber waterstop (3) is arranged on the concrete box body (7), and the back-attached rubber waterstop (3) is arranged along a pocket ring around the concrete box body (7); a middle-buried steel-edge rubber water stop (4) stretching across the deformation joint is arranged at the deformation joint of the concrete box body (7), and the middle-buried rubber water stop (4) is fixed with a tie steel wire (2) through a deformation joint positioning steel bar (1); a polystyrene foam plate (6) is arranged in the deformation joint, and the inner wall of the joint is sealed by a double-grease polysulfide sealant (5); the composite self-adhesive rubber asphalt waterproof roll (8) is covered outside the structural joint, a fine aggregate concrete protective layer (9) is arranged outside the composite self-adhesive rubber asphalt waterproof roll (8), and a waterproof mortar plastering layer (10) is arranged outside the fine aggregate concrete protective layer (9) to form the structural deformation joint integrally.
2. The cast-in-place utility tunnel structure movement joint of claim 1, characterized in that: the middle-buried steel-edged rubber waterstop (4) is made of chloroprene rubber materials, and the applicable temperature of the galvanized steel edge is-35-60 ℃.
3. The cast-in-place utility tunnel structure movement joint of claim 2, characterized in that: two sides steel band outsides are higher than middle rubber waterstop and form the installation of U style of calligraphy when back of body pastes formula rubber waterstop (3) is fixed a position in the outer wall of plate structure.
4. The cast-in-place utility tunnel structure movement joint of claim 1, characterized in that: the composite self-adhesive rubber asphalt waterproof coiled material (8) is covered on the whole periphery of the outer side of the outer wall of the plate according to the thickness of 4mm per channel; the fine stone concrete protection layer (9) is formed by pouring C20 fine stone concrete with the thickness of 80mm, and the waterproof mortar plastering layer (10) is formed by pouring C20 fine stone concrete with the thickness of 20mm, namely 1: 2.5, the waterproof mortar realizes two waterproof layers in the structural joint and three waterproof layers outside the structural joint.
5. The cast-in-place utility tunnel structure movement joint of claim 1, characterized in that: the middle-buried steel edge rubber water stop (4) is fixedly connected with the deformation joint positioning steel bar (1) before concrete pouring, steel edge mounting holes are formed in two sides of the middle-buried steel edge rubber water stop (4), and the middle-buried steel edge rubber water stop (4) and the main structural steel bar (12) are bundled and positioned by the tie steel wire (2).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010255529.3A CN111287216A (en) | 2020-04-02 | 2020-04-02 | Cast-in-place utility tunnel structure movement joint |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010255529.3A CN111287216A (en) | 2020-04-02 | 2020-04-02 | Cast-in-place utility tunnel structure movement joint |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111287216A true CN111287216A (en) | 2020-06-16 |
Family
ID=71027442
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010255529.3A Pending CN111287216A (en) | 2020-04-02 | 2020-04-02 | Cast-in-place utility tunnel structure movement joint |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111287216A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111962565A (en) * | 2020-08-18 | 2020-11-20 | 中国五冶集团有限公司 | Waterproof structure for deformation joint of pipe gallery and construction method |
| CN113322804A (en) * | 2021-05-10 | 2021-08-31 | 中国铁路设计集团有限公司 | Single-face combined reverse-adhesion type back-attached water stop belt with simple structure |
| CN113846701A (en) * | 2021-09-22 | 2021-12-28 | 中国一冶集团有限公司 | Method for installing and positioning middle-buried steel-edge water stop |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204060729U (en) * | 2014-07-28 | 2014-12-31 | 厦门中平公路勘察设计院有限公司 | Tunnel waterproofing construction |
| CN207121936U (en) * | 2017-07-19 | 2018-03-20 | 广东裕达建设集团有限公司 | A kind of pipe gallery roof deformation stitches waterproof construction |
| CN207130790U (en) * | 2017-07-19 | 2018-03-23 | 中铁隧道集团二处有限公司 | A kind of tunnel floor waterproof structure for deformation seams |
| CN207700220U (en) * | 2017-12-07 | 2018-08-07 | 中国市政工程西北设计研究院有限公司 | A kind of waterproof construction of pipe gallery outer wall |
| CN108385731A (en) * | 2018-03-14 | 2018-08-10 | 中国铁路设计集团有限公司 | A kind of improved underground-structure deformation joint water proof structure |
| CN108571016A (en) * | 2018-06-14 | 2018-09-25 | 上海建工五建集团有限公司 | The deformation joint structure and construction method of underground pipe gallery |
| CN209179060U (en) * | 2018-11-23 | 2019-07-30 | 中国建筑第五工程局有限公司 | The deformation joint structure of underground pipe gallery |
| CN209875185U (en) * | 2019-03-26 | 2019-12-31 | 陕西华山路桥集团有限公司 | Tunnel waterproof construction |
| CN212052869U (en) * | 2020-04-02 | 2020-12-01 | 中建四局第五建筑工程有限公司 | Cast-in-place utility tunnel structure movement joint |
-
2020
- 2020-04-02 CN CN202010255529.3A patent/CN111287216A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204060729U (en) * | 2014-07-28 | 2014-12-31 | 厦门中平公路勘察设计院有限公司 | Tunnel waterproofing construction |
| CN207121936U (en) * | 2017-07-19 | 2018-03-20 | 广东裕达建设集团有限公司 | A kind of pipe gallery roof deformation stitches waterproof construction |
| CN207130790U (en) * | 2017-07-19 | 2018-03-23 | 中铁隧道集团二处有限公司 | A kind of tunnel floor waterproof structure for deformation seams |
| CN207700220U (en) * | 2017-12-07 | 2018-08-07 | 中国市政工程西北设计研究院有限公司 | A kind of waterproof construction of pipe gallery outer wall |
| CN108385731A (en) * | 2018-03-14 | 2018-08-10 | 中国铁路设计集团有限公司 | A kind of improved underground-structure deformation joint water proof structure |
| CN108571016A (en) * | 2018-06-14 | 2018-09-25 | 上海建工五建集团有限公司 | The deformation joint structure and construction method of underground pipe gallery |
| CN209179060U (en) * | 2018-11-23 | 2019-07-30 | 中国建筑第五工程局有限公司 | The deformation joint structure of underground pipe gallery |
| CN209875185U (en) * | 2019-03-26 | 2019-12-31 | 陕西华山路桥集团有限公司 | Tunnel waterproof construction |
| CN212052869U (en) * | 2020-04-02 | 2020-12-01 | 中建四局第五建筑工程有限公司 | Cast-in-place utility tunnel structure movement joint |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111962565A (en) * | 2020-08-18 | 2020-11-20 | 中国五冶集团有限公司 | Waterproof structure for deformation joint of pipe gallery and construction method |
| CN113322804A (en) * | 2021-05-10 | 2021-08-31 | 中国铁路设计集团有限公司 | Single-face combined reverse-adhesion type back-attached water stop belt with simple structure |
| CN113846701A (en) * | 2021-09-22 | 2021-12-28 | 中国一冶集团有限公司 | Method for installing and positioning middle-buried steel-edge water stop |
| CN113846701B (en) * | 2021-09-22 | 2023-01-13 | 中国一冶集团有限公司 | Method for installing and positioning middle-buried steel-edge water stop |
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