CN210395386U - Water-bed tunnel strong-permeable sandy soil layer anti-permeation damage structure - Google Patents
Water-bed tunnel strong-permeable sandy soil layer anti-permeation damage structure Download PDFInfo
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- CN210395386U CN210395386U CN201921334858.6U CN201921334858U CN210395386U CN 210395386 U CN210395386 U CN 210395386U CN 201921334858 U CN201921334858 U CN 201921334858U CN 210395386 U CN210395386 U CN 210395386U
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Abstract
The utility model belongs to the technical field of submarine tunnel construction, specifically provide a sandy soil layer infiltration resistance destruction structure permeates water by force in submarine tunnel, and this infiltration resistance destruction structure includes first stage cofferdam, second stage cofferdam and tube coupling stagnant water curtain. Constructing the first-stage cofferdam and the second-stage cofferdam alternately and partially overlapping; and a first-stage water-stop curtain and a second-stage water-stop curtain are respectively arranged in the first-stage cofferdam and the second-stage cofferdam, and pass through the strong permeable layer to reach the water-stop layer below the strong permeable layer. The pipe joint waterproof curtain can be a lower pipe joint waterproof curtain arranged below the pipe joint of the tunnel and connected with the second-stage waterproof curtain, and can also be a side pipe joint waterproof curtain arranged on two sides of the pipe joint and connected with the second-stage waterproof curtain. The pipe joint waterproof curtain prevents a strong permeable layer below the pipe joint from becoming a main channel for seepage damage, and realizes safe construction of a water-bottom tunnel in a sand soil layer with strong permeability.
Description
Technical Field
The utility model belongs to the technical field of submarine tunnel construction, concretely relates to submarine tunnel strong sandy soil layer infiltration resistance destroys structure that permeates water.
Background
With the rapid development of national economy in China, the downward tunnel is more and more widely applied to urban traffic engineering. However, the underpass tunnel inevitably passes through the lake bottom or the river bottom, so that the engineering construction difficulty is high and the risk is high.
At present, a method for constructing a lake bottom or river bottom tunnel by using a cofferdam is widely used, and the cofferdam construction method comprises the steps of constructing a cofferdam in water to block water, then lowering the water in the cofferdam, and finally excavating a foundation pit in the cofferdam and constructing the tunnel. In order to ensure normal flow of river water and water surface navigation, the cofferdam construction method is generally divided into two stages: in the first stage, a first-stage cofferdam is constructed at one end of a water-bottom tunnel along the length direction of the tunnel, after the tunnel construction in the first-stage cofferdam is finished, a part of second-stage cofferdam is constructed and a part of first-stage cofferdam is removed to recover the water flow or navigation above the built tunnel; and in the second stage, the second-stage cofferdam construction is finished at the other end of the underwater tunnel, and then the rest part of the underwater tunnel is constructed in the second-stage cofferdam. The second-stage cofferdam in the cofferdam construction method is inevitably intersected with the built tunnel pipe joints, so that the partial cofferdam body and the waterproof curtain in the cofferdam cannot penetrate through the built tunnel pipe joints to be inserted into the deep part of the water bottom, and when the bottom of the tunnel is the weak permeable cohesive soil, the cofferdam construction method can utilize the cohesive soil layer to enable the second-stage cofferdam to form a closed waterproof structure, so that the first-stage cofferdam is dismantled and backwater is not generated, and a water inrush accident is not generated in the second-stage cofferdam. However, when the bottom of the tunnel pipe joint is a strong water-permeable sandy soil layer, the second-stage cofferdam water-stopping structure is lost under the tunnel pipe joint, and the small water head difference can cause permeation damage and water-permeable accidents, thereby seriously threatening the construction safety and the engineering quality. Taking the north regions of Anhui Yan Huai and Huai river as examples, the strong permeable sandy soil layer is widely distributed, and can be in water conservancy communication with the upper water body through the local permeable layer or be a pressure bearing water layer, so that the great technical problem is brought to the construction of urban tunnels, and the permeation damage caused by the strong permeable sandy soil layer appears for many times in recent years.
Therefore, it is necessary to provide a structure for preventing the water bottom tunnel from being damaged by penetration of the sand soil layer due to the insufficient water permeability in the prior art.
Disclosure of Invention
An object of the utility model is to provide a sandy soil layer anti-permeability of permeating water by force destroys structure in submarine tunnel to at least, solve in the sandy soil layer of permeating water by force at present and alternate cofferdam construction and take place gushing water accident scheduling problem easily.
In order to achieve the above object, the present invention provides the following technical solutions:
the utility model provides a submarine tunnel sandy soil layer permeation resistant destruction structure that permeates water by force, the permeation resistant destruction structure includes:
the first-stage cofferdam comprises a first-stage side longitudinal cofferdam in the same direction as the tunnel and a first-stage end transverse cofferdam perpendicular to the tunnel, and the first-stage side longitudinal cofferdam and the first-stage end transverse cofferdam are connected to form a U-shaped structure.
The secondary cofferdam comprises a secondary side longitudinal cofferdam in the same direction with the tunnel and a secondary end transverse cofferdam perpendicular to the tunnel, and the secondary side longitudinal cofferdam and the secondary end transverse cofferdam are connected to form a U-shaped structure.
The first-stage cofferdam and the second-stage cofferdam are partially overlapped in the length direction of the tunnel.
The first-stage water-stop curtain is arranged in the first-stage cofferdam, the second-stage water-stop curtain is arranged in the second-stage cofferdam, and the first-stage water-stop curtain and the second-stage water-stop curtain penetrate through the underwater highly permeable layer to reach the water-stop layer below the highly permeable layer.
A pipe section waterproof curtain, wherein the pipe section waterproof curtain and the second-stage waterproof curtain are connected together to form a closed waterproof curtain; the pipe joint waterproof curtain is a tunnel pipe joint lower waterproof curtain or a pipe joint side waterproof curtain, and the tunnel pipe joint lower waterproof curtain is arranged below a tunnel pipe joint connected with a second-stage end transverse cofferdam; the waterproof curtain under the tunnel pipe joint penetrates through the highly permeable layer to reach the waterproof layer below the highly permeable layer; and the second-stage waterproof curtain is connected with the lower waterproof curtain of the tunnel pipe section to form a closed waterproof curtain.
In the structure for resisting the penetration and the damage of the strongly permeable sandy soil layer of the underwater tunnel, as a preferred scheme, the first-stage cofferdam and the second-stage cofferdam are both of a double-layer steel sheet pile structure, the inner and outer steel sheet piles are respectively driven into the water bottom, a steel pull rod for pulling and fixing is connected between the inner and outer steel sheet piles, and the inner sides of the inner and outer steel sheet piles are paved with impermeable geomembranes; sand is filled between the inner layer steel sheet pile and the outer layer steel sheet pile paved with the anti-seepage geomembrane; the first-stage waterproof curtain is arranged in the middle of the thickness of the first-stage cofferdam, and the second-stage waterproof curtain is arranged in the middle of the thickness of the second-stage cofferdam; preferably, the Larsen steel sheet piles are adopted as the steel sheet piles of the first-stage cofferdam and the second-stage cofferdam.
In the structure for resisting permeation and damage of the sandy soil layer with strong water permeability of the underwater tunnel, as a preferred scheme, two groups of parallel concrete clamping grooves are arranged on the outer wall of the tunnel pipe joint connected with the second-stage end transverse cofferdam, the concrete clamping grooves protrude out of the outer side wall and the upper surface of the tunnel pipe joint, the distance between the two groups of parallel concrete clamping grooves is consistent with the thickness value of the second-stage end transverse cofferdam, and two rows of steel sheet piles intersected with the tunnel pipe joint and the second-stage end transverse cofferdam are respectively arranged in the two groups of parallel concrete clamping grooves, so that the underwater tunnel is tightly connected with the tunnel pipe joint.
In the structure for resisting seepage damage of the strongly permeable sandy soil layer of the underwater tunnel, as a preferred scheme, the waterproof curtain below the tunnel pipe joint is a cement soil mixing pile or a high-pressure jet grouting pile which are mutually occluded; preferably, a plurality of rows of cement soil stirring piles or high-pressure jet grouting piles are arranged on two sides of the waterproof curtain below the tunnel pipe section, the plurality of rows of cement soil stirring piles or high-pressure jet grouting piles extend to two sides from the waterproof curtain below the tunnel pipe section along the longitudinal direction of the tunnel, and the driving depths of the plurality of rows of cement soil stirring piles or high-pressure jet grouting piles are gradually decreased along with the increase of the extending distance.
In the underwater tunnel strong permeable sandy soil layer anti-permeation damage structure, as a preferred scheme, a connecting groove is formed in the upper part of the waterproof curtain below the tunnel pipe joint, connecting reinforcing steel bars are arranged inside the connecting groove, and the connecting reinforcing steel bars are connected with a reinforcing steel bar framework in the tunnel pipe joint; and pouring the concrete in the connecting groove and the concrete of the tunnel pipe joint synchronously.
The utility model also provides a construction method of submarine tunnel sandy soil layer anti-penetration destruction structure of permeating water by force, construction method includes following step:
and step S1, constructing a first-stage cofferdam, and excavating a foundation pit after the first-stage cofferdam falls into water.
And step S2, constructing a tunnel pipe joint lower waterproof curtain below the foundation pit in the first-stage cofferdam, and constructing the pipe joint in the foundation pit.
And step S3, constructing the transverse cofferdam at the end part of the second stage, reserving the overlapped part of the first-stage cofferdam and the second-stage cofferdam, and dismantling the other longitudinal cofferdams at the side surface of the first stage.
And S4, constructing a second-stage cofferdam, dismantling the transverse cofferdam at the end part of the first stage, excavating a foundation pit in the second-stage cofferdam, and constructing pipe joints.
And step S5, removing the second-stage cofferdam to finish the tunnel construction.
In the above construction method for the underwater tunnel strong permeable sandy soil layer permeation resistant destruction structure, as a preferable scheme, the step S2 specifically includes the following steps:
step S201, constructing a waterproof curtain below the tunnel pipe joint below the foundation pit.
Step S202, multiple rows of cement soil mixing piles or high-pressure jet grouting piles are arranged in the foundation pit at the two sides of the waterproof curtain under the tunnel pipe joint at intervals, and the depth of the cement soil mixing piles or the high-pressure jet grouting piles is gradually decreased from the waterproof curtain under the tunnel pipe joint to the tunnel axis direction at the two sides.
Step S203, performing tunnel pipe joint construction; the upper part of the waterproof curtain below the tunnel pipe joint is provided with a connecting groove, and connecting reinforcing steel bars are bound in the connecting groove; binding a tunnel pipe joint reinforcing steel bar framework, and connecting reinforcing steel bars in connecting grooves with the reinforcing steel bar framework in the tunnel pipe joint; and synchronously pouring concrete in the connecting groove and the concrete of the tunnel pipe joint so as to form a water stop joint sealed under the tunnel pipe joint.
Preferably, the waterproof curtain under the tunnel pipe section in step S201 is a cemented soil mixing pile or a high-pressure jet grouting pile which are engaged with each other.
In the above construction method for the underwater tunnel strong permeable sandy soil layer permeation resistant destruction structure, as a preferable scheme, the step S3 specifically includes the following steps:
step S301, constructing a second-stage end transverse cofferdam in a plane where the waterproof curtain is located under the tunnel pipe joint, enabling steel sheet piles on two sides and the top of the second-stage end transverse cofferdam at the tunnel pipe joint to be installed in corresponding concrete clamping grooves on the tunnel pipe joint, and then connecting the steel sheet piles with the concrete clamping grooves by using plain concrete.
Step S302, paving an anti-seepage geomembrane on the inner sides of the second-stage end transverse cofferdam steel sheet piles at the two sides of the tunnel pipe joints, filling the cofferdam with sandy soil and compacting, and filling backfill materials in the second-stage end transverse cofferdam at the top of the tunnel pipe joints.
Step S303, constructing a cement soil mixing pile or a high-pressure rotary spraying pile in the thickness of the cofferdam body of the second-stage end transverse cofferdam at two sides of the tunnel pipe joint to serve as a second-stage water-stop curtain, wherein the cement soil mixing pile or the high-pressure rotary spraying pile downwards penetrates through the water bottom strong permeable layer from the top of the second-stage end transverse cofferdam to the water-stop layer below the strong permeable layer, and is connected with the lower water-stop curtain of the tunnel pipe joint in the horizontal direction.
And step S304, backfilling the upper part of the tunnel pipe joint constructed in the first-stage cofferdam to finish the construction of the tunnel pipe joint in the first-stage cofferdam.
And S305, reserving the overlapped part of the first-stage cofferdam and the second-stage cofferdam, and dismantling the other longitudinal cofferdams at the side of the first stage.
Preferably, the backfill material above the tunnel pipe joints in the step S304 is plain concrete.
The utility model also provides another kind of construction method of submarine tunnel strong sand nature soil layer infiltration resistance destruction structure that permeates water, construction method includes following step:
step one, constructing a first-stage cofferdam and lowering water in the first-stage cofferdam.
And step two, constructing a pipe joint side waterproof curtain and a foundation pit support structure, then excavating the foundation pit and constructing the pipe joints.
And step three, constructing a transverse cofferdam at the end part of the second stage, reserving the overlapped part of the first-stage cofferdam and the second-stage cofferdam, and dismantling the other longitudinal cofferdams at the side surface of the first stage.
And step four, constructing a second-stage cofferdam, dismantling the transverse cofferdam at the end part of the first stage, excavating a foundation pit in the second-stage cofferdam, and performing pipe joint construction.
And fifthly, dismantling the second-stage cofferdam to finish the tunnel construction.
In the construction method of the underwater tunnel strong permeable sandy soil layer permeation damage resistant structure, as a preferable scheme, the second specific operation method of the step is as follows:
firstly, constructing pipe joint side waterproof curtains on two sides of a length direction of a foundation pit to be excavated in a first-stage cofferdam; then constructing a foundation pit enclosure structure in the pipe joint side waterproof curtain; finally, after a foundation pit is excavated, pipe joint construction is carried out; preferably, the pipe section side waterproof curtain is a cement-soil mixing pile or a high-pressure jet grouting pile which are mutually occluded; preferably, the foundation pit enclosure structure is a cast-in-place pile.
Compared with the closest prior art, the utility model provides a technical scheme has following excellent effect:
the utility model provides a sand nature soil layer anti infiltration destruction structure permeates water by force in submarine tunnel sets up tunnel tube coupling stagnant water curtain through below the tunnel tube coupling or both sides, links together tunnel tube coupling lower stagnant water curtain or tube coupling side stagnant water curtain and the interior stagnant water curtain of the horizontal cofferdam of second phase tip to avoided tube coupling below the strong permeable bed to become the main passageway that the infiltration destruction takes place. And a concrete clamping groove is arranged outside the tunnel pipe joint connected with the second-stage end part transverse cofferdam, so that the pipe joint is tightly connected with the second-stage end part transverse cofferdam, and seepage is avoided between the second-stage end part transverse cofferdam and the pipe joint. The utility model discloses a construction of tube coupling side water stop curtain prior to foundation ditch envelope bored concrete pile, such construction order can be in the same place tube coupling side water stop curtain and bored concrete pile zonulae occludens. The utility model discloses well totally enclosed stagnant water structure has realized that the safe construction and the economy of strong sand nature soil layer middle water bottom tunnel that permeates water are reasonable.
Drawings
The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.
Wherein:
fig. 1 is a schematic view of the distribution of cofferdam and tunnel pipe joints of embodiment 1 of the present invention;
fig. 2 is a schematic view of the distribution of cofferdam and tunnel pipe joints of embodiment 2 of the present invention;
fig. 3 is a sectional view of the connection between the second-stage transverse cofferdam and the tunnel tube joints and the waterproof curtain under the tunnel tube joints in embodiment 1 of the present invention;
FIG. 4 is a schematic structural view of a concrete slot in an embodiment of the present invention;
fig. 5 is a construction flow chart of the anti-penetration and anti-damage structure of the sandy soil layer of the underwater tunnel in the embodiment 3 of the present invention;
fig. 6 is a construction flow chart of the anti-penetration and anti-damage structure of the sandy soil layer of the underwater tunnel in embodiment 4 of the present invention;
FIG. 7 is a cross-sectional view A-A of FIG. 2;
fig. 8 is a schematic view of the connection between the lower waterproof curtain of the tunnel pipe joint and the tunnel pipe joint in embodiment 1 of the present invention;
fig. 9 is a top view of the second-stage waterproof curtain of embodiment 1 of the present invention, connected to the lower waterproof curtain of the tunnel pipe section, and the foundation pit enclosure;
fig. 10 is a distribution diagram of a cement mixing pile or a high-pressure jet grouting pile under a foundation pit in embodiment 1 of the invention;
fig. 11 is a schematic connection diagram of larsen steel sheet piles according to an embodiment of the present invention;
fig. 12 is a side sectional view of a steel sheet pile according to an embodiment of the present invention installed in a concrete slot on an upper portion of a tunnel pipe section;
fig. 13 is a top view section of the steel sheet pile of the embodiment of the present invention installed in the concrete grooves on both sides of the tunnel pipe section.
In the figure: 11. longitudinal cofferdams at the first stage side; 12. a first-stage end transverse cofferdam; 21. longitudinal cofferdams at the second stage side; 22. a second-stage end part transverse cofferdam; 3. a first-stage waterproof curtain; 4. a second stage waterproof curtain; 51. a waterproof curtain is arranged below the tunnel pipe joint; 52. a waterproof curtain at the pipe joint side; 53. connecting a waterproof curtain; 6. a tunnel pipe section; 61. a concrete clamping groove; 7. a strongly water permeable layer; 8. a water barrier layer; 9. a foundation pit support structure; 13. steel sheet piles; 15. and connecting the reinforcing steel bars.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.
In the description of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description of the present invention and do not require that the present invention must be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense, and may be, for example, either fixed or detachable; they may be directly connected or indirectly connected through intermediate members, and specific meanings of the above terms will be understood by those skilled in the art as appropriate.
Example 1
According to the utility model discloses a specific embodiment, as shown in fig. 1, fig. 3, fig. 4, fig. 8 to fig. 13, this embodiment provides a submarine tunnel strong sand soil layer infiltration resistance destruction structure that permeates water, and this infiltration resistance destruction structure includes first stage cofferdam, second stage cofferdam and tube coupling waterproof curtain.
The first-stage cofferdam comprises a first-stage side longitudinal cofferdam 11 consistent with the trend of the tunnel and a first-stage end transverse cofferdam 12 perpendicular to the trend of the tunnel, and the first-stage side longitudinal cofferdam 11 and the first-stage end transverse cofferdam 12 are connected to form a U-shaped structure.
The second-stage cofferdam comprises a second-stage side longitudinal cofferdam 21 consistent with the trend of the tunnel and a second-stage end transverse cofferdam 22 perpendicular to the trend of the tunnel, and the second-stage side longitudinal cofferdam 21 and the second-stage end transverse cofferdam 22 are connected to form a U-shaped structure.
The first-stage cofferdam and the second-stage cofferdam have overlapped parts in the length direction of the underwater tunnel, and the second-stage cofferdam can directly adopt the first-stage cofferdam at the overlapped parts without being rebuilt.
A first-stage water-stop curtain 3 is arranged in the first-stage cofferdam, a second-stage water-stop curtain 4 is arranged in the second-stage cofferdam, and the first-stage water-stop curtain 3 and the second-stage water-stop curtain 4 penetrate through the underwater highly permeable layer 7 to reach the water-stop layer 8 below the highly permeable layer 7. The waterproof curtain of the pipe joint, the transverse cofferdam 22 at the second-stage end part of the upper part of the pipe joint and the waterproof curtain 4 at the second stage form a closed waterproof curtain; the pipe joint waterproof curtain is specifically a tunnel pipe joint lower waterproof curtain 51, the tunnel pipe joint lower waterproof curtain 51 is arranged below the tunnel pipe joint 6 and is constructed before the tunnel pipe joint 6; the waterproof curtain 51 under the tunnel pipe joint passes through the highly permeable layer 7 to reach the waterproof layer 8 below the highly permeable layer 7; the second stage waterproof curtain 4 is connected with the lower waterproof curtain 51 of the tunnel pipe section in the horizontal direction to form a closed waterproof curtain when being arranged. As shown in fig. 1, in the embodiment of the present invention, in order to avoid insufficient connection between the waterproof curtain 51 and the second-stage waterproof curtain 4 under the tunnel pipe section, the connecting waterproof curtain 53 is provided at both sides of the tunnel pipe section 6 intersecting with the second-stage end horizontal cofferdam 22, the connecting waterproof curtain 53 is a plurality of rows of mutually engaged soil cement mixing piles or high-pressure jet grouting piles, and since the width of the connecting waterproof curtain 53 is relatively wide, the waterproof curtain 51 and the second-stage waterproof curtain 4 can have good lap joint function under the tunnel pipe section when being connected. The waterproof curtain 51 under the tunnel pipe joint is a cement mixing pile or a high-pressure jet grouting pile which are mutually occluded. In order to prevent the tunnel pipe joint 6 and the adjacent tunnel pipe joint from obviously and unevenly settling due to the fact that the waterproof curtain is arranged under the tunnel pipe joint 6, multiple rows of cement-soil mixing piles or high-pressure jet grouting piles are arranged on two sides of the waterproof curtain 51 under the tunnel pipe joint at intervals, the multiple rows of cement-soil mixing piles or high-pressure jet grouting piles extend to two sides from the waterproof curtain 51 under the tunnel pipe joint along the longitudinal direction of the tunnel, and the driving depth of the multiple rows of cement-soil mixing piles or high-pressure jet grouting piles is gradually decreased along with the increase of the extending distance (see figure 10) so as to play a role in gradually changing the rigidity of the foundation, and therefore the tunnel pipe joint is guaranteed to be deformed slightly and settle evenly after operation.
Furthermore, when the strong permeable sand layer is a pressure-bearing water layer, an end transverse waterproof curtain is arranged below the pipe joint closest to the bank in the first-stage cofferdam and the second-stage cofferdam and horizontally extends to be connected with the first-stage or second-stage waterproof curtain.
Further, the first-stage cofferdam and the second-stage cofferdam are both of double-layer steel sheet pile 13 structures, a steel pull rod for tie fixing is connected between the inner layer of steel sheet pile 13 and the outer layer of steel sheet pile 13, an anti-seepage geomembrane is laid on the inner side of the inner layer of steel sheet pile 13 and the inner layer of steel sheet pile 13 laid with the anti-seepage geomembrane, and compacted sand is filled between the inner layer of steel sheet pile 13 and the outer layer.
Further, an anti-seepage geomembrane is arranged in the second-stage end transverse cofferdam 22 above the tunnel pipe joints 6 and filled with plain concrete, so as to play a role in bearing force and stopping water. When the water seepage possibility still exists at the corners of the cofferdam and the joints of the first-stage cofferdam and the second-stage cofferdam by adopting the geomembrane, the inner parts of the cofferdam bodies at the positions can be filled with plain concrete or cohesive soil. The embodiment of the utility model provides an in, first phase waterproof curtain 3 sets up the intermediate position in first phase cofferdam thickness, and second phase waterproof curtain 4 sets up the intermediate position in second phase cofferdam thickness. The cofferdam thickness herein refers to the distance between the double-deck steel sheet piles 13 of the cofferdam. In the embodiment of the present invention, the steel sheet pile 13 is a larsen steel sheet pile. The Larsen steel sheet pile has high bending rigidity and is easy to connect when in use.
Further, the outer wall of the tunnel pipe section 6 intersecting with the second-stage end portion transverse cofferdam 22 is provided with two groups of concrete clamping grooves 61 which are parallel to each other, the concrete clamping grooves 61 protrude out of the outer side wall and the upper surface of the tunnel pipe section 6 and are poured with the tunnel pipe section 6 at the same time, and the distance between the two groups of concrete clamping grooves 61 which are parallel to each other is consistent with the thickness of the second-stage end portion transverse cofferdam 22. When the second-stage end transverse cofferdam 22 is intersected with the tunnel pipe joint 6, two rows of steel sheet piles 13 are respectively arranged in the corresponding concrete clamping grooves 61, so that the tunnel pipe joint 6 is tightly connected. When the cofferdam is used, the transverse cofferdam 22 at the second-stage end part is hermetically connected with the concrete clamping groove 61, so that the water seepage phenomenon at the connecting joint is avoided.
Furthermore, the upper part of the waterproof curtain 51 under the tunnel pipe joint is provided with a connecting groove, and 1-3 connecting grooves can be arranged according to the thickness of the waterproof curtain 51 under the tunnel pipe joint; the utility model discloses an in the embodiment, be provided with three spread grooves that are parallel to each other altogether, set up many spread grooves and can play the sealed effect of multilayer, seal up layer upon layer and realize better stagnant water effect. As shown in fig. 8, the connecting bars 15 are arranged in the connecting grooves and connected with the steel reinforcement framework in the pipe joint; and synchronously pouring concrete in the connecting groove and concrete in the tunnel pipe section 6 so as to form a water-stopping joint sealed below the tunnel pipe section 6.
Example 2
As shown in fig. 2, 4, 7, 11 to 13, the present embodiment provides a penetration damage resisting structure of a strongly permeable sandy soil layer of a submarine tunnel, which includes a first-stage cofferdam, a second-stage cofferdam and a pipe joint waterproof curtain.
The first-stage cofferdam comprises a first-stage side longitudinal cofferdam 11 consistent with the trend of the tunnel and a first-stage end transverse cofferdam 12 perpendicular to the trend of the tunnel, and the first-stage side longitudinal cofferdam 11 and the first-stage end transverse cofferdam 12 are connected to form a U-shaped structure.
The second-stage cofferdam comprises a second-stage side longitudinal cofferdam 21 consistent with the trend of the tunnel and a second-stage end transverse cofferdam 22 perpendicular to the trend of the tunnel, and the second-stage side longitudinal cofferdam 21 and the second-stage end transverse cofferdam 22 are connected to form a U-shaped structure.
The first-stage cofferdam and the second-stage cofferdam have overlapped parts in the length direction of the underwater tunnel, and the second-stage cofferdam can directly adopt the first-stage cofferdam at the overlapped parts without being rebuilt.
A first-stage water-stop curtain 3 is arranged in the first-stage cofferdam, a second-stage water-stop curtain 4 is arranged in the second-stage cofferdam, and the first-stage water-stop curtain 3 and the second-stage water-stop curtain 4 penetrate through the underwater highly permeable layer 7 to reach the water-stop layer 8 below the highly permeable layer 7.
The waterproof curtain of the pipe joint, the transverse cofferdam 22 at the second-stage end part of the upper part of the pipe joint and the waterproof curtain 4 at the second stage form a closed waterproof curtain; the pipe joint water-stop curtain is specifically a pipe joint side water-stop curtain 52, the pipe joint side water-stop curtain 52 is continuously arranged along two sides of a foundation pit in the first-stage cofferdam, a plurality of rows of mutually meshed cement soil mixing piles or high-pressure jet grouting piles form the pipe joint side water-stop curtain 52, and the pipe joint side water-stop curtain 52 is in lap joint with the second-stage water-stop curtain 4 when the transverse cofferdam 22 at the end part of the second stage of subsequent construction is constructed. Whether the pipe joint side waterproof curtain 52 is arranged in the second-stage cofferdam can be determined according to the precipitation amount in the engineering, and when the pipe joint side waterproof curtain 52 is continuously arranged along the two sides of the foundation pit in the second-stage cofferdam, the precipitation amount of the engineering can be reduced.
Further, the first-stage cofferdam and the second-stage cofferdam are both of double-layer steel sheet pile 13 structures, the inner and outer layers of steel sheet piles 13 are fixed by drawing through steel pull rods, and the inner sides of the inner and outer layers of steel sheet piles 13 are backfilled and compacted by adopting sandy soil after impermeable geomembranes are laid on the inner sides. Preferably, an impermeable geomembrane is arranged in the second-stage end transverse cofferdam 22 above the tunnel pipe sections 6 and filled with plain concrete. When the water seepage possibility still exists at the corners of the cofferdam and the joints of the first-stage cofferdam and the second-stage cofferdam by adopting the geomembrane, the inner parts of the cofferdam bodies at the positions can be filled with plain concrete or cohesive soil. The embodiment of the utility model provides an in, first phase waterproof curtain 3 sets up the intermediate position in first phase cofferdam thickness, and second phase waterproof curtain 4 sets up the intermediate position in second phase cofferdam thickness. The cofferdam thickness herein refers to the distance between the double-deck steel sheet piles 13 of the cofferdam. In the embodiment of the present invention, the steel sheet pile 13 is a larsen steel sheet pile. The Larsen steel sheet pile has high bending rigidity and is easy to connect when in use.
Further, the outer wall of the tunnel pipe section 6 intersecting with the second-stage end portion transverse cofferdam 22 is provided with two groups of concrete clamping grooves 61 which are parallel to each other, the concrete clamping grooves 61 protrude out of the outer side wall and the upper surface of the tunnel pipe section 6 and are poured with the tunnel pipe section 6 at the same time, and the distance between the two groups of concrete clamping grooves 61 which are parallel to each other is consistent with the thickness of the second-stage end portion transverse cofferdam 22. When the second-stage end transverse cofferdam 22 is intersected with the tunnel pipe joint 6, two rows of steel sheet piles 13 are respectively arranged in the corresponding concrete clamping grooves 61, so that the tunnel pipe joint 6 is tightly connected. When the cofferdam is used, the transverse cofferdam 22 at the second-stage end part is hermetically connected with the concrete clamping groove 61, so that the water seepage phenomenon at the connecting joint is avoided.
Example 3
As shown in fig. 5, the present embodiment provides a construction method of a structure of an underwater tunnel with strong water permeability and sandy soil layer resistant to permeation and damage, the construction method includes the following steps:
step S1, constructing a first-stage cofferdam, and excavating a foundation pit after the first-stage cofferdam falls; the method specifically comprises the following steps:
and S101, constructing a first-stage cofferdam from one side bank edge to the underwater part along the tunnel line direction. Specifically, two rows of steel sheet piles 13 are constructed and fixed by steel pull rods in a pulling mode, an anti-seepage geomembrane is hung on the inner side of each steel sheet pile 13, sand is filled in the center of a weir of a primary cofferdam, gravels are filled at the bottoms of the upstream surface and the back surface of the cofferdam, geogrids are arranged on the upper portions of the gravels, and sand bags are used for slope protection.
Step S102, constructing a cement soil stirring pile or a high-pressure rotary spraying pile at the middle position of the thickness of the cofferdam body of the first-stage cofferdam, mutually meshing a plurality of cement soil stirring piles or high-pressure rotary spraying piles to form a first-stage water-stopping curtain 3 consistent with the trend of the first-stage cofferdam, and enabling the first-stage water-stopping curtain 3 to penetrate through the water bottom strong permeable layer 7 from the upper surface of the cofferdam body to the water-stopping layer 8 below the strong permeable layer 7.
And S103, dewatering the interior of the first-stage cofferdam, and excavating the foundation pit after constructing foundation pit support structures 9 on two sides of the foundation pit. The specific operation method of the step is as follows: firstly, dewatering the interior of a first-stage cofferdam; secondly, constructing a plurality of rows of mutually meshed cement-soil mixing piles or high-pressure jet grouting piles as connecting waterproof curtains 53 at the periphery of two side walls of the foundation pit to be excavated at the position of the second-stage end part transverse cofferdam 22, and then constructing a foundation pit enclosure structure 9 at the periphery of the two side walls of the foundation pit to be excavated, wherein in the embodiment, the foundation pit enclosure structure 9 is a concrete filling pile; and finally, excavating a foundation pit and arranging an inner support or an anchor rod of the foundation pit. The thickness of the connecting waterproof curtain 53 is preferably 3-5 times of the diameter of a cast-in-place pile, the length of the connecting waterproof curtain is not less than 2 times of the thickness of the second-stage end transverse cofferdam 22, and the connecting waterproof curtain is arranged symmetrically to the second-stage end transverse cofferdam 22. In the position where the waterproof curtain 53 and the cast-in-place pile are simultaneously installed, the cast-in-place pile should be constructed in the middle of the thickness of the waterproof curtain 53. The construction of the connecting waterproof curtain 53 is prior to the construction of the cast-in-place pile, because the connecting waterproof curtain 53 adopts a cement soil mixing pile or a high-pressure jet grouting pile, during the construction, a drill bit of a mixer drills into the soil body, and cement slurry is sprayed from the inside of the drill bit to the periphery in the process of drilling and mixing, so that the cement slurry and the soil are fully mixed to form an occlusive pile body as the connecting waterproof curtain 53; the cast-in-place pile is formed by forming a hole in soil, placing a reinforcement cage into a pile hole and then pouring concrete into the pile hole. The cast-in-place pile has higher structural strength, and if the cast-in-place pile is constructed first and then the waterproof curtain 53 is constructed and connected, in order to avoid the damage of equipment or a pile body caused by the fact that a drill bit of a stirrer is driven on the cast-in-place pile, a slightly long distance exists between the drill bit and the cast-in-place pile due to the operation factors of constructors during construction, and therefore a gap is reserved between the waterproof curtain 53 and the cast-in-place pile to form a possible seepage channel. However, the waterproof curtain has lower strength, the waterproof curtain 53 is connected and then the cast-in-place pile is constructed, and the pile hole of the cast-in-place pile can be directly arranged inside the waterproof curtain 53, so as to avoid the occurrence of a seepage channel.
Step S2, constructing a tunnel pipe joint lower waterproof curtain 51 below a foundation pit in the first-stage cofferdam, and constructing a pipe joint in the foundation pit; the method specifically comprises the following steps:
step S201, as shown in FIG. 9, constructing a cement-soil mixing pile or a high-pressure jet grouting pile below the foundation pit, and forming a lower waterproof curtain 51 of the tunnel pipe joint by a plurality of mutually meshed pile bodies; the connecting waterproof curtain 53 is arranged at the crossed plane position of the lower waterproof curtain 51 of the transverse cofferdam 22 at the second-stage end part and the tunnel pipe joint, 3-5 times of the diameter of a cast-in-place pile is selected, and the cast-in-place pile is arranged at the middle part of the connecting waterproof curtain 53, so that when the lower waterproof curtain 51 of the tunnel pipe joint and the second-stage waterproof curtain 4 are constructed, a drill bit of a stirrer does not need to be particularly close to the cast-in-place pile, the lower waterproof curtain 51 of the tunnel pipe joint and the second-stage waterproof curtain 4 can be connected together through the connecting waterproof curtain 53, and therefore a closed waterproof curtain is formed.
Step S202, as shown in fig. 10, multiple rows of cement-soil mixing piles or high-pressure jet grouting piles are arranged at intervals in the foundation pit on both sides of the waterproof curtain 51 below the tunnel pipe section along the tunnel axis direction, and the depth of the cement-soil mixing piles or high-pressure jet grouting piles decreases progressively from the waterproof curtain 51 below the tunnel pipe section to the tunnel axis directions on both sides.
Step S203, as shown in FIG. 8 and FIG. 9, constructing a tunnel pipe section 6, arranging a connecting groove at the upper part of the waterproof curtain 51 below the tunnel pipe section, and binding and connecting the reinforcing steel bars 15 in the connecting groove; binding a steel bar framework of the tunnel pipe section 6, and mechanically connecting or welding the connecting steel bars 15 and the steel bar framework of the tunnel pipe section 6 together; binding the steel bars of the concrete clamping grooves 61 and mechanically connecting or welding the steel bars with the steel bar frameworks of the tunnel pipe sections 6, wherein the concrete clamping grooves 61 are arranged at corresponding positions of the gap intervals of the cast-in-place piles; pouring concrete in the connecting grooves, concrete of the tunnel pipe sections 6 and concrete of the clamping grooves; the formed joint can greatly reduce the water seepage amount from the interface between the waterproof curtain and the tunnel pipe joint 6 in the waterproof sand layer, and the steel sheet pile 13 of the transverse cofferdam 22 at the second-stage end part can also be directly connected with the tunnel pipe joint 6, so that the waterproof joint with the periphery closed by the tunnel pipe joint 6 is formed.
Step S3, constructing the transverse cofferdam 22 at the end part of the second stage, reserving the superposed part of the first-stage cofferdam and the second-stage cofferdam, and dismantling the longitudinal cofferdam 11 at the side surface of the other first stage; the method specifically comprises the following steps:
step S301, constructing a second-stage end transverse cofferdam 22 in a plane where the waterproof curtain 51 is located under the tunnel pipe joint, tying and fixing two rows of steel sheet piles 13 of the second-stage end transverse cofferdam 22 at two sides and the top of the tunnel pipe joint 6 by steel tie rods and arranging the steel sheet piles in the concrete clamping grooves 61 corresponding to the tunnel pipe joint 6, and filling gaps between the steel sheet piles 13 and the concrete clamping grooves 61 with plain concrete, as shown in fig. 12 and 13, the specific operation method is as follows: the steel sheet piles 13 are sequentially inserted into the concrete clamping grooves 61, and two adjacent steel sheet piles 13 are mutually occluded, so that the plurality of steel sheet piles 13 are connected to form a whole (see fig. 11). Because the steel sheet pile 13 is of a U-shaped structure, when a gap between the steel sheet pile 13 and the concrete clamping groove 61 is filled, the side surface of the concrete clamping groove 61 is sealed by a wood board or a steel plate, and then plain concrete is poured into the groove of the steel sheet pile 13 from top to bottom and is tamped and filled. The steel sheet pile 13 is connected with the concrete clamping groove 61, so that seepage at the joint of the second-stage end transverse cofferdam 22 and the tunnel pipe joint 6 can be avoided, and the impermeability and the stability of the structure are improved.
Step S302, arranging anti-seepage geomembranes in the second-stage end transverse cofferdams 22 at the two sides of the tunnel pipe joints 6, and then filling and compacting the cofferdams with sandy soil; an anti-seepage geomembrane is arranged in the second-stage end transverse cofferdam 22 above the tunnel pipe joints 6 and filled with plain concrete so as to play the roles of stress and water stop at the same time. As shown in fig. 12, the steel sheet pile 13 of the embodiment of the present invention is disposed in the concrete slot 61 on the upper portion of the tunnel pipe section 6, and the steel bars in the concrete slot 61 are mechanically connected or welded to the steel bars of the tunnel pipe section 6, and the concrete of the tunnel pipe section 6 and the concrete slot 61 is poured synchronously. Fig. 13 is a top sectional view of the steel sheet pile 13 of the embodiment of the present invention installed in the concrete slots 61 on both sides of the tunnel pipe section 6, wherein the concrete slots 61 and the steel bar structures in the tunnel pipe section 6 are not shown.
Step S303, constructing a second-stage waterproof curtain 4 in the thickness of the cofferdam body of the second-stage end part transverse cofferdam 22 at two sides of the tunnel pipe joint 6, enabling the second-stage waterproof curtain 4 to downwards penetrate through the underwater highly permeable layer 7 from the upper surface of the second-stage end part transverse cofferdam 22 to the waterproof layer 8 below the highly permeable layer 7, and enabling the second-stage waterproof curtain 4 to be connected with the lower waterproof curtain 51 of the tunnel pipe joint in the horizontal direction through the connecting waterproof curtain 53. Preferably, the second-stage waterproof curtain 4 adopts a cement soil mixing pile or a high-pressure jet grouting pile.
And step S304, backfilling plain concrete above the tunnel pipe joints 6 constructed in the first-stage cofferdam to finish the construction of the tunnel pipe joints 6 in the first-stage cofferdam.
Step S305, reserving the overlapped part of the first-stage cofferdam and the second-stage cofferdam, and dismantling the other longitudinal cofferdams 11 at the first-stage side.
Step S4, constructing a second-stage cofferdam, dismantling the transverse cofferdam at the first-stage end part, excavating a foundation pit in the second-stage cofferdam, and performing pipe joint construction; the method specifically comprises the following steps:
step S401, constructing a second-stage side longitudinal cofferdam 21 along the length direction of the tunnel, so that the second-stage side longitudinal cofferdam 21 is connected with the first-stage side longitudinal cofferdam 11; specifically, two rows of steel sheet piles 13 are constructed and fixed by steel pull rods in a pulling mode, anti-seepage geomembrane anti-seepage water is hung on the inner sides of the steel sheet piles 13, sand is filled in the weir core of the secondary cofferdam, gravel soil is filled at the bottoms of the upstream surface and the downstream surface of the cofferdam, and geogrids are arranged on the upper portion of the gravel soil and sand bags are adopted for slope protection.
Step S402, constructing a second-stage waterproof curtain 4 in the thickness of the cofferdam body of the second-stage side longitudinal cofferdam 21, enabling the second-stage waterproof curtain 4 to penetrate through the strong permeable layer 7 from the upper surface of the cofferdam body to the waterproof layer 8 below the strong permeable layer 7, and enabling the second-stage waterproof curtain 4 to be connected with the first-stage waterproof curtain 3 in the horizontal direction. Preferably, the second-stage waterproof curtain 4 adopts a cement soil mixing pile or a high-pressure jet grouting pile.
And S403, dewatering the inner part of the second-stage cofferdam, and dismantling the transverse cofferdam 12 at the end part of the first stage.
And S404, constructing foundation pit support structures 9 on two sides of the foundation pit to be excavated in the second-stage cofferdam, excavating the foundation pit, and constructing the tunnel pipe joints 6. The concrete construction method of the step is as follows: firstly, constructing a cast-in-place pile on the side wall of a foundation pit to be excavated to serve as a foundation pit enclosure structure 9; secondly, arranging a foundation pit inner support or an anchor rod and excavating the foundation pit; then, constructing the tunnel pipe joint 6 along the excavated foundation pit; and finally, backfilling plain concrete above the tunnel pipe joints 6 constructed in the second-stage cofferdam after the concrete of the tunnel pipe joints 6 reaches the design strength.
And step S5, removing the second-stage cofferdam to finish the tunnel construction.
Example 4
The embodiment also provides another construction method for the underwater tunnel strong-water-permeability sandy soil layer permeation damage resistant structure, which comprises the following steps:
step one, constructing a first-stage cofferdam, and lowering water in the first-stage cofferdam; the detailed operation method of the step is as follows: first, a first-stage cofferdam is constructed from one bank side to the underwater part along the tunnel line direction. Specifically, two rows of steel sheet piles 13 are constructed and fixed by steel pull rods in a pulling mode, an anti-seepage geomembrane is hung on the inner side of each steel sheet pile 13, sand is filled in the center of a weir of a primary cofferdam, gravels are filled at the bottoms of the upstream surface and the back surface of the cofferdam, geogrids are arranged on the upper portions of the gravels, and sand bags are used for slope protection. And then, constructing a cement soil stirring pile or a high-pressure rotary spraying pile at the middle position of the thickness of the cofferdam body of the first-stage cofferdam, mutually meshing a plurality of cement soil stirring piles or high-pressure rotary spraying piles to form a first-stage water-stopping curtain 3 consistent with the trend of the first-stage cofferdam, and enabling the first-stage water-stopping curtain 3 to penetrate through the water-bottom strong permeable layer 7 from the upper surface of the cofferdam body to the water-resisting layer 8 below the strong permeable layer 7. And finally, dewatering the inner part of the cofferdam in the first period, so as to facilitate the subsequent tunnel construction.
Constructing a pipe joint side waterproof curtain 52 and a foundation pit support structure 9, then excavating a foundation pit and constructing pipe joints; the specific operation method of the step is as follows:
firstly, constructing mutually-occluded cement soil mixing piles or high-pressure jet grouting piles as pipe joint side waterproof curtains 52 on two sides of the length direction of a foundation pit to be excavated in a first-stage cofferdam, and continuously arranging the pipe joint side waterproof curtains 52 along the direction of a tunnel and penetrating through a highly permeable layer 7 to reach a waterproof layer 8 below the highly permeable layer 7; then constructing a concrete cast-in-place pile in the pipe joint side waterproof curtain 52 as a foundation pit support structure 9; and finally, after the foundation pit is excavated, constructing the tunnel pipe joints 6, and pouring concrete clamping grooves 61 at the top and the side surfaces of the tunnel pipe joints 6 intersected with the second-stage end transverse cofferdam 22.
Step three, constructing a transverse cofferdam 22 at the end part of the second stage, reserving the superposed part of the first-stage cofferdam and the second-stage cofferdam, and dismantling the other longitudinal cofferdams 11 at the side surface of the first stage; the concrete construction method of the step is as follows:
firstly, constructing a second-stage end transverse cofferdam 22, tying and fixing two rows of steel sheet piles 13 on two sides and the top of a tunnel pipe joint 6 of the second-stage end transverse cofferdam 22 by steel pull rods, arranging the steel sheet piles in concrete clamping grooves 61 corresponding to the tunnel pipe joint 6, and filling gaps between the steel sheet piles 13 and the concrete clamping grooves 61 by using plain concrete. As shown in fig. 12 and 13, the specific operation method is as follows: the steel sheet piles 13 are sequentially inserted into the concrete clamping grooves 61, and two adjacent steel sheet piles 13 are mutually occluded, so that the plurality of steel sheet piles 13 are connected to form a whole (see fig. 11). Because the steel sheet pile 13 is of a U-shaped structure, when a gap between the steel sheet pile 13 and the concrete clamping groove 61 is filled, the side surface of the concrete clamping groove 61 is sealed by a wood board or a steel plate, and then plain concrete is poured into the groove of the steel sheet pile 13 from top to bottom and is tamped and filled. The steel sheet pile 13 is connected with the concrete clamping groove 61, so that seepage at the joint of the second-stage end transverse cofferdam 22 and the tunnel pipe joint 6 can be avoided, and the impermeability and the stability of the structure are improved.
Secondly, arranging an anti-seepage geomembrane in the second-stage end transverse cofferdam 22 at two sides of the tunnel pipe joint 6, and then filling the cofferdam with sandy soil and compacting; preferably, an impermeable geomembrane is arranged in the second-stage end transverse cofferdam 22 above the tunnel pipe sections 6 and filled with plain concrete. As shown in fig. 12, the steel sheet pile 13 of the embodiment of the present invention is disposed in the concrete slot 61 on the upper portion of the tunnel pipe section 6, and the steel bars in the concrete slot 61 are mechanically connected or welded to the steel bars of the tunnel pipe section 6, and the concrete of the tunnel pipe section 6 and the concrete slot 61 is poured synchronously. Fig. 13 is a top sectional view of the steel sheet pile 13 of the embodiment of the present invention installed in the concrete slots 61 on both sides of the tunnel pipe section 6, wherein the concrete slots 61 and the steel bar structures in the tunnel pipe section 6 are not shown.
Then, a second-stage waterproof curtain 4 is constructed in the thickness of the cofferdam body of the second-stage end part transverse cofferdam 22 at two sides of the tunnel pipe joint 6, the second-stage waterproof curtain 4 downwards passes through the underwater highly permeable layer 7 from the upper surface of the second-stage end part transverse cofferdam 22 to the waterproof layer 8 below the highly permeable layer 7, and the lap joint with the pipe joint side waterproof curtain 52 is realized in the horizontal direction. Preferably, the second-stage waterproof curtain 4 adopts a cement soil mixing pile or a high-pressure jet grouting pile.
And finally, backfilling plain concrete above the tunnel pipe joints 6 constructed in the first-stage cofferdam, reserving the overlapped part of the first-stage cofferdam and the second-stage cofferdam, and removing the other longitudinal cofferdams 11 on the side surfaces of the first stage.
Constructing a second-stage cofferdam, dismantling the transverse cofferdam at the end part of the first stage, excavating a foundation pit in the second-stage cofferdam, and performing pipe joint construction; the concrete construction method of the step is as follows:
firstly, constructing a second-stage side longitudinal cofferdam 21 along the length direction of the tunnel, so that the second-stage side longitudinal cofferdam 21 and a first-stage side longitudinal cofferdam 11 are connected together; specifically, two rows of steel sheet piles 13 are constructed and fixed by steel pull rods in a pulling mode, anti-seepage geomembranes are hung on the inner sides of the steel sheet piles 13 to prevent water seepage, sand is filled in the cores of the secondary cofferdams, gravel soil is filled at the bottoms of the upstream surfaces and the downstream surfaces of the cofferdams, geogrids are arranged on the upper portions of the gravel soil, and sand bags are used for slope protection.
Secondly, a second-stage waterproof curtain 4 is constructed in the thickness of the cofferdam body of the second-stage side longitudinal cofferdam 21, the second-stage waterproof curtain 4 penetrates through the strong permeable layer 7 from the upper surface of the cofferdam body to the waterproof layer 8 below the strong permeable layer 7, and the second-stage waterproof curtain 4 is connected with the first-stage waterproof curtain 3 in the horizontal direction. Preferably, the second-stage waterproof curtain 4 adopts a cement soil mixing pile or a high-pressure jet grouting pile.
And then, dewatering the inner part of the second-stage cofferdam, and dismantling the transverse cofferdam 12 at the end part of the first stage.
And finally, constructing foundation pit retaining structures 9 on two sides of the foundation pit to be excavated in the second-stage cofferdam, excavating the foundation pit, and constructing the tunnel pipe joints 6. The concrete construction method of the step is as follows: constructing cast-in-place piles at the peripheries of two side walls of the foundation pit to be excavated and excavating the foundation pit; then, constructing a tunnel pipe joint 6 along the excavated foundation pit; and finally, backfilling plain concrete above the tunnel pipe joints 6 constructed in the second-stage cofferdam.
And fifthly, dismantling the second-stage cofferdam to finish the tunnel construction.
Example 5
The specific operation method of step S103 in embodiment 3 is changed to:
and S103, dewatering the interior of the first-stage cofferdam, and excavating the foundation pit after constructing foundation pit support structures 9 on two sides of the foundation pit. The specific operation method of the step is as follows: firstly, dewatering the interior of a first-stage cofferdam; secondly, waterproof curtain 51 under the construction tunnel tube coupling, waiting to excavate foundation ditch department construction cement mixing pile or high-pressure jet grouting pile, waterproof curtain 51 under the pile body formation tunnel tube coupling of a plurality of mutual interlocks is for the convenience of follow-up and second stage waterproof curtain 4 be connected the embodiment of the utility model discloses an in, waterproof curtain 51's length is greater than tunnel tube coupling 6's width under the tunnel tube coupling, makes its both ends all exceed tunnel tube coupling 6 both sides 3 ~ 5m to waterproof curtain 51 meets with second stage waterproof curtain 4 and seals under the tunnel tube coupling of being convenient for. Then, constructing a foundation pit enclosure structure 9 on the periphery of two side walls of the foundation pit to be excavated, wherein the foundation pit enclosure structure 9 is a concrete cast-in-place pile; and finally, excavating a foundation pit and arranging an inner support or an anchor rod of the foundation pit.
Step S2 is changed to:
step S2, performing pipe joint construction in the foundation pit;
step S201 is removed.
Other operation steps are the same as those in embodiment 3, and are not described herein again.
In this embodiment, the construction of the waterproof curtain 51 under the tunnel pipe section is performed before the construction of the foundation pit support structure 9, so that the width of the waterproof curtain 51 under the tunnel pipe section is greater than that of the tunnel pipe section 6, and the waterproof curtain is convenient to be connected with the second-stage waterproof curtain 4 in an overlapping manner, and the construction sequence avoids the interference influence on the waterproof curtain construction after the construction of the foundation pit support structure 9, thereby causing difficulty in forming a closed waterproof joint.
Example 6
In the step S103 of the embodiment 5, the construction width of the waterproof curtain 51 under the tunnel pipe joint is changed to the construction width of the waterproof curtain 51 under the tunnel pipe joint to be connected with the first-stage waterproof curtain 3 on both sides of the tunnel, and when the second-stage waterproof curtain 4 is subsequently constructed, only the cement soil mixing pile or the high-pressure jet grouting pile needs to be constructed downwards from the top of the transverse cofferdam 22 at the end part of the second stage, and the waterproof curtain 51 under the tunnel pipe joint constructed in the above way is connected in a vertical lap joint manner. The remaining operation steps are the same as those in embodiment 5, and are not described again here.
To sum up, the utility model provides a submarine tunnel strong permeability sandy soil layer anti-infiltration destroys structure and construction method through set up tunnel tube coupling stagnant water curtain below tunnel tube coupling 6 or both sides, links together tunnel tube coupling lower stagnant water curtain 51 or tube coupling side stagnant water curtain 52 and second phase waterproof curtain 4 in the horizontal cofferdam 22 of second phase tip to avoided tube coupling below strong permeable bed 7 to become the main passageway that the infiltration destruction takes place. And a concrete clamping groove 61 is arranged outside the tunnel pipe joint 6 connected with the second-stage end part transverse cofferdam 22, so that the pipe joint is tightly connected with the second-stage end part transverse cofferdam 22, and seepage of the second-stage end part transverse cofferdam 22 and a pipe joint is avoided. The utility model discloses a pipe coupling side water stop curtain 52 is in advance the construction of foundation ditch envelope structure 9 bored concrete pile, and such construction order can be in the same place pipe coupling side water stop curtain 52 and bored concrete pile zonulae occludens. The totally enclosed stagnant water structure has realized the safe construction and the economic rationality of strong sandy soil layer underwater tunnel that permeates water.
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 (7)
1. The utility model provides a submarine tunnel strong sandy soil layer permeation resistant destroys structure that permeates water, its characterized in that, the permeation resistant destroys the structure and includes:
the first-stage cofferdam comprises a first-stage side longitudinal cofferdam in the same direction as the tunnel and a first-stage end transverse cofferdam perpendicular to the tunnel, and the first-stage side longitudinal cofferdam and the first-stage end transverse cofferdam are connected to form a U-shaped structure;
the secondary cofferdam comprises a secondary side longitudinal cofferdam in the same direction as the tunnel and a secondary end transverse cofferdam perpendicular to the direction of the tunnel, and the secondary side longitudinal cofferdam and the secondary end transverse cofferdam are connected to form a U-shaped structure;
the first-stage cofferdam and the second-stage cofferdam are partially overlapped in the length direction of the tunnel;
a first-stage water-stop curtain is arranged in the first-stage cofferdam, a second-stage water-stop curtain is arranged in the second-stage cofferdam, and the first-stage water-stop curtain and the second-stage water-stop curtain pass through the underwater highly permeable layer to reach a water-stop layer below the highly permeable layer;
a pipe section waterproof curtain, wherein the pipe section waterproof curtain and the second-stage waterproof curtain are connected together to form a closed waterproof curtain; the pipe joint waterproof curtain is a tunnel pipe joint lower waterproof curtain or a pipe joint side waterproof curtain, and the tunnel pipe joint lower waterproof curtain is arranged below a tunnel pipe joint connected with a second-stage end transverse cofferdam; the waterproof curtain under the tunnel pipe joint penetrates through the highly permeable layer to reach the waterproof layer below the highly permeable layer; and the second-stage waterproof curtain is connected with the lower waterproof curtain of the tunnel pipe section to form a closed waterproof curtain.
2. The structure of claim 1, wherein the first cofferdam and the second cofferdam are both double steel sheet pile structures, the inner and outer steel sheet piles are driven into the water bottom, a steel pull rod for fixing by pulling is connected between the inner and outer steel sheet piles, and an impermeable geomembrane is laid on the inner side of the inner and outer steel sheet piles; sand is filled between the inner layer steel sheet pile and the outer layer steel sheet pile paved with the anti-seepage geomembrane;
the first-stage waterproof curtain is arranged in the middle of the thickness of the first-stage cofferdam, and the second-stage waterproof curtain is arranged in the middle of the thickness of the second-stage cofferdam.
3. The underwater tunnel strong water permeability sandy soil layer permeation resistant damage structure according to claim 2, wherein two sets of mutually parallel concrete clamping grooves are arranged on the outer wall of the tunnel tube section connected with the second-stage end portion transverse cofferdam, the concrete clamping grooves protrude out of the outer side wall and the upper surface of the tunnel tube section, the distance between the two sets of mutually parallel concrete clamping grooves is consistent with the thickness value of the second-stage end portion transverse cofferdam, and two rows of steel sheet piles intersected with the tunnel tube section at the second-stage end portion transverse cofferdam are respectively arranged in the two sets of mutually parallel concrete clamping grooves, so that the tunnel tube section is tightly connected.
4. The underwater tunnel strong permeable sandy soil layer permeation damage resistant structure of claim 1, wherein the waterproof curtains below the tunnel pipe sections are mutually engaged cement soil mixing piles or high pressure jet grouting piles.
5. The underwater tunnel strong permeable sandy soil layer permeation damage resistant structure of claim 1, wherein a connecting groove is formed in the upper portion of the waterproof curtain below the tunnel pipe section, a connecting steel bar is arranged inside the connecting groove, and the connecting steel bar is connected with a steel bar framework in the tunnel pipe section; and pouring the concrete in the connecting groove and the concrete of the tunnel pipe joint synchronously.
6. The underwater tunnel strong permeable sandy soil layer permeation damage resistant structure of claim 2, wherein the steel sheet piles of the first stage cofferdam and the second stage cofferdam are larsen steel sheet piles.
7. The underwater tunnel strongly permeable sandy soil layer permeation damage resistant structure according to claim 4, wherein a plurality of rows of cement soil mixing piles or high pressure jet grouting piles are provided at both sides of the waterproof curtain under the tunnel tube section, the plurality of rows of cement soil mixing piles or high pressure jet grouting piles extend to both sides from the waterproof curtain under the tunnel tube section in the longitudinal direction of the tunnel, and driving depths of the plurality of rows of cement soil mixing piles or high pressure jet grouting piles are sequentially decreased as the extending distance increases.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201921334858.6U CN210395386U (en) | 2019-08-16 | 2019-08-16 | Water-bed tunnel strong-permeable sandy soil layer anti-permeation damage structure |
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| CN201921334858.6U CN210395386U (en) | 2019-08-16 | 2019-08-16 | Water-bed tunnel strong-permeable sandy soil layer anti-permeation damage structure |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110359471A (en) * | 2019-08-16 | 2019-10-22 | 安徽建筑大学 | Subaqueous tunnel highly permeable sandy soil layer impermeabilisation destroys structure and construction method |
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2019
- 2019-08-16 CN CN201921334858.6U patent/CN210395386U/en not_active Withdrawn - After Issue
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110359471A (en) * | 2019-08-16 | 2019-10-22 | 安徽建筑大学 | Subaqueous tunnel highly permeable sandy soil layer impermeabilisation destroys structure and construction method |
| CN110359471B (en) * | 2019-08-16 | 2024-04-26 | 安徽建筑大学 | Anti-seepage damage structure of strong water-permeable sandy soil layer of underwater tunnel and construction method |
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