A concrete internal support system for actively controlling foundation pit deformation

Abstract

The present invention discloses a concrete inner support system for actively controlling the deformation of a foundation pit, including a retaining structure arranged along the edge of the foundation pit, a purlin arranged on the inner side wall of the retaining structure, and an inner support beam supported between the purlins, and also including a steel column arranged in the foundation pit to support the inner support beam, the inner support beam is supported on the purlin through a force transmission pier, and a hydraulic jack is arranged between the force transmission pier and the purlin; the intersection of the inner support beam and the steel column is connected by a semi-dry connection device, and the semi-dry connection device includes a steel skeleton with the inner support beam spliced ​​at both ends, the steel skeleton is passed through the steel column, and is connected at the intersection of the steel column by concrete pouring. This solution is fast in construction and easy to assemble and disassemble, and can quickly form a force system, with large support stiffness, good integrity, strong resistance to accidental impact, and little influence by temperature changes. It can achieve the recycling and reuse of most materials, low carbon and environmental protection, and good comprehensive economic benefits.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit support, and in particular to a concrete inner support system for actively controlling foundation pit deformation. Background Art

[0002] Effective control of foundation pit deformation is a key technology to ensure the safety of underground structures and surrounding environment and realize the development of underground space. At present, the support system of foundation pit engineering includes two forms: cast-in-place reinforced concrete support and steel support.

[0003] Cast-in-place reinforced concrete supports have high rigidity, good integrity, and strong resistance to unexpected impacts; however, the construction time of concrete supports is long, and the force system is formed slowly, so that the foundation pit support structure is affected by the rheological effect of the soil and the temperature, and its deformation increases significantly with the extension of time. The concrete support structure also has shrinkage creep problems. Even if the axial compressive stress of the concrete no longer increases, its deformation will continue to increase with time. In addition, since the horizontal internal support of the foundation pit is generally a temporary structure, it can be removed after the basement construction is completed, while the cast-in-place reinforced concrete support is difficult to remove and has a low recovery rate, causing greater environmental pollution and not in line with the concept of low-carbon environmental protection.

[0004] Steel structure supports are quick to construct, easy to assemble and disassemble, and can quickly form a force-bearing system. However, due to the weak anti-instability stiffness and poor stability of the steel support system, and the great influence of temperature changes, steel supports are generally not used for large-span foundation pits and the first support of foundation pits.

[0005] In actual projects, due to factors such as deep foundation pits, large plane scales, complex sites and climate change, foundation pits often deform too much, causing irreversible damage to surrounding facilities, making it impossible to continue the project and resulting in huge economic losses.

[0006] For example, Chinese patent publication number CN112854242B, publication date August 23, 2022, is named "Concrete support system capable of actively controlling lateral deformation of foundation pit retaining wall", including foundation pit retaining piles or foundation pit retaining walls, perimeter purlins arranged on the inner side walls of the foundation pit retaining piles or foundation pit retaining walls, and inner support beams supported between the perimeter purlins. The perimeter purlins include outer perimeter purlins arranged on the inner side walls of the foundation pit retaining piles or foundation pit retaining walls, inner perimeter purlins located on the inner side of the outer perimeter purlins, and a number of perimeter purlin support beams located between the outer perimeter purlins and the inner perimeter purlins. One end of the perimeter purlin support beam is fixed to the inner perimeter purlin, and the other end of the perimeter purlin support beam is supported on the outer perimeter purlin through an anchor plate. A hydraulic jack is provided between the outer perimeter purlin and the inner perimeter purlin.

[0007] The disadvantages of the existing patents are that the existing support system in the foundation pit adopts cast-in-place reinforced concrete support or steel support. The cast-in-place reinforced concrete support has the problems of long construction time and difficult dismantling, and the steel support has the problems of weak support stiffness and weak resistance to accidental impact. Summary of the invention

[0008] The purpose of the present invention is to solve the problems that the existing support system in the foundation pit adopts cast-in-place reinforced concrete support or steel support, which cannot simultaneously solve the problems of long construction time, difficult dismantling, weak support stiffness and weak resistance to unexpected impact of the support system in the foundation pit, and to provide a concrete support system that actively controls foundation pit deformation, has the advantages of quick construction, convenient disassembly and assembly, strong support stiffness and strong resistance to unexpected impact.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions: A concrete inner support system for actively controlling the deformation of a foundation pit comprises a retaining structure arranged along the edge of the foundation pit, a purlin arranged on the inner side wall of the retaining structure and an inner support beam supported between the purlins, and also comprises a steel column arranged in the foundation pit and supporting the inner support beam, the inner support beam is supported on the purlin through a force transmission pier, and a hydraulic jack is arranged between the force transmission pier and the purlin; the intersection of the inner support beam and the steel column is connected by a semi-dry connection device, the semi-dry connection device comprises a steel frame with the inner support beam spliced ​​at both ends, the steel frame is passed through the steel columns, and is connected at the intersection of the steel columns by concrete pouring. The concrete inner support system for actively controlling the deformation of the foundation pit described in the technical solution, firstly, when the deformation of the retaining structure within a certain distance from the edge of the foundation pit exceeds the set value, the surrounding purlin and the retaining structure are pushed back outward by the hydraulic jack, and the gap formed between the force transmission pier and the surrounding purlin is filled with high-strength grouting material, thereby effectively solving the problem that the existing outer retaining piles or outer retaining walls of the foundation pit are deformed too much into the foundation pit under the combined action of the external soil pressure of the foundation pit and the deformation of the inner support beam, which poses a major hidden danger to the safety of the foundation pit and the surrounding facilities. The concrete support system for actively controlling the foundation pit described in the technical solution, based on real-time monitoring or interval monitoring, synchronously pushes back after monitoring to avoid excessive deformation of the foundation pit, and ensures that the deformation of the foundation pit meets the requirements; secondly, the intersection of the inner support beam and the steel column is connected by a semi-dry connection device, which includes a steel frame with the inner support beam spliced ​​at both ends, the steel frame is passed through the steel column, and is connected by concrete pouring at the intersection of the steel column. The inner support beams, steel columns and steel skeletons can all be prefabricated, transported to the construction site and assembled. The inner support beams are connected at both ends of the steel skeleton. The steel skeleton is placed on the steel columns and connected to the intersection of the steel skeleton and the steel columns by pouring concrete. The assembly is simple and the construction is fast. At the same time, the molding time is shortened, and the problem of excessive deformation of the foundation pit caused by too long construction time is avoided. Thirdly, the inner support beams are prefabricated concrete components. The rapid construction of the concrete inner support structure of the foundation pit project is achieved through the on-site splicing method of the prefabricated concrete components. The construction is fast and the assembly and disassembly are convenient. The force system can be quickly formed. The support has high stiffness, good integrity, strong resistance to unexpected impacts, and is less affected by temperature changes. Since prefabricated concrete components can be quickly disassembled and assembled, most of the materials can be recycled and reused, which is low-carbon and environmentally friendly, with good comprehensive economic benefits.

[0010] The hydraulic jack is installed between the purlin and the force transmission pier to adjust the problem of excessive deformation of the foundation pit and the internal support beam, which causes a gap between the end of the internal support beam supported on the purlin and the purlin.

[0011] This technical solution takes into account the high rigidity, good integrity, strong resistance to unexpected impact of reinforced concrete support beams, and the rapid construction, easy assembly and disassembly of steel structure support, and the ability to quickly form a force system. At the same time, it solves the problems of long construction time of reinforced concrete support beams, slow formation of force systems, shrinkage creep of concrete support structures, and weak rigidity against instability, poor stability, and great influence of temperature changes on steel support systems. It can give full play to the advantages of cast-in-place concrete support and steel support, and avoid the shortcomings of the two support systems, to achieve a foundation pit support structure that is fast to install, reliable in structure, and material-saving and green.

[0012] The active control concrete support system for foundation pit described in the technical solution has a force transmission path of: soil pressure and water pressure-enclosing structure-purlin-hydraulic jack-inner support beam-steel column.

[0013] Preferably, one end of the force transmission pier supporting the purlin is provided with a groove, and the hydraulic jack is supported between the groove and the purlin. The inner support beam and the force transmission pier are convenient for production and assembly, and the force transmission pier and the hydraulic jack are used for deformation compensation of the foundation pit and the inner support beam.

[0014] Preferably, when the deformation of the retaining structure within a certain distance from the edge of the foundation pit exceeds a set value, the surrounding purlin and the retaining structure are pushed back outward by a hydraulic jack, and high-strength grouting material is filled in the gap formed between the force-transmitting pier and the surrounding purlin. This effectively solves the problem that the existing outer retaining piles or outer retaining walls of the foundation pit are deformed too much into the foundation pit under the combined effect of the external soil pressure of the foundation pit and the deformation of the internal support beams, posing a major hidden danger to the safety of the foundation pit and the surrounding facilities. The active control concrete support system for the foundation pit described in the technical solution is based on real-time monitoring or interval monitoring, and synchronously pushes back after monitoring to avoid excessive deformation of the foundation pit, ensuring that the deformation of the foundation pit meets the requirements.

[0015] Preferably, the inner support beam and the force transmission pier are connected by bolts and nuts, and the connection between the inner support beam and the force transmission pier is clamped by a steel clamp. The end of the inner support beam is provided with an embedded end plate, and the end of the force transmission pier connected to the inner support beam is provided with an embedded end plate. The embedded end plate of the inner support beam is connected to the embedded end plate of the force transmission pier by bolts and nuts, and the connection between the inner support beam and the force transmission pier is clamped by a steel clamp to improve the connection strength.

[0016] Preferably, the inner wall of the steel hoop is provided with an anti-slip rib, and the inner support beam and the force transmission pier are provided with an anti-slip groove that cooperates with the anti-slip rib. The anti-slip rib cooperates with the anti-slip groove to prevent the steel hoop from sliding along the inner support beam.

[0017] Preferably, the steel skeleton is connected to the inner support beam by anchor bolts, and the steel skeleton includes two end plates and a plurality of steel bones connecting the two end plates, and the steel bones are passed through the steel columns. During on-site construction, the steel bones are set at the splicing of the inner support beams according to the actual length and connected through the steel skeleton. After the steel skeleton passes through the steel column, concrete is poured at the intersection of the steel skeleton and the steel column. This improves the connection strength, reduces the difficulty of assembly, and shortens the molding time.

[0018] Preferably, the steel frame extends along the length direction of the inner support beam to which it is connected, and the steel frame is arranged perpendicular to the steel column.

[0019] Preferably, the same steel column supports one support beam or multiple support beams of the same elevation or multiple support beams of different elevations. The inner support beam can be arranged at different elevations of the same column through a semi-dry connection device, which is convenient to connect and can be arranged at any elevation of the steel column.

[0020] Preferably, the force transfer pier is a prefabricated concrete pier, and the inner support beam includes several sections of prefabricated reinforced concrete beams. The prefabricated force transfer pier and inner support beam are spliced ​​in the foundation pit, and the inner support beam splicing place is provided with steel skeletons according to the actual length and connected by steel skeletons. After the steel skeleton passes through the steel column, it is only necessary to pour concrete at the intersection of the steel skeleton and the steel column. The assembly is simple, the construction is fast, and the molding time is shortened, so as to avoid the problem of excessive deformation of the foundation pit caused by too long construction time.

[0021] Preferably, the purlin is a prefabricated reinforced concrete beam.

[0022] Therefore, the present invention has the following beneficial effects: effectively solve the problem that the existing foundation pit outer protection piles or foundation pit outer protection walls are deformed too much into the foundation pit under the combined effect of the external soil pressure of the foundation pit and the deformation of the internal support beam, causing major hidden dangers to the safety of the foundation pit and the safety of surrounding facilities; the construction is fast, the assembly and disassembly are convenient, and the force system can be quickly formed, the support stiffness is large, the integrity is good, the ability to resist unexpected impact is strong, and the influence of temperature changes is small. Because the prefabricated concrete components can be quickly disassembled and assembled, most of the materials can be recycled and reused, which is low-carbon and environmentally friendly, and has good comprehensive economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of embodiment 1 of the present invention.

[0024] Figure 2 It is an exploded view of the inner support beam and the force transmission pier in the first embodiment of the present invention.

[0025] Figure 3 It is a structural schematic diagram of the inner support beam and the steel column in the first embodiment of the present invention.

[0026] Figure 4It is a structural schematic diagram of the inner support beam and the force transmission pier in the first embodiment of the present invention.

[0027] As shown in the figure: Enclosure structure 1, purlin 2, Inner support beam 3, anti-slip groove 3.1, Hydraulic jack 4, steel column 5, Semi-dry connection device 6, Steel frame 6.1, end plate 6.1.1, steel frame 6.1.2, Force transfer buttress 7, groove 7.1, Steel hoop 8, anti-slip rib 8.1, DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the technical solution embodiments of the present invention clearer, the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0029] Embodiment 1, as Figure 1 , Figure 2 , Figure 3 , Figure 4 A concrete inner support system for actively controlling the deformation of a foundation pit is shown, comprising a retaining structure 1 arranged along the edge of the foundation pit, a purlin 2 arranged on the inner wall of the retaining structure 1, and an inner support beam 3 supported between the purlins 2, and also comprising a steel column 5 arranged in the foundation pit to support the inner support beam 3, the inner support beam 3 is supported on the purlin 2 through a force transmission pier 7, and a hydraulic jack 4 is provided between the force transmission pier 7 and the purlin 2; the intersection of the inner support beam 3 and the steel column 5 is connected by a semi-dry connection device 6, the semi-dry connection device 6 comprises a steel skeleton 6.1 with the inner support beam 3 spliced ​​at both ends, the steel skeleton 6.1 is passed through the steel column 5, and is connected at the intersection of the steel column 5 by concrete pouring.

[0030] Effective control of foundation pit deformation is a key technology to ensure the safety of underground structures and surrounding environment and realize the development of underground space. At present, the support system of foundation pit engineering includes two forms: cast-in-place reinforced concrete support and steel support.

[0031] Cast-in-place reinforced concrete supports have high rigidity, good integrity, and strong resistance to unexpected impacts; however, the construction time of concrete supports is long, and the force system is formed slowly, so that the foundation pit support structure is affected by the rheological effect of the soil and the temperature, and its deformation increases significantly with the extension of time. The concrete support structure also has shrinkage creep problems. Even if the axial compressive stress of the concrete no longer increases, its deformation will continue to increase with time. In addition, since the horizontal internal support of the foundation pit is generally a temporary structure, it can be removed after the basement construction is completed, while the cast-in-place reinforced concrete support is difficult to remove and has a low recovery rate, causing greater environmental pollution and not in line with the concept of low-carbon environmental protection.

[0032] Steel structure supports are quick to construct, easy to assemble and disassemble, and can quickly form a force-bearing system. However, due to the weak anti-instability stiffness and poor stability of the steel support system, and the great influence of temperature changes, steel supports are generally not used for large-span foundation pits and the first support of foundation pits.

[0033] In actual projects, due to factors such as deep foundation pits, large plane scales, complex sites and climate change, foundation pits often deform too much, causing irreversible damage to surrounding facilities, making it impossible to continue the project and resulting in huge economic losses.

[0034] In order to solve the problems that the existing support system in the foundation pit adopts cast-in-place reinforced concrete support or steel support, which cannot solve the problems of long construction time, difficult removal, weak support rigidity and weak resistance to unexpected impact of the support system in the foundation pit, a kind of Figure 1 , Figure 2 , Figure 3 , Figure 4 The concrete internal support system shown has the advantages of quick construction, easy assembly and disassembly, strong support rigidity and strong resistance to unexpected impact, and is capable of actively controlling foundation pit deformation.

[0035] like Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, a concrete inner support system for actively controlling the deformation of the foundation pit in the above-mentioned embodiment, firstly, when the deformation of the retaining structure 1 within a certain distance from the edge of the foundation pit into the foundation pit exceeds a set value, the surrounding purlin 2 and the retaining structure 1 are pushed back outward by the hydraulic jack 4, and high-strength grouting material is filled in the gap formed between the force transmission pier 7 and the surrounding purlin 2, thereby effectively solving the problem that the existing outer retaining piles or outer retaining walls of the foundation pit are deformed too much into the foundation pit under the combined action of the external soil pressure of the foundation pit and the deformation of the internal support beam 3, posing a major hidden danger to the safety of the foundation pit and the surrounding facilities. An active control concrete support system for foundation pits in the technical solution is based on real-time monitoring or interval monitoring. After monitoring, the top is synchronously returned to avoid excessive deformation of the foundation pit, ensuring that the deformation of the foundation pit meets the requirements; secondly, the intersection of the inner support beam 3 and the steel column 5 is connected by a semi-dry connection device 6. The semi-dry connection device 6 includes a steel skeleton 6.1 with the inner support beam 3 spliced ​​at both ends. The steel skeleton 6.1 is passed through the steel column 5 and connected at the intersection of the steel column 5 by concrete pouring. The inner support beam 3, the steel column 5, and the steel skeleton 6.1 can all be prefabricated, transported to the construction site and assembled. The steel skeleton 6.1 is connected to the inner support beam 3 at both ends. The steel skeleton 6.1 is passed through the steel column 5 and connected to the intersection of the steel skeleton 6.1 and the steel column 5 by concrete pouring. The assembly is simple, the construction is fast, and the molding time is shortened, so as to avoid the problem of excessive deformation of the foundation pit caused by too long construction time; thirdly, the inner support beam 3 is a prefabricated concrete component, and the rapid construction of the concrete inner support structure of the foundation pit project is realized by the on-site splicing method of the prefabricated concrete components. The construction is fast, the assembly and disassembly are convenient, and the force system can be quickly formed. The support has high rigidity, good integrity, strong resistance to unexpected impact, and is less affected by temperature changes. Since the prefabricated concrete components can be quickly disassembled and assembled, most of the materials can be recycled and reused, which is low-carbon and environmentally friendly, and has good comprehensive economic benefits.

[0036] The hydraulic jack 4 is arranged between the purlin 2 and the force transmission pier 7, and is used to adjust the problem of excessive deformation of the foundation pit and the inner support beam 3, which causes a gap between the end of the inner support beam 3 supported on the purlin 2 and the purlin 2.

[0037] This technical solution takes into account the high rigidity, good integrity, strong resistance to unexpected impact of reinforced concrete support beams, and the rapid construction, easy assembly and disassembly of steel structure support, and the ability to quickly form a force system. At the same time, it solves the problems of long construction time of reinforced concrete support beams, slow formation of force systems, shrinkage creep of concrete support structures, and weak rigidity against instability, poor stability, and great influence of temperature changes on steel support systems. It can give full play to the advantages of cast-in-place concrete support and steel support, and avoid the shortcomings of the two support systems, to achieve a foundation pit support structure that is fast to install, reliable in structure, and material-saving and green.

[0038] In this embodiment, an active control foundation pit concrete support system is provided. Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the force transmission path is: soil pressure and water pressure-retaining structure 1-purlin 2-hydraulic jack 4-inner support beam 3-steel column 5.

[0039] Specifically, Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the force transfer pier 7 is a prefabricated concrete pier, and the inner support beam 3 includes several sections of prefabricated reinforced concrete beams. The prefabricated force transfer pier 7 and the inner support beam 3 are spliced ​​in the foundation pit, and the splicing of the inner support beam 3 is provided with steel skeleton 6.1.2 according to the actual length and connected through the steel frame 6.1. After the steel frame 6.1 passes through the steel column 5, it is only necessary to pour concrete at the intersection of the steel frame 6.1 and the steel column 5. The assembly is simple, the construction is fast, and the molding time is shortened, so as to avoid the problem of excessive deformation of the foundation pit caused by too long construction time.

[0040] Further optimization of the purlin 2, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the purlin 2 is a prefabricated reinforced concrete beam.

[0041] In summary, this embodiment effectively solves the problem that the existing outer retaining piles or outer retaining walls of the foundation pit are deformed too much into the foundation pit under the combined effect of the external soil pressure of the foundation pit and the deformation of the internal support beam 3, posing a major hidden danger to the safety of the foundation pit and the safety of surrounding facilities; the construction is rapid and the assembly and disassembly are convenient, and a force system can be quickly formed, with high support stiffness, good integrity, strong resistance to unexpected impacts, and little impact by temperature changes. Since precast concrete components can be quickly disassembled and assembled, most materials can be recycled and reused, which is low-carbon and environmentally friendly, with good comprehensive economic benefits. This embodiment greatly solves the problem that the existing support system in the foundation pit adopts cast-in-place reinforced concrete support or steel support, and cannot simultaneously solve the problems of long construction time, difficult disassembly, weak support stiffness, and weak resistance to unexpected impacts of the support system in the foundation pit.

[0042] Embodiment 2, as Figure 1 , Figure 2 , Figure 3 , Figure 4A concrete inner support system for actively controlling the deformation of a foundation pit is shown, comprising a retaining structure 1 arranged along the edge of the foundation pit, a purlin 2 arranged on the inner wall of the retaining structure 1, and an inner support beam 3 supported between the purlins 2, and also comprising a steel column 5 arranged in the foundation pit to support the inner support beam 3, the inner support beam 3 is supported on the purlin 2 through a force transmission pier 7, and a hydraulic jack 4 is provided between the force transmission pier 7 and the purlin 2; the intersection of the inner support beam 3 and the steel column 5 is connected by a semi-dry connection device 6, the semi-dry connection device 6 comprises a steel skeleton 6.1 with the inner support beam 3 spliced ​​at both ends, the steel skeleton 6.1 is passed through the steel column 5, and is connected at the intersection of the steel column 5 by concrete pouring.

[0043] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, one of the above-mentioned concrete internal support systems for actively controlling the deformation of the foundation pit, firstly, when the deformation of the retaining structure 1 within a certain distance from the edge of the foundation pit into the foundation pit exceeds a set value, the surrounding purlin 2 and the retaining structure 1 are pushed back outward by the hydraulic jack 4, and high-strength grouting material is filled in the gap formed between the force transmission pier 7 and the surrounding purlin 2, thereby effectively solving the problem that the existing outer retaining piles or outer retaining walls of the foundation pit are deformed too much into the foundation pit under the combined action of the external soil pressure of the foundation pit and the deformation of the internal support beam 3, posing a major hidden danger to the safety of the foundation pit and the surrounding facilities. An active control concrete support system for foundation pits in the technical solution is based on real-time monitoring or interval monitoring. After monitoring, the top is synchronously returned to avoid excessive deformation of the foundation pit, ensuring that the deformation of the foundation pit meets the requirements; secondly, the intersection of the inner support beam 3 and the steel column 5 is connected by a semi-dry connection device 6. The semi-dry connection device 6 includes a steel skeleton 6.1 with the inner support beam 3 spliced ​​at both ends. The steel skeleton 6.1 is passed through the steel column 5 and connected at the intersection of the steel column 5 by concrete pouring. The inner support beam 3, the steel column 5, and the steel skeleton 6.1 can all be prefabricated, transported to the construction site and assembled. The steel skeleton 6.1 is connected to the inner support beam 3 at both ends. The steel skeleton 6.1 is passed through the steel column 5 and connected to the intersection of the steel skeleton 6.1 and the steel column 5 by concrete pouring. The assembly is simple, the construction is fast and the molding time is shortened, thus avoiding the problem of excessive deformation of the foundation pit caused by long construction time; thirdly, the inner support beam 3 is a prefabricated concrete component, and the rapid construction of the concrete inner support structure of the foundation pit project is achieved through the on-site splicing method of the prefabricated concrete components. The construction is fast, the assembly and disassembly are convenient, and the force system can be quickly formed. The support has high rigidity, good integrity, strong resistance to unexpected impact, and is less affected by temperature changes. Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, since precast concrete components can be quickly disassembled and assembled, most of the materials can be recycled and reused, which is low-carbon and environmentally friendly, and has good overall economic benefits.

[0044] The hydraulic jack 4 is arranged between the purlin 2 and the force transmission pier 7, and is used to adjust the problem of excessive deformation of the foundation pit and the inner support beam 3, which causes a gap between the end of the inner support beam 3 supported on the purlin 2 and the purlin 2.

[0045] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, this technical solution takes into account the high rigidity, good integrity, strong resistance to unexpected impact of reinforced concrete support beams, and the rapid construction, easy assembly and disassembly of steel structure support, and the ability to quickly form a force system. At the same time, it solves the problems of long construction time of reinforced concrete support beams, slow formation of force system, shrinkage creep of concrete support structures, and weak rigidity against instability, poor stability, and great influence of temperature changes of steel support systems. It can give full play to the advantages of cast-in-place concrete support and steel support, and avoid the shortcomings of the two support systems, to achieve a foundation pit support structure that is fast to install, reliable in structure, and material-saving and green.

[0046] In this embodiment, an active control concrete support system for foundation pit is provided, and its force transmission path is: soil pressure and water pressure-retaining structure 1-purlin 2-hydraulic jack 4-inner support beam 3-steel column 5.

[0047] The force transmission buttress 7 is further optimized, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, a groove 7.1 is provided at one end of the force transmission buttress 7 supported on the purlin 2, and a hydraulic jack 4 is supported between the groove 7.1 and the purlin 2. The inner support beam 3 and the force transmission buttress 7 are convenient for production and assembly, and the force transmission buttress 7 and the hydraulic jack 4 are used for deformation compensation of the foundation pit and the inner support beam 3.

[0048] Specifically, Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, when the deformation of the retaining structure 1 within a certain distance of the foundation pit edge exceeds the set value, the surrounding purlin 2 and the retaining structure 1 are pushed back outward by the hydraulic jack 4, and high-strength grouting material is filled in the gap formed between the force transmission pier 7 and the surrounding purlin 2. This effectively solves the problem that the existing outer retaining piles or outer retaining walls of the foundation pit are deformed too much into the foundation pit under the combined effect of the external soil pressure of the foundation pit and the deformation of the internal support beam 3, posing a major hidden danger to the safety of the foundation pit and the surrounding facilities. An active control concrete support system for the foundation pit in this technical solution is based on real-time monitoring or interval monitoring, and synchronously pushes back after monitoring to avoid excessive deformation of the foundation pit, ensuring that the deformation of the foundation pit meets the requirements.

[0049] The connection mode between the inner support beam 3 and the force transmission pier 7 is further optimized, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the inner support beam 3 and the force transmission pier 7 are connected by bolts and nuts, and the connection between the inner support beam 3 and the force transmission pier 7 is clamped by a steel clamp 8. The end of the inner support beam 3 is provided with an embedded end plate 6.1.1, and the end of the force transmission pier 7 connected to the inner support beam 3 is provided with an embedded end plate 6.1.1. The embedded end plate 6.1.1 of the inner support beam 3 is connected with the embedded end plate 6.1.1 of the force transmission pier 7 by bolts and nuts. At the same time, the connection between the inner support beam 3 and the force transmission pier 7 is clamped by a steel clamp 8 to improve the connection strength.

[0050] The steel hoop 8 is further optimized, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the inner wall of the steel hoop 8 is provided with an anti-slip rib 8.1, and the inner support beam 3 and the force transmission pier 7 are provided with an anti-slip groove 3.1 that cooperates with the anti-slip rib 8.1. The anti-slip rib 8.1 cooperates with the anti-slip groove 3.1 to prevent the steel hoop 8 from sliding along the inner support beam 3.

[0051] Further optimization of the steel skeleton 6.1, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the steel skeleton 6.1 is spliced ​​with the inner support beam 3 through anchor bolts, and the steel skeleton 6.1 includes two end plates 6.1.1 and a plurality of steel frames 6.1.2 connecting the two end plates 6.1.1, and the steel frames 6.1.2 are passed through the steel columns 5. During on-site construction, the steel frames 6.1.2 are set at the splicing of the inner support beam 3 according to the actual length and connected through the steel skeleton 6.1. After the steel skeleton 6.1 passes through the steel column 5, concrete is poured at the intersection of the steel skeleton 6.1 and the steel column 5. The connection strength is improved, the assembly difficulty is reduced, and the molding time is shortened.

[0052] Further optimization of Steel 6.1.2, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the steel frame 6.1.2 extends along the length direction of the inner support beam 3 to which it is connected, and the steel frame 6.1.2 is arranged perpendicular to the steel column 5.

[0053] The inner support beam 3 is further optimized, such as Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, the same steel column 5 supports one support beam or multiple inner support beams 3 of the same elevation or multiple inner support beams 3 of different elevations. The inner support beam 3 can be set at different elevations of the same column through a semi-dry connection device 6, which is easy to connect and can be set at any elevation of the steel column 5.

[0054] Specifically, Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the force transfer pier 7 is a prefabricated concrete pier, and the inner support beam 3 includes several sections of prefabricated reinforced concrete beams. The prefabricated force transfer pier 7 and the inner support beam 3 are spliced ​​in the foundation pit, and the splicing of the inner support beam 3 is provided with steel skeleton 6.1.2 according to the actual length and connected through the steel frame 6.1. After the steel frame 6.1 passes through the steel column 5, it is only necessary to pour concrete at the intersection of the steel frame 6.1 and the steel column 5. The assembly is simple, the construction is fast, and the molding time is shortened, so as to avoid the problem of excessive deformation of the foundation pit caused by too long construction time.

[0055] Further optimization of the purlin 2, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the purlin 2 is a prefabricated reinforced concrete beam.

[0056] In order to solve the problems that the existing support system in the foundation pit adopts cast-in-place reinforced concrete support or steel support, which cannot solve the problems of long construction time, difficult removal, weak support rigidity and weak resistance to unexpected impact of the support system in the foundation pit, a kind of Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, a concrete internal support system for actively controlling the deformation of the foundation pit is provided, which has the advantages of rapid construction, convenient assembly and disassembly, strong support rigidity and strong resistance to unexpected impact. This embodiment effectively solves the problem that the existing outer retaining piles or outer retaining walls of the foundation pit are deformed too much into the foundation pit under the combined effect of the external soil pressure of the foundation pit and the deformation of the internal support beam 3, posing a major hidden danger to the safety of the foundation pit and the surrounding facilities. It has rapid construction, convenient assembly and disassembly, and can quickly form a force system with high support rigidity, good integrity, strong resistance to unexpected impact, and little influence by temperature changes. Since precast concrete components can be quickly disassembled and assembled, most of the materials can be recycled and reused, which is low-carbon and environmentally friendly, with good comprehensive economic benefits.

[0057] Embodiment 3, based on Embodiment 1 or Embodiment 2, a construction method of a concrete inner support system for actively controlling foundation pit deformation specifically comprises the following steps: Step 1: Prefabricate the load-transmitting piers and the reinforced concrete beams required for splicing the internal support beams, and construct the enclosure structure, surrounding purlins and steel columns in the foundation pit; Step 2: In the foundation pit, the inner support beams are spliced ​​with prefabricated reinforced concrete beams. The inner support beams are supported on the inner side of the purlins by prefabricated force-transfer piers. The inner support beams are supported by steel columns. The intersection of the inner support beams and the steel columns is supported and connected by a semi-dry connection device. The semi-dry connection device includes a steel frame with inner support beams spliced ​​at both ends. The steel frame is passed through the steel columns and connected by concrete pouring at the intersection of the steel columns. The length of the steel frame is constructed on site according to the length required for splicing the inner support beams at the construction site.

[0058] The specific embodiments described above are only preferred implementations of the present invention, and are not intended to limit the specific implementation scope of the present invention. All equivalent changes made according to the shape and structure of the present invention should be included in the protection scope of the present invention.

Claims

1. A concrete inner support system for actively controlling foundation pit deformation, comprising a retaining structure arranged along the edge of the foundation pit, a purlin arranged on the inner side wall of the retaining structure, and an inner support beam supported between the purlins, characterized in that: It also includes steel columns arranged in the foundation pit to support the inner support beam. The inner support beam is supported on the perimeter purlin through force transmission piers. Hydraulic jacks are arranged between the force transmission piers and the perimeter purlin. The intersection of the inner support beam and the steel column is connected by a semi-dry connection device. The semi-dry connection device includes a steel frame with the inner support beam spliced ​​at both ends. The steel frame is passed through the steel columns and connected by concrete pouring at the intersection of the steel columns.

2. The concrete inner support system for actively controlling foundation pit deformation according to claim 1 is characterized in that: One end of the force transmission buttress supported on the surrounding purlin is provided with a groove, and the hydraulic jack is supported between the groove and the surrounding purlin.

3. The concrete inner support system for actively controlling foundation pit deformation according to claim 2 is characterized in that: When the deformation of the retaining structure within a certain distance from the edge of the foundation pit exceeds the set value, the purlin and the retaining structure are pushed back outward by the hydraulic jack, and high-strength grouting material is filled in the gap formed between the force-transmitting pier and the purlin.

4. A concrete inner support system for actively controlling foundation pit deformation according to claim 1, 2 or 3, characterized in that: The inner support beam and the force transmission pier are connected by bolt and nut locking, and the connection between the inner support beam and the force transmission pier is clamped by a steel clamp.

5. The concrete inner support system for actively controlling foundation pit deformation according to claim 4 is characterized in that: The inner wall of the steel hoop is provided with anti-slip ribs, and the inner support beam and the force transmission pier are provided with anti-slip grooves matched with the anti-slip ribs.

6. A concrete inner support system for actively controlling foundation pit deformation according to claim 1, 2 or 3, characterized in that: The steel frame is spliced ​​with inner support beams through anchor bolts. The steel frame includes two end plates and a plurality of steel bones connecting the two end plates. The steel bones are penetrated on steel columns.

7. The concrete inner support system for actively controlling foundation pit deformation according to claim 6 is characterized in that: The steel frame extends along the length direction of the inner support beam connected to it, and the steel frame is vertically arranged to the steel column.

8. A concrete inner support system for actively controlling foundation pit deformation according to claim 1, 2 or 3, characterized in that: The same steel column supports one internal support beam or multiple internal support beams of the same elevation or multiple internal support beams of different elevations.

9. A concrete inner support system for actively controlling foundation pit deformation according to claim 1, 2 or 3, characterized in that: The force transmission pier is a precast concrete pier, and the inner support beam comprises a plurality of sections of precast reinforced concrete beams.

10. A concrete inner support system for actively controlling foundation pit deformation according to claim 1, 2 or 3, characterized in that: The surrounding purlin is a prefabricated reinforced concrete beam.

Images