CN113585237B - Diaphragm wall joint and diaphragm wall construction method - Google Patents

Abstract

The application relates to a diaphragm wall joint and a diaphragm wall construction method, wherein the diaphragm wall joint is used for connecting two adjacent unit wall sections and comprises an isolation plate and a perforated plate; the partition plate is embedded between two adjacent unit wall sections, the perforated plates are fixedly connected with the partition plate, through holes are arranged at intervals on the perforated plates, and the perforated plates are embedded into the unit wall sections and enable the through holes to be located in the unit wall sections; the two sides of the isolation plate are fixedly connected with at least two perforated plates. The perforated plates and the unit walls on the two sides form a tight embedding and meshing effect, so that shearing force on vertical joints of the underground diaphragm wall can be borne, adjacent unit walls form a whole body to jointly bear vertical load of an upper structure, uneven settlement of the unit walls is coordinated, and meanwhile, because the two perforated plates increase a flow path required by water leakage, the local diaphragm wall joint also has better water stopping performance.

Description

Diaphragm wall joint and diaphragm wall construction method

Technical Field

The application relates to the field of capital construction engineering, in particular to a ground connection wall joint and a ground connection wall construction method.

Background

The underground diaphragm wall is used as an effective water-intercepting, seepage-proofing, load-bearing and water-retaining structure and is commonly used for supporting construction of engineering such as deep foundation pits, municipal pipe ditches, culverts, revetments, dry docks and the like.

In actual construction, affected by factors such as geological conditions, surrounding environment and foundation pit depth, the underground diaphragm wall usually adopts one or more joint forms to connect two adjacent unit wall sections with each other, thereby solving the problems of water leakage and connection integrity at the joint of the two unit wall sections.

The I-shaped steel joint for the underground continuous wall is a common joint form, but because the wing plate of the I-shaped steel joint is short, the I-shaped steel joint is only wrapped on the joints of the wall sections of the two side units, and the seepage-proofing performance is limited.

Disclosure of Invention

In order to improve the seepage-proofing performance and the overall stability of the underground diaphragm wall, the application provides a diaphragm wall joint and a diaphragm wall construction method.

In a first aspect, the present application provides a ground is wall joint, adopts following technical scheme:

a ground connection wall joint is used for connecting two adjacent unit wall sections and comprises an isolation plate and a perforated plate; the partition plate is embedded between two adjacent unit wall sections, the perforated plates are fixedly connected with the partition plate, through holes are arranged at intervals on the perforated plates, and the perforated plates are embedded into the unit wall sections and enable the through holes to be located in the unit wall sections;

the two sides of the isolation plate are fixedly connected with at least two perforated plates.

By adopting the technical scheme, the perforated plates and the wall bodies of the two side units form a tight embedding and meshing effect, so that the shearing force on the vertical joint of the underground diaphragm wall can be borne, the adjacent wall bodies form a whole body and bear the vertical load of the upper structure together, the uneven settlement of the wall bodies of the coordination units is realized, and meanwhile, the two perforated plates increase the flow path required by water leakage, so that the local diaphragm wall joint also has better water stopping performance.

Preferably, the perforated plate is perpendicular to the partition plate.

Preferably, the perforated plate comprises a connecting plate and a bite plate; the connecting plate is fixedly connected to the isolation plate; the occluding plate is positioned at one end of the connecting plate far away from the partition plate, and the through hole is formed in the occluding plate.

In a second aspect, the present application provides a diaphragm wall construction method, which adopts the following technical scheme:

a diaphragm wall construction method applies the diaphragm wall joint and comprises the following steps:

constructing a support pile and a guide wall, excavating a guide groove around the excavated earthwork, constructing a reinforcing pile on the ground of the side wall of the guide groove, installing and fixing the prefabricated guide wall into the guide groove, and tamping the soil on the surface layer;

forming a groove, injecting wall protection slurry into the guide groove, and extending the grab bucket into the guide groove to dig the groove to form a unit groove section;

hoisting a reinforcement cage and a joint box, welding a plurality of reinforcements to form the reinforcement cage, welding and fixing the reinforcement cage and the ground wall joint, hoisting the reinforcement cage into the unit groove section, and hoisting the joint box into the unit groove section;

underwater concrete pouring, wherein the concrete is poured into the unit groove sections to form unit wall sections after solidification;

and repeating the steps until the underground continuous wall is formed.

By adopting the technical scheme, when the groove is formed, the soil body at the groove wall is reinforced by the reinforcing piles, the movement of the soil body is limited, and the probability of the collapse of the groove section is reduced.

Preferably, the reinforcing pile is positioned on one side of the guide groove facing the earth to be excavated.

Preferably, the reinforcing piles are cement mixing piles.

Preferably, in the step of supporting pile and guiding wall construction, the method further comprises: and during water injection pre-stirring construction, drainage ditches are dug around the water injection pre-stirring construction, and water collecting wells are arranged.

Preferably, the guide wall opening is at least 100mm higher than the ground.

By adopting the technical scheme, the pollution or mud dilution in the guide groove formed by the guide wall by flushing garbage and rainwater is prevented.

Preferably, the opening width of the guide wall is larger than the width of the grab bucket.

Through adopting above-mentioned technical scheme, widen 50mm during the guide wall construction to in the follow-up work progress, the smooth business turn over of parts such as grab bucket, drill bit, steel reinforcement cage.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the perforated plates and the wall bodies of the units on the two sides form a tight embedding and meshing effect, so that shearing force on vertical joints of the underground continuous wall can be borne, adjacent wall bodies form a whole body to jointly bear vertical load of an upper structure, uneven settlement of the wall bodies of the coordinated units is realized, and meanwhile, as the two perforated plates increase a flow path required by water leakage, a local wall connecting joint also has better water stopping performance;

2. when the groove is formed, the soil body at the groove wall is reinforced by the reinforcing piles, the movement of the soil body is limited, and particularly, the probability of the collapse of the groove section is effectively reduced when silt soft soil and sand soil are in an interaction stratum.

Drawings

Fig. 1 is a schematic view of the construction of a diaphragm wall joint.

Fig. 2 is a schematic view showing the positions of guide grooves and reinforcing piles.

Description of reference numerals: 1. a separator plate; 2. a perforated plate; 21. a connecting plate; 22. a bite plate; 23. a through hole;

3. a guide groove; 4. reinforcing piles; 5. and (7) a guide wall.

Detailed Description

The present application is described in further detail below with reference to figures 1-2.

The embodiment of the application discloses ground is wall joint even for connect two adjacent unit wall sections

Referring to fig. 1, the ground wall joint includes an isolation plate 1 and a perforated plate 2; the partition plate 1 and the perforated plate 2 are both plates.

The isolation plate 1 is used for being embedded between two adjacent unit wall sections; both sides of the division board 1 are fixedly connected with at least two perforated plates 2. In this embodiment, two perforated plates 2 are welded to both sides of the partition plate 1.

The perforated plate 2 includes a connecting plate 21 and a bite plate 22 which are integrally formed. The connecting plate 21 is fixedly connected to the isolation plate 1 in a welding manner; the engagement plate 22 is located at one end of the connecting plate 21 away from the partition plate, and the engagement plate 22 is provided with through holes 23 at intervals, in this embodiment, the through holes 23 are square holes. In one embodiment, the perforated plate 2 is perpendicular to the partition plate 1; in another embodiment, the two perforated plates 2 on the same side of the partition 1 have a larger distance between the two engagement plates 22 than between the two connection plates 21.

When the diaphragm wall is constructed, concrete slurry is coated on one side of the partition plate 1 and covers the perforated plate 2, and then part of the concrete slurry is filled into the through hole 23. And forming a unit wall body after the concrete slurry is solidified, so that the perforated plate 2 is embedded into the unit wall section, and the through hole 23 is positioned in the unit wall section, thereby realizing the tight embedding and meshing of the perforated plate 2 and the unit wall body.

The implementation principle of the ground wall connector in the embodiment of the application is as follows: the perforated plates 2 and the unit walls on the two sides form a tight embedding and meshing effect, so that shearing force on vertical joints of the underground diaphragm wall can be borne, adjacent unit walls form a whole body to jointly bear vertical load of an upper structure, uneven settlement of the unit walls is coordinated, and meanwhile, because the two perforated plates 2 increase a flow path required by water leakage, the local diaphragm wall joint also has better water stopping performance.

The embodiment of the application also discloses a diaphragm wall construction method, which comprises the following steps:

s10 construction of a retaining pile and a guide wall 5, referring to fig. 2, excavating a guide groove 3 around the earth to be excavated, constructing a reinforcing pile 4 on the ground of the side wall of the guide groove 3, installing and fixing the prefabricated guide wall 5 in the guide groove 3, and tamping the soil on the surface layer.

Specifically, the field is leveled, 15cm of the periphery of the earth position to be excavated is placed outside to measure the underground wall axis control pile, and the control pile is a protection pile. And (4) leading the elevation into a field, and setting a level point in the field by adopting a closed-loop measuring method so as to control the elevation of the guide wall 5 and the underground continuous wall.

Based on the position of underground wall shaft control stake, excavate guide slot 3, then construction reinforcing pile 4. The reinforcing pile 4 is a cement mixing pile and is positioned on one side of the guide groove 3 facing the earthwork to be excavated; if necessary, reinforcing piles 4 may be constructed on both sides of the guide groove 3.

Meanwhile, the technical parameters of the cement mixing pile are as follows: the reinforcing agent is ordinary Portland cement with strength grade of 42.5 or above, the water cement ratio is controlled between 0.45 and 0.55, and the consumption of cement per meter is not lower than 75 kg. Meanwhile, the lifting speed of the guniting stirring in the sludge layer and the sludge fine sand layer is not more than 0.8m/min, and the construction interval time of the mutually overlapped stirring piles is not more than 24 h.

When the surface layer of the field is hard and needs to be pre-stirred by water injection, drainage ditches are dug around the field, and water collecting wells are arranged, and the positions of the drainage ditches and the water collecting wells cannot influence the construction of the stirring machine.

Moreover, the upper opening of the prefabricated guide wall 5 is at least 100mm higher than the ground, so that the garbage and rainwater are prevented from rushing into the guide groove 3 formed by the guide wall 5 to pollute or dilute slurry; the opening width of the guide wall 5 is larger than the width of the grab bucket (the width of the guide wall 5 is 50mm during construction), so that the grab bucket, a drill bit, a reinforcement cage and other parts can smoothly enter and exit in the subsequent construction process.

S20, preparing and constructing wall protection slurry; the slurry should be stored for 24h after being stirred, and can be used after the slurry material is fully hydrated.

S30 grooving, the wall protection slurry is injected into the guide groove 3, the grab bucket extends into the guide groove 3 to dig grooves, and a unit groove section is formed.

Specifically, the central surface of the grab bucket is matched with the central surface of the guide wall 5. The grooving is generally carried out at intervals, the standard groove section is subjected to three-step grooving, two sides are firstly dug, then the middle partition wall is dug, the length of the middle partition wall is smaller than the opening length of the grab bucket, the grab bucket can be stressed uniformly to cover the partition wall for digging, the grooving perpendicularity is ensured, and the perpendicularity deviation is avoided.

And (4) stopping excavating when the groove section is excavated to be 0.5 m away from the wall bottom, brushing the wall by using the joint, and requiring that the wall is brushed at the last time, wherein the wall brushing steel plate does not contain any soil residue and mud skin.

After the whole construction groove section is dug to the designed depth, the construction groove section is stopped for 1h, and then the sediment at the bottom of the construction groove section is cleaned by a method of grabbing and digging once when the construction groove section moves 1m along the length direction of the construction groove section at the designed depth.

And after wall brushing is finished, removing sediments at the bottom of the tank, strictly controlling the feed rule of each hopper to be about 15cm in the removing process, and removing the soil left at 0.5 m at the bottom of the tank, the sediments and the silt at the bottom of the tank from one end to the other end by adopting a slow grabbing and slow lifting method to ensure that the thickness of the deposited sediments is not more than 100 mm.

After the grooving is finished, the groove section is inspected by adopting a measuring hammer, a steel ruler, an ultrasonic wall measuring instrument and a slurry proportion instrument to detect the depth, the width and the plane position of the groove section, the verticality of the wall surface of the groove section, the sediment thickness and the slurry proportion of the groove bottom, and whether the quality of the groove section meets the design and standard requirements is ensured.

And during grooving, the slurry supply and treatment equipment meets the requirement of the use amount of the slurry, and the slurry surface is higher than the underground water level and is not more than 300mm away from the ground until concrete pouring in the subsequent step S50 is finished.

And when the hydraulic grab bucket is grooved to the rock surface, if the designed final hole elevation cannot be reached, carrying out rock entering treatment by adopting an impact pile machine. The concrete method is that a round hammer is used for forming a hole, and then a square hammer is used for trimming the hole into a groove.

S40 hoisting the reinforcement cage and the joint box, welding a plurality of reinforcements to form the reinforcement cage, welding and fixing the reinforcement cage and the ground wall joint, hoisting the reinforcement cage into the unit groove section, and hoisting the joint box into the unit groove section.

Specifically, two sets of reinforcement cage platforms are arranged on site, so that reinforcement cages can be manufactured on the reinforcement cage platforms; meanwhile, an instrument is used for leveling the steel reinforcement cage platform, and the flatness of the steel reinforcement cage platform is checked at any time, so that the precision of the steel reinforcement cage is guaranteed.

In the process of manufacturing the reinforcement cage, the connection of the reinforcements is welded, the interface rate of the same section is not more than 50 percent, and the welding is carried out by staggering 500 mm; the vertical rib joint welding must ensure that the two ribs are vertical and consistent and cannot be twisted and shifted. The thickness of the welding seam which is not noted is 6mm, and full welding is required to ensure the strength of the reinforcement cage.

Meanwhile, the ground connection wall joint is also formed by welding on site, the processed Q235B isolation plate 1 is paved on the ground, and is scribed and positioned according to the design size, and the position of the perforated plate 2 is determined so as to facilitate the subsequent processing. Fixing the perforated plates 2 at the preset white line, then fully welding the perforated plates and the two sides of the isolation plate 1 by adopting carbon dioxide arc welding, wherein the thickness of a welding line is 6mm, after welding the two perforated plates 2 on one side of the isolation plate 1, reversely and stably fixing the two perforated plates on the ground, and then welding the two perforated plates 2 behind by using the same method for welding the two front perforated plates.

The ground is connected wall joint and steel reinforcement cage's is connected mainly with the horizontal muscle welding to division board 1, adopts E50XX welding rod double-sided welding, and welding seam thickness is 6mm, and welding length satisfies 5d requirements.

Under the action of gravity, the joint box is vertically placed at the joint of the diaphragm wall, and the sand bags are filled at the back side of the joint box, so that the lateral pressure generated in the diaphragm wall pouring process is resisted.

S50, underwater concrete pouring, pouring the concrete into the unit groove sections, and forming unit wall sections after solidification.

The construction method mainly comprises the steps of groove cleaning, concrete mixing, equipment configuration, pouring and the like, and a lattice type ground diaphragm wall structure is constructed, wherein the cross section of the structure is in an I shape.

And after the groove cleaning is finished, the slurry is qualified through inspection, and the concrete is poured within 4 h. When concrete is poured, a group of concrete compression-resistant test blocks and a group of concrete anti-permeability test blocks are reserved in each unit groove section. And the impervious grade of the continuous wall is P6, the strength of the underground wall is C35, the slump is preferably 180-210mm, and the continuous wall is cast by using the conduit type underwater concrete, wherein the grade of the conduit type underwater concrete is improved by one grade compared with the design grade so as to ensure the requirements of strength and impervious performance. In order to meet the strength requirement, the mixing proportion is designed to be increased by at least 5 MPa.

Meanwhile, during the pouring operation, if the water leakage and blockage of the conduit or the mixing of slurry in the concrete are found, the pouring is immediately stopped and processed, and the record is made so as to ensure the strength requirement of the diaphragm wall.

S60 pushing and pulling the joint box; and after the concrete is solidified, pulling the joint box.

S70 repeating the above steps S20-60 until the underground continuous wall is formed.

The implementation principle of the diaphragm wall construction method in the embodiment of the application is as follows: when the groove is formed, soil at the groove wall is reinforced by the reinforcing piles 4, the movement of the soil is limited, and the probability of the collapse of the groove section is reduced; after the diaphragm wall construction is completed, the diaphragm wall joint is matched, so that the adjacent unit wall bodies form a whole body to jointly bear the vertical load of the upper structure, the uneven settlement of the unit wall bodies is coordinated, and meanwhile, because the two perforated plates 2 increase the flow path required by water leakage, the diaphragm wall joint also has better water stopping performance.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: equivalent changes in structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims (1)

1. The utility model provides a ground is wall joint even for connect two adjacent unit wall sections, its characterized in that: comprises an isolation plate (1) and a perforated plate (2); the partition plate (1) is embedded between two adjacent unit wall sections, the perforated plate (2) is fixedly connected with the partition plate (1), through holes (23) are formed in the perforated plate (2) at intervals, the perforated plate (2) is embedded into the unit wall sections, and the through holes (23) are located in the unit wall sections;

two perforated plates (2) are fixedly connected to two surfaces of the isolation plate (1);

the perforated plate (2) comprises a connecting plate (21) and a bite plate (22); the connecting plate (21) is fixedly connected to the isolation plate (1); the occlusion plate (22) is positioned at one end of the connecting plate (21) far away from the isolation plate (1), and the through hole (23) is formed in the occlusion plate (22);

in the two perforated plates (2) positioned on the same side of the isolation plate (1), the distance between the two occlusion plates (22) is larger than the distance between the two connecting plates (21);

the partition plate (1) is used for welding and connecting horizontal bars of the reinforcement cage.

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