Z-shaped diaphragm wall construction method

Abstract

The invention relates to a Z-shaped diaphragm wall construction method which comprises the following steps: providing a trenching machine, and digging a Z-shaped groove on a construction surface through the trenching machine; a crane, a first L-shaped reinforcement cage and a second L-shaped reinforcement cage are provided, a butt joint end is formed at the end of the first L-shaped reinforcement cage, a notch is formed in the position, corresponding to the butt joint end, of the end of the second L-shaped reinforcement cage, and the first L-shaped reinforcement cage and the second L-shaped reinforcement cage are hung into the Z-shaped groove through the crane; the crane is adjusted, so that the butt joint end is clamped in the notch; concrete is poured into the Z-shaped groove to form the underground diaphragm wall, the structure is simple, and operation is convenient.

Description

Technical Field

[0001] The invention relates to the technical field of construction robots, in particular to a Z-type ground-connected wall construction method. Background Art

[0002] The supporting structure of the subway station foundation pit usually adopts the form of ground-connected wall + internal support. The "Z"-shaped ground-connected wall is a special-shaped structure with high construction quality and safety risks. The following problems are often prone to occur during construction: 1) Since the lifting points of the "Z"-shaped steel cage are not in the same plane, it will flip over after lifting, causing damage to the side "knock" and collision, which has a high safety risk of lifting. Moreover, after lifting, the lifting points and flange positions of the steel cage are subject to great force and are prone to deformation or even disintegration. 2) Since the "Z"-shaped ground-connected wall has three bent edges, if the slot of the ground-connected wall has verticality or cross-sectional size deviations, it may cause the steel cage to scratch the slot wall when it is put into the slot, the steel cage to get stuck in the slot, and it may be difficult or impossible to enter the slot, which will eventually lead to excessive sediment at the bottom of the ground-connected wall or water leakage. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and provide a Z-shaped ground-connected wall construction method, by configuring the Z-shaped steel cage into a first L-shaped steel cage and a second L-shaped steel cage, lifting the first L-shaped steel cage and the second L-shaped steel cage into a Z-shaped groove and splicing them, so as to avoid the problem of inconvenience in lifting caused by the Z-shaped ground-connected wall being an irregular structure.

[0004] The technical solution to achieve the above purpose is a Z-type ground-connected wall construction method, comprising the following steps:

[0005] Providing a slotting machine, and digging a Z-shaped slot on the construction surface by the slotting machine;

[0006] A crane, a first L-shaped steel cage and a second L-shaped steel cage are provided, wherein a butt end is formed at the end of the first L-shaped steel cage, and a notch is formed at the end of the second L-shaped steel cage corresponding to the butt end, the first L-shaped steel cage and the second L-shaped steel cage are hoisted into the Z-shaped groove by the crane, and the crane is adjusted so that the butt end is clamped in the notch;

[0007] Concrete is poured into the Z-shaped groove to form a ground-connected wall.

[0008] Furthermore, the Z-shaped groove includes two parallel sections parallel to each other and a connecting section connecting the two parallel sections;

[0009] When digging the Z-shaped groove, the parallel section is dug by the groove forming machine, and after the parallel section is dug, the connecting section is dug.

[0010] Furthermore, after the excavation of the Z-shaped groove is completed, the bottom of the Z-shaped groove is cleaned.

[0011] Furthermore, a first joint is welded at the end of the first L-shaped steel cage, and the butt end is formed on the first joint.

[0012] Furthermore, a second joint is welded at the end of the second L-shaped steel cage, and the notch is formed on the second joint.

[0013] Furthermore, when the first L-shaped steel cage is suspended, a first lifting lug is welded on the first L-shaped steel cage, and the lifting joint is connected to the first lifting lug to suspend the first L-shaped steel cage into the Z-shaped groove.

[0014] Furthermore, when the second L-shaped steel cage is suspended, a second lifting lug is welded on the second L-shaped steel cage, and the lifting joint is connected to the second lifting lug to suspend the second L-shaped steel cage into the Z-shaped groove.

[0015] Furthermore, after the excavation of the Z-shaped groove is completed, an ultrasonic wall measuring instrument is provided to scan and record the protrusion or recess of the inner wall of the Z-shaped groove.

[0016] Furthermore, the heights of the first L-shaped steel cage and the second L-shaped steel cage are adapted to the depth of the Z-shaped groove.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] By configuring the Z-shaped steel cage into a first L-shaped steel cage and a second L-shaped steel cage, the first L-shaped steel cage and the second L-shaped steel cage are hoisted into the Z-shaped groove and spliced, so as to avoid the problem of inconvenience in hoisting due to the Z-shaped ground connection wall being an irregular structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The overall structural diagram of the steel cage of a Z-type ground-connected wall construction method.

[0020] Figure 2 The invention relates to a Z-shaped ground-connected wall construction method, and the excavation construction steps of the Z-shaped groove section are provided. Figure 1 .

[0021] Figure 3 The invention relates to a Z-shaped ground-connected wall construction method, and the excavation construction steps of the Z-shaped groove section are provided. Figure 2 .

[0022] Figure 4 The invention relates to a Z-shaped ground-connected wall construction method, and the excavation construction steps of the Z-shaped groove section are provided. Figure 3 .

[0023] Legend: 1. The first L-shaped steel cage; 2. The second L-shaped steel cage; 3. Grooving machine; 4. Z-shaped groove. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0025] See also Figure 1 A Z-shaped ground-connected wall construction method comprises the following steps: providing a grooving machine 3, digging a Z-shaped groove 4 on a construction surface by the grooving machine 3; providing a crane, a first L-shaped steel cage 1 and a second L-shaped steel cage 2, wherein the end of the first L-shaped steel cage 1 is formed with a butt end, and the end of the second L-shaped steel cage 2 is formed with a notch corresponding to the butt end, the first L-shaped steel cage 1 and the second L-shaped steel cage 2 are hoisted into the Z-shaped groove 4 by the crane, and the crane is adjusted so that the butt end is clamped in the notch; concrete is poured into the Z-shaped groove 4 to form a ground-connected wall.

[0026] In the present invention, a preferred implementation method is: the underground continuous wall trenching machine 3 adopts the SG46 trenching machine 3, and the underground continuous wall trench section construction adopts the skip excavation construction method (that is, the trench section is skipped every other trench section). When the excavated trench section length cannot meet the minimum excavation length of the grab bucket, it can be considered to extend a certain length or modify the section length according to the on-site conditions to meet the trenching requirements; after the Z-shaped trench 4 is excavated, the pre-assembled first L-shaped steel cage 1 and the second L-shaped steel cage 2 are hoisted into the Z-shaped trench 4, and the first L-shaped steel cage 1 and the second L-shaped steel cage 2 are hoisted and placed by double machines, straightened in the air, and then placed in the trench by the main crane to ensure the stability of the hoisting. After the cage is hoisted into the Z-shaped groove 4, when hoisting another steel cage, the position of the steel cage can be adjusted in the air, so that after the other steel cage is placed in the Z-shaped groove 4, the butt joint section and the groove are spliced. After the hoisting is completed, the first L-shaped steel cage 1 and the second L-shaped steel cage 2 are fine-tuned by the crane; after the steel cage is placed, concrete is poured, and the concrete pouring adopts the method of self-unloading concrete material and lifting the conduit by the concrete hopper; during the pouring process, the conduit should always be buried in the concrete for 2 to 6 meters, and the minimum burial depth shall not be less than 1.5 meters. Concrete pouring should be carried out continuously, and the concrete surface rising speed shall not be less than 3 to 5 meters / hour, and the longest allowed interval time is 20 to 30 minutes. During the pouring process, the concrete surface rising height is measured every 30 minutes to ensure accurate and timely pipe pulling.

[0027] Furthermore, the lengths of the three sections of the "Z"-shaped ground-connected wall Q14 are adjusted to 2.6m, 2.15m, and 3.2m respectively, and the special-shaped Z-shaped steel cage is decomposed into two "L"-shaped ground-connected walls. Preferably, the docking interface of the first L-shaped steel cage 1 is set to 45°, which is combined with the "V"-shaped mutually interlocking groove interface of the second L-shaped steel cage 2. After the ground-connected wall is grooved, the two steel cages are hoisted into the groove in batches and installed in place, which can effectively avoid deformation or disintegration of the steel cage during hoisting, and problems such as the steel cage getting stuck in the groove, difficulty in entering the groove, or inability to enter the groove. At the same time, the modified "Z"-shaped ground-connected wall can arbitrarily adjust the construction sequence with the adjacent ground-connected wall, which improves the flexibility of the construction organization. After the steel cage is lowered, concrete is poured, and the construction safety and quality are effectively improved.

[0028] Furthermore, after the four sections of the Z-shaped trough are formed, the steel cage needs to be lowered and concrete poured as soon as possible to avoid trough collapse due to prolonged time.

[0029] Furthermore, during the excavation of the Z-shaped trench 4, in order to ensure the safety of the trenching process, the mud density can be appropriately increased to ensure the stability of the trench section. When the trench section is excavated, the special-shaped ground connection wall is prone to collapse during the trenching process because its positive corner soil is vacant on both sides. The trench section should not be too long, and the construction should be completed quickly. Heavy machinery and equipment should not be allowed to operate close to it.

[0030] Furthermore, when excavating the Z-shaped groove 4, the excavation is expanded by 400mm, both ends of the first excavation are expanded by 400mm, and the newly excavated end of the connecting width is expanded by another 400mm. After the steel cage is lowered, sandbags are filled in the 400mm over-excavation range as a measure to prevent concrete bypass.

[0031] Furthermore, the Z-shaped groove 4 includes two parallel sections parallel to each other and a connecting section connecting the two parallel sections;

[0032] When the Z-shaped groove 4 is excavated, the parallel section is excavated by the groove forming machine 3, and after the parallel section is excavated, the connecting section is excavated.

[0033] Furthermore, when excavating the parallel section of the Z-shaped groove 4, the excavation is expanded by 400mm, both ends of the first excavation are expanded by 400mm, and the newly excavated end of the connecting section is expanded by another 400mm. After the steel cage is lowered, sandbags are filled in the 400mm over-excavation range as a measure to prevent concrete bypass.

[0034] Further, after the excavation of the Z-shaped trough 4 is completed, the bottom of the Z-shaped trough 4 is cleaned. Preferably, after the Z-shaped trough 4 is accepted, the trough is cleaned and the slurry is replaced in time, and the air suction mud method is used for reverse circulation cleaning. The suction mud pipe adopts a Φ125 steel pipe, and the mud sand is sucked out by the suction mud device that presses compressed air into the bottom of the trough. At the same time, fresh mud is continuously transported into the trough section to replace the mud with slag. The suction mud pipe should be continuously moved to ensure that the thickness of the sediment at the bottom of the Z-shaped trough 4 meets the requirements after cleaning.

[0035] Furthermore, after the excavation of the Z-shaped groove 4 is completed, a wall brush is provided, and the inner wall of the Z-shaped groove 4 is brushed by the wall brush. Preferably, in order to improve the anti-seepage and shear resistance of the joint of the Z-shaped groove 4, the joint of the underground continuous wall is brushed up and down (more than 10 times) with a joint box close to the ground wall I-beam. When brushing the wall, the mud on the wall brush must be cleaned after each wall brush is lifted up, and then the brushing is continued until there is no mud on the wall brush as the termination standard, and then the hole is swept, and the grab bucket is kept away from the ground wall joint by about 50cm when sweeping the hole.

[0036] Furthermore, a first joint is welded at the end of the first L-shaped steel cage 1, and the butt end is formed on the first joint.

[0037] Furthermore, the first L-shaped steel cage 1 is hoisted as a whole at one time according to a unit slot section and is manufactured on site. The length of the processing platform is 300mm shorter than the length of the steel cage at each end, and the width is 150mm wider than the width of the steel cage on each side. On the flat and hardened ground, No. 12 I-beams are evenly laid at a spacing of 2.0m in the length direction of the steel cage. Both ends of the I-beams are connected into a whole with a full-length Φ18 steel bar at the top and bottom, and the height difference of the top surface of the I-beam is less than 20mm. Before production, the position of the bottom distribution reinforcement is pre-painted on the top of the I-beam with red paint, and then the bottom steel mesh is laid. After all the steel bars are spot welded, the frame reinforcement is set, and then the upper steel mesh is laid. The first L-shaped steel cage 1 is made by a construction method of welding the entire section on the production platform. The steel bars of the first L-shaped steel cage 1 are processed and bent in the steel shed. The main reinforcement joints are preferably welded. The steel bar protective layer is welded to the main reinforcement with a 5mm thick steel plate and is formed at one time on the production table. When processing the first L-shaped steel cage 1, the first joint is welded to the steel cage as a whole. The first joint is an "I"-shaped steel plate. The "I"-shaped steel plate joint and the first L-shaped steel cage 1 are hoisted into the slot section together. Iron sheets should be welded between the first L-shaped steel cage 1 and the I-beam to prevent concrete from bypassing. The first joint is formed with a butt end, which is a 45-degree triangle.

[0038] Furthermore, a second joint is welded at the end of the second L-shaped steel cage 2, and the notch is formed on the second joint.

[0039] Furthermore, the second L-shaped steel cage 2 is manufactured on site as a unit slot section and hoisted as a whole at one time. The length of the processing platform is 300mm shorter than the length of the steel cage at each end, and the width is 150mm wider than the width of the steel cage on each side. On the flat hardened ground, No. 12 I-beams are evenly laid at a spacing of 2.0m in the length direction of the steel cage. The two ends of the I-beams are connected into a whole with a full-length Φ18 steel bar at the top and bottom, and the height difference of the top surface of the I-beam is less than 20mm. Before production, the position of the bottom distribution reinforcement is pre-painted on the top of the I-beam with red paint, and then the bottom steel mesh is laid. After all the steel bars are spot-welded, the frame reinforcement is set, and then the upper steel mesh is laid. The second L-shaped steel cage 2 is made by a construction method of welding the entire section on the production platform. The steel bars of the second L-shaped steel cage 2 are processed and bent in the steel shed. The main reinforcement joints are preferably welded. The steel bar protective layer is welded to the main reinforcement with a 5mm thick steel plate and is formed at one time on the production table. When processing the second L-shaped steel cage 2, the second joint is welded to the steel cage as a whole. The second joint is an "I"-shaped steel plate. The "I"-shaped steel plate joint and the second L-shaped steel cage 2 are hoisted into the slot section together. Iron sheet should be welded between the second L-shaped steel cage 2 and the I-beam to prevent concrete from bypassing. The second joint is formed with a notch, and a 45-degree groove is formed at the corresponding butt end of the notch.

[0040] Further, when the first L-shaped steel cage 1 is suspended, a first lifting lug is welded on the first L-shaped steel cage 1, and the lifting connection is connected to the first lifting lug, so as to suspend the first L-shaped steel cage 1 to the Z-shaped groove 4. Preferably, a lifting point is provided on the first L-row steel cage, at which a first lifting lug of "J" shape is made of φ28 plain round steel bar and welded to the steel cage, and the lifting point should be set at the intersection of the longitudinal and transverse truss bars, and the lifting point is connected to the wire rope through a shackle, which is convenient for removing the buckle during the lifting process. In addition, a "door" shape is made of φ28 plain round steel bar and reinforced at the lifting point, and the corresponding main bars on the top and bottom surfaces are pulled and connected. The first lifting point position uses a shackle to clamp the wire rope on the "J"-shaped lifting lugs cross-set on the soil facing and backing surfaces of the steel cage, and the remaining lifting points use shackles to clamp the wire rope on the "J"-shaped lifting lugs set on the top surface of the steel cage.

[0041] Furthermore, the crane is provided with a main and auxiliary hook, the main hook controls the 1st and 2nd lifting points, the 1st lifting point is arranged at the upper and lower layers of the steel cage, and the 2nd lifting point is arranged at the upper layer of the steel cage; when the length of the ground-connected wall steel cage is greater than 30m, the auxiliary hook controls the 3rd, 4th and 5th lifting points, and the 3rd, 4th and 5th lifting points are all arranged at the upper layer of the steel cage. When the length of the ground-connected wall steel cage is less than 30m, the auxiliary hook controls the 3rd and 4th lifting points, and the 3rd and 4th lifting points are all arranged at the upper layer of the steel cage.

[0042] Furthermore, when the second L-shaped steel cage 2 is suspended, a second lifting lug is welded on the second L-shaped steel cage 2, and the lifting connection is connected to the second lifting lug, so as to suspend the second L-shaped steel cage 2 to the Z-shaped groove 4. Preferably, a lifting point is provided on the second L-row steel cage, at which a second lifting lug of "J" shape is made of φ28 round steel bar and welded to the steel cage, and the lifting point should be set at the intersection of the longitudinal and transverse truss bars, and the lifting point is connected to the wire rope by a shackle, which is convenient for removing the buckle during the lifting process. In addition, a "door" shape is made of φ28 round steel bar and reinforced at the lifting point, and the corresponding main bars on the top and bottom surfaces are pulled and connected. The second lifting point position uses a shackle to clamp the wire rope on the "J"-shaped lifting lugs cross-set on the soil facing and backing surfaces of the steel cage, and the remaining lifting points use shackles to clamp the wire rope on the "J"-shaped lifting lugs set on the top surface of the steel cage.

[0043] Furthermore, the crane is provided with a main and auxiliary hook, the main hook controls the 1st and 2nd lifting points, the 1st lifting point is arranged at the upper and lower layers of the steel cage, and the 2nd lifting point is arranged at the upper layer of the steel cage; when the length of the ground-connected wall steel cage is greater than 30m, the auxiliary hook controls the 3rd, 4th and 5th lifting points, and the 3rd, 4th and 5th lifting points are all arranged at the upper layer of the steel cage. When the length of the ground-connected wall steel cage is less than 30m, the auxiliary hook controls the 3rd and 4th lifting points, and the 3rd and 4th lifting points are all arranged at the upper layer of the steel cage.

[0044] Furthermore, after the excavation of the Z-shaped groove 4 is completed, an ultrasonic wall measuring instrument is provided to scan and record the protrusion or recess of the inner wall of the Z-shaped groove 4. Preferably, the ultrasonic wall measuring instrument is used to scan the groove wall surface at three positions of the left, middle and right in the groove section of the Z-shaped groove 4, and the protrusion or recess at the bottom of the middle wall surface is scanned and recorded (the ratio to the groove section depth is the wall surface verticality, and the average value of the three positions is the average verticality of the groove section wall surface).

[0045] Furthermore, after the excavation of the Z-shaped trench 4 is completed, the positions of the two ends of the trench section are measured with a hammer, and the deviation between the measured position lines at the two ends and the dividing line of the trench section is the plane position deviation of the trench section; the depth of the bottom of the trench at the left, middle and right positions of the trench section is measured with a hammer, and the minimum depth of the three positions is the depth of the trench section.

[0046] Furthermore, the heights of the first L-shaped steel cage 1 and the second L-shaped steel cage 2 are adapted to the depth of the Z-shaped groove 4 .

[0047] The following is an explanation of the use process of a Z-type ground-connected wall construction method of the present invention.

[0048] The underground continuous wall trenching machine 3 adopts the SG46 trenching machine 3, and the underground continuous wall trench section construction adopts the skip excavation construction method (that is, the trench section is skipped every other trench section). When the excavated trench section length cannot meet the minimum excavation length of the grab bucket, it can be considered to extend a certain length or modify the section length according to the on-site conditions to meet the trenching requirements; after the Z-shaped trench 4 is excavated, the first L-shaped steel cage 1 and the second L-shaped steel cage 2 are provided. Since the L-shaped steel cage has only two bent edges, the contact area between the wall section slot hole and the steel cage is reduced, which can effectively avoid the problems of steel cage stuck in the slot, difficulty in entering the slot or inability to enter the slot, etc. The first L-shaped steel cage 1 and the second L-shaped steel cage 2 are hoisted and placed by double machines, straightened in the air, and then placed in the slot by the main crane to ensure the stability of the hoisting. After one of the steel cages is hoisted into the Z-shaped trench 4, the position of the steel cage can be adjusted in the air when the other steel cage is hoisted, so that after the other steel cage is placed in the Z-shaped trench 4, the docking section and the slot mouth are aligned. After the assembly and hoisting are completed, the first L-shaped steel cage 1 and the second L-shaped steel cage 2 are fine-tuned by the crane. The first L-shaped steel cage 1 and the second L-shaped steel cage 2 reduce the difficulty of suspended installation during hoisting, and the construction efficiency is improved. Compared with the method of directly using the whole steel cage processing of the "Z" type ground-connected wall, the labor cost is lower, and the construction quality is easier to ensure. The weight of the two L-shaped steel cages is half of the whole steel cage of the "Z" type ground-connected wall. There will be no overturning after hoisting. The overall force of the steel cage hoisting point is uniform, and the safety risk of hoisting is reduced; after the steel cage is placed, concrete pouring is carried out. The concrete pouring adopts the method of self-unloading concrete material and concrete hopper lifting conduit; during the pouring process, the conduit should always be buried in the concrete for 2 to 6 meters, and the minimum burial depth shall not be less than 1.5 meters. Concrete pouring should be carried out continuously, and the concrete surface rising speed shall not be less than 3 to 5 meters / hour. The longest allowed interval time is 20 to 30 minutes. During the pouring process, the concrete surface rising height is measured every 30 minutes to ensure accurate and timely pipe pulling.

[0049] The present invention is described in detail above in conjunction with the embodiments of the accompanying drawings. A person skilled in the art can make various variations of the present invention according to the above description. Therefore, certain details in the embodiments should not constitute a limitation of the present invention, and the scope of protection of the present invention shall be defined by the scope of the attached claims.

Claims

1. A Z-type ground-connected wall construction method, Its characteristics are: The steps include: Providing a slotting machine, and digging a Z-shaped slot on the construction surface by the slotting machine; A crane, a first L-shaped steel cage and a second L-shaped steel cage are provided, wherein a butt end is formed at the end of the first L-shaped steel cage, and a notch is formed at the end of the second L-shaped steel cage corresponding to the butt end, the first L-shaped steel cage and the second L-shaped steel cage are hoisted into the Z-shaped groove by the crane, and the crane is adjusted so that the butt end is clamped in the notch; Concrete is poured into the Z-shaped groove to form a ground-connected wall.

2. A Z-type ground-connected wall construction method according to claim 1, Its characteristics are: The Z-shaped groove comprises two parallel sections parallel to each other and a connecting section connecting the two parallel sections; When digging the Z-shaped groove, the parallel section is dug by the groove forming machine, and after the parallel section is dug, the connecting section is dug.

3. A Z-type ground-connected wall construction method according to claim 1, Its characteristics are: After the Z-shaped groove is excavated, the bottom of the Z-shaped groove is cleaned.

4. A Z-type ground-connected wall construction method according to claim 1, Its characteristics are: A first joint is welded at the end of the first L-shaped steel cage, and the butt end is formed on the first joint.

5. A Z-type ground-connected wall construction method according to claim 1, Its characteristics are: A second joint is welded at the end of the second L-shaped steel cage, and the notch is formed on the second joint.

6. A Z-type ground-connected wall construction method according to claim 1, Its characteristics are: When the first L-shaped steel cage is suspended, a first lifting lug is welded on the first L-shaped steel cage, and the lifting joint is connected to the first lifting lug to suspend the first L-shaped steel cage into the Z-shaped groove.

7. A Z-type ground-connected wall construction method according to claim 1, Its characteristics are: When the second L-shaped steel cage is suspended, a second lifting lug is welded on the second L-shaped steel cage, and the lifting joint is connected to the second lifting lug to suspend the second L-shaped steel cage into the Z-shaped groove.

8. A Z-type ground-connected wall construction method according to claim 1, Its characteristics are: After the excavation of the Z-shaped groove is completed, an ultrasonic wall measuring instrument is provided to scan and record the protrusion or recess of the inner wall of the Z-shaped groove.

9. A Z-type ground-connected wall construction method according to claim 1, Its characteristics are: The heights of the first L-shaped steel cage and the second L-shaped steel cage are adapted to the depth of the Z-shaped groove.

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