A plugging wall structure capable of reducing foundation pit deformation and a foundation pit stepping construction method

Abstract

A kind of plugging wall structure capable of reducing foundation pit deformation and a split pit stepping construction method, characterized in that the long and narrow deep foundation pit is divided into multiple split foundation pits, and each split foundation pit is further divided into two sub-foundation pits; the split foundation pits are connected by a first plugging wall structure, which bears the earth pressure behind the walls on both sides of the unexcavated foundation pit; the two sub-foundation pits in the same split foundation pit are connected by a second plugging wall structure, which can save construction cost and shorten the construction period compared to the first plugging wall structure; the two plugging wall structures form a support system with the support structure in the foundation pit, which can greatly reduce the deformation of the foundation pit; the foundation pit is excavated by a split pit stepping excavation method. The method greatly reduces the deformation of the foundation pit enclosure structure during the construction of the long and narrow deep foundation pit under complex surrounding environmental conditions, ensures the stability of the support structure and meets the protection requirements of the surrounding sensitive buildings and structures, and is simple and low in cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building engineering, and in particular to a plugging wall supporting structure capable of reducing deformation of a narrow and deep foundation pit and a construction method of step-by-step excavation and removal of the foundation pit. BACKGROUND

[0002] With the acceleration of urbanization process in China and the rapid development of foundation pit construction, the scale of foundation pit engineering is getting larger, the excavation depth is getting deeper, and the surrounding environment is getting more complex. The construction of narrow and deep foundation pits has generally reached a depth of 20-30 meters and an area of 20-60 thousand square meters. The surrounding buildings involved in foundation pit construction are increasing, and higher requirements are put forward for the deformation control of narrow and deep foundation pits. How to effectively minimize the deformation of foundation pit construction to ensure the stability of the supporting structure and meet the protection requirements of surrounding sensitive buildings is a problem that needs to be solved. SUMMARY

[0003] The present application relates to the technical field of building engineering, and in particular to a plugging wall supporting structure capable of reducing deformation of a narrow and deep foundation pit and a construction method of step-by-step excavation and removal of the foundation pit.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0005] A plugging wall supporting structure capable of reducing deformation of a narrow and deep foundation pit, characterized in that: the narrow and deep foundation pit is divided into a plurality of sub-pits, and each sub-pit is further divided into two sub-pits; a first plugging wall structure is used to connect the sub-pits and bear the earth pressure behind the walls on both sides of the unexcavated foundation pit; a second plugging wall structure is used to separate the two sub-pits in the same sub-pit and can save construction cost and shorten the construction removal period compared to the first plugging wall structure; the two plugging wall structures form a support system with the supporting structure in the foundation pit, which can greatly reduce the deformation of the foundation pit. The foundation pit is excavated using a construction method of step-by-step excavation and removal of the foundation pit.

[0006] A diaphragm wall structure is used around the narrow and deep foundation pit, and reinforcement measures are taken for the pit bottom to meet the requirements of foundation pit deformation and sudden gushing prevention.

[0007] The narrow and deep foundation pit is divided into a plurality of sub-pits according to the actual working conditions of the foundation pit along the length direction of the foundation pit, and each sub-pit is further divided into two sub-pits along the length direction.

[0008] The first sealing wall structure is arranged between the sub-pits along the width direction of the foundation pit, the thickness of the first sealing wall structure is consistent with the diaphragm wall, the buried depth of the sealing wall structure is consistent with the depth of the foundation pit, and the length of the sealing wall is consistent with the width of the sub-pit; the first sealing wall structure is provided with reinforcement, and the reinforcement of the first sealing wall structure is arranged in a "H" shape with the reinforcement of the diaphragm wall.

[0009] The second sealing wall structure is arranged between two sub-pits in the same sub-pit, the thickness of the second sealing wall structure is consistent with the diaphragm wall, the buried depth of the sealing wall structure is consistent with or slightly longer than the depth of the foundation pit, and the length of the sealing wall is consistent with the width of the sub-pit; the reinforcement of the second sealing wall structure is only arranged within 1m of the connection between the two ends of the sealing wall and the diaphragm wall, and the reinforcement of the second sealing wall structure is arranged in a "T" shape with the reinforcement of the diaphragm wall.

[0010] The support system comprises: a supporting structure, a first sealing wall structure and a second sealing wall structure, wherein the supporting structure is arranged with multiple horizontal support structures and inclined supports in the foundation pit according to design requirements; meanwhile, horizontal supports are arranged at a position 1m away from both sides of the second sealing wall structure of the two sub-pits in the same sub-pit to replace the supporting effect after the sealing wall is removed, and the inclined supports are arranged at the connection position of the first sealing wall structure and the diaphragm wall to assist the first sealing wall structure in resisting the lateral pressure of the unexcavated sub-pit soil.

[0011] As a further explanation of the scheme of the application: the construction method for excavating the foundation pit by using the sub-pit step-by-step excavation method of any of the above-mentioned structures comprises the following steps:

[0012] (1) reinforcing structures are arranged at the bottom of the foundation pit;

[0013] (2) the long and narrow deep foundation pit is divided into multiple sub-pits according to actual conditions, and further divided into sub-pits;

[0014] (3) according to the distribution positions of the sub-pits and the sub-pits, diaphragm wall reinforcement cages, "H" shaped reinforcement of the first sealing wall structure and "T" shaped reinforcement of the second sealing wall structure are respectively prepared;

[0015] (4) before trenching, the trench wall of the diaphragm wall is reinforced, after trenching, the reinforcement cage is lowered, and the underground continuous wall, the first sealing wall structure and the second sealing wall structure are arranged;

[0016] (5) after all the structures are arranged, according to the positions of the sub-pits, the non-adjacent sub-pits are excavated by using the skip pit excavation method, when a sub-pit is excavated, the two sub-pits in the same sub-pit are excavated by using the segmented and layered construction method at the same time;

[0017] (6) when the two sub-pits in the same sub-pit are excavated, the construction is carried out in the order of excavating the internal soil of the sub-pit first, then erecting the concrete (steel) support, and finally removing the sealing wall structure;

[0018] (7) When the second kind of sealing wall both sides of the sub-pit excavation to the first support design depth 0.5m below, the first support is set up, and ensure that the distance of the second kind of sealing wall both sides 1m place is set up concrete (steel) support;

[0019] (8) When the second kind of sealing wall both sides of the sub-pit excavation to the second support design depth 0.5m below, the second support is set up, and ensure that the distance of the second kind of sealing wall both sides 1m place is set up concrete (steel) support, the excavation process is synchronous to remove the second kind of sealing wall to the first support setting depth;

[0020] (9) When the second kind of sealing wall both sides of the sub-pit excavation to the third support design depth 0.5m below, the third support is set up, and ensure that the distance of the second kind of sealing wall both sides 1m place is set up concrete (steel) support, the excavation process is synchronous to remove the second kind of sealing wall to the second support setting depth;

[0021] (10) When the second kind of sealing wall both sides of the sub-pit excavation to the last support design depth, the last support is set up, and ensure that the distance of the second kind of sealing wall both sides 1m place is set up concrete (steel) support, the excavation process is synchronous to remove the second kind of sealing wall to the last support setting depth;

[0022] (11) When excavation to the pit bottom position, the excavation process is synchronous to remove the second kind of sealing wall to the last support setting depth.

[0023] (12) After pouring the bottom plate, the second kind of sealing wall is completely removed, and the floor sealing wall position is poured after the pouring belt;

[0024] (13) The lining structure in the sub-pit is back built;

[0025] (14) Repeat steps (6) to (13), and simultaneously remove the first kind of sealing wall to complete the remaining sub-pit construction;

[0026] (15) After all sub-pits and sub-pits excavation and support system construction is completed, in the order from bottom to top, the main structure in the pit is constructed in sections, and the corresponding support is removed respectively;

[0027] (16) After all sub-pits and sub-pits excavation and support system construction is completed, in the order from bottom to top, the main structure in the pit is constructed in sections, and the corresponding support is removed respectively;

[0028] The advantages of the present application are that, compared with the prior construction method: the first kind of blocking wall structure is used to connect between the sub-pits, and bears the earth pressure on both sides of the wall of the unexcavated sub-pit; the second kind of blocking wall structure is used to connect between the two sub-pits in the same sub-pit, and compared with the first kind of blocking wall structure, the construction cost is saved, and the construction period is shortened; the two kinds of blocking walls form a support system with the supporting structure in the foundation pit, which can greatly reduce the deformation of the foundation pit; and the sub-pit stepping demolition excavation construction method is used for the excavation of the foundation pit. The deformation of the foundation pit enclosure structure in the construction process of the long and deep foundation pit under the complex surrounding environment condition is greatly reduced, the stability of the supporting structure is ensured, and the protection requirements of the surrounding sensitive buildings are met. The construction method is simple and low in cost. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the long and deep foundation pit blocking wall supporting structure of the present application, wherein Figure I and Figure A-A shows a comparison diagram of the deformation of the diaphragm wall in the case of having the second kind of blocking wall structure and not having the second kind of blocking wall structure;

[0030] Figure 2 It is a schematic diagram of the connection of the sub-pit and the blocking wall and the diaphragm wall of the long and deep foundation pit of the present application, wherein I and II are partial enlarged views of the reinforcement of the first kind of blocking wall and the second kind of blocking wall, respectively;

[0031] Figure 3 It is a schematic diagram of the arrangement of the horizontal support in the depth direction;

[0032] Figure 4 It is a schematic diagram of the preparation for excavation after the completion of the diaphragm wall and the blocking wall structure;

[0033] Figure 5 It is a schematic diagram of the erection of the first support after the excavation to below the design depth of 0.5 m of the first support;

[0034] Figure 6 It is a schematic diagram of the erection of the second support and the removal of the second kind of blocking wall to the setting depth of the first support after the excavation to below the design depth of 0.5 m of the second support;

[0035] Figure 7 It is a schematic diagram of the erection of the third support and the removal of the second kind of blocking wall to the setting depth of the second support after the excavation to below the design depth of 0.5 m of the third support;

[0036] Figure 8 It is a schematic diagram of the erection of the last support and the removal of the second kind of blocking wall to the setting depth of the last support after the excavation to the design depth of the last support;

[0037] Figure 9: Schematic diagram of excavating to the bottom of the pit and chiseling the second kind of blocking wall to the setting depth of the last support

[0038] Figure 10 : Schematic diagram of completely chiseling the second kind of blocking wall after pouring the bottom plate.

[0039] In the figure: 1 - diaphragm wall, 2 - first kind of blocking wall, 3 - second kind of blocking wall, 4 - concrete (steel) support, 5 - pit bottom reinforcing structure, 6 - soil body, 11 - diaphragm wall stress reinforcement, 12 - diaphragm wall standing reinforcement, 21 - first kind of blocking wall stress reinforcement, 22 - first kind of blocking wall standing reinforcement, 31 - second kind of blocking wall stress reinforcement, 32 - second kind of blocking wall standing reinforcement, 41 - first horizontal support, 42 - second horizontal support, 43 - third horizontal support, 44 - last horizontal support, 71 - maximum deformation value of diaphragm wall (with second kind of blocking wall), 72 - deformation value of a vertical section of diaphragm wall (with second kind of blocking wall), 81 - maximum deformation value of diaphragm wall (without second kind of blocking wall), 82 - deformation of a vertical section of diaphragm wall (without second kind of blocking wall), 9 - inclined support. DETAILED DESCRIPTION

[0040] The technical solutions of the present application will be further described in detail below in combination with the drawings and examples. It can be understood that the specific embodiments described herein are only used to explain the related content, and are not a limitation on the present disclosure. In addition, it needs to be explained that, for the convenience of description, only the parts related to the present application are shown in the drawings.

[0041] It needs to be explained that, in some embodiments of the present disclosure, for a newly built deep and narrow foundation pit, the length direction refers to the x direction indicated in each figure, the width direction refers to the y direction indicated in each figure, and the vertical direction, the vertical direction or the depth direction refers to the z direction indicated in each figure.

[0042] The present application relates to a kind of blocking wall supporting structure capable of reducing the deformation of long and narrow deep foundation pit, as shown in Figure 1 、 Figure 2 Characterized in that: long and narrow deep foundation pit is divided into multiple sub-foundation pits, each sub-foundation pit is further divided into two sub-foundation pits;Sub-foundation pit is connected using first kind of blocking wall 2, two sub-foundation pits in the same sub-foundation pit are separated using second kind of blocking wall 3;Sub-foundation pit is supported using concrete (steel) support 4 and cooperates with blocking wall structure to form support system.

[0043] In the example of the present application, the foundation pit excavation depth is in the range of 16-19m, the length of each sub-pit is in the range of 47-77m, and the total is divided into 9 sub-pits. In the related art, the sub-pit division is determined according to the actual design requirements. In addition, the pit bottom reinforcement structure 5 adopts φ650mm@450mm triaxial mixing pile for skirt edge plus strip reinforcement, and the reinforcement depth is 3m below the pit bottom. The skirt reinforcement width is 5m, the strip reinforcement width is 3m, and the interval is 4.35m-6m. In the related art, the pit bottom reinforcement can also adopt other feasible methods and structures.

[0044] In the example of the present application, the thickness of the underground continuous wall 1 is set to 1m, and the reinforcement is arranged according to the design requirements: the longitudinal reinforcement adopts HRB400 grade steel with a diameter of 32mm, which is uniformly arranged on each side of the wall body with a spacing of 200mm and a net spacing of 75mm, and the longitudinal reinforcement is not less than 50% of the total number; the horizontal reinforcement adopts HPB235 grade steel with a diameter of 12mm, and the spacing is 300mm, which is welded into a net shape with the longitudinal reinforcement; the sealing reinforcement adopts HPB235 grade steel with a diameter of 12mm, and the vertical spacing is the same as the horizontal reinforcement or is arranged at intervals according to the horizontal reinforcement spacing, and is welded with the horizontal reinforcement with the same strength; the structural reinforcement is arranged according to the overall stability and deformation requirements of the reinforcement cage during hoisting; the main reinforcement protection layer thickness is not less than 70mm on the outside of the foundation pit and not less than 50mm on the inside of the foundation pit. Before the implementation of the underground continuous wall 1, the slot wall is reinforced. The slot wall is reinforced by φ650mm@450mm triaxial mixing pile with a pile length of 17m. In the related art, the slot wall reinforcement can also adopt other feasible methods and structures.

[0045] In the example of the present application, the first sealing wall structure 2 is arranged between the sub-foundation pits along the width direction of the foundation pit, the thickness of the first sealing wall structure is consistent with the diaphragm wall 1, the buried depth of the sealing wall structure is consistent with the depth of the foundation pit, and the length of the sealing wall is consistent with the width of the sub-foundation pit.

[0046] In the example of the present application, the second sealing wall structure 3 is arranged between two sub-foundation pits in the same sub-foundation pit, the thickness of the second sealing wall structure is consistent with the diaphragm wall 1, the buried depth of the sealing wall structure is consistent with or slightly longer than the depth of the foundation pit, and the length of the sealing wall is consistent with the width of the sub-foundation pit.

[0047] Figure 2 The connection schematic diagram of the diaphragm wall 1 in the sub-pit and the first sealing wall 2 and the second sealing wall 3 is shown, and the detailed structure of the internal reinforcement connection mode is shown in Figure 2 The local enlarged view of part I and part II, and the reinforcement is arranged according to the design requirements.

[0048] As Figure 2As shown in the first kind of blocking wall 2, the first kind of blocking wall 2 is connected with the diaphragm wall 1, and the horizontal steel bars in the first kind of blocking wall 2 are bent and welded with the horizontal steel bars in the diaphragm wall 1 to form a "H" shaped structure.

[0049] As shown in the first kind of blocking wall 2, the first kind of blocking wall 2 is connected with the diaphragm wall 1, and the horizontal steel bars in the first kind of blocking wall 2 are bent and welded with the horizontal steel bars in the diaphragm wall 1 to form a "H" shaped structure. Figure 2 As shown in the second kind of blocking wall 3, the second kind of blocking wall 3 is connected with the diaphragm wall 1, and the horizontal steel bars in the second kind of blocking wall 3 are bent and welded with the horizontal steel bars in the diaphragm wall 1 to form a "T" shaped structure.

[0050] In the example of the present application, the supporting structure, the first kind of blocking wall structure 2 and the second kind of blocking wall structure 3 are combined to form the supporting system of the example, wherein the supporting structure is arranged with multiple horizontal supports 4 and inclined supports in the foundation pit according to the design requirements. Figure 2 As shown in the first kind of blocking wall 2, the first kind of blocking wall 2 is connected with the diaphragm wall 1, and the horizontal steel bars in the first kind of blocking wall 2 are bent and welded with the horizontal steel bars in the diaphragm wall 1 to form a "H" shaped structure.

[0051] As shown in the first kind of blocking wall 2, the first kind of blocking wall 2 is connected with the diaphragm wall 1, and the horizontal steel bars in the first kind of blocking wall 2 are bent and welded with the horizontal steel bars in the diaphragm wall 1 to form a "H" shaped structure. Figure 3 As shown in the first kind of blocking wall 2, the first kind of blocking wall 2 is connected with the diaphragm wall 1, and the horizontal steel bars in the first kind of blocking wall 2 are bent and welded with the horizontal steel bars in the diaphragm wall 1 to form a "H" shaped structure.

[0052] As shown in the first kind of blocking wall 2, the first kind of blocking wall 2 is connected with the diaphragm wall 1, and the horizontal steel bars in the first kind of blocking wall 2 are bent and welded with the horizontal steel bars in the diaphragm wall 1 to form a "H" shaped structure. Figures 4 to 10 The construction method flowchart of the step-by-step excavation and removal of the foundation pit of the present application is shown in the figure, and the construction method steps of the step-by-step excavation and removal of the foundation pit of the example of the present application are as follows:

[0053] (1) reinforcing structure 5 is arranged at the bottom of the foundation pit;

[0054] (2) the long and narrow deep foundation pit is divided into multiple sub-foundation pits according to the actual situation, and further divided into sub-foundation pits;

[0055] (3) According to the distribution position of the sub-pit and the sub-pit, the diaphragm wall steel cage, the first plugging wall structure "H" shaped reinforcement and the second plugging wall structure "T" shaped reinforcement are respectively made;

[0056] (4) Before the trench is formed, the trench wall of the diaphragm wall is reinforced, and after the trench is formed, the steel cage is lowered, and the underground continuous wall 1, the first plugging wall structure 2 and the second plugging wall structure 3 are constructed;

[0057] (5) After all the structures are constructed, according to the position of the sub-pit, the non-adjacent sub-pits are excavated by the jump pit excavation method, the sub-pits 1, 3, 5, 7 and 9 are the first phase pit engineering, and the sub-pits 2, 4 and 6 are the second phase pit engineering, the construction of the first phase pit engineering is carried out first, when a sub-pit is excavated, the two sub-pits of the same sub-pit are excavated simultaneously by the construction method of sub-pit and layer by layer;

[0058] (6) When the two sub-pits of the same sub-pit are excavated, the construction is carried out in the order of excavating the internal soil of the sub-pit first, then erecting the concrete (steel) support, and finally removing the plugging wall structure, the structure section before the horizontal support is constructed as shown in Figure 4 ;

[0059] (7) As shown in Figure 5 , when the excavation of the two sub-pits on both sides of the second plugging wall 3 reaches below the design depth of the first support 0.5m, the first support 41 is erected, and the support is ensured to be erected at a distance of 1m from both sides of the second plugging wall 3;

[0060] (8) As shown in Figure 6 , when the excavation of the two sub-pits on both sides of the second plugging wall 3 reaches below the design depth of the second support 0.5m, the second support 42 is erected, and the support is ensured to be erected at a distance of 1m from both sides of the second plugging wall 3, and the excavation process is synchronized with the removal of the second plugging wall 3 to the setting depth of the first support 41;

[0061] (9) As shown in Figure 7 , when the excavation of the two sub-pits on both sides of the second plugging wall 3 reaches below the design depth of the third support 0.5m, the third support 43 is erected, and the support is ensured to be erected at a distance of 1m from both sides of the second plugging wall 3, and the excavation process is synchronized with the removal of the second plugging wall 3 to the setting depth of the second support 42;

[0062] (10) As shown in Figure 8 , when the excavation of the two sub-pits on both sides of the second plugging wall 3 reaches the last first support design depth, the last first support 44 is erected, and the support is ensured to be erected at a distance of 1m from both sides of the second plugging wall 3, and the excavation process is synchronized with the removal of the second plugging wall 3 to the setting depth of the last second support 43;

[0063] (11) As shown in Figure 9As shown, when excavated to the pit bottom position, the excavation process is synchronized with the removal of the second kind of blocking wall 3 to the depth of the last support 44.

[0064] (12) As Figure 10 As shown, after pouring the bottom plate, the second kind of blocking wall 3 is completely removed, and the post-pouring blocking wall position is poured into the strip;

[0065] (13) The lining structure in the sub-pit is built back;

[0066] (14) Repeat steps (6) to (13) to complete the remaining sub-pit construction in the first phase of the project;

[0067] (15) After completing the construction of the first phase of the foundation pit, repeat steps (6) to (14) to complete the construction of the second phase of the foundation pit;

[0068] (16) After the excavation and support system construction of all sub-pits and sub-pits is completed, the main structure in the foundation pit is constructed in a bottom-up order, and the corresponding supports are removed;

[0069] (17) After all the sub-area main structures are capped, all the first kind of blocking wall 2 is removed;

[0070] Although the present application has been illustrated and described with reference to certain example embodiments thereof, the foregoing description is not intended to be exhaustive or to limit the application to the precise form described and disclosed. Changes, modifications, additions or substitutions, within the ability of those skilled in the art, can be made to the present application without departing from the spirit thereof.

Claims

1. A construction method for a sealing wall support structure capable of reducing deformation of narrow, deep foundation pits, characterized in that: The long and narrow deep foundation pit is divided into multiple sub-foundations, and each sub-foundation pit is further divided into two sub-foundations; The first type of sealing wall structure is used to connect the sub-excavation pits, which bears the soil pressure behind the walls on both sides of the unexcavated pits. Two sub-pits within the same sub-pit are separated by a second type of sealing wall structure; The construction method includes the following steps: (1) Construct a reinforcement structure at the bottom of the foundation pit; (2) Divide the long and narrow deep foundation pit into multiple sub-foundations according to the actual situation, and further divide them into sub-foundations; (3) Based on the distribution location of the sub-foundation pits and sub-foundation pits, respectively fabricate the diaphragm wall reinforcement cage, the first type of sealing wall structure with "I" shaped reinforcement and the second type of sealing wall structure with "T" shaped reinforcement; (4) Before trenching, the trench walls of the diaphragm wall are reinforced. After trenching, the steel cage is lowered and the underground continuous wall, the first type of sealing wall structure and the second type of sealing wall structure are constructed. (5) After all the structures are completed, the non-adjacent sub-foundations are excavated according to the location of the sub-foundations by skip-pit excavation. When excavating a certain sub-foundation, the two sub-foundations of the same sub-foundation are excavated simultaneously by segmented and layered construction. (6) When excavating two sub-pits of the same sub-pit, the construction shall be carried out in the following order: first excavate the soil inside the sub-pit, then erect concrete supports, and finally remove the sealing wall structure. (7) When the sub-foundation pits on both sides of the second type of sealing wall are excavated to a depth of 0.5m below the design depth of the first support, the first support shall be erected and concrete support shall be erected at a distance of 1m from both sides of the second type of sealing wall. (8) When the sub-foundation pits on both sides of the second type of sealing wall are excavated to a depth of 0.5m below the design depth of the second support, the second support shall be erected and concrete support shall be erected at a distance of 1m from both sides of the second type of sealing wall. During the excavation process, the second type of sealing wall shall be chiseled away to the depth of the first support. (9) When the sub-foundation pits on both sides of the second type of sealing wall are excavated to a depth of 0.5m below the design depth of the third support, the third support shall be erected and concrete support shall be erected 1m away from both sides of the second type of sealing wall. During the excavation process, the second type of sealing wall shall be chiseled away to the depth of the second support. (10) When the sub-foundation pits on both sides of the second type of sealing wall are excavated to the design depth of the penultimate support, the penultimate support shall be erected, and concrete support shall be erected 1m away from both sides of the second type of sealing wall. During the excavation process, the second type of sealing wall shall be chiseled away to the depth of the second-to-last support. (11) When the excavation reaches the bottom of the pit, the second type of sealing wall shall be removed simultaneously during the excavation process up to the depth of the last support; (12) After pouring the base slab, completely remove the second type of sealing wall and pour the post-pouring strip at the location of the sealing wall on the base slab; (13) Reconstruct the lining structure of the sub-foundation pit; (14) Repeat steps (6) to (13) and simultaneously remove the first type of sealing wall to complete the remaining sub-foundation pit construction; (15) After all the sub-pits and sub-pits have been excavated and the support system has been completed, the main structure in the pits shall be constructed in sections from bottom to top, and the corresponding supports shall be removed respectively. (16) After the main structure of all zones is capped, remove all the first type of sealing walls.

2. The construction method of the sealing wall support structure capable of reducing deformation of narrow and deep foundation pits according to claim 1, characterized in that, Long and narrow deep foundation pit: The perimeter of the foundation pit adopts a diaphragm wall structure, and the bottom of the pit is reinforced to meet the requirements for foundation pit deformation and prevention of sudden surge.

3. The construction method of the sealing wall support structure capable of reducing deformation of narrow and deep foundation pits according to claim 1, characterized in that, Long and narrow deep foundation pit: According to the actual working conditions of the foundation pit, it is divided into multiple sub-foundations along the length of the foundation pit, and each sub-foundation pit is further divided into two sub-foundations along the length.

4. The construction method of the sealing wall support structure capable of reducing deformation of narrow and deep foundation pits according to claim 1, characterized in that, The first type of sealing wall structure is set between the sub-pits along the width of the foundation pit. The thickness of the first type of sealing wall structure is the same as that of the diaphragm wall, the burial depth of the sealing wall structure is the same as that of the foundation pit, and the length of the sealing wall is the same as that of the sub-pit. The first type of sealing wall structure is reinforced and is arranged in an "I" shape with the reinforcement of the diaphragm wall.

5. The construction method of the sealing wall support structure capable of reducing deformation of narrow and deep foundation pits according to claim 1, characterized in that, The second type of sealing wall structure: It is set between two sub-pits in the same sub-pit. The thickness of the second type of sealing wall structure is the same as that of the diaphragm wall. The burial depth of the sealing wall structure is the same as or slightly longer than the depth of the pit. The length of the sealing wall is the same as the width of the sub-pit. The reinforcement of the second type of sealing wall structure is only set within 1m at both ends of the sealing wall and the connection with the diaphragm wall, and the reinforcement is set in a "T" shape with the reinforcement of the diaphragm wall.

6. The construction method of the sealing wall support structure capable of reducing deformation of narrow and deep foundation pits according to claim 1, characterized in that, Support system: includes a support structure, a first type of sealing wall structure and a second type of sealing wall structure. The support structure is arranged with multiple horizontal support structures and diagonal braces in the foundation pit according to the design requirements. At the same time, horizontal supports are arranged 1m away from the two sub-foundations in the same sub-foundation pit on both sides of the second type of sealing wall structure to replace the support effect after the sealing wall is removed. The diagonal braces are arranged at the connection position of the first type of sealing wall structure and the diaphragm wall to assist the first type of sealing wall structure in resisting the lateral pressure of the soil in the unexcavated sub-foundation pit.

Images