Underground foundation pit construction supporting structure
By connecting the bottom plate and the enclosure wall by cast-in-place concrete parts, the problems of complex construction of foundation pit support structures and water overflow are solved, and construction simplification and lateral force resistance are achieved.
Patent Information
- Application Number
- CN202422029140.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-08-21
AI Technical Summary
The construction process of the existing foundation pit support structure is complex and costly, and the auxiliary diagonal braces need to be prefabricated and removed, which affects the construction progress and is prone to water overflow.
Cast-in-place concrete parts are used as auxiliary support, including cast-in-place steel cages and cast concrete bodies. The bottom plate and enclosure wall are connected by embedded frame main ribs and horizontal stirrups, simplifying the construction process and improving the resistance to lateral force.
The construction process is simplified, the construction difficulty and cost are reduced, the water overflow is avoided, and the lateral force resistance and construction progress of the enclosure wall are improved.
Smart Images
Figure CN223151194U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of foundation pit earthwork construction, in particular to a construction support structure for an underground foundation pit. Background Art
[0002] In China, deep foundation pit engineering started in the 1980s. Due to the rapid development of urban high-rise buildings, various needs such as underground parking lots, the buried depth of high-rise buildings, and civil air defense, high-rise buildings need to be equipped with basements. There are usually various structures such as traffic roads, existing buildings or pipelines around the basement foundation pit. In order to ensure the safety of project construction, it is necessary to add foundation pit support during the foundation pit excavation construction. Foundation pit support is used to ensure the safety of underground structure construction and the surrounding environment of the foundation pit, and is a retaining, reinforcement and protection measure taken for the foundation pit side wall.
[0003] In the prior art, as Figure 1 shown, the foundation pit support mainly consists of a retaining wall and auxiliary inclined struts. Multiple retaining walls cooperate to retain, reinforce and protect the foundation pit side wall. After it is poured, due to the large cantilever size of the retaining wall, it is necessary to rely on the auxiliary inclined struts for side support. Under the combined action of multiple auxiliary inclined struts, the retaining wall is continuously subjected to the lateral pushing force, thereby avoiding the occurrence of excessive horizontal displacement and water overflow of the foundation pit. However, in practical applications, the above technical solutions have the following problems: 1) The auxiliary inclined struts need to be prefabricated in the factory, and installation seats also need to be preformed in the basement foundation pit and on the inner wall of the retaining wall respectively to assemble the auxiliary inclined struts. The construction process is relatively complex and the construction cost is extremely high; 2) Since the auxiliary inclined struts need to penetrate the basement exterior wall, they can only be cut off after the surrounding soil is backfilled. The construction volume is large, and water overflow is likely to occur in the area where the auxiliary inclined struts are cut off because it cannot be effectively and timely blocked, which will inevitably increase the subsequent construction difficulty and affect the normal construction process. Therefore, it is urgent for technical personnel to solve the above problems. Summary of the Utility Model
[0004] Therefore, in view of the above existing problems and defects, the research and development team of the utility model collected relevant materials, through multi-party evaluation and consideration, and through continuous experiments and modifications by the research and development team members, finally led to the emergence of the construction support structure for the underground foundation pit.
[0005] In order to solve the above technical problems, the utility model relates to an underground foundation pit construction support structure, including a base plate, a retaining wall and an auxiliary support member. A plurality of retaining walls cooperate to support, reinforce and protect the side walls of the foundation pit. The base plate uses the base wall of the foundation pit as a bearing base. A plurality of auxiliary support members are used to improve the lateral force resistance performance of the corresponding retaining wall, which serves as a connection transition between the base plate and the retaining wall. The auxiliary support member is a cast-in-place concrete member. The cast-in-place concrete member passes over the base plate, and includes a cast-in-place steel cage and a cast concrete body. The cast-in-place steel cage includes a frame main bar and a horizontal stirrup, wherein one end of a plurality of frame main bars is rooted in the base plate, and undergoes multiple bending and forming to form a frame structure with a "trapezoidal" longitudinal section for filling the cast concrete body. One end of the horizontal stirrup is rooted in the retaining wall, and undergoes multiple bending and forming to circumferentially embrace the tightly hoop frame structure. The number of horizontal stirrups is set to multiple, and is linearly evenly distributed along the height direction of the frame structure.
[0006] As a further improvement of the technical solution disclosed in the utility model, the enclosure wall and the base plate are both cast in situ with concrete.
[0007] As a further improvement of the technical solution disclosed in the utility model, the main reinforcement of the frame is embedded in the base plate in a pre-embedded manner, and the first main reinforcement hook embedded in the base plate and the second main reinforcement hook embedded in the cast concrete body are bent at both ends. The horizontal stirrups are also embedded in the enclosure wall in a pre-embedded manner, and the stirrup hooks embedded in the enclosure wall are bent at their rooted ends.
[0008] As a further improvement of the technical solution disclosed in the utility model, the cast-in-place steel cage further includes L-shaped additional ribs which are rooted in the bottom plate and pull the bottom plate and the cast concrete body at the same time.
[0009] As a further improvement of the technical solution disclosed in the utility model, the two free ends of the L-shaped additional ribs are respectively bent to form a first additional rib hook embedded in the base plate and a second additional rib hook embedded in the cast concrete body.
[0010] As a further improvement of the technical solution disclosed in the utility model, the L-shaped additional rib is connected by a horizontal section and a vertical section. The first additional rib hook is formed at the free end of the horizontal section, and the second additional rib hook is formed at the free end of the vertical section. The distance between the horizontal section and the top wall of the bottom plate is d1, and the distance between the vertical section and the inner wall of the enclosure wall is d2, then 30mm≤d1≤50mm, 30mm≤d2≤50mm.
[0011] As a further improvement of the technical solution disclosed in the utility model, the distance that the cast-in-place concrete member passes over the bottom plate is d, and the height dimension of the enclosing wall is h, then 1 / 8h≤d≤1 / 5h.
[0012] In actual construction applications, the underground foundation pit construction support structure disclosed by the present utility model can achieve at least the following beneficial technical effects, specifically:
[0013] 1) Compared with the traditional auxiliary inclined strut design structure, the factory prefabrication and the prefabricated installation seats at the bottom of the foundation pit and the retaining wall are eliminated. In the present utility model, the cast-in-place concrete member used as the auxiliary support only needs to fabricate the cast-in-place steel reinforcement cage on-site, and then perform on-site concrete pouring and solidification, which greatly simplifies the construction process and reduces the construction difficulty;
[0014] 2) The cast-in-place concrete member does not need to penetrate the basement exterior wall. On the one hand, it does not need to be demolished after use, and the earthwork backfilling of the basement foundation pit can be carried out, saving time and effort; on the other hand, it effectively guarantees the integrity of the basement exterior wall, thus effectively avoiding the occurrence of water overflow phenomenon and facilitating the smooth progress of subsequent construction;
[0015] 3) Since the cast-in-place concrete member crosses the floor slab, the cantilever length of the retaining wall is reduced. In this way, not only is it beneficial to improve the lateral force resistance ability of the retaining wall, but also it helps to reduce the requirements for the strength of the horizontal support structure;
[0016] 4) According to the specific construction environment on-site (including the dimensions of the retaining wall, the floor slab, and the relative position relationship between the retaining wall and the floor slab), parameters such as the position, size, and shape of the cast-in-place concrete member can be adjusted adaptively on-site, thus greatly improving the convenience and flexibility of construction. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0018] Figure 1 is a construction schematic diagram of an underground foundation pit construction support structure in the prior art.
[0019] Figure 2 is a construction schematic diagram of the first implementation manner of the underground foundation pit construction support structure in the present utility model.
[0020] Figure 3 is a structural schematic diagram of the cast-in-place concrete member in the first implementation manner of the underground foundation pit construction support structure of the present utility model.
[0021] Figure 4 is a structural schematic diagram of the cast-in-place steel reinforcement cage in the first implementation manner of the underground foundation pit construction support structure of the present utility model.
[0022] Figure 5 It is a construction schematic diagram of the second implementation mode of the underground foundation pit construction support structure in the utility model.
[0023] Figure 6 It is a structural schematic diagram of a cast-in-place steel cage in the second implementation manner of the utility model underground foundation pit construction support structure.
[0024] Figure 7 It is a structural schematic diagram of L-shaped additional reinforcement in the second implementation mode of the underground foundation pit construction support structure of the utility model.
[0025] 1-base plate; 2-enclosing wall; 3-auxiliary support member; 31-cast-in-place concrete member; 311-cast-in-place steel cage; 3111-frame main reinforcement; 31111-first main reinforcement hook; 31112-second main reinforcement hook; 3112-horizontal stirrups; 31121-stirrup hook; 3113-L-shaped additional reinforcement; 31131-horizontal section; 311311-first additional reinforcement hook; 31132-vertical section; 311321-second additional reinforcement hook; 312-cast concrete body. DETAILED DESCRIPTION
[0026] The following is a further detailed description of the present invention in conjunction with specific embodiments. Figure 2 The schematic diagram of the construction of the first embodiment of the support structure for underground foundation pit construction in the utility model is shown. It can be seen that it is mainly composed of several parts such as a base plate 1, a retaining wall 2 and an auxiliary support member 3. Among them, a plurality of retaining walls 2 are arranged around the side walls of the foundation pit, and cooperate with each other to support, reinforce and protect the side walls of the foundation pit. The base plate 1 uses the bottom wall of the foundation pit as a bearing base. A plurality of auxiliary support members 3 are used to improve the lateral force resistance of the corresponding retaining wall 2, which serves as a connection transition between the base plate 1 and the retaining wall 2. Under the premise of ensuring construction safety, in order to reduce the difficulty and cost of construction, the retaining wall 2 and the base plate 1 are preferably cast on-site by concrete. The auxiliary support member 3 is preferably a cast-in-place concrete member 31. The cast-in-place concrete member 31 passes over the base plate 1, and includes a cast-in-place steel cage 311 and a cast concrete body 312 (such as Figure 3 ). The cast-in-place steel cage 311 includes a frame main bar 3111 and horizontal stirrups 3112, wherein one end of the plurality of frame main bars 3111 is rooted in the bottom plate 1, and undergoes multiple bending and forming to form a frame structure with a "trapezoidal" longitudinal section for filling the cast concrete body 312. One end of the horizontal stirrup 3112 is rooted in the retaining wall 2, and undergoes multiple bending and forming to circumferentially embrace the frame structure. The number of horizontal stirrups 3112 is set to be multiple, and is linearly evenly distributed along the height direction of the frame structure (such as Figure 4 ).
[0027] In actual construction applications, the underground foundation pit construction support structure disclosed by the present utility model has achieved at least the following beneficial technical effects, specifically:
[0028] 1) Compared with the traditional auxiliary inclined strut design structure, the factory prefabrication and the prefabricated installation seats at the bottom of the foundation pit and the retaining wall are eliminated. In the present utility model, the cast-in-place concrete member 31 used as the auxiliary support member only needs to fabricate the cast-in-place steel reinforcement cage on site, and then pour and solidify the concrete on site, thus greatly simplifying the construction process and reducing the construction difficulty;
[0029] 2) The cast-in-place concrete member 31 does not need to penetrate the basement exterior wall. On the one hand, after being utilized, it does not need to be demolished, and the earthwork backfilling of the basement foundation pit can be carried out, saving time and effort; on the other hand, it effectively ensures the integrity of the basement exterior wall, thus effectively avoiding the occurrence of water overflow phenomenon and facilitating the smooth progress of subsequent construction;
[0030] 3) Since the cast-in-place concrete member 31 crosses the bottom plate 1, the cantilever length of the retaining wall 2 is reduced. In this way, not only is it beneficial to improve the lateral force resistance ability of the retaining wall 2, but also it helps to reduce the requirements for the strength of the horizontal support structure;
[0031] It should also be noted here that according to the specific construction environment on site, parameters such as the position, size, and shape of the cast-in-place concrete member 31 can be adjusted adaptively on site, thus greatly improving the convenience and flexibility of construction.
[0032] Just as Figure 2 shown, the frame main reinforcement 3111 is rooted in the bottom plate 1 in a pre-embedded manner, and the horizontal stirrups 3112 are also rooted in the retaining wall 2 in a pre-embedded manner. As Figure 3 、 4 shown, at both ends of the frame main reinforcement 3111, a first main reinforcement hook 31111 pre-embedded in the bottom plate 1 and a second main reinforcement hook 31112 pre-embedded in the cast-in-place concrete body 312 are respectively bent and formed. At the rooted end of the horizontal stirrups 3112, a stirrup hook 31121 pre-embedded in the retaining wall is bent and formed. In this way, without significantly increasing the complexity of the design structure and the construction difficulty, it effectively ensures that the cast-in-place concrete member 31 is reliably and stably connected to the bottom plate 1 and the retaining wall 2, and avoids the occurrence of the phenomenon that the frame main reinforcement 3111 and the stirrup hook 31121 break away from the bottom plate 1 or the retaining wall 2 due to excessive force.
[0033] Furthermore, as Figure 2As shown, the distance that the cast-in-place concrete member 31 extends beyond the bottom plate 1 is d, and the height dimension of the retaining wall 2 is h, then 1 / 8h ≤ d ≤ 1 / 5h. In this way, without significantly increasing the design size of the cast-in-place concrete member 31, it not only helps to reduce the construction difficulty and cost, but also effectively ensures that it can continuously, stably, and reliably apply a lateral pushing force to the retaining wall 2.
[0034] Figure 5 The construction schematic diagram of the second implementation manner of the underground foundation pit construction support structure in the present utility model is shown. It can be seen that the difference compared with the above first implementation manner is that: the cast-in-place steel reinforcement cage 311 is further provided with an L-shaped additional reinforcement 3113. The L-shaped additional reinforcement 3113 is rooted in the bottom plate 1 and simultaneously pulls the bottom plate 1 and the cast-in-place concrete body 31 (as Figure 6 shown). In this way, it not only effectively improves the structural stability of the cast-in-place concrete body 312 formed in the cast-in-place steel reinforcement cage 311 and avoids the occurrence of the phenomenon of its breaking due to excessive stress, but also greatly improves the connection strength between the cast-in-place concrete member 31 and the bottom plate 1 and avoids the occurrence of the phenomenon that the cast-in-place concrete member 31 is displaced or breaks away from the bottom plate 1 due to excessive stress.
[0035] Considering further improving the connection strength between the cast-in-place concrete member 31 and the bottom plate 1, as a further optimization of the above technical solution, as Figure 7 shown, the L-shaped additional reinforcement 3113 is composed of a horizontal section 31131 and a vertical section 31132 connected. At the free end of the horizontal section 31131, a first additional reinforcement hook 311311 embedded in the bottom plate 1 is bent and formed, and at the free end of the vertical section 31132, a second additional reinforcement hook 311321 embedded in the cast-in-place concrete body 312 is bent and formed.
[0036] Finally, it should also be noted that according to common sense, the specific positions of the L-shaped additional reinforcement 3113 relative to the bottom plate 1 and the retaining wall 2 not only affect the structural stability of the cast-in-place steel reinforcement cage 311, but also affect the connection stability between the cast-in-place concrete member 31 and the bottom wall 1 and between the cast-in-place concrete member 31 and the retaining wall 2. In view of this, as a further optimization of the above technical solution, as Figure 5 shown, assuming the distance between the horizontal section 31131 and the top wall of the bottom plate 1 is d1, and the distance between the vertical section 31132 and the inner wall of the retaining wall 2 is d2, then 30mm ≤ d1 ≤ 50mm, 30mm ≤ d2 ≤ 50mm.
[0037] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present utility model. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present utility model. Therefore, the present utility model will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.
Claims
1. An underground foundation pit construction support structure, comprising a bottom plate, retaining walls and auxiliary support members; a plurality of the retaining walls cooperate to support, reinforce and protect the side walls of the foundation pit; the bottom plate takes the bottom wall of the foundation pit as a bearing foundation; a plurality of the auxiliary support members are used to improve the lateral resistance performance of the corresponding retaining walls, and serve as a connection transition between the bottom plate and the retaining walls, characterized in that, The auxiliary support member is a cast-in-place concrete member; the cast-in-place concrete member extends beyond the bottom plate, and it includes a cast-in-place steel reinforcement cage and a cast-in-place concrete body; the cast-in-place steel reinforcement cage includes frame main reinforcements and horizontal stirrups; wherein, one end of each of the multiple frame main reinforcements is rooted in the bottom plate, and is formed by multiple bends to form a frame structure with a "trapezoidal" longitudinal section for filling the cast-in-place concrete body; one end of the horizontal stirrup is rooted in the retaining wall, and is formed by multiple bends to circumferentially surround and tightly hoop the frame structure; the number of the horizontal stirrups is set to be multiple, and they are linearly evenly distributed along the height direction of the frame structure.
2. The underground foundation pit construction support structure according to claim 1, wherein Both the retaining wall and the bottom plate are cast in place on site with concrete.
3. The underground foundation pit construction support structure according to claim 2, characterized in that, The frame main reinforcements are rooted in the bottom plate in a pre-embedded manner, and first main reinforcement hooks pre-embedded in the bottom plate and second main reinforcement hooks pre-embedded in the cast-in-place concrete body are respectively bent and formed at both ends; the horizontal stirrups are also rooted in the retaining wall in a pre-embedded manner, and a stirrup hook pre-embedded in the retaining wall is bent and formed at its rooted end.
4. The underground foundation pit construction support structure according to claim 3, characterized in that, The cast-in-place steel reinforcement cage further includes L-shaped additional reinforcements; the L-shaped additional reinforcements are rooted in the bottom plate and simultaneously pull the bottom plate and the cast-in-place concrete body.
5. The underground foundation pit construction support structure according to claim 4, wherein, First additional reinforcement hooks pre-embedded in the bottom plate and second additional reinforcement hooks pre-embedded in the cast-in-place concrete body are respectively bent and formed at the two free ends of the L-shaped additional reinforcements.
6. The underground foundation pit construction support structure according to claim 5, characterized in that, The L-shaped additional reinforcement is formed by connecting a horizontal section and a vertical section; the first additional reinforcement hook is formed at the free end of the horizontal section, and the second additional reinforcement hook is formed at the free end of the vertical section; the distance between the horizontal section and the top wall of the bottom plate is d1, and the distance between the vertical section and the inner side wall of the retaining wall is d2, then 30mm ≤ d1 ≤ 50mm, 30mm ≤ d2 ≤ 50mm.
7. The underground foundation pit construction support structure according to any one of claims 1-6, characterized in that, The distance that the cast-in-place concrete member extends beyond the bottom plate is d, and the height dimension of the retaining wall is h, then 1 / 8h ≤ d ≤ 1 / 5h.