Permanent and temporary combined sheet pile type retaining wall

Abstract

The utility model relates to a permanent and temporary combined sheet pile type retaining wall, which is provided with a panel positioned on a water side and a plurality of cast-in-place piles, the cast-in-place piles are positioned on a backwater side of the panel and are distributed at intervals along the extension direction of the panel, connecting steel bars are arranged between the panel and the cast-in-place piles, and two sides of the connecting steel bars are respectively anchored on the panel and the cast-in-place piles. The top beam, the wave wall and the hat stone are sequentially arranged on the face plate and the cast-in-place piles. During construction, the cast-in-place piles are firstly drilled and poured, the cast-in-place piles serve as a temporary supporting system to implement excavation and foundation cleaning needed by the face plate and the face plate foundation, and after the face plate foundation and the face plate are poured, the cast-in-place piles are reserved to serve as a permanent supporting system. According to the utility model, the land occupation requirement of construction can be obviously reduced, and the construction of the river retaining wall on the occasion without enough sloping conditions is facilitated.

Description

Technical Field

[0001] This utility model relates to a permanent and temporary combined sheet pile retaining wall and its construction method. Background Technology

[0002] Currently, most methods for constructing river retaining walls include concrete pouring, masonry masonry, and reinforced concrete pouring. These methods are quite common. When constructing these retaining walls, a certain width of excavation slope is required. Support methods such as soil nailing and shotcrete, retaining piles, and sheet piles can be used. After the main structure is completed, some temporary support measures such as shotcrete, pile tops, and sheet piles need to be removed before subsequent construction can proceed. For example, Chinese patent document CN114263212A discloses a single-sided formwork support system for an inclined retaining wall, comprising two or more support mechanisms. Each support mechanism includes steel formwork, telescopic rods, vertical tie bolts, diagonal tie bolts, connectors, and an adjustable base. There are one or more vertical tie bolts and one or more diagonal tie bolts. The steel formwork, vertical tie bolts, and diagonal tie bolts are respectively fixed to a concrete pad. Each diagonal tie bolt is welded to one or more vertical tie bolts, and each diagonal tie bolt is fixed to the steel formwork. The upper end of each vertical tie bolt is connected to a telescopic rod. One end of the telescopic rod is connected to the top of the steel formwork via a connector. The adjustable base is fixed to the other end of the telescopic rod, and the adjustable base abuts against the slope of the soil. The steel formwork of multiple support mechanisms is interconnected. This utility model has a simple structure and a short construction time. Chinese patent document CN219508638U discloses a retaining wall support device, relating to the field of retaining wall support technology. It includes a support plate abutting against a slope, with adjacent support plates connected by connectors. The bottom of each support plate has a base plate, and the bottom of the base plate has a connecting rod. Support components for pressing the support plate firmly against the slope wall are connected to the support plate. This application allows for rapid assembly of the retaining wall support structure, ensuring the stability of excavated or filled slopes and effectively improving construction efficiency. Chinese patent document CN113417301A discloses a slope protection construction method integrated with the main structure of a building, including the following steps: leveling the site, excavating the construction working surface for the base slab of the retaining wall, constructing the base slab, wall body, and foundation of the retaining wall, performing the first backfill, reserving a first platform on the top of the retaining wall, constructing the foundation pipe piles of the main structure of the building, performing the second backfill, reserving a second platform, constructing the main foundation pipe piles, foundation, and elevated structural columns of this platform, performing the third backfill, reserving a third platform, constructing the main foundation pipe piles, foundation, and elevated structural columns of this platform, performing the final backfill, and leveling the site, constructing the main foundation pipe piles, and completing the slope protection. By flexibly adopting a combination of vertical support and slope protection of different heights, and utilizing the elevated main structure of the building for graded slope protection, the method aims to reduce the height of vertical support, reduce the risk of ultra-high retaining walls, reduce the amount of earthwork backfill, and save on project costs. These technologies have unique features and are suitable for their respective occasions. However, if the riverbank is very close to the road and the slope requirements cannot be met, the above-mentioned excavation and support construction method cannot meet the requirements for river retaining wall construction. Utility Model Content

[0003] The purpose of this invention is to reduce the land required for construction and to facilitate the construction of river retaining walls in situations where sufficient slope conditions are not available.

[0004] The technical solution of this utility model is: a permanent and temporary combined sheet pile retaining wall, which is provided with a panel on the water-facing side and a number of cast-in-place piles (drilled cast-in-place piles). The cast-in-place piles are located on the back side of the panel and are distributed at intervals (alternating) along the extension direction of the panel (the extension direction of the wall). A connecting steel bar is provided between the panel and the cast-in-place piles. The two sides of the connecting steel bar are respectively anchored to the panel and the cast-in-place piles. A uniform capping beam is provided on the panel and the cast-in-place piles. A wave-breaking wall is provided on the capping beam. Drainage pipes are respectively provided at the bottom of the wave-breaking wall and on the panel.

[0005] Typically, the depth of a cast-in-place pile is much greater than the depth of the face panel, depending on the project requirements and geological conditions.

[0006] Furthermore, the panel adopts a reinforced concrete structure with an internal panel steel mesh (including longitudinal and transverse steel bars).

[0007] Furthermore, the cast-in-place pile is a reinforced concrete cast-in-place pile, with an internal cast-in-place pile reinforcement cage (including longitudinal bars and stirrups, etc.).

[0008] Preferably, the backwater side of the panel is fixed together with the water-near side of the cast-in-place pile (the corresponding part of the cast-in-place pile).

[0009] Preferably, a connecting steel bar is provided between the panel and the cast-in-place pile (the corresponding part of the cast-in-place pile). One side of the connecting steel bar (panel side) passes through the panel steel mesh inside the panel, and the other side (cast-in-place pile side) passes into the cast-in-place pile steel cage inside the cast-in-place pile.

[0010] Furthermore, a panel base is provided below the panel.

[0011] Preferably, the panel foundation is a reinforced concrete foundation or a concrete foundation, which is cast integrally with the panel.

[0012] Furthermore, a capping beam is provided above the panel and the cast-in-place pile.

[0013] Furthermore, the cap beam is a reinforced concrete structure.

[0014] Furthermore, the top of the panel and the cast-in-place pile are fixed together with the bottom of the cap beam.

[0015] Preferably, the longitudinal reinforcement of the cast-in-place pile extends into the capping beam.

[0016] Furthermore, a wave-proof wall is provided on top of the crown beam.

[0017] Preferably, the wave-breaking wall is a reinforced concrete structure, cast integrally with the capping beam.

[0018] Preferably, the cap beam has a cap beam panel layer on the water-facing side (near water side), and the cap beam panel layer is cast integrally with the panel.

[0019] Furthermore, the cap beam panel and the water-facing surface of the panel are aligned to form the same smooth surface (which can usually be a vertical surface).

[0020] Preferably, a portion of the reinforcing steel bars in the capping beam are located within the capping beam panel.

[0021] Furthermore, a cap stone is provided on the top of the crown beam.

[0022] The following construction method can be used for the retaining wall construction of this utility model: first, drill and cast-in-place piles, using the piles as a temporary support system for the excavation and foundation clearing required for the panel and panel foundation; after the panel foundation and panel are poured, retain the piles as a permanent support system. Therefore, based on the pile support, there is no need for slope protection during the construction of the panel and panel foundation, and it is also permissible not to set up / not to set up other support systems.

[0023] The beneficial effects of this utility model are as follows: This utility model uses cast-in-place piles as a temporary and permanent support system. Steel mesh is installed between the piles and on the pile surface, and concrete is poured to form a river retaining wall (panel) structure. There is no need for slope excavation, and no other support system needs to be set up. Therefore, the construction range is small, the impact on the surrounding area is small, and the construction efficiency is high. It is particularly suitable for the construction of river retaining walls where slope conditions are not available, and it is also suitable for the construction of similar retaining walls or other similar walls in other situations. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the retaining wall structure involved in this utility model;

[0025] Figure 2 This is a schematic diagram of the reinforcement of the retaining wall support piles involved in this utility model;

[0026] Figure 3 This is a schematic diagram of the wall reinforcement of the retaining wall involved in this utility model;

[0027] Figure 4 This is a top view schematic diagram of the wall reinforcement of the retaining wall involved in this utility model;

[0028] Figure 5 This is a schematic diagram of the integrated reinforcement of the cap beam and wave-breaking wall involved in this utility model;

[0029] Figure 6 This is a construction flowchart related to this utility model. Detailed Implementation

[0030] See Figures 1-6The retaining wall involved in this utility model mainly consists of a panel 30 and cast-in-place piles 20. Several cast-in-place piles are distributed at certain intervals on the backwater side of the panel, serving as a temporary support system during construction and a permanent support system for the retaining wall. Before excavation (the surface can be cleared first), holes are drilled on the riverbank 10 according to the required locations of the cast-in-place piles, and the piles are poured. Then, relying on the supporting effect of the cast-in-place piles, the excavation and foundation clearing of the retaining wall are carried out.

[0031] The panel is connected to the cast-in-place pile, and a uniform cap beam 40 is set on the top. A wave wall 50 is set on the cap beam, and a cap stone 60 or other structures can be set on the wave wall according to actual needs.

[0032] The panel is located on the water-facing side of the riverbank and can be a vertical facade. A panel foundation 70 is set at the bottom of the panel, and the panel and panel foundation can be regarded as a whole, with steel bars laid and concrete poured in a unified manner.

[0033] According to actual needs, a seepage pipe 16 passing through the panel and a drainage pipe 17 passing through the wave-breaking wall are installed.

[0034] Depending on actual needs, walkways or other ground structures 12 and protective structures can be installed on the top surface of the riverbank on the back side of the breakwater.

[0035] The steel cage used for cast-in-place piles is mainly composed of several vertically arranged longitudinal bars 24 and spiral bars (or stirrups) 25. Several tie bars 26 can also be set. Several positioning bars 27 are set on the outer side (circumferential surface) of the steel cage to achieve positioning in the hole.

[0036] The longitudinal reinforcement bars of the cast-in-place pile reinforcement cage should extend into the capping beam (the casting space of the capping beam) to form the corresponding reinforcement bars in the capping beam. This not only facilitates construction but also helps to improve the connection strength between the capping beam and the cast-in-place pile.

[0037] For the same reason, the longitudinal reinforcement 34 of the panel should also extend into the capping beam (capping beam panel layer).

[0038] The connecting reinforcing bars 38 can be installed in layers. Two connecting reinforcing bars can be used for each pile, with an included angle β of 60° between them, and they should be symmetrically arranged. The number of layers / layer spacing of the connecting reinforcing bars depends on actual needs.

[0039] The capping beam and the wave-breaking wall can be reinforced and cast together as a whole. The corresponding steel bars 43 in the capping beam and the corresponding steel bars 53 in the wave-breaking wall extend to the common area of ​​the capping beam and the wave-breaking wall to improve the overall structural strength.

[0040] The location and height of each part can be set according to the existing ground line 11 and other topographical features and geological conditions.

[0041] The general construction process of this utility model can be as follows: clearing the surface → construction of cast-in-place piles → construction of concrete panels → construction of cap beams and wave walls.

[0042] by Figure 1 The specific embodiments involved include:

[0043] 1) Clear the table

[0044] Based on the actual on-site exploration, tree roots, weeds, garbage, waste residue, flood deposits and other obstructions in the excavation area were cleared.

[0045] 2) Construction of cast-in-place piles

[0046] i) Construction preparation

[0047] Pile location measurement: Based on the general plan and pile location plan, the surveyor lays out the lines. First, the axis position is measured and marked with wooden stakes. After verification, the position of each pile is measured according to the pile location plan and a 30-50cm steel bar is inserted as a marker. The steel bar ends are buried in the ground and clearly marked to prevent the pile driver from moving or the concrete truck from colliding with it. The allowable deviation of the pile position is 1 / 6d in the direction perpendicular to the axis and 1 / 4d in the direction along the axis.

[0048] Casing Installation: The casing length is adjusted according to the groundwater level. It is made of 5mm steel plate, with reinforcing ribs welded to the upper, lower, and outer sides of the middle section to increase rigidity. The inner diameter of the casing is 0.2m larger than the designed pile diameter. A 20cm x 40cm overflow hole is installed 20cm below the top of the casing. After the casing is fabricated, cross lines are drawn according to the pile location markings, and wooden stakes are driven to mark the pile centerline. Then, a pit is manually dug to install the casing. After installation, the center point is re-checked; the deviation between the casing center and the pile center should be ≤50mm. The bottom of the casing is treated with cement mortar, and within a 60cm radius around it, clay is layered and compacted until level with the top of the casing.

[0049] Drilling Rig Positioning: Before constructing the bored pile foundation, the site must be leveled, debris removed, soft soil replaced, and compacted to ensure the drilling rig remains stable during construction. The drilling rig base should not be placed directly on unstable fill to avoid uneven settlement. For steep slopes, the slope should be leveled before construction.

[0050] Pile location layout: Drive the drilling rig to the hole to be drilled, adjust the mast angle, operate the winch, align the center of the drill bit with the center of the hole, and put it into the hole. Adjust the verticality parameters of the drilling rig to make the drill rod vertical, and at the same time slightly raise the drill bit to ensure that the drill bit floats freely in the hole.

[0051] ii) Drilling and cleaning

[0052] Drilling: Position the drilling rig and align the drill bit centerline with the center of the pile hole, controlling the error within 2cm. Start the mud pump and begin drilling. Initially, use a low speed and drill slowly until you reach 1m below the casing, then adjust to normal speed. During drilling, select different types of drill bits according to different geological conditions. In soil or gravelly strata, use a spiral soil drill or rotary drilling bucket. During drilling, frequently extract cuttings and verify them against the design geology, paying attention to changes in strata to adjust the speed and drilling pressure accordingly. During drilling, check the hole position, depth, shape, diameter, inclination, and various mud parameters, and adjust as needed. Maintain appropriate mud consistency and stable water level inside the hole, adding water and clay as needed to maintain the water head difference and prevent hole collapse. Adopt appropriate drilling methods and mud consistency based on changes in strata.

[0053] Hole cleaning: Hole cleaning is carried out by pump suction, in which sediment is sucked out by a mud pump and mud is added to the hole in a timely manner until the design and specification requirements are met before the next construction process can be carried out.

[0054] iii) Reinforcing cage hoisting

[0055] After the borehole is cleaned and inspected, the reinforcing cage is lowered into the hole using a truck crane, with the lifting point set at the stiffening hoops. The reinforcing cage is lowered in sections. After one section is placed in the hole, a steel section is inserted under the stiffening hoops to temporarily support the cage at the borehole opening. The second section is then lowered, and the sections are joined at the opening. During the joining, the upper and lower main reinforcement bars are aligned, ensuring the upper and lower axes of the cage are consistent. The main reinforcement bars are staggered at the joint position, and straight thread connections are used. When lowering the reinforcing cage into the hole, it should be aligned with the hole position and lowered gently and slowly. If obstruction is encountered, the lowering should be stopped, the cause investigated, and the problem addressed. After the entire reinforcing cage is in the hole, the placement position should be checked according to the design and specifications, and records should be made. If the requirements are met and the cage is approved by the supervising engineer, the next construction procedure can proceed.

[0056] iv) Catheter placement

[0057] The guide pipe uses a specialized spiral threaded guide pipe with an inner diameter of 300mm. The middle section is 2.7m long, and the bottom section is 3.8-4m long, with 0.5m, 1m, and 1.5m non-standard sections available. The guide pipe must be sturdy, with a smooth, straight inner wall and no local dents or bumps. The guide pipe should be lowered vertically and gently to avoid colliding with the reinforcing cage. The number of sections lowered should be recorded during lowering. After reaching the bottom of the hole, the theoretical length should be compared with the actual length to ensure they match. After the guide pipe is fully lowered to the bottom of the hole and verified to be correct, gently lift the guide pipe, controlling the bottom opening to be 0.25-0.4m from the bottom of the hole and centered in the borehole.

[0058] v) Underwater concrete pouring

[0059] After acceptance, concrete pouring shall commence, with the discharge port extending at least 2m into the previously poured concrete to prevent mud and water from entering the pipe, and not exceeding 6m. The elevation of the concrete surface layer within the borehole shall be frequently measured, and the corresponding position of the tremie pipe discharge port relative to the concrete surface shall be adjusted promptly, with constant close monitoring. The tremie pipe shall be filled only when no water enters. At all times, the bottom of the pipe shall be 2m below the top surface of the concrete. Concrete delivered to the pile shall be a continuous operation in one go. Before initial setting, any contaminated concrete shall be removed from the top of the pile. Concrete should be poured continuously until the top surface of the poured concrete exceeds the cutoff height specified in the drawings or determined by the supervising engineer (generally 0.5–1.0m) before stopping pouring, to ensure that all concrete below the cutoff section reaches the strength standard.

[0060] 3) Concrete panel construction

[0061] Construction sequence: tying reinforcement bars and setting up formwork for the panel foundation → pouring foundation concrete → installing reinforcement bars for cast-in-place piles → tying panel reinforcement bars and pre-embedding drainage pipes → setting up panel formwork → pouring panel concrete.

[0062] As per design requirements, before pouring the concrete panel, reinforcing bars were installed on the cast-in-place piles and connected and fixed to the panel mesh reinforcement, using 16mm diameter bars spaced 400mm apart. Drainage pipes for the retaining wall were installed, using 75mm inner diameter PVC pipes, 850mm long per pipe, spaced 1.50m apart in a staggered pattern. The panel foundation was excavated and cleaned, the soil on the cast-in-place piles was removed, and the foundation and panel reinforcement bars were tied. After tying, the side formwork of the bottom slab was erected for bottom slab concrete pouring, followed by panel formwork erection and concrete pouring.

[0063] The reinforcing bars have straight surfaces free of cracks and oil stains. The number of joints, lap lengths, and welding quality of the reinforcing bars at the same cross-section meet the requirements of the technical specifications. The spacing, length, protective layer thickness, and position of bent-up reinforcing bars are controlled within the error range specified in the technical specifications. When binding the reinforcing bars of supporting beams and crossbeams, attention should be paid to their connection with the drilled piles and embedded reinforcing bars of the columns. The binding and materials of the reinforcing bars meet the design requirements, and soil contamination should be avoided during the transportation and binding of the reinforcing bars.

[0064] Wooden formwork is used for the base, and steel formwork is used for the panels. Formwork is fabricated and installed according to design requirements. After installation, the position, verticality, and stability of the formwork are checked. Any deformation or damage to the formwork during use is repaired promptly.

[0065] 4) Construction of capping beams and wave walls

[0066] Construction sequence: tying the reinforcing bars of the capping beam and wave wall → erecting the formwork for the capping beam and wave wall → pouring concrete.

[0067] The reinforcing bars have straight surfaces free of cracks and oil stains. The number of joints, lap lengths, and welding quality of the reinforcing bars at the same cross-section meet the requirements of the technical specifications. The spacing, length, protective layer thickness, and position of bent-up reinforcing bars are controlled within the error range specified in the technical specifications. When binding the reinforcing bars of supporting beams and crossbeams, attention should be paid to their connection with the drilled piles and embedded reinforcing bars of the columns. The binding and materials of the reinforcing bars meet the design requirements, and soil contamination should be avoided during the transportation and binding of the reinforcing bars.

[0068] Wooden formwork was used for the capping beam and wave wall. The formwork was fabricated and installed according to the design requirements, and inspected after installation.

[0069] Concrete is transported to the construction site by a concrete mixer truck, and the concrete is placed into the hopper. After the hopper is lifted to the construction site by a crane, the hopper valve is opened to allow the concrete to enter the formwork. Alternatively, the concrete mixer truck can directly pour the concrete into the chute to allow the concrete to enter the formwork. The concrete is poured in horizontal sections and compacted using an immersion vibrator.

[0070] For two or more parts (areas) that are cast in one piece, reinforcement should be laid out as a whole.

[0071] Unless otherwise specified, the preferred and optional technical means disclosed in this utility model can be arbitrarily combined to form several different specific embodiments when one preferred or optional technical means is a further limitation of another technical means.

Claims

1. A permanent and temporary combined sheet pile retaining wall, comprising a panel located on the water-facing side, characterized in that... Several cast-in-place piles are also provided. The cast-in-place piles are located on the back side of the panel and are distributed at intervals along the extension direction of the panel. Connecting steel bars are provided between the panel and the cast-in-place piles. The two sides of the connecting steel bars are respectively anchored to the panel and the cast-in-place piles. A uniform capping beam is provided on the panel and the cast-in-place piles. A wave-breaking wall is provided on the capping beam. Drainage pipes are respectively provided at the bottom of the wave-breaking wall and on the panel.

2. The permanent and temporary combined sheet pile retaining wall as described in claim 1, characterized in that... The panel is made of reinforced concrete and has an internal panel steel mesh. The cast-in-place piles are reinforced concrete cast-in-place piles with an internal cast-in-place pile steel cage.

3. The permanent and temporary combined sheet pile retaining wall as described in claim 2, characterized in that... The backwater side of the panel is fixed together with the water-near side of the cast-in-place pile.

4. The permanent and temporary combined sheet pile retaining wall as described in claim 2, characterized in that... A connecting steel bar is provided between the panel and the cast-in-place pile. One side of the connecting steel bar passes through the panel steel mesh inside the panel, and the other side passes through the cast-in-place pile steel cage inside the cast-in-place pile.

5. The permanent and temporary combined sheet pile retaining wall as described in claim 2, characterized in that... A panel base is located below the panel.

6. The permanent and temporary combined sheet pile retaining wall as described in claim 5, characterized in that... The panel foundation is a reinforced concrete foundation or a concrete foundation, which is cast integrally with the panel.

7. The permanent and temporary combined sheet pile retaining wall as described in claim 2, characterized in that... The capping beam is a reinforced concrete structure, and the longitudinal reinforcement of the cast-in-place piles extends into the capping beam.

8. The permanent and temporary combined sheet pile retaining wall as described in claim 2, characterized in that... The wave-breaking wall is a reinforced concrete structure, cast integrally with the capping beam.

9. The permanent and temporary combined sheet pile retaining wall as described in claim 2, characterized in that... The water-facing side of the cap beam is provided with a cap beam panel layer, which is cast integrally with the panel.

10. The permanent and temporary combined sheet pile retaining wall as described in claim 9, characterized in that... A portion of the reinforcing steel in the capping beam is located within the capping beam panel.

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