Construction process and application of plastic concrete diaphragm wall joint treatment

Abstract

The application belongs to the field of hydraulic engineering, and particularly relates to a plastic concrete cutoff wall body joint processing construction process and application. In the cutoff wall joint of a construction section I and a construction section II of a cutoff wall which has been poured and formed, plastic concrete is poured after mechanical secondary hole forming; compared with the existing construction technology, the method of pouring plastic concrete after hole forming can eliminate the construction interface (connecting joint) and mud at the original construction joint, and the adjacent two wall bodies are connected into a whole through the poured plastic concrete; meanwhile, the function of crack self-healing and migration and penetration of the permeable crystalline material in the plastic concrete can effectively repair the new construction interface (connecting joint) formed between the poured plastic concrete and the adjacent two wall bodies, and the technical bottleneck that the wall body joint of the cutoff wall is easy to leak is broken through.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic engineering, in particular to a plastic concrete cutoff wall body joint processing construction process and application. BACKGROUND

[0002] The core of earth-rockfill dam is the anti-seepage body, and many dam disasters are mostly caused by the damage or failure of the anti-seepage body, resulting in disastrous consequences. Therefore, it is of great significance to improve the safety of the dam anti-seepage body. In the earth-rockfill dam reinforcement project, more than 80% of the plastic concrete cutoff walls are used. The connection between the wall segments of the cutoff wall is usually two-stage construction, and the connection between the wall segments of the cutoff wall is the weak link of the plastic concrete cutoff wall. The wall segment joints are not connected, and a large amount of mud is stored, which is easy to appear joints, directly affecting the overall anti-seepage capacity of the cutoff wall. At present, the existing technologies for processing wall segment connections mainly include drilling, joint pipe, double reverse-arc joint, milling joint and other flat joint methods and sleeve joint methods. Influenced by construction factors and mechanical equipment, the above measures have construction interfaces and mud at the wall segment joint, which becomes the source of leakage at the wall segment joint. Therefore, how to eliminate the construction interface and the stored mud at the wall segment joint and connect the adjacent two wall bodies into a whole is the key to solving the leakage at the wall segment joint. SUMMARY

[0003] The purpose of the present application is to provide a plastic concrete cutoff wall body joint processing construction process and application to solve the problems existing in the prior art.

[0004] To achieve the above-mentioned purpose, the present application provides the following scheme: the present application provides a plastic concrete cutoff wall body joint processing construction process, which comprises the following steps:

[0005] Building plastic concrete cutoff wall of dam: according to the construction requirements, the cutoff wall of construction section I and the cutoff wall of construction section II are built in turn;

[0006] Hole opening: when the cutoff wall of the construction section II is completed, the cutoff wall of the construction section II has a wall strength greater than 70% of the design strength, and the hole opening is performed at the joint of the cutoff wall of the construction section I and the cutoff wall of the construction section II, respectively. The hole diameter of the hole opening is not greater than the wall thickness of the cutoff wall;

[0007] Pouring plastic concrete: when the hole opening reaches the standard, the mixed plastic concrete is poured, and the plastic concrete includes rubber aggregate and permeable crystalline material.

[0008] Preferably, in the hole opening process, the hole opening is performed along the wall axis of the cutoff wall of the construction section I and the cutoff wall of the construction section II from the center of the joint of the cutoff wall of the construction section I and the cutoff wall of the construction section II to both sides.

[0009] Preferably, the number of the holes is n, and n is greater than or equal to 1.

[0010] Preferably, the rubber aggregate comprises rubber particles, and the content of the rubber particles is 10-30 kg / m 3 .

[0011] Preferably, the plastic concrete further comprises cementitious material, and the cementitious material is composed of cement, fly ash, clay and bentonite.

[0012] Preferably, the content of the permeable crystalline material is 1-2% of the content of the cementitious material.

[0013] To achieve the above object, the application further provides the following scheme: the application further provides an application of a plastic concrete cutoff wall wall joint processing construction process. The joint between a construction section I and a construction section II of a cutoff wall which has been poured and formed is reinforced and processed by using the plastic concrete cutoff wall wall joint processing construction process, the construction interface (connecting joint) and mud at the original construction joint are eliminated, and the cutoff wall of the adjacent construction section I and the cutoff wall of the construction section II are connected into an integral whole by the poured plastic concrete.

[0014] The application has the following technical effects: compared with the existing construction technology, the method of pouring plastic concrete after hole forming can eliminate the construction interface (connecting joint) and mud at the original construction joint, and the adjacent two walls are connected into an integral whole by the poured plastic concrete; meanwhile, the function of crack self-healing and migration and permeation of the permeable crystalline material in the plastic concrete can effectively repair the new construction interface (connecting joint) formed between the poured plastic concrete and the adjacent two walls, the technical bottleneck that the connecting joint of the cutoff wall is prone to leakage is broken, the construction process disclosed by the application is convenient and fast, the cost can be saved, the safety is improved, the wall at the joint is reinforced, the entire cutoff wall becomes a complete whole, and the overall strength is improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can be obtained from these drawings without creative labor.

[0016] Figure 1 The figure is a construction process of the application;

[0017] Figure 2 The figure is a schematic diagram of the interface structure of the plastic concrete in the prior art;

[0018] Figure 3 SEM of the interface structure of the concrete mixed with the penetration crystalline material in the application;

[0019] Figure 4 Pore structure curve of the existing concrete;

[0020] Figure 5 Pore structure curve of the concrete mixed with the penetration crystalline material in the application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the application will be apparently and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all the other embodiments obtained by a person of ordinary skill in the art without any creative work fall within the protection scope of the application.

[0022] In order to make the above objectives, characteristics and advantages of the application more apparent, comprehensible and easier to understand, the application will be further described in detail below with reference to the drawings and specific embodiments.

[0023] With reference to Figure 1 The application provides a plastic concrete cutoff wall body joint processing construction process, which comprises the following steps:

[0024] The plastic concrete cutoff wall is built according to the construction requirements, i.e., the requirements of the actual construction site, and relevant machinery is used to sequentially build the cutoff wall of construction section I and the cutoff wall of construction section II. After the cutoff wall of construction section II is built and its strength reaches the requirements, the next process can be performed.

[0025] Hole opening: when the cutoff wall of construction section II is completed and the cutoff wall of construction section II has a wall strength greater than 70% of the design strength, holes are respectively opened at the joint of the cutoff wall of construction section I and the cutoff wall of construction section II, and the hole diameter of the holes is not greater than the wall thickness of the cutoff wall.

[0026] Pouring Plastic Concrete: When the borehole reaches the standard, the mixed plastic concrete, which includes rubber aggregate and penetrating crystallizing material, is poured in. Mechanical methods are used to perform secondary borehole drilling on the cutoff wall that has reached a certain strength. After the borehole meets the standard, the plastic concrete mixed according to the specified ratio is poured in. The use of penetrating crystallizing material serves a waterproofing function and repairs cracks. This allows the newly poured plastic concrete to repair the joint between the cutoff wall in construction section I and construction section II, preventing the formation of a construction interface. Furthermore, the addition of rubber aggregate avoids stress concentration between the newly poured concrete and the wall concrete, effectively fusing the newly poured plastic concrete with the cutoff wall in construction sections I and II into a unified structure, ensuring the integrity of the entire cutoff wall.

[0027] To further optimize the scheme, in the process of opening the holes, starting from the center of the joint between the seepage barrier wall of construction section I and the seepage barrier wall of construction section II, holes are opened to both sides along the wall axis of the seepage barrier wall of construction section I and the seepage barrier wall of construction section II, respectively.

[0028] Furthermore, the number of openings is n, and n≧1.

[0029] like Figure 1 As shown, specifically, the seepage barrier walls in construction section I and construction section II are ordinary rubber-coated concrete; while the areas where plastic concrete is poured after drilling are made are made of infiltrated crystalline rubber-coated concrete; when the strength requirements of the seepage barrier walls in construction section I and construction section II meet the specified technical parameters, bored piles are mechanically drilled at their joints, and the pile diameter is not greater than the wall thickness. In order to improve the seepage prevention effect of the project, holes are drilled from the joint along the axis to both sides; furthermore, the number of holes is determined according to the construction site, but at least one.

[0030] In a further optimized version, the rubber aggregate includes rubber particles, and the dosage of the rubber particles is 10-30 kg / m³. 3 .

[0031] Furthermore, the plastic concrete also includes a cementitious material, which is composed of cement, fly ash, clay, and bentonite, wherein the mass ratio of cement:bentonite:clay is 25%-40%:3%-15%:40%-57%.

[0032] like Figures 2-5 As shown, specifically, such as Figure 2 and Figure 3 As shown; the number of minor pores in concrete increases, while the number of harmful and multiple pores decreases, and the most probable pore diameter decreases, such as... Figure 4 and Figure 5 By comparing the curves of the two concrete hole structures, it can be seen that... Figure 5The anti-permeability of the concrete mixed with the permeable crystalline material is improved. Compared with the same type of permeable crystalline waterproof material abroad, the crack healing width and the penetration depth are large, the crack healing width of the concrete is less than 1.0 mm, while the crack healing width abroad is less than 0.4 mm; the penetration depth is up to 120 mm, while the penetration depth abroad is 80 mm; and the applicable conditions are not limited to the humid environment, and the material can be applied in the environment with the relative humidity greater than 65%.

[0033] The application also provides a plastic concrete cutoff wall wall joint processing construction process.

[0034] Further, the material composition of the perfusion plastic concrete is optimized and designed, the optimal mixing amount of the rubber aggregate and the permeable crystalline material is determined, and technical support is provided for actual engineering application. By using the rubber aggregate and the permeable crystalline material composite technology, the mixing amount of the rubber aggregate and the permeable crystalline material is synergistically controlled, the mixing amount of the rubber aggregate is 30 kg / m 3 , the mixing amount of the permeable crystalline material is 4-6 kg / m 3 , the permeability coefficient of the perfusion plastic concrete is 0.26*10 -7 cm / s-0.12*10 -7 cm / s, the elastic modulus is 480 MPa-520 MPa, and the compressive strength is 4.4 MPa-4.7 MPa, as shown in Table 1. The material composition provides guarantee for repairing the new construction interface formed between the perfusion plastic concrete and the adjacent two wall bodies, and the strength and the elastic modulus of the material are basically consistent with those of the adjacent two wall bodies, so that stress concentration is avoided, and the overall durability and the anti-permeability of the cutoff wall are improved.

[0035] Table 1 Influence of the permeable crystalline material on the performance of the plastic rubber concrete

[0036]

[0037]

[0038] As can be directly seen from the mixing amount of the permeable crystalline material in Table 1, when the plastic concrete is not mixed with the permeable crystalline material, the permeability coefficient is high, that is, the anti-permeability of the cutoff wall formed is low, and with the continuous addition of the permeable crystalline material and the continuous increase of the mixing amount, the permeability coefficient gradually decreases, which shows that the plastic concrete mixed with the permeable crystalline material has better anti-permeability and can more effectively prevent the leakage at the joint.

[0039] Furthermore, through the collection of multiple actual engineering detection data, and engineering verification shows that, by using the construction method of secondary hole forming and pouring concrete, the permeability coefficient of the wall body connecting part, i.e. the joint part, is 0.32*10 -7 cm / s-0.49*10 -7 cm / s, which is the average interval of multiple actual engineering detection data, and is basically consistent with the wall body permeability coefficient of other cutoff walls. From the actual engineering, it can be seen that the construction process of the present application using the construction process of secondary hole forming and pouring concrete can be practically applied, and at the same time, the original construction connecting part existing construction interface (connecting joint) and mud can be eliminated, and the adjacent two wall bodies are connected as a whole by pouring plastic concrete; at the same time, by using the functions of crack self-healing and migration of the permeable crystalline material in the plastic concrete, the new construction interface (connecting joint) formed between the poured plastic concrete and the adjacent two wall bodies can be effectively repaired, and the effect is relatively significant, which breaks through the technical bottleneck that the wall body connecting part of the cutoff wall is easy to leak.

[0040] Example one

[0041] A certain reservoir earth dam seepage reinforcement adopts a plastic concrete cutoff wall scheme, the cutoff wall has a total length of 345.6m, and the starting stake number is X0+000 (B0+263). The cutoff wall top elevation is 338.65m, and the bottom part is required to be deep into the bedrock by not less than 1.0m. The cutoff wall allows the seepage slope to be taken as 60, the deepest cutoff wall is 54.15m, and the wall thickness is 60cm. The wall body is 50# plastic concrete, and the compressive strength is:

[0042] R28d≥3Mpa; the elastic modulus: E28d=500-1000Mpa; the permeability coefficient: ≤1*10

[0043] 10 -7 cm / s.

[0044] The concrete cutoff wall construction includes the main procedures of building construction platform and guide wall, mud preparation, slot making, hole cleaning and concrete pouring. The slot length is 7.2m, and is constructed in two periods. The hydraulic grab bucket is used to make the slot three times, after the slot is made, the mud is protected, and the concrete is poured. After the wall body of the first and second period slot sections, i.e. the cutoff wall of construction section I and the cutoff wall of construction section II are constructed, the center position of the wall section connecting part, i.e. the joint part of the cutoff wall of construction section I and the cutoff wall of construction section II is drilled to form a hole with a diameter of 40cm and a depth of 1.0m into the rock. After the hole is formed, the plastic concrete is poured. The material consumption of 1 cubic meter of concrete is about 2000kg, and the weight ratio of each component in the plastic concrete is cement: clay: bentonite: sand: crushed stone: permeable crystalline material: rubber particles: water=4.82%:7.72%:1.93%:34.60%:36.90%:0.09%:0.94%:13.00%.

[0045] Example Two

[0046] A plastic concrete cutoff wall reinforcement scheme was adopted to reinforce a reservoir dam. The cutoff wall is 614.7 m long. The cutoff wall top elevation is 314.06 m, and the cutoff wall bottom is required to be at least 1.0 m deep into the bedrock. The cutoff wall is 60 cm thick and has a maximum depth of 60.31 m. The cutoff wall is made of 50# plastic concrete with a compressive strength of R28d≥3 Mpa, an elastic modulus of E28d≤1000 Mpa, and a permeability coefficient of ≤1×10 - 7 cm / s.

[0047] The concrete cutoff wall construction includes the construction of a construction platform and a guide wall, mud preparation, trenching, hole cleaning, and concrete pouring. The trench is 8.4 m long and is constructed in two stages. The trench is constructed by using a hydraulic grab bucket three times to dig a hole. After the trench is dug, mud is used to protect the wall, and the center of the hole is poured with concrete. After the first and second stage trench sections are constructed into walls, the cutoff wall of construction section I and the cutoff wall of construction section II are completed. A drill is used to drill holes into the first and second stage walls from the center of the connection between the walls, i.e., the joint between the cutoff wall of construction section I and the cutoff wall of construction section II. The holes are connected along the wall axis, and the outer diameter of one hole passes through the center of the other hole. There are three holes, each with a diameter of 30 cm and a depth of 1.0 m into the rock. After the holes are drilled, plastic concrete is poured. The weight ratio of the components in the plastic concrete is cement: clay: bentonite: sand: crushed stone: permeable crystalline material: rubber particles: water = 5.63%: 6.56%: 2.35%: 34.57%: 36.82%: 0.16%: 1.41%: 12.50%.

[0048] Engineering applications show that, compared with existing construction techniques, the method of pouring plastic concrete after hole drilling eliminates the construction interface (joint) and mud at the original construction joint, and the adjacent two walls are connected as a whole by the poured plastic concrete. At the same time, the function of crack self-healing and migration of permeable crystalline material in the plastic concrete can effectively repair the new construction interface (joint) formed between the poured plastic concrete and the adjacent two walls, breaking through the technical bottleneck of easy leakage at the cutoff wall joint.

[0049] By using the rubber aggregate and permeable crystalline material composite technology and by synergistically controlling the amount of rubber aggregate and permeable crystalline material, the permeability coefficient of the poured plastic concrete is 0.26×10 -7 cm / s-0.12×10 -7cm / s, the elastic modulus is 480 MPa-520 MPa, and the compressive strength is 4.4 MPa-4.7 MPa. The material composition provides guarantee for realizing plastic concrete repair perfusion and forming a new construction interface between the adjacent two walls, and the strength and elastic modulus of the material composition are basically consistent with those of the adjacent two walls, so that stress concentration is avoided, and the overall durability and impermeability of the cutoff wall are improved.

[0050] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0051] The above-described embodiments are only descriptions of the preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A construction process for the treatment of wall joints of a diaphragm wall made of plastic concrete, characterized in that: The method comprises the following steps: Building the impervious wall: according to the construction requirements, the impervious wall of the construction section I and the impervious wall of the construction section II are built in sequence; Hole opening: when the impervious wall of the construction section II is completed, the impervious wall of the construction section II has a wall strength greater than 70% of the design strength, and holes are opened at the joint of the impervious wall of the construction section I and the impervious wall of the construction section II, the diameter of the hole is not greater than the wall thickness of the impervious wall; Pouring plastic concrete: when the hole opening reaches the standard, the mixed plastic concrete is poured, the plastic concrete includes rubber aggregate and permeable crystalline material; The rubber aggregate is rubber particles, and the content of the rubber particles is 30 kg / m 3 ; The plastic concrete further includes cementing material, the cementing material is composed of cement, fly ash, clay and bentonite, wherein The mass ratio of cement, bentonite and clay is 25%-40%, 3%-15% and 40%-57% respectively; The content of the osmotic crystallization material is 4-6 kg / m 3 The permeability coefficient of the perfusion plastic concrete is 0.26*10 -7 cm / s-0.12*10 -7 cm / s, the elastic modulus is 480 MPa-520 MPa, and the compressive strength is 4.4 MPa-4.7 MPa.

2. The diaphragm wall joint treatment construction process of plastic concrete according to claim 1, characterized in that: In the hole opening process, the holes are opened along the wall axis of the impervious wall of the construction section I and the impervious wall of the construction section II from the center of the joint of the impervious wall of the construction section I and the impervious wall of the construction section II to both sides.

3. The diaphragm wall joint treatment construction process according to claim 1 or 2, characterized in that: The number of holes is n, and n≧1.

4. Application of a construction technology for processing of a wall joint of a diaphragm wall made of plastic concrete, characterized in that: The construction process of the plastic concrete impervious wall joint treatment of any one of claims 1-3 is used to reinforce the joint of the construction section I and the construction section II of the poured and shaped impervious wall, which can eliminate the construction interface and mud at the original construction joint, and the wall of the adjacent impervious wall of the construction section I and the impervious wall of the construction section II is connected into a whole by pouring plastic concrete.

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