A Deep H-Shaped Underground Anti-scour Wall and Its Construction Technology

Abstract

The present application belongs to the technical field of hydraulic engineering construction, and relates to a large-depth H-shaped underground anti-scour wall, which is composed of a plurality of H-shaped unit grooves. The H-shaped unit groove comprises a T-shaped wall body, a steel reinforcement cage and a joint assembly. Two T-shaped wall bodies are connected by the joint assembly, and a steel reinforcement cage is arranged in the two T-shaped wall bodies. The present application also relates to a construction process of the large-depth H-shaped underground anti-scour wall. Two T-shaped wall bodies are formed in succession, and the two T-shaped wall bodies are connected by a joint assembly. This connection mode significantly reduces the construction difficulty of steel reinforcement connection and concrete pouring, solves the problem that steel reinforcement connection is difficult to implement in a large-depth and narrow space, and solves the problem of cold joints, so that the construction quality can be guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of water conservancy engineering construction technology, and relates to an underground anti-scour wall and its construction technology, particularly a deep H-shaped underground anti-scour wall and its construction technology. Background Technology

[0002] Underground scour walls are concrete structures used to reinforce river embankments. They prevent scouring of the embankment foundation during floods due to the large flow and high velocity of the river, thus mitigating the risk of embankment breaches. The underground scour walls are constructed using diaphragm wall technology. The wall structure consists of multiple diaphragm walls connected to form a single row of structures. Common connection methods include flexible and rigid joints. Flexible joints include: circular locking pipe joints, corrugated pipe joints, wedge joints, I-beam joints, and precast concrete joints. Rigid joints include straight or cross-shaped perforated steel plate joints and steel rebar socket joints.

[0003] Taking into account factors such as hydrology, geology, working conditions, and calculation verification, a single-row scour barrier structure cannot meet the engineering requirements. Therefore, an H-type underground scour barrier structure was invented. The H-type underground scour barrier is composed of several H-type unit trenches, and each H-type unit trench consists of two longitudinal walls and one transverse wall (hereinafter referred to as transverse partition wall).

[0004] The specific construction steps for the existing H-type underground erosion control wall are as follows: 1. Conduct construction preparation work, namely site clearing and leveling; 2. According to the design requirements and surveying and setting out of the longitudinal walls on both sides of the underground erosion control wall, carry out guide wall excavation, rebar tying, formwork erection, concrete pouring and curing, etc.; 3. Prepare the mud slurry for the wall foundation trench and make the rebar cage required for the wall; 4. Position the trenching machine and excavate the wall foundation trench; 5. Lower and install the rebar cages of the longitudinal walls on both sides and pour concrete, thus completing the construction of the longitudinal walls on both sides; 6. After the concrete strength of the longitudinal walls on both sides meets the design requirements, excavate the foundation pit between the longitudinal walls on both sides to prepare for the dry construction of the intermediate transverse wall in the foundation pit. According to the specifications, layered excavation and support are required; 7. Excavation, support, dewatering, and safety monitoring during construction should be carried out simultaneously to ensure the overall safety of the foundation pit structure; 8. When the foundation pit is excavated to the bottom elevation of the transverse partition wall and dry construction conditions are met, the steel reinforcement of the inner walls of the longitudinal walls on both sides should be installed and connected with the steel reinforcement of the transverse partition wall, the formwork of the transverse partition wall should be erected, and the concrete should be poured, thus completing the structural construction of the underground anti-scour wall.

[0005] The above construction method has the following problems:

[0006] 1. The construction method involves first constructing the longitudinal walls on both sides. After the longitudinal walls on both sides are formed and their concrete strength meets the process requirements, the middle transverse partition wall is then constructed. The longitudinal walls and transverse partition walls are poured separately. Due to the different pouring times, cold joints are easily generated, which affects the overall quality of the underground anti-erosion wall in the later stage.

[0007] 2. To ensure the overall strength, rigidity, and stability of the H-shaped underground erosion control wall structure, the steel reinforcement and concrete of the transverse diaphragm walls must be effectively connected to the longitudinal walls on both sides. Based on this connection process, high requirements are placed on the construction of the guide wall, trench excavation, steel reinforcement connection, and concrete pouring, posing significant challenges to construction quality, safety, and schedule. Furthermore, this steel reinforcement connection process is difficult to achieve in deep, confined spaces.

[0008] 3. In particular, for the construction of deep H-shaped underground anti-scour walls, due to the large excavation depth required, there are also problems such as long construction preparation time, large amount of equipment (such as excavators, cranes, dump trucks, dewatering equipment, generators and safety monitoring instruments, etc.), and complicated construction procedures, which are not conducive to progress and cost control.

[0009] Deep foundation pit excavation is a high-risk project that exceeds a certain scale. The construction will disturb the surrounding soil and has high construction risks. It is necessary to set up a support and retaining structure. The construction safety risks are increased when workers work inside the deep foundation pit.

[0010] The massive amount of earthwork excavation is detrimental to soil and water conservation and environmental management, making it difficult to achieve the goals of high-quality, efficient, and green environmental protection.

[0011] Therefore, it is essential for this industry to design a construction process for H-type underground anti-scour wall transverse diaphragm wall plug joints that can avoid the safety and environmental risks of deep foundation pit excavation, reduce equipment investment, reduce the difficulty of construction procedures, improve construction efficiency and quality control, and has wide applicability. Summary of the Invention

[0012] The purpose of this invention is to propose a deep H-shaped underground anti-erosion wall and its construction process to solve the technical problems mentioned in the background art.

[0013] The technical problem solved by this invention is achieved through the following technical solution:

[0014] A deep H-shaped underground erosion barrier, composed of several H-shaped unit trenches, is characterized in that: the H-shaped unit trench includes a T-shaped wall, a reinforcing cage, and a joint assembly; the T-shaped wall includes a vertical longitudinal wall and a transverse wall vertically arranged in the middle of the upper half of the longitudinal wall; two T-shaped walls are arranged opposite each other; the two transverse walls are connected by a joint assembly to form a transverse partition wall; the T-shaped wall is a cast-in-place structure; and a reinforcing cage is installed within the two T-shaped walls.

[0015] Furthermore, the steel cage includes bent horizontal steel bars and longitudinal steel bars. The bent horizontal steel bars are evenly spaced in the vertical direction, and each bent horizontal steel bar is connected by evenly spaced longitudinal steel bars. The bent horizontal steel bars are composed of a front horizontal section, a broken line section, a middle horizontal section, a rear horizontal section, a front vertical section, and a rear vertical section. The rear vertical section has a rear horizontal section bent forward vertically at both ends, the front vertical section has a front vertical section bent inward vertically at the root of the two rear horizontal sections, the middle horizontal section has a middle vertical section bent forward vertically at the root of the two front vertical sections, the broken line section is bent forward and inclined inward at the front end of the two middle horizontal sections, and the front horizontal section is bent horizontally at the front end of the two broken line sections.

[0016] Furthermore, the joint assembly includes an I-beam and connecting mesh. Connecting mesh is symmetrically welded to both ends of the outer side of each flange of the I-beam. The connecting mesh is welded from steel bars arranged in a crisscross pattern. The height of the I-beam is the same as the height of the transverse partition wall. The two front horizontal sections of the bent horizontal steel bar are inserted between the two oppositely arranged connecting meshes, and the ends of the two front horizontal sections of the bent horizontal steel bar abut against the web of the I-beam.

[0017] Furthermore, the overlap length between the transverse reinforcing bars on the connecting mesh and the flange of the I-beam is 5 times the diameter of the reinforcing bars.

[0018] Moreover, the lateral length of the rectangular joint box is greater than 35 times the diameter of the reinforcing bar.

[0019] A construction process for a deep H-shaped underground erosion barrier wall, characterized by the following steps:

[0020] S1: Complete the site clearing and leveling process within the construction area;

[0021] S2: Complete the excavation of the guide wall, reinforcement binding, formwork erection, concrete pouring and curing procedures in accordance with the design requirements and surveying and setting out of the underground anti-scouring wall;

[0022] S3: Complete the placement of trenching equipment, arrangement of mud pits, and arrangement of rebar cage processing area within the construction area;

[0023] S4: Use a trenching machine to excavate the first trench section and the excavation boundary between the first trench section and the later trench section in the construction area.

[0024] S5: Complete the lowering and installation of the reinforcing cage within the first construction section;

[0025] S6: Place an I-beam with a connecting mesh welded on it at the joint between the first and second construction sections.

[0026] S7: Place a rectangular joint box in the slot formed by the I-beam and the connecting mesh on one side of the rear construction trench section. At the same time, fill the rectangular joint box and the rear construction trench section with sandbags to prevent the I-beam and the rectangular joint box from shifting or tilting.

[0027] S8: Pour concrete into the pre-construction trench section;

[0028] S9: When the concrete in the first construction section reaches the process requirements, the second construction section on the other side of the excavation boundary line is excavated. At the same time, the sandbags are dug out. After the excavation is completed, the rectangular joint box is taken out. After completion, the steel cage in the construction section is lowered and installed and the concrete is poured.

[0029] When the concrete in the subsequent construction section reaches the process requirements, the forming construction of the deep H-shaped underground anti-scour wall unit trench is completed.

[0030] S10: Repeat steps 1-9 to complete the construction of several H-shaped unit trenches, thereby completing the construction of the entire deep H-shaped underground anti-scour wall.

[0031] The advantages and beneficial effects of this invention are as follows:

[0032] 1. This deep H-shaped underground anti-scour wall and its construction technology, by designing the existing technology of constructing the longitudinal wall and the transverse partition wall in stages, into a process of constructing two T-shaped walls sequentially, with the two T-shaped walls connected by a joint component, avoids the cold joint problem caused by the sequential pouring of the longitudinal wall and the transverse partition wall, and ensures the quality of the overall underground anti-scour wall in the later stage.

[0033] 2. This deep H-shaped underground erosion barrier and its construction technology involve connecting the pre-constructed and subsequent construction sections using a joint assembly. This joint assembly is pre-embedded before concrete pouring, ensuring good integrity with the concrete after pouring and extending the service life of the underground erosion barrier. Simultaneously, this connection method significantly reduces the difficulty of rebar connection and concrete pouring, solving the problem of difficult rebar connection in confined spaces, thus guaranteeing construction quality.

[0034] 3. The construction process of this deep H-shaped underground anti-scour wall is such that only trenching machines are needed for excavation, which greatly reduces the workload of foundation pit excavation, foundation pit support and dewatering construction between the longitudinal walls on both sides of the underground anti-scour wall (because of the proximity to the river, water will seep out during excavation, so water-stopping protection and dewatering construction are required), and increases the working efficiency of the underground anti-scour wall unit trench by 4-5 times.

[0035] At the same time, it reduces the safety and environmental risks caused by deep foundation pit excavation, reduces the disturbance to the surrounding soil, eliminates the need for foundation pit support, requires less equipment, and saves construction costs; it also avoids the risks of dust and soil erosion caused by earthwork excavation, which is conducive to improving the overall level of green and low-carbon construction. Attached Figure Description

[0036] Figure 1 This is a plan view of the H-type underground anti-erosion wall unit trench of the present invention;

[0037] Figure 2 The facade of the H-type underground erosion protection wall of the present invention ( Figure 1 Schematic diagram (in the direction of AA);

[0038] Figure 3 This is a schematic diagram of the excavation of the foundation trench and the installation of the reinforcing cage in the transverse partition wall area of ​​the present invention;

[0039] Figure 4 This is a plan view of the I-beams and their welded connecting mesh within the transverse partition wall area of ​​the present invention;

[0040] Figure 5 This is a schematic diagram of the installation of a rectangular joint box and filling sandbags in the rear construction trench area within the transverse partition wall area of ​​the present invention;

[0041] Figure 6 This is a schematic diagram of the construction process of the first construction section of the transverse partition wall area, including concrete pouring, excavation (including sandbag excavation), and removal of the rectangular joint box.

[0042] Figure 7 A schematic diagram of the installation of the reinforcing cage and the pouring of concrete in the rear construction trench section within the transverse partition wall area of ​​the present invention.

[0043] Figure 8 This is a schematic diagram of the steel cage structure of the present invention.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1-H-type unit trench, 2-pre-construction trench section, 3-rear-construction trench section, 4-longitudinal wall, 5-transverse partition wall, 6-I-beam, 7-transverse reinforcement, 8-longitudinal reinforcement, 9-rectangular joint box, 10-excavation boundary line, 11-sandbag, 12-connecting mesh, 13-reinforcing cage, 14-front horizontal section, 15-zigzag section, 16-middle horizontal section, 17-front vertical section, 18-rear horizontal section, 19-rear vertical section. Detailed Implementation

[0046] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0047] A deep H-shaped underground erosion barrier, composed of several H-shaped unit trenches 1, is innovative in that: Figure 1 and Figure 2 As shown, the H-shaped unit trench includes a T-shaped wall, a steel cage 13, and a connector assembly. The T-shaped wall includes a vertical longitudinal wall 4 and a transverse wall that is centrally and vertically arranged in the upper half of the longitudinal wall. The two T-shaped walls are arranged opposite each other, and the two transverse walls are connected by the connector assembly to form a transverse partition wall 5. The T-shaped wall is a cast-in-place structure, and a steel cage is set in the two T-shaped walls.

[0048] like Figure 8 As shown, the reinforcing cage includes bent horizontal reinforcing bars and longitudinal reinforcing bars 8. The bent horizontal reinforcing bars are evenly spaced in the vertical direction, and each bent horizontal reinforcing bar is connected by evenly spaced longitudinal reinforcing bars. The bent horizontal reinforcing bars are composed of a front horizontal section 14, a broken line section 15, a middle horizontal section 16, a rear horizontal section 18, a front vertical section 17, and a rear vertical section 19. The rear horizontal section is bent forward vertically at both ends of the rear vertical section, the front vertical section is bent inward vertically at the root of the two rear horizontal sections, the middle horizontal section is bent forward vertically at the root of the two front vertical sections, the broken line section is bent forward and inclined inward at the front end of the two middle horizontal sections, and the front horizontal section is bent horizontally at the front end of the two broken line sections.

[0049] The joint assembly includes an I-beam 6 and connecting mesh 12. Connecting mesh is symmetrically welded to both ends of the outer side of each flange of the I-beam. The connecting mesh is welded from steel bars arranged in a crisscross pattern. The height of the I-beam is the same as the height of the transverse partition wall. The two front horizontal sections of the bent horizontal steel bars are inserted between the two oppositely arranged connecting meshes, and the ends of the two front horizontal sections of the bent horizontal steel bars abut against the web of the I-beam.

[0050] The overlap length between the transverse reinforcing bars on the connecting mesh and the flange of the I-beam is 5 times the diameter of the reinforcing bars.

[0051] An innovative construction process for a deep H-shaped underground erosion barrier includes the following steps:

[0052] S1: Complete the site clearing and leveling process within the construction area;

[0053] S2: Complete the excavation of the guide wall, reinforcement binding, formwork erection, concrete pouring and curing procedures in accordance with the design requirements and surveying and setting out of the underground anti-scouring wall;

[0054] S3: Complete the placement of trenching equipment, arrangement of mud pits, and arrangement of rebar cage processing area within the construction area;

[0055] S4: The underground erosion barrier is a linear concrete protective structure composed of several H-shaped unit trenches. Each H-shaped underground erosion barrier unit trench 1 consists of two longitudinal walls 4 on either side and a transverse partition wall 5 in the middle, divided into two T-shaped walls by the center line of the transverse partition wall 5. According to the construction sequence, these are respectively called the first construction section 2 and the last construction section 3. The excavation boundary line is marked on the transverse wall of the last construction section, and I-beams serve as the boundary between the first and last construction sections. This construction process eliminates the need for large-area, deep excavation of the foundation pit using excavators; instead, a trenching machine is positioned on the ground on one side of the guide wall to excavate the foundation trenches for the T-shaped walls.

[0056] S5: Complete the cutting, bending and assembly of the steel cages for two T-shaped walls in the steel cage processing plant;

[0057] S6: As Figure 3 As shown, the construction of the first-construction trench section is carried out first, and the steps are as follows:

[0058] S6.1: Prepare the mud slurry;

[0059] S6.2: Pour the prepared mud into the trench wall;

[0060] S6.3: Excavate the foundation trench for the first construction section and the area between the first construction section and the excavation boundary line 10 in the later construction section, and lower and install the processed steel cage into the foundation trench.

[0061] S7: As Figure 4 As shown, in the middle of the transverse partition wall, according to the survey lines, the joint assembly is lowered. This joint assembly consists of an H-beam and connecting mesh welded to the outer sides of the two flanges of the H-beam. The connecting mesh is made of transverse reinforcing bars 7 and longitudinal reinforcing bars welded in a crisscross pattern. During the lowering process, the planar deviation and verticality of the H-beam should be controlled. Simultaneously, collisions should be prevented between the transverse reinforcing bars 7 of the previously constructed trench section and the transverse reinforcing bars welded to the flanges of the H-beam, which could cause bending and deformation of the transverse reinforcing bars, making it impossible to lower them to the correct position. The lap length between the transverse reinforcing bars and the flanges of the H-beam is 5 times the diameter of the reinforcing bar, and it is welded on both sides.

[0062] S8: As Figure 5 As shown, a rectangular joint box 9 is lowered along one side of the I-beam (i.e. the other side of the first excavated section). At the same time, sandbags 11 are filled in the area on the side of the excavation boundary between the rectangular joint box and the subsequent excavation section (the side adjacent to the first excavated section) to prevent displacement and tilting of the I-beam and the rectangular joint box. The I-beam and the rectangular joint box are set vertically along the entire length, and the transverse length of the rectangular joint box is greater than 35 times the diameter of the transverse reinforcing bar.

[0063] S9: Pour concrete into the pre-construction trench section;

[0064] S10: After the concrete in the first construction section reaches the required strength, the construction of the second construction section 3 will proceed. The steps are as follows:

[0065] S10.1: Prepare the mud;

[0066] S10.2: Pour the prepared mud into the trench wall;

[0067] S10.3: Excavate the foundation trench for the subsequent construction section and remove the sandbags placed in the subsequent construction section;

[0068] S11: As Figure 5 , Figure 6 As shown, after the foundation trench passes inspection, the rectangular joint box is pulled out, and the steel cage of the subsequent construction section is installed and the concrete is poured, thus completing all construction procedures of the deep H-shaped underground anti-scour wall unit trench.

[0069] The present invention relates to a deep H-shaped underground erosion control wall and its construction process, which innovatively solves the construction problem of connecting transverse diaphragm wall joints. The H-beams and their welded transverse and longitudinal reinforcing bars serve as connectors for the first and second construction sections, achieving effective connection between the reinforcing bars and concrete of the two sections.

[0070] It should be noted that the elevation of the leveled site must meet the design requirements. If not, excavation or backfilling is required. The concrete strength grade of the guide wall should not be lower than C20, the thickness should not be less than 200mm, the burial depth should be 1.5m-2.0m, and its top surface should be 100mm above the existing ground level. The mud slurry level must be at least 1m above the groundwater level. The net clearance between the inner walls should be 40mm-60mm greater than the design thickness of the diaphragm wall.

[0071] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A large depth H-type underground anti-impact wall composed of a plurality of H-type unit grooves, characterized in that: The H-shaped unit groove comprises T-shaped walls, a steel reinforcement cage and a joint assembly, the T-shaped wall comprises a vertical longitudinal wall and a transverse wall vertically arranged in the upper half of the longitudinal wall, two T-shaped walls are arranged opposite to each other, the two transverse walls are connected into a transverse partition wall through the joint assembly, the T-shaped wall is integrally formed by pouring, and the steel reinforcement cage is arranged in the T-shaped wall; The steel reinforcement cage comprises bent horizontal steel reinforcements and longitudinal steel reinforcements, the bent horizontal steel reinforcements are uniformly distributed in the vertical direction, and each bent horizontal steel reinforcement is connected through the longitudinal steel reinforcements which are uniformly distributed in the vertical direction; the bent horizontal steel reinforcement comprises a front horizontal section, a bent section, a middle horizontal section, a rear horizontal section, a front vertical section and a rear vertical section, the rear horizontal section is vertically bent forward at the two ends of the rear vertical section, the front vertical section is vertically bent inward at the roots of the two front vertical sections, the middle horizontal section is vertically bent forward at the roots of the two front vertical sections, the bent section which is inclined inward is bent forward at the front ends of the two middle horizontal sections, and the front horizontal section is horizontally bent at the front ends of the two bent sections; The joint assembly comprises an I-beam and a connecting mesh, the connecting mesh is symmetrically welded at the outer ends of each flange plate of the I-beam, the connecting mesh is welded by the transversely and longitudinally staggered steel reinforcements, and the height of the I-beam is the same as the height of the transverse partition wall; the two front horizontal sections of the bent horizontal steel reinforcement are inserted between the two opposite connecting meshes, and the end heads of the two front horizontal sections of the bent horizontal steel reinforcement abut against the web plate of the I-beam.

2. The large-depth H-shaped underground anti-impact wall according to claim 1, characterized in that: The overlapping length of the transverse steel reinforcement on the connecting mesh and the flange plate of the I-beam is 5 times the diameter of the steel reinforcement.

3. A construction process of a large-depth H-shaped underground anti-scour wall, characterized in that: The construction process is used for realizing the large-depth H-shaped underground anti-scour wall, and comprises the following steps: S1: completing site clearing and leveling procedures in a construction area; S2: completing guide wall excavation, steel reinforcement binding, formwork erection, concrete pouring and curing procedures according to the design requirements and measurement and lofting of the underground anti-scour wall; S3: completing trencher equipment positioning, mud pool arrangement and steel reinforcement cage processing field arrangement in the construction area; S4: using the trencher to complete the excavation of a first construction groove section and an excavation division line between the first construction groove section and a second construction groove section in the construction area; S5: completing the lowering and installation of the steel reinforcement cage in the first construction groove section; S6: lowering and welding the I-beam with the connecting mesh at the position where the first construction groove section and the second construction groove section are connected; S7: lowering the rectangular joint box into the slot formed by the I-beam and the connecting mesh on one side of the second construction groove section, and filling sand bags in the rectangular joint box and the second construction groove section to prevent displacement and inclination of the I-beam and the rectangular joint box; S8: pouring concrete into the first construction groove section; S9: when the concrete in the first construction groove section reaches the process requirements, excavating the second construction groove section on the other side of the excavation division line, digging out the sand bags while excavating, taking out the rectangular joint box after the excavation is completed, and completing the lowering and installation of the steel reinforcement cage and the concrete pouring in the second construction groove section. When the concrete in the groove section to be constructed later reaches the process requirements, the forming construction of the large-depth H-shaped underground anti-scour wall unit groove is completed; S10: repeating steps S1-S9 to complete the construction of several H-shaped unit grooves, thereby completing the construction of the entire large-depth H-shaped underground anti-scour wall.

4. The construction process of a large-depth H-shaped underground anti-impact wall according to claim 3, characterized in that: The transverse length of the rectangular joint box is greater than 35 times the diameter of the steel bar.

Images