Single-sided composite underground continuous wall structure and construction method

Abstract

The application discloses a single-sided composite underground continuous wall structure which can be used as a main structure and a construction method thereof. The single-sided composite underground continuous wall structure is a concrete wall arranged below the ground surface of the periphery of a foundation pit. The soil body of the periphery of the foundation pit is excavated to form a groove section, and the concrete wall is cast and formed in the groove section. The concrete wall is provided with continuously distributed composite walls. Each composite wall is fixed in the groove section through the composite wall support frames which are distributed at intervals. The composite wall is located on the side close to the foundation pit in the groove section, and the composite wall support frame is located on the side away from the foundation pit in the groove section. The application can adopt a prefabricated structure on the side which can be used as the main structure to achieve good wall forming quality, adopt a cast-in-situ structure at other positions, maintain the advantages of the traditional underground continuous wall structure such as large rigidity and good water stopping effect, and minimize the size and self-weight of the prefabricated component as much as possible, so that good operability is ensured on the construction site.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of foundation pit engineering, and particularly relates to a single-sided composite underground continuous wall structure capable of serving as a main structure and a construction method. BACKGROUND

[0002] In traditional deep foundation pit engineering, a temporary support structure such as an underground continuous wall or a row of piles is usually built to ensure the safety of the foundation pit. The above scheme is intuitive and effective, but in the design, the contribution of the temporary enclosure structure to the performance of the permanent main structure is usually considered little or even ignored, resulting in a thick outer wall of the underground building, which causes a huge waste of building materials and construction period. Some industry insiders have proposed a method of using a diaphragm wall as a side wall of the main structure (this method is not mature, and in other documents, this method is also called "two walls in one", "wall-wall in one", "single wall", etc.). This method can solve the problem of waste caused by the temporary enclosure structure, but it brings two new defects: 1. The wall near the foundation pit side is difficult to ensure the flatness, and the quality of the underwater concrete pouring is also difficult to guarantee, so the wall needs to be processed when it is used as a main structure; 2. Steel reinforcement needs to be reserved on the steel reinforcement cage for connection with the later-poured main structure, but due to the uncertainty of the diaphragm wall trenching, the steel reinforcement cage is difficult to be accurately positioned, so the reserved steel reinforcement is also difficult to be accurately positioned, which will affect the connection between the main structure and the diaphragm wall during pouring.

[0003] Some industry insiders have proposed a fully prefabricated diaphragm wall to solve the above problems, but there are still problems that make it difficult to be applied on a large scale in the construction site. 1. The volume and self-weight of the fully prefabricated diaphragm wall are large, so transportation, hoisting and other operations are difficult; 2. The splicing process is carried out underground, and the splicing process is difficult to guarantee; 3. The quality of the joint waterproof is difficult to guarantee. SUMMARY

[0004] Therefore, the present application provides a single-sided composite underground continuous wall structure capable of serving as a main structure and a construction method, which can use a prefabricated structure on the side of the main structure to achieve good wall-forming quality, use cast-in-place structure at other positions, maintain the advantages of traditional underground continuous wall structure such as large stiffness and good water stop effect, and minimize the size and self-weight of the prefabricated component to ensure good operability in the construction site.

[0005] The present application is achieved by the following technical solutions:

[0006] A single-sided composite underground continuous wall structure capable of serving as a main structure, the single-sided composite underground continuous wall structure being a concrete wall arranged below the ground surrounding the foundation pit;

[0007] The soil surrounding the foundation pit is excavated to form a slot section, and the concrete wall is cast and formed in the slot section;

[0008] The concrete wall is provided with continuously distributed composite walls, each of which is fixed in the groove section by a spaced-apart composite wall support frame, and the composite wall is located close to the foundation pit in the groove section, and the composite wall support frame is located away from the foundation pit in the groove section.

[0009] Further, the composite wall support frame comprises a support column, a middle support beam and a bottom support beam.

[0010] The support column is a rod-shaped structure, the middle part of the support column is provided with a middle support beam, the bottom of the support column is provided with a bottom support beam, and the support column, the middle support beam and the bottom support beam are integrally formed; the end of the bottom support beam is provided with an upward protrusion;

[0011] The support columns of two or more composite wall support frames are fixed side by side in the groove section away from the foundation pit, and the middle support beams and the bottom support beams of the composite wall support frames all extend towards the direction of the foundation pit.

[0012] Further, the composite wall comprises a composite wall main body, a diaphragm wall embedded steel bar and a main structure connecting section embedded steel bar.

[0013] The composite wall main body is a flat plate structure; the bottom of the composite wall main body is processed with one or more spaced-apart positioning grooves; when the composite wall main body is installed in the groove section, the positioning grooves at the bottom of the composite wall main body are matched with the protrusions on the bottom support beam.

[0014] Two or more diaphragm wall embedded steel bars arranged side by side are fixed on one side of the composite wall main body; two or more main structure connecting section embedded steel bars arranged in a matrix are processed on the other side of the composite wall main body, each main structure connecting section embedded steel bar slot is fixed with two or more main structure connecting section embedded steel bars arranged side by side; and the side of the main structure connecting section embedded steel bars faces the foundation pit.

[0015] Further, the left and right sides of the composite wall main body are both processed with thinning sections.

[0016] Further, the protrusion of the bottom support beam is a tetrahedral structure; the positioning groove at the bottom of the composite wall main body is a tetrahedral recess.

[0017] Further, the composite wall and the composite wall support frame are both prefabricated in the factory.

[0018] A construction method of a single-sided composite underground continuous wall structure that can also serve as a main structure, based on the above underground continuous wall structure, the specific steps of the method are as follows:

[0019] Step one, excavate two parallel slot section side wall slots in the soil outside the foundation pit, and pour concrete in the two slot section side wall slots to form two guide walls;

[0020] Step two, excavate two or more than two interval distributed slot sections in the soil between the two guide walls, so that the two or more than two interval distributed slot sections are 1 sequence slot sections;

[0021] Step three, mud protection is used in the 1 sequence slot section, and then excavation is carried out to the required depth of the poured concrete wall;

[0022] Step four, the bottom of the 1 sequence slot section is cleaned, and after the cleaning is completed, the composite wall support frame is placed in each 1 sequence slot section away from the side of the foundation pit according to the specified interval;

[0023] Step five, the composite wall is placed in each 1 sequence slot section near the side of the foundation pit, and the positioning groove at the bottom of the composite wall is matched with the protrusion of the bottom support beam of the composite wall support frame;

[0024] Step six, one lock pipe is placed on the left and right sides of the composite wall in each 1 sequence slot section;

[0025] Step seven, after the lock pipe is placed, concrete is poured into each 1 sequence slot section to the top of the 1 sequence slot section, and after the concrete is solidified, a 1 sequence concrete wall is formed, and finally the lock pipe is removed;

[0026] Step eight, excavate a slot section at the interval between each adjacent two 1 sequence slot sections, so that the slot section between the 1 sequence slot sections is a 2 sequence slot section;

[0027] Step nine, after repeating steps three to five, a circular steel reinforcement cage is placed on the left and right sides of the composite wall in each 2 sequence slot section;

[0028] Step ten, after the circular steel reinforcement cage is placed, concrete is poured into each 2 sequence slot section to the top of the 2 sequence slot section, and after the concrete is solidified, a 2 sequence concrete wall is formed; finally, the 1 sequence concrete wall and the 2 sequence concrete wall form a continuous concrete wall.

[0029] Advantages:

[0030] (1) The present application provides a single-sided composite underground continuous wall structure which can be used as a side of the main structure, has high flatness, and the positioning of the embedded steel is accurate. The precast structure can be used on the side of the main structure to achieve good wall forming quality, greatly improving the flatness of the wall near the foundation pit and the accuracy of the embedded steel position. The cast-in-place structure is used in other positions, which preserves the mechanical properties and waterproof and impermeable properties of the underground continuous wall structure in a macroscopic manner. At the same time, the size and self-weight of the precast component are minimized to ensure good operability on the construction site.

[0031] (2) The present invention reserves embedded steel bars in the main structure connection section on the side of the composite wall adjacent to the foundation pit, which can provide a steel bar interface when the main structure is constructed, so that the single-sided composite underground continuous wall structure of the present invention can also serve as the main structure, that is, it can be directly used as the inner wall of the main structure, greatly improving the economic benefits.

[0032] (3) The protrusion of the bottom support beam of the present invention is a tetrahedral structure, and the positioning groove at the bottom of the composite wall body is a tetrahedral groove. The combination of the protrusion and the positioning groove is a tetrahedral combination, which can improve the accuracy of the composite wall positioning.

[0033] (4) The composite wall and composite wall support frame of the present invention are prefabricated in the factory. By using prefabricated composite walls and pre-embedding the circular steel cage in the composite wall, a large amount of construction site work is transferred to the factory, which meets the requirements of green construction while speeding up the construction progress and also provides the possibility for industrialization of related processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a top view of the first sequence trough section before pouring concrete (step seven) in the present invention.

[0035] Figure 2 This is a top view of the second sequence trough section before pouring concrete (step ten) in the present invention.

[0036] Figure 3 for Figure 1 Delete the schematic diagram of the soil and guide wall near the foundation pit side.

[0037] Figure 4 for Figure 2 Delete the schematic diagram of the soil and guide wall near the foundation pit side.

[0038] Figure 5 for Figure 1 and Figure 2 Schematic diagram of the middle composite wall close to the foundation pit side.

[0039] Figure 6 for Figure 1 and Figure 2 Schematic diagram of the middle composite wall facing away from the foundation pit.

[0040] Figure 7 for Figure 1 and Figure 2 A partial enlarged view of the composite wall.

[0041] Figure 8 for Figure 1 and Figure 2 Schematic diagram of the structure of the middle composite wall support frame.

[0042] Figure 9 for Figure 1 andFigure 2 Partial enlarged view of the middle composite wall support frame.

[0043] Figure 10 Construction flow chart of the present application (for easy display, the soil body and guide wall near the foundation pit are deleted in other figures except 10-a); wherein Figure 10 -a is pouring the concrete guide wall on the side wall of the excavation slot section of the soil body; Figure 10 -b is continuing to excavate to the required depth in the 1st slot section; Figure 10 -c is hoisting the composite wall, the composite wall support frame and the locking pipe; Figure 10 -d is pouring the 1st concrete wall body; Figure 10 -e is pulling out the locking pipe; 10-f is continuing to excavate to the required depth in the 2nd slot section; 10-g is hoisting the composite wall, the composite wall support frame and the circular reinforcement cage; and 10-h is pouring the 2nd concrete wall body.

[0044] Wherein, 0 is the soil body, 1 is the concrete wall body, 2 is the slot section, 3 is the composite wall, 4 is the composite wall support frame, 5 is the main body of the composite wall, 6 is the positioning slot, 7 is the embedded reinforcement of the diaphragm wall, 8 is the embedded reinforcement slot of the connection section of the main structure, 9 is the embedded reinforcement of the connection section of the main structure, 10 is the thinning section, 11 is the support column, 12 is the middle support beam, 13 is the bottom support beam, 14 is the guide wall, 15 is the locking pipe, and 16 is the circular reinforcement cage. DETAILED DESCRIPTION

[0045] The present application will be described in detail below with reference to the accompanying drawings and examples.

[0046] Example 1

[0047] This example provides a single-sided composite underground diaphragm wall structure which can also serve as the main structure, wherein the single-sided composite underground diaphragm wall structure is a concrete wall body 1 arranged below the ground surface of the periphery of the foundation pit;

[0048] The soil body 0 of the periphery of the foundation pit is excavated to form a slot section 2, and the concrete wall body 1 is poured and formed in the slot section 2;

[0049] Referring to the accompanying drawings, Figures 1-4 The concrete wall body 1 is provided with continuously distributed composite walls 3, each of which is fixed in the slot section 2 by the composite wall support frames 4 which are distributed at intervals, and the composite walls 3 are located on the side close to the foundation pit in the slot section 2, and the composite wall support frames 4 are located on the side away from the foundation pit in the slot section 2, i.e. the composite wall support frames 4 and the foundation pit are respectively located on the two sides of the composite walls 3;

[0050] Referring to the accompanying drawings, Figures 8-9The laminated wall support frame 4 is an auxiliary positioning and auxiliary support structure of the laminated wall 3, which is prefabricated in a factory, has a length equal to the height of the laminated wall 3, and has a strength equal to the strength of the laminated wall 3, and comprises a support column 11, a middle support beam 12, and a bottom support beam 13;

[0051] The support column 11 is a rod-shaped structure, the middle part of the support column 11 is provided with the middle support beam 12, the bottom part of the support column 11 is provided with the bottom support beam 13, and the support column 11, the middle support beam 12, and the bottom support beam 13 are integrally formed; the end part of the bottom support beam 13 is provided with an upward protrusion, and the protrusion is a tetrahedron structure with a small upper part and a large lower part;

[0052] Two or more support columns 11 of the laminated wall support frame 4 are fixed side by side in the groove section 2 at a side away from the foundation pit, and the middle support beam 12 and the bottom support beam 13 of the laminated wall support frame 4 both extend towards the direction of the foundation pit; wherein the support column 11 is used to bear the self-load of the laminated wall support frame 4, and the strength thereof needs to meet the requirements of design in bending resistance, compression resistance, shear resistance, etc.; the middle support beam 12 is used to assist in supporting the laminated wall 3; and the bottom support beam 13 is used to assist in positioning the laminated wall 3;

[0053] Referring to the accompanying drawings, Figures 5-7 The laminated wall 3 is prefabricated in a factory, and comprises a laminated wall main body 5, a diaphragm wall embedded steel bar 7, and a main structure connecting section embedded steel bar 9;

[0054] The laminated wall main body 5 is a flat plate structure, which is used to bear the load of the laminated wall 3 itself and a steel reinforcement cage, and bear part of the water and soil pressure; the bottom part of the laminated wall main body 5 is processed with one or more than one positioning groove 6 distributed at intervals, and the positioning groove 6 is a tetrahedron-shaped recess with a small upper part and a large lower part; when the laminated wall main body 5 is installed in the groove section 2, the positioning groove 6 at the bottom part of the laminated wall main body 5 cooperates with the protrusion on the bottom support beam 13, so that the positioning installation of the laminated wall main body 5 is realized, and the positioning groove 6 is used to ensure the position accuracy of the laminated wall 3 in the groove section 2;

[0055] One side surface of the laminated wall main body 5 is fixed with two or more than two diaphragm wall embedded steel bars 7 arranged side by side, and the diaphragm wall embedded steel bar 7 is used to ensure the integrity of the cast-in-place part and the prefabricated part of the concrete wall 1; the other side surface of the laminated wall main body 5 is processed with two or more than two main structure connecting section embedded steel bar grooves 8 arranged in a matrix, and each main structure connecting section embedded steel bar groove 8 is fixed with two or more than two main structure connecting section embedded steel bars 9 arranged side by side; and the side surface where the main structure connecting section embedded steel bar 9 is located faces the foundation pit; the main structure connecting section embedded steel bar 9 is used to provide a steel bar interface when the main structure (the main structure is a building or a railway, etc. which needs to be constructed in the foundation pit) is constructed, so as to ensure the integrity;

[0056] The left and right sides of the composite wall body 5 are provided with thinning sections 10, which are used to leave space for the locking pipe and circular reinforcement cage between the adjacent two composite wall bodies 5, so as to ensure that the continuously arranged composite walls 3 are sealed at the joint and achieve the water stopping effect.

[0057] Embodiment 2

[0058] The embodiment provides a construction method of a single-sided composite underground continuous wall structure which can also be used as a main structure, as shown in the accompanying drawings. Figure 10 The specific steps of the method are as follows.

[0059] Step one: two parallel slot section side wall slots are excavated in the soil 0 outside the foundation pit, and concrete is poured in the two slot section side wall slots to form two guide walls 14.

[0060] Step two: two or more than two interval distributed slot sections 2 are excavated in the soil 0 between the two guide walls 14, so that the two or more than two interval distributed slot sections 2 are all first slot sections.

[0061] Step three: mud protection is used in the first slot section, and then excavation is performed to the required depth of the poured concrete wall 1.

[0062] Step four: the bottom of the first slot section is cleaned, and after the cleaning is completed, the composite wall support frame 4 is placed in each first slot section away from the side of the foundation pit at a specified interval, and the positioning accuracy of the composite wall support frame 4 needs to be within 50 mm.

[0063] Step five: the composite wall 3 is placed in each first slot section close to the side of the foundation pit from below, and the positioning groove 6 at the bottom of the composite wall 3 is matched with the protrusion of the bottom support beam 13 of the composite wall support frame 4, so that the composite wall 3 is accurately positioned.

[0064] Step six: one locking pipe 15 is placed on the left and right sides of the composite wall 3 in each first slot section.

[0065] Step seven: after the locking pipe 15 is lowered, concrete is poured into each first slot section to the top of the first slot section, and after the concrete is solidified, the first concrete wall body is formed, and finally the locking pipe 15 is removed.

[0066] Step eight: a slot section 2 is excavated at the interval between each adjacent two first slot sections, so that the slot section 2 between the first slot sections is a second slot section.

[0067] Step nine: after steps three to five are repeated, one circular reinforcement cage 16 is placed on the left and right sides of the composite wall 3 in each second slot section.

[0068] Step ten, after the circular reinforcement cage 16 is lowered, the concrete is poured into each 2 sequence slot section to the top of the 2 sequence slot section, and the concrete is solidified to form a 2 sequence concrete wall; the final 1 sequence concrete wall and the 2 sequence concrete wall form a continuous concrete wall 1.

[0069] To sum up, the above is only the preferred embodiment of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A single-sided superimposed underground continuous wall structure that can also serve as the main structure, characterized in that: The single-sided superimposed underground continuous wall structure is a concrete wall arranged below the ground surface outside the foundation pit; A groove section is excavated in the soil around the foundation pit, and the concrete wall is cast in the groove section; The concrete wall is provided with continuously distributed composite walls, each composite wall is fixed in the groove section by composite wall support frames distributed at intervals, and the composite wall is located in the groove section on the side close to the foundation pit, and the composite wall support frames are located in the groove section on the side away from the foundation pit; The composite wall support frame includes: a support column, a middle support beam and a bottom support beam; the support column is a rod-shaped structure, the middle part of the support column is provided with a middle support beam, the bottom of the support column is provided with a bottom support beam, and the support column, the middle support beam and the bottom support beam are integrally formed; the end of the bottom support beam is provided with an upward protrusion; the support columns of two or more composite wall support frames are fixed in parallel in the groove section on the side away from the foundation pit, and the middle support beam and the bottom support beam of the composite wall support frame both extend toward the direction of the foundation pit; The composite wall comprises: a composite wall body, embedded steel bars for the ground-connected wall, and embedded steel bars for the main structure connection section; the composite wall body is a flat plate-shaped structure; the bottom of the composite wall body is machined with one or more positioning grooves spaced apart; when the composite wall body is installed in the groove section, the positioning grooves at the bottom of the composite wall body cooperate with the protrusions on the bottom support beam; both left and right sides of the composite wall body are machined with thinned sections; the protrusions on the bottom support beam are tetrahedral in structure; and the positioning groove at the bottom of the composite wall body is a tetrahedral groove. One side of the composite wall body is fixed with more than two embedded ground-connected wall steel bars arranged in parallel; the other side of the composite wall body is processed with more than two main structure connecting section embedded steel bar grooves arranged in a matrix, and each main structure connecting section embedded steel bar groove is fixed with more than two main structure connecting section embedded steel bars arranged in parallel; and the side where the main structure connecting section embedded steel bars are located faces the foundation pit.

2. The single-sided laminated underground continuous wall structure that can also serve as the main structure as claimed in claim 1, characterized in that: The composite wall and the composite wall support frame are all prefabricated in a factory.

3. A construction method for a single-sided overlapping underground continuous wall structure that can also serve as a main structure, based on the underground continuous wall structure of claim 1 or 2, characterized in that: The specific steps of this method are as follows: Step 1: excavating two parallel trench side wall grooves in the soil outside the foundation pit, and pouring concrete in the two trench side wall grooves to form two guide walls; Step 2: excavating two or more slot sections at intervals in the soil between the two guide walls, so that the two or more slot sections at intervals are all first-order slot sections; Step 3: Use slurry to protect the wall in the first sequence trench section, and then excavate to the required depth for pouring the concrete wall; Step 4: Clean the bottom of the first sequence trench section. After the cleaning is completed, place the composite wall support frames one by one at a specified interval on the side away from the foundation pit in each first sequence trench section; Step 5: Place the composite walls one by one below the foundation pit in each first-order trench section, with the positioning grooves at the bottom of the composite walls fitting with the protrusions of the bottom support beams of the composite wall support frames; Step 6: Place a locking pipe on each side of the composite wall in each 1st slot section; Step 7: After the locking tube is lowered, concrete is poured into each first-order trough section to the top of the first-order trough section. After the concrete solidifies, a first-order concrete wall is formed. Finally, the locking tube is removed; Step 8: excavating a slot segment between each two adjacent 1st-order slot segments, and making the slot segment between the 1st-order slot segments the 2nd-order slot segment; Step 9: After repeating steps 3 to 5, place a circular steel cage on each side of the composite wall in each 2-sequence slot segment; Step 10: After the circular steel cage is lowered, concrete is poured into each second-order trough section to the top of the second-order trough section. After the concrete solidifies, a second-order concrete wall is formed; finally, the first-order concrete wall and the second-order concrete wall form a continuous concrete wall.

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