Underground continuous wall and construction method thereof

Abstract

The application discloses a kind of underground continuous walls, comprising: reinforcement cage;Steel formwork assembly is set to the inside and outside of the reinforcement cage;First I-shaped frame;Second I-shaped frame;Upper connecting piece is set in the narrow space enclosed by adjacent first I-shaped frame, second I-shaped frame;Lower connecting piece is set in the narrow space enclosed by adjacent first I-shaped frame, second I-shaped frame;The steel formwork assembly and the first I-shaped frame, second I-shaped frame enclosed in the reinforcement cage space of its upstream end, downstream end, and the narrow space enclosed by adjacent first I-shaped frame, second I-shaped frame, after laying geotextile post-cast concrete forms underground continuous wall.The application can enhance the bending resistance and deformation resistance of underground continuous wall, has the advantage that the permeability is strong, prolongs the service life of underground continuous wall.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building technology. More particularly, the present application relates to a diaphragm wall and a construction method thereof. BACKGROUND

[0002] The diaphragm wall is a foundation engineering. A trenching equipment is used to excavate a long and narrow underground trench along the longitudinal axis of the excavation area under the protection of the slurry wall. After the trenching, the trench is cleaned, the reinforcement cage is hoisted and placed, and the concrete is poured to form a diaphragm wall unit. The continuous diaphragm wall units form a reinforced concrete wall, which serves as a diaphragm wall for water interception, seepage prevention, load bearing and water retaining. Since the diaphragm wall is a main blocking structure and is constructed in sections, the more the number of diaphragm wall units, the more the number of joints, and the more the number of joints, the greater the probability of leakage. If the adjacent diaphragm wall units are connected in the form of vertical joints and rod insertion, even if geotextile is placed, it is still easy to cause joint leakage, which will have a great impact on the foundation pit excavation and later use. SUMMARY

[0003] The present application provides a diaphragm wall and a construction method thereof, which can enhance the bending resistance and deformation resistance of the diaphragm wall, has the advantage of strong anti-seepage ability, and prolongs the service life of the diaphragm wall.

[0004] In order to achieve these objects and other advantages in accordance with the present application, a diaphragm wall is provided, comprising:

[0005] a reinforcement cage;

[0006] a steel formwork assembly arranged on the inner and outer sides of the reinforcement cage;

[0007] a first I-shaped frame, the web of the first I-shaped frame connecting the downstream end of the reinforcement cage, and a pair of flanges of the first I-shaped frame connecting the downstream end of the steel formwork assembly;

[0008] a second I-shaped frame, the web of the second I-shaped frame connecting the upstream end of the reinforcement cage, and a pair of flanges of the second I-shaped frame connecting the upstream end of the steel formwork assembly;

[0009] an upper connecting piece arranged in a narrow space enclosed by adjacent first and second I-shaped frames, the upper connecting piece comprising a first fixed block, a first sliding block and a first insertion block, the first fixed block being arranged on the web of the first I-shaped frame, the first sliding block being arranged on the web of the second I-shaped frame, and the first fixed block and the first sliding block being in sliding fit and connected through the first insertion block;

[0010] The lower connector is disposed within the narrow space enclosed by the adjacent first I-beam and second I-beam. The lower connector includes a second fixing block and a second sliding block. The second fixing block is disposed on the web of the first I-beam, and the second sliding block is disposed on the web of the second I-beam. The second fixing block and the second sliding block are slidably engaged.

[0011] Within the steel formwork assembly and the steel cage space enclosed by the first and second I-beams at its upstream and downstream ends, as well as the narrow space enclosed by adjacent first and second I-beams, geotextile is laid and then concrete is poured to form a continuous underground wall.

[0012] Preferably, the steel formwork assembly includes a detachable formwork located inside the reinforcing cage and a fixed formwork located outside the reinforcing cage.

[0013] Preferably, the first I-beam has a pair of wing plates with positioning grooves, and the second I-beam has a pair of wing plates with matching positioning blocks.

[0014] Preferably, the upper connector includes:

[0015] The first fixing block includes an integrally formed first part, a second part, and a third part. The longitudinal section of the first part is a U-shaped structure, the longitudinal section of the second part is a square structure, and the longitudinal section of the third part is a Z-shaped structure. The first part, the second part, and the third part have equal lateral lengths, a longitudinal length ratio of 2:1:3, and a height ratio of 3:1:2. The bottom surfaces of the first part, the second part, and the third part are integrally formed.

[0016] The first sliding block includes an integrally formed third part, fourth part, and fifth part. The longitudinal section of the third part is a Z-shaped structure, the longitudinal section of the fourth part is a square structure, and the longitudinal section of the fifth part is a C-shaped structure. The transverse lengths of the third part, fourth part, and fifth part are equal, the longitudinal length ratio is 3:1:2, and the height ratio is 2:1:3. The top surfaces of the third part, fourth part, and fifth part are integrally formed.

[0017] The first connector block has the same specifications as the second and fourth parts;

[0018] When the first fixed block and the first sliding block slide together and are connected by the first plug-in block, they are assembled into a complete cuboid structure.

[0019] Preferably, the lower connector includes:

[0020] The second fixing block has a groove on its top surface. The groove includes a first groove and a second groove that run from upstream to downstream. The first groove has a trapezoidal cross-section, and the second groove has a square cross-section. The bottom surfaces of the first groove and the second groove have equal horizontal lengths, and the longitudinal lengths and depths of the first groove and the second groove are equal.

[0021] The second sliding block has a sliding part on its bottom surface. The sliding part has a trapezoidal cross-section and cooperates with the first groove.

[0022] When the sliding part slides in conjunction with the first groove, the second fixed block and the second sliding block are spliced ​​together to form a complete cuboid structure.

[0023] When the sliding part is inserted into the second groove, the bottom surface of the first sliding block is flush with the bottom surface of the first fixed block and the longitudinal distance between them is equal to the width of the first plug-in block. When the sliding part is slidably engaged with the first groove, the first fixed block and the first sliding block are slidably engaged and connected through the first plug-in block.

[0024] Preferably, the downstream end of the top surface of the first part is recessed in the longitudinal direction to form a limiting groove, and the upstream end of the top surface of the fourth part is protruded in the longitudinal direction to form a limiting block, and the limiting block cooperates with the limiting groove.

[0025] The construction method for the aforementioned diaphragm wall includes:

[0026] Step 1: Hoist a first I-beam frame, connect the upstream ends of the pair of flanges of the first I-beam frame to the starting joint of the underground trench, lay geotextile and pour concrete.

[0027] Step 2: Install steel formwork assemblies on the inside and outside of the reinforcing cage, and install a second I-beam and a first I-beam at the upstream and downstream ends of the reinforcing cage and the steel formwork assemblies respectively to form the reinforcing cage assembly;

[0028] Step 3: Hoist the steel cage assembly and connect the second I-beam of the steel cage assembly to the first I-beam that has been installed upstream. Lay geotextile and pour concrete in the steel cage space and the narrow space.

[0029] Step 4: Repeat steps 2 and 3 until the end of the underground trench. Hoist a second I-beam and connect it to the first I-beam that has been installed upstream. Then connect the downstream ends of the pair of flanges of the second I-beam to the terminal joint of the underground trench. Lay geotextile on both ends of the web of the second I-beam and pour concrete.

[0030] The present invention has at least the following beneficial effects:

[0031] First, this invention sets steel formwork components inside and outside the steel cage, which are not affected by the outer soil layer, forming a flat and smooth concrete structure. The steel cage is enclosed by the first and second I-beams, and the joint stability of the underground continuous wall unit is enhanced by the upper and lower connectors, which enhances the bending resistance and deformation resistance of the underground continuous wall. It has the advantage of strong anti-seepage ability and extends the service life of the underground continuous wall.

[0032] Secondly, the size of the reinforcing cage is selected according to the longitudinal length, transverse length, and depth of the foundation pit, and the number of reinforcing bars is selected according to the design requirements. Steel formwork components are set on the inner and outer sides of the reinforcing cage to form a smooth and flat concrete structure. The first and second I-beams each include a web and a pair of flanges. The web is set transversely, and the pair of flanges are set longitudinally. For a sub-assembly consisting of a reinforcing cage and a steel formwork component, the first and second I-beams are set at the downstream and upstream ends, respectively. For two adjacent sub-assemblies, the first I-beam of the upstream sub-assembly and the second I-beam of the downstream sub-assembly are tightly connected by upper and lower connectors. The first fixing block and the first sliding block of the upper connector slide in fit, and the second fixing block and the second sliding block of the lower connector slide in fit. The first insertion block of the upper connector also realizes insertion positioning, further realizing the stability and anti-seepage capability of the joint. By pouring concrete in the space of the reinforcing cage and the narrow space, the bending resistance and deformation resistance of the underground continuous wall are enhanced.

[0033] Third, the detachable template facilitates recycling and reuse, while the fixed template facilitates the formation of a concrete protective layer. The positioning grooves and blocks facilitate the hoisting of the rebar cage assembly, composed of the rebar cage, steel formwork components, first I-beam, and second I-beam, serving as top-to-bottom guiding and positioning. The first and second fixing blocks of the upper connector are irregularly shaped structures, with the same dimensions but inverted. The bottom surfaces of the first, second, and third parts are integrally formed, as are the top surfaces of the fourth, fifth, and sixth parts. The concave portion of the first part and the convex portion of the fourth part fit together, and the convex portion of the third part and the concave portion of the fifth part fit together. During hoisting, the bottom surface of the first sliding block is flush with the bottom surface of the first fixing block. Then, the first sliding block slides towards the first fixing block until it contacts it. The first insert block is inserted into the gap, achieving longitudinal and vertical relative fixation of the first fixing block and the first sliding block. This, in turn, uses the upper connector to fix adjacent rebar cage assemblies.

[0034] Fourth, the main bodies of the second fixing block and the second sliding block of the lower connector are both cuboid structures. The second fixing block has a groove, and the second sliding block has a sliding part. The groove includes an upstream trapezoidal groove and a downstream square groove. The size of the sliding part matches the trapezoidal groove. When hoisting, the bottom surface of the sliding part is inserted flush with the bottom surface of the square groove. Then, the second sliding block slides towards the second fixing block until it touches it. At this time, the sliding part slides into the trapezoidal groove. Due to its structure of being smaller at the top and larger at the bottom, the second fixing block and the second sliding block are relatively fixed in the lateral and vertical directions, thereby fixing two adjacent steel cage components through the lower connector. The setting of the limiting groove and the limiting block further realizes the lateral relative fixation of the upper connector, enhancing the bending resistance and deformation resistance of the diaphragm wall.

[0035] Fifth, during construction, construction proceeds continuously from the beginning to the end of the underground trench, in segments. Each segment is a rebar cage assembly. At the beginning, a first I-beam is hoisted separately, and the upstream ends of the pair of flanges of the first I-beam are connected to the beginning joint to fix the beginning. After fixing, concrete is poured. Then, the rebar cage assemblies are assembled sequentially, hoisted, and fixed at the upstream and downstream ends. Concrete is poured in the rebar cage space and the narrow space to complete the construction of one underground continuous wall unit. At the end, a second I-beam is hoisted separately, and the upstream ends of the pair of flanges of the second I-beam are connected to the adjacent first I-beam. Then, the downstream ends of the pair of flanges of the second I-beam are connected to the end joint to fix the end.

[0036] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of one technical solution of the present invention;

[0038] Figure 2 This is a schematic diagram of the structure of the upper connector described in this invention;

[0039] Figure 3 This is a schematic diagram of the structure of the lower connector described in this invention;

[0040] Figure 4 This is a schematic diagram of the structure of the present invention before it is lifted and translated.

[0041] Figure 5 This is a schematic diagram of the structure of the present invention after translation into position. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0043] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0044] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods, and the reagents and materials mentioned are commercially available. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0045] like Figure 1 As shown, the present invention provides a diaphragm wall, comprising:

[0046] Reinforcing cage 1;

[0047] Steel formwork assemblies are installed inside and outside the steel cage 1;

[0048] The first I-beam 4, the web of the first I-beam 4 is connected to the downstream end of the steel cage 1, and a pair of flanges of the first I-beam 4 are connected to the downstream end of the steel formwork assembly.

[0049] The second I-beam 5, the web of the second I-beam 5 is connected to the upstream end of the steel cage 1, and a pair of flanges of the second I-beam 5 are connected to the upstream end of the steel formwork assembly;

[0050] The upper connector 6 is disposed within the narrow space enclosed by the adjacent first I-beam 4 and second I-beam 5. The upper connector 6 includes a first fixing block 7, a first sliding block 8, and a first plug-in block 9. The first fixing block 7 is disposed on the web of the first I-beam 4, and the first sliding block 8 is disposed on the web of the second I-beam 5. The first fixing block 7 and the first sliding block 8 are slidably engaged and connected by the first plug-in block 9.

[0051] The lower connector 10 is disposed in the narrow space enclosed by the adjacent first I-beam 4 and second I-beam 5. The lower connector 10 includes a second fixing block 11 and a second sliding block 12. The second fixing block 11 is disposed on the web of the first I-beam 4, and the second sliding block 12 is disposed on the web of the second I-beam 5. The second fixing block and the second sliding block are slidably engaged.

[0052] Within the steel formwork assembly and the steel cage space enclosed by the first I-beam 4 and the second I-beam 5 at its upstream and downstream ends, as well as the narrow space enclosed by the adjacent first I-beam 4 and the second I-beam 5, geotextile is laid and then concrete is poured to form a continuous underground wall.

[0053] In the above technical solution, the present invention sets steel formwork components inside and outside the steel cage 1, which is not affected by the outer soil layer, forming a flat and smooth concrete structure. The steel cage 1 is enclosed by the first I-beam 4 and the second I-beam 5. At the same time, the joint stability of the underground continuous wall unit is enhanced by the upper connector 6 and the lower connector 10, which enhances the bending resistance and deformation resistance of the underground continuous wall, has the advantage of strong anti-seepage ability, and extends the service life of the underground continuous wall.

[0054] The size of the reinforcing cage 1 is selected according to the longitudinal length, transverse length, and depth of the foundation pit, and the number of reinforcing bars is selected according to the design requirements. Steel formwork components are set on the inner and outer sides of the reinforcing cage 1 to form a flat and smooth concrete structure. The first I-beam 4 and the second I-beam 5 both include a web and a pair of flanges. The web is set transversely, and the pair of flanges are set longitudinally. For a sub-assembly consisting of a reinforcing cage 1 and a steel formwork component, the first I-beam 4 and the second I-beam 5 are set at the downstream and upstream ends, respectively. For two adjacent sub-assemblies, the first I-beam 4 of the upstream sub-assembly and the second I-beam 5 of the downstream sub-assembly are tightly connected by an upper connector 6 and a lower connector 10. The first fixing block 7 of the upper connector 6 slides with the first sliding block 8, and the second fixing block 11 of the lower connector 10 slides with the second sliding block 12. The first insertion block 9 of the upper connector 6 also realizes insertion positioning, further realizing the stability of the joint and the anti-seepage ability. By pouring concrete in the reinforcing cage space and the narrow space respectively, the bending resistance and deformation resistance of the underground continuous wall are enhanced.

[0055] In another technical solution, the steel formwork assembly includes a detachable formwork 2 located inside the reinforcing cage 1 and a fixed formwork 3 located outside the reinforcing cage 1. The detachable formwork 2 facilitates recycling and reuse, while the fixed formwork 3 facilitates the formation of a concrete protective layer.

[0056] In another technical solution, a pair of wing plates of the first I-beam 4 are provided with positioning grooves, and a pair of wing plates of the second I-beam are provided with corresponding positioning blocks. The positioning grooves and positioning blocks facilitate the hoisting of the rebar cage assembly consisting of the rebar cage 1, the steel formwork assembly, the first I-beam 4, and the second I-beam 5, and serve as a top-down guiding and positioning mechanism.

[0057] In another technical solution, such as Figure 2 As shown, the upper connector 6 includes:

[0058] The first fixing block 7 includes an integrally formed first part, a second part, and a third part. The longitudinal section of the first part is a U-shaped structure, the longitudinal section of the second part is a square structure, and the longitudinal section of the third part is a Z-shaped structure. The first part, the second part, and the third part have equal lateral lengths, a longitudinal length ratio of 2:1:3, and a height ratio of 3:1:2. The bottom surfaces of the first part, the second part, and the third part are integrally formed.

[0059] The first sliding block 8 includes an integrally formed third part, fourth part, and fifth part. The longitudinal section of the third part is a Z-shaped structure, the longitudinal section of the fourth part is a square structure, and the longitudinal section of the fifth part is a C-shaped structure. The transverse lengths of the third part, fourth part, and fifth part are equal, the longitudinal length ratio is 3:1:2, and the height ratio is 2:1:3. The top surfaces of the third part, fourth part, and fifth part are integrally formed.

[0060] The first plug-in block 9 has the same specifications as the second and fourth parts;

[0061] When the first fixed block 7 and the first sliding block 8 slide together and are connected by the first plug-in block 9, they are assembled into a complete cuboid structure.

[0062] In the above technical solution, the first fixing block 7 and the second fixing block 11 of the upper connector 6 are both irregular structures, and are inverted structures of the same size and specifications. The bottom surfaces of the first part, the second part, and the third part are integrally formed, and the top surfaces of the fourth part, the fifth part, and the sixth part are integrally formed. The concave part formed by the first part and the convex part formed by the fourth part are matched, and the convex part formed by the third part and the concave part formed by the fifth part are matched. When hoisting, the bottom surface of the first sliding block 8 is flush with the bottom surface of the first fixing block 7. Then the first sliding block 8 slides toward the first fixing block 7 until it touches. The first plug-in block 9 is inserted into the gap to achieve the longitudinal and vertical relative fixation of the first fixing block 7 and the first sliding block 8, thereby achieving the fixation of two adjacent steel cage components through the upper connector 6.

[0063] In another technical solution, such as Figure 3As shown, the lower connector 10 includes:

[0064] The second fixing block 11 has a sliding groove on its top surface. The sliding groove includes a first groove and a second groove that run from upstream to downstream. The first groove has a trapezoidal cross-section, and the second groove has a square cross-section. The bottom surfaces of the first groove and the second groove have equal horizontal lengths, and the longitudinal lengths and depths of the first groove and the second groove are equal.

[0065] The second sliding block 12 has a sliding part on its bottom surface. The sliding part has a trapezoidal cross-section and cooperates with the first groove.

[0066] When the sliding part slides in conjunction with the first groove, the second fixed block 11 and the second sliding block 12 are spliced ​​together to form a complete cuboid structure.

[0067] When the sliding part is inserted into the second groove, the bottom surface of the first sliding block 8 is flush with the bottom surface of the first fixing block 7 and the longitudinal distance is equal to the width of the first plug-in block 9. When the sliding part is slidably engaged with the first groove, the first fixing block 7 and the first sliding block 8 are slidably engaged and connected through the first plug-in block 9.

[0068] In the above technical solution, the main bodies of the second fixing block 11 and the second sliding block 12 of the lower connector 10 are both cuboid structures. The second fixing block 11 has a sliding groove, and the second sliding block 12 has a sliding part. The sliding groove includes an upstream trapezoidal groove and a downstream square groove. The size of the sliding part matches the trapezoidal groove. When hoisting, the bottom surface of the sliding part is inserted flush with the bottom surface of the square groove. Then, the second sliding block 12 slides towards the second fixing block 11 until it abuts. At this time, the sliding part slides into the trapezoidal groove. Due to its structure of being smaller at the top and larger at the bottom, the second fixing block 11 and the second sliding block 12 are relatively fixed horizontally and vertically, thereby fixing two adjacent steel cage assemblies through the lower connector 10. The setting of the limiting groove and the limiting block further realizes the relative horizontal fixation of the upper connector 6, enhancing the bending resistance and deformation resistance of the diaphragm wall.

[0069] In another technical solution, the downstream end of the top surface of the first part is recessed along the longitudinal direction to form a limiting groove, and the upstream end of the top surface of the fourth part is protruded along the longitudinal direction to form a limiting block, and the limiting block cooperates with the limiting groove.

[0070] The construction method of the diaphragm wall, such as Figures 4-5 As shown, it includes:

[0071] Step 1: Hoist a first I-beam 4, connect the upstream ends of a pair of flanges of the first I-beam 4 to the starting joint of the underground trench, lay geotextile and pour concrete.

[0072] Step 2: Install steel formwork assemblies on the inner and outer sides of the steel cage 1, and install a second I-beam 5 and a first I-beam 4 at the upstream and downstream ends of the steel cage 1 and the steel formwork assemblies respectively to form the steel cage assembly;

[0073] Step 3: Hoist the steel cage assembly and connect the second I-beam 5 of the steel cage assembly to the first I-beam 4 that has been installed upstream. Lay geotextile and pour concrete in the steel cage space and the narrow space.

[0074] Step 4: Repeat steps 2 and 3 until the end of the underground trench. Hoist a second I-beam 5 and connect it to the first I-beam 4 that has been installed upstream. Then connect the downstream ends of a pair of flanges of the second I-beam 5 to the terminal joint of the underground trench. Lay geotextile on both ends of the web of the second I-beam 5 and pour concrete.

[0075] In the above technical solution, during construction, continuous construction is carried out from the beginning to the end of the underground trench, and the construction is carried out in segments. Each segment is a steel cage assembly. During the construction at the beginning, a first I-beam 4 is hoisted separately, and the upstream ends of a pair of flanges of the first I-beam 4 are connected to the beginning joint to fix the beginning. After fixing, concrete is poured. Then, the steel cage assembly is assembled in sequence, and the steel cage assembly is hoisted and fixed at the upstream and downstream ends. Concrete is poured in the steel cage space and the narrow space respectively to complete the construction of one underground continuous wall unit. During the construction at the end, a second I-beam 5 is hoisted separately, and the upstream ends of a pair of flanges of the second I-beam 5 are connected to the adjacent first I-beam 4. Then, the downstream ends of a pair of flanges of the second I-beam 5 are connected to the end joint to fix the end.

[0076] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0077] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A diaphragm wall, characterized in that, include: Reinforcing cage; Steel formwork assemblies are installed inside and outside the reinforcing cage; The first I-beam, the web of which is connected to the downstream end of the reinforcing cage, and a pair of flanges of which are connected to the downstream end of the steel formwork assembly. The second I-beam has its web plate connected to the upstream end of the reinforcing cage, and a pair of flanges of the second I-beam are connected to the upstream end of the steel formwork assembly. The upper connector is disposed within the narrow space enclosed by the adjacent first I-beam and second I-beam. The upper connector includes a first fixing block, a first sliding block, and a first plug-in block. The first fixing block is disposed on the web of the first I-beam, and the first sliding block is disposed on the web of the second I-beam. The first fixing block and the first sliding block are slidably engaged and connected by the first plug-in block. The lower connector is disposed within the narrow space enclosed by the adjacent first I-beam and second I-beam. The lower connector includes a second fixing block and a second sliding block. The second fixing block is disposed on the web of the first I-beam, and the second sliding block is disposed on the web of the second I-beam. The second fixing block and the second sliding block are slidably engaged. Within the steel formwork assembly and the steel cage space enclosed by the first and second I-beams at its upstream and downstream ends, as well as the narrow space enclosed by adjacent first and second I-beams, geotextile is laid and then concrete is poured to form a continuous underground wall.

2. The diaphragm wall as described in claim 1, characterized in that, The steel formwork assembly includes a detachable formwork located inside the reinforcing cage and a fixed formwork located outside the reinforcing cage.

3. The diaphragm wall as described in claim 1, characterized in that, The first I-beam has a pair of wing plates with positioning grooves, and the second I-beam has a pair of wing plates with matching positioning blocks.

4. The diaphragm wall as described in claim 1, characterized in that, The upper connector includes: The first fixing block includes an integrally formed first part, a second part, and a third part. The longitudinal section of the first part is a U-shaped structure, the longitudinal section of the second part is a square structure, and the longitudinal section of the third part is a Z-shaped structure. The first part, the second part, and the third part have equal lateral lengths, a longitudinal length ratio of 2:1:3, and a height ratio of 3:1:

2. The bottom surfaces of the first part, the second part, and the third part are integrally formed. The first sliding block includes an integrally formed third part, fourth part, and fifth part. The longitudinal section of the third part is a Z-shaped structure, the longitudinal section of the fourth part is a square structure, and the longitudinal section of the fifth part is a C-shaped structure. The transverse lengths of the third part, fourth part, and fifth part are equal, the longitudinal length ratio is 3:1:2, and the height ratio is 2:1:

3. The top surfaces of the third part, fourth part, and fifth part are integrally formed. The first connector block has the same specifications as the second and fourth parts; When the first fixed block and the first sliding block slide together and are connected by the first plug-in block, they are assembled into a complete cuboid structure.

5. The diaphragm wall as described in claim 4, characterized in that, The lower connector includes: The second fixing block has a groove on its top surface. The groove includes a first groove and a second groove that run from upstream to downstream. The first groove has a trapezoidal cross-section, and the second groove has a square cross-section. The bottom surfaces of the first groove and the second groove have equal horizontal lengths, and the longitudinal lengths and depths of the first groove and the second groove are equal. The second sliding block has a sliding part on its bottom surface. The sliding part has a trapezoidal cross-section and cooperates with the first groove. When the sliding part slides in conjunction with the first groove, the second fixed block and the second sliding block are spliced ​​together to form a complete cuboid structure. When the sliding part is inserted into the second groove, the bottom surface of the first sliding block is flush with the bottom surface of the first fixed block and the longitudinal distance between them is equal to the width of the first plug-in block. When the sliding part is slidably engaged with the first groove, the first fixed block and the first sliding block are slidably engaged and connected through the first plug-in block.

6. The diaphragm wall as described in claim 4, characterized in that, The downstream end of the top surface of the first part is recessed along the longitudinal direction to form a limiting groove, and the upstream end of the top surface of the fourth part is protruded along the longitudinal direction to form a limiting block, which cooperates with the limiting groove.

7. The construction method for a diaphragm wall as described in any one of claims 4-6, characterized in that, include: Step 1: Hoist a first I-beam frame, connect the upstream ends of the pair of flanges of the first I-beam frame to the starting joint of the underground trench, lay geotextile and pour concrete. Step 2: Install steel formwork assemblies on the inside and outside of the reinforcing cage, and install a second I-beam and a first I-beam at the upstream and downstream ends of the reinforcing cage and the steel formwork assemblies respectively to form the reinforcing cage assembly; Step 3: Hoist the steel cage assembly and connect the second I-beam of the steel cage assembly to the first I-beam that has been installed upstream. Lay geotextile and pour concrete in the steel cage space and the narrow space. Step 4: Repeat steps 2 and 3 until the end of the underground trench. Hoist a second I-beam and connect it to the first I-beam that has been installed upstream. Then connect the downstream ends of the pair of flanges of the second I-beam to the terminal joint of the underground trench. Lay geotextile on both ends of the web of the second I-beam and pour concrete.

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