Permanent and temporary retaining wall structure and its construction method

Abstract

The present invention belongs to a permanent and temporary combined retaining wall structure and a construction method thereof for a water conservancy project. The technical scheme is: comprising a newly built permanent structure reinforced concrete retaining wall, a temporary structure diagonal brace, and foundation cast-in-place piles; the permanent and temporary combined retaining wall structure is located in the river channel, with the existing river channel revetment behind it, the mud surface in front of the existing river channel revetment is excavated to the designed mud surface in front of the newly built permanent structure reinforced concrete retaining wall, the newly built permanent structure reinforced concrete retaining wall is smoothly connected to the upstream and downstream of the river channel, and shall not block water; the temporary structure diagonal brace is connected to the foundation cast-in-place piles arranged before and after. The present invention provides a permanent and temporary combined retaining wall structure and a construction method thereof, which neither destroys the original shoreline nor meets the scale and functional requirements of the newly built river channel project, and is a safe, reliable, economical, and low-investment bank protection structure.

Description

Technical Field

[0001] The invention relates to water conservancy projects, and in particular to a retaining wall structure and a construction method thereof which requires retaining an old river bank and has a limited construction site. Background Art

[0002] The river bank protection structures built in the last century are often located close to residential areas. Although the land area 6m to 10m behind the river bank protection structures is protected by water conservancy projects, due to historical reasons, the land behind the river bank protection structures is also within the management scope of residential areas. The construction of new river bank protection structures involves land acquisition and the impact on the lives of surrounding residents during the construction period.

[0003] In recent years, with the construction and development of urban water conservancy, the appearance of rivers and lakes and the ecological environment have changed with each passing day. At the same time, the contradiction between the river layout and the surrounding environment in the development and construction has become increasingly prominent. The overall layout of the river project must not only meet the functional requirements, but also take into account the stability requirements of the surrounding residents, the coordination between districts, the retreat of industries, the impact of the surrounding environment and other factors.

[0004] Therefore, the scale of river channel projects needs to be expanded according to the planning and construction needs. The original river bank is often demolished and rebuilt, and the river is widened on both sides, which requires land acquisition and relocation. However, under certain specific conditions, such as restrictions on construction land, the cost of demolition and relocation, site restrictions during the construction period, and the impact on residential areas, the existing river retaining wall structure cannot meet the above needs. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a permanent and temporary retaining wall structure and a construction method thereof, which neither destroys the original shoreline nor meets the scale and functional requirements of the newly built river project. It is a safe, reliable, economical and low-investment bank protection structure.

[0006] The technical solution of the present invention is: a permanent and temporary combined retaining wall structure, including a newly built permanent structure reinforced concrete retaining wall, a temporary structure diagonal brace and foundation cast-in-place piles; the permanent and temporary combined retaining wall structure is located in the river channel, with the existing river channel revetment behind it, the mud surface in front of the existing river channel revetment is deepened to the designed mud surface in front of the newly built permanent structure reinforced concrete retaining wall, and the newly built permanent structure reinforced concrete retaining wall is smoothly connected to the upstream and downstream; the temporary structure diagonal brace is connected to the foundation cast-in-place piles arranged before and after.

[0007] Based on the above technical features: two rows of foundation bored piles are arranged, the front row of foundation bored piles are arranged on the water side and are arranged at intervals; the rear row of foundation bored piles are arranged on the shore side, which are densely packed bored piles and are set close to the existing river bank protection.

[0008] Based on the above technical features: the wall of the newly built permanent reinforced concrete retaining wall is arranged closely to the rear row of foundation cast-in-place piles, and the bottom plate of the newly built permanent reinforced concrete retaining wall is cast together with the front row of foundation cast-in-place piles as a whole to form an L-shaped retaining wall.

[0009] Based on the above technical features: a first reinforced concrete crown beam is set on the top of the rear row of foundation cast-in-place piles; a second reinforced concrete crown beam is set on the top of the front row of foundation cast-in-place piles; and a temporary structure diagonal brace connects the first reinforced concrete crown beam and the second reinforced concrete crown beam.

[0010] Based on the above technical features: the temporary structure diagonal braces are steel pipe diagonal braces.

[0011] A construction method of a permanent and temporary retaining wall structure is:

[0012] Step 1: First, construct the river channel interruption cofferdam. After the cofferdam is completed and accepted, backfill the construction soil platform in front of the existing river bank wall and drain the river water. The width of the construction platform is sufficient for the construction of bored pile machinery and equipment, and the height of the construction platform is the low water level of the river.

[0013] Step 2: Implement the front row foundation cast-in-place piles and the rear row foundation cast-in-place piles; construct the second reinforced concrete crown beam and the first reinforced concrete crown beam on the front row foundation cast-in-place piles and the rear row foundation cast-in-place piles respectively.

[0014] Step 3: After the concrete strength of the front row foundation cast-in-place piles, the rear row foundation cast-in-place piles, the first reinforced concrete crown beam and the second reinforced concrete crown beam reaches the design requirements, construct temporary structure diagonal braces.

[0015] Based on the above technical features, a construction method of a permanent and temporary retaining wall structure also includes:

[0016] Step 4: After the construction of the temporary structure diagonal brace is completed, first excavate the earth platform in front of the existing river bank to the designed elevation, and then construct the reinforced concrete of the wall and bottom plate of the new permanent structure reinforced concrete retaining wall to form a whole with the front row of foundation cast-in-place piles.

[0017] Step 5: After the newly built permanent reinforced concrete retaining wall reaches the designed strength, remove the temporary structure diagonal bracing and chisel out the front row of foundation piles and the second reinforced concrete cap beam above the bottom plate; finally, remove the cofferdam and release the water from the river.

[0018] Through the above technical scheme, the present invention has the following technical effects compared with the prior art: the existing river bank protection is better preserved, and the land acquisition and demolition behind the existing river bank protection are not involved; the residential area behind the wall is not entered during construction, which minimizes the impact of construction on the surrounding environment; the new bank protection expands the scale of the river channel, the river water is drained during construction, and the mud surface in front of the existing river bank protection wall is deepened to ensure the stability and safety of the existing river bank protection structure; after the permanent structure is completed and the strength of the reinforced concrete retaining wall meets the design requirements, the temporary structure brace is removed, and the permanent structure reinforced concrete retaining wall becomes an L-shaped retaining wall. There are no water-blocking buildings in the river channel, which does not affect the flow state of the river channel, and the temporary structure brace can be reused after removal, saving project investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic cross-sectional view of the permanent bonding structure of the present invention.

[0020] 1 Existing river bank protection

[0021] 2 Wall

[0022] 3 Bottom plate

[0023] 4 Rear foundation cast-in-place piles

[0024] 5 Front row foundation cast-in-place piles

[0025] 6 Temporary structure diagonal bracing

[0026] 7 First reinforced concrete crown beam

[0027] 8 Second reinforced concrete crown beam

[0028] 9 Design water level

[0029] 10 Design mud surface DETAILED DESCRIPTION

[0030] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, but not to limit the present invention.

[0031] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0034] like Figure 1 As shown, a permanent and temporary retaining wall structure comprises a newly built permanent reinforced concrete retaining wall, a temporary structure diagonal brace 6, and foundation cast-in-place piles; the permanent and temporary retaining wall structure is located in the river channel, with the existing river bank 1 at the rear, and during construction, the river water in front of the existing river bank 1 is first drained, and then the mud surface in front of the existing river bank 1 is deepened to the designed mud surface 10 in front of the newly built permanent reinforced concrete retaining wall, and the newly built reinforced concrete retaining wall is smoothly connected to the upstream and downstream of the river channel without water blocking; the temporary structure diagonal brace 6 connects the foundation cast-in-place piles arranged in front and behind.

[0035] In the above scheme, the existing river bank 1 is an old structure that needs to be protected. The old structure was originally a river bank, with water in front of the wall and a high mud surface in front of the wall. The newly designed river needs to be pumped out and dug down to the designed mud surface 10 in front of the newly built permanent reinforced concrete retaining wall. In this case, the existing river bank 1 will become unstable, tilted, or even collapse. Therefore, it is necessary to first implement foundation cast-in-place piles and temporary structure diagonal braces 6. Generally, two rows of foundation cast-in-place piles can be set, and the temporary structure diagonal braces 6 connect the front and rear rows of foundation cast-in-place piles. Only under the action of the temporary structure diagonal braces 6 can the existing river bank 1 be supported.

[0036] In order to protect the existing river bank 1, the foundation of the permanent and temporary combined structure should be cast-in-place piles. If prefabricated piles such as squeezed soil piles and driven vibration piles are used for construction, the safety of the existing river bank 1 will be affected. The mixing piles are not rigid enough, and the steel sheet piles are generally not used as permanent structures in water conservancy projects due to the anti-corrosion requirements. Therefore, cast-in-place piles should be used in this technical solution, and other pile forms cannot be replaced.

[0037] like Figure 1 As shown, the front row of foundation piles 5 are arranged at intervals on the water side, and the spacing is determined according to the stress conditions. The rear row of foundation piles 4 are arranged on the shore side, and are densely arranged piles, and are arranged close to the existing river bank 1.

[0038] The wall body 2 of the newly built permanent reinforced concrete retaining wall is arranged close to the rear row of foundation cast-in-place piles 4, and the bottom plate 3 of the newly built permanent reinforced concrete retaining wall is integrally cast with the front row of foundation cast-in-place piles 5 to form an L-shaped retaining wall. The bottom plate 3 is consistent with the designed mud surface 10, that is, consistent with the designed river bottom elevation, does not occupy the river section, does not block water, and does not affect the existing river bank 1. It also plays a role in connecting the cast-in-place piles together to bear force.

[0039] A first reinforced concrete crown beam 7 is preferably provided on the top of the rear row of cast-in-place foundation piles 4; a second reinforced concrete crown beam 8 is preferably provided on the top of the front row of cast-in-place foundation piles 5; a temporary structure diagonal brace 6 connects the first reinforced concrete crown beam 7 and the second reinforced concrete crown beam 8. The temporary structure diagonal brace 6 is connected with the two rows of cast-in-place piles through the first reinforced concrete crown beam 7 and the second reinforced concrete crown beam 8 and plays a supporting role. The temporary structure diagonal brace 6 can be a steel pipe or other forms.

[0040] When the present invention is implemented, the following construction sequence should be followed and the construction sequence shall not be changed.

[0041] 1. First, carry out the construction of the river channel interruption cofferdam. After the completion and acceptance of the cofferdam, backfill the construction soil platform in front of the existing river channel revetment wall 1 and drain the river water. The width of the construction platform is sufficient for the construction of bored pile machinery and equipment. The height of the construction platform is the low water level of the river channel to ensure the stability and safety of the existing revetment structure after the river water is drained.

[0042] 2. Implement the rear row foundation cast-in-place piles 4, the front row foundation cast-in-place piles 5, the first reinforced concrete crown beam 7, and the second reinforced concrete crown beam 8.

[0043] 3. After the concrete strength of the rear row foundation cast-in-place piles 4, the front row foundation cast-in-place piles 5, the first reinforced concrete crown beam 7, and the second reinforced concrete crown beam 8 reaches the design requirements, a temporary structure diagonal brace 6 is implemented between the front and rear rows of piles.

[0044] 4. After the construction of the temporary structure diagonal brace 6 is completed, the reinforced concrete construction of the wall body 2 and the bottom plate 3 of the new permanent structure reinforced concrete retaining wall is then carried out to form a whole with the front row foundation cast-in-place piles 5.

[0045] 5. After the newly built permanent reinforced concrete retaining wall reaches the designed strength, the temporary structure diagonal brace 6 is removed and the front row foundation cast-in-place piles 5 and the second reinforced concrete cap beam 8 above the bottom plate 3 are chiseled out; finally, the cofferdam is removed and the river channel is released to the designed water level 9.

[0046] In summary, the permanent and temporary combined retaining wall structure of the present invention not only retains the existing river bank protection, does not involve land acquisition and demolition behind the existing river bank protection, but also ensures the safety of the existing river bank protection when the mud surface in front of the existing river bank protection wall is deepened and the river water is drained for dry land construction; the community behind the wall is not entered during construction, which minimizes the impact on the surrounding environment during construction; the wall body of the newly built permanent structure reinforced concrete retaining wall is close to the rear row of foundation cast-in-place piles, and the bottom plate of the newly built permanent structure reinforced concrete retaining wall is integrally cast with the front row of foundation cast-in-place piles. After the wall body and the bottom plate concrete reach the designed strength, the temporary structure diagonal brace is removed and the river channel is open to water. The temporary structure diagonal brace can be reused after removal, saving project investment, and the newly built permanent structure becomes an L-shaped retaining wall after the temporary structure diagonal brace is removed. There are no water-blocking buildings in the river channel, which does not affect the flow state of the river channel water. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A construction method for a permanent and temporary retaining wall structure, characterized in that: include: Step 1: First, construct a river channel interruption cofferdam. After the cofferdam is completed and accepted, fill a construction soil platform in front of the existing river channel revetment (1) wall and drain the river channel water. The width of the construction platform is sufficient for the construction of cast-in-place pile machinery and equipment, and the height of the construction platform is the low water level of the river channel. Step 2: constructing front-row foundation cast-in-place piles (5) and rear-row foundation cast-in-place piles (4); constructing second reinforced concrete crown beams (8) and first reinforced concrete crown beams (7) on the front-row foundation cast-in-place piles (5) and rear-row foundation cast-in-place piles (4), respectively; Step 3: constructing a temporary structure diagonal brace (6) after the concrete strength of the front row foundation cast-in-place piles (5), the rear row foundation cast-in-place piles (4), the first reinforced concrete crown beam (7), and the second reinforced concrete crown beam (8) reaches the design requirements; The temporary structure diagonal brace (6) connects the first reinforced concrete crown beam (7) and the second reinforced concrete crown beam (8); Also includes: Step 4: After the construction of the temporary structure diagonal brace (6) is completed, the soil platform in front of the existing river bank (1) is first excavated to the designed elevation, and then the reinforced concrete construction of the wall body (2) and the bottom plate (3) of the new permanent structure reinforced concrete retaining wall is carried out to form a whole with the front row foundation cast-in-place piles (5); Step 5: After the newly built permanent reinforced concrete retaining wall reaches the designed strength, the temporary structure diagonal brace (6) is removed and the front row foundation cast-in-place piles (5) and the second reinforced concrete cap beam (8) above the bottom plate (3) are chiseled out; finally, the cofferdam is removed and the river channel is released; The mud surface in front of the existing river bank (1) is excavated to the designed mud surface in front of the newly built permanent reinforced concrete retaining wall, and the newly built permanent reinforced concrete retaining wall is smoothly connected to the upstream and downstream of the river; The wall body (2) of the newly built permanent reinforced concrete retaining wall is arranged closely to the rear row of foundation cast-in-place piles (4), and the bottom plate (3) of the newly built permanent reinforced concrete retaining wall is integrally cast together with the front row of foundation cast-in-place piles (5), forming an L-shaped retaining wall.

2. The construction method of a permanent and temporary retaining wall structure according to claim 1, characterized in that: The front row of foundation cast-in-place piles (5) are arranged on the water side and are spaced apart; the rear row of foundation cast-in-place piles (4) are arranged on the shore side and are densely packed cast-in-place piles, and are arranged close to the existing river bank (1).

3. The construction method of a permanent and temporary retaining wall structure according to claim 1, characterized in that: The temporary structure diagonal brace (6) is a steel pipe diagonal brace.

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