Active control system for deformation of foundation pit

Abstract

The utility model discloses an active control system for deformation of a foundation pit. The active control system comprises a double-telescopic jacking assembly (9), the double-telescopic jacking assembly comprises an upper telescopic jacking mechanism and a lower telescopic jacking mechanism, the lower telescopic jacking mechanism can swing to the angle that the jacking end of the lower telescopic jacking mechanism obliquely downwards faces a lower force bearing seat (921), and the jacking end of the lower telescopic jacking mechanism can obliquely downwards stretch out and is jacked on the lower force bearing seat; the upper telescopic jacking mechanism can swing to the angle that the jacking end of the upper telescopic jacking mechanism obliquely upwards faces the upper force bearing base (922), and the jacking end of the upper telescopic jacking mechanism can obliquely upwards stretch out and be jacked on the upper force bearing base. The active control system further comprises a grouting bag (61), and the grouting bag is arranged between the enclosure structure (6) and the peripheral engineering structure. The grouting bag is arranged between the enclosure structure and the peripheral engineering structure, deformation of the peripheral engineering structure is controlled through grouting and soil squeezing, and the influence of foundation pit engineering on the peripheral engineering structure is prevented.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of foundation pit engineering technical field, especially a kind of foundation pit deformation initiative control system. BACKGROUND

[0002] The scheme of prior art "concrete support combined with force adding device" cannot timely exert top support prestress on the position of retaining near pit bottom. Especially before the completion of lower level foundation pit structure construction, it cannot exert top support prestress on the position of retaining near pit bottom. As a result, the position of retaining near pit bottom may be displaced and deformed before the completion of lower level foundation pit structure construction.

[0003] A double-support prestress top support structure and prestress exerting method in foundation pit have been developed, which is based on the following concept: after the construction of near-pit-bottom horizontal support 41 is completed, prestress top support structure is immediately constructed based on the near-pit-bottom horizontal support 41; the prestress top support structure is used to exert top support prestress on the position of retaining near pit bottom; the position of retaining near pit bottom can obtain top support prestress in the first time, so that the displacement and deformation of the position of retaining near pit bottom can be timely corrected.

[0004] The current problem is that:

[0005] The existing scheme can only control the displacement and deformation of the position of retaining near pit bottom of foundation pit, but cannot control the adverse effects of foundation pit engineering on surrounding engineering structures (such as pipeline structure, civil air defense engineering or another foundation pit engineering). Specifically, the construction process of foundation pit engineering can cause displacement and deformation of surrounding engineering structures. SUMMARY

[0006] The utility model aims at providing a kind of foundation pit deformation initiative control system, grouting bag is arranged between retaining structure and surrounding engineering structure, and the deformation of surrounding engineering structure is controlled by grouting soil compaction, to prevent the influence of foundation pit engineering on surrounding engineering structure.

[0007] In order to achieve the above technical purpose, the utility model adopts the following technical scheme:

[0008] The application discloses a foundation pit deformation active control system, which comprises a double telescopic roof support assembly, wherein the double telescopic roof support assembly comprises an upper telescopic roof support mechanism and a lower telescopic roof support mechanism, and the upper telescopic roof support mechanism and the lower telescopic roof support mechanism are both provided with a telescopic roof support end; the body of the upper telescopic roof support mechanism is connected with a near-pit-bottom horizontal support assembly through a shaft pin mechanism, the body of the lower telescopic roof support mechanism is connected with the near-pit-bottom horizontal support assembly through a shaft pin mechanism, and the upper telescopic roof support mechanism and the lower telescopic roof support mechanism can both swing up and down based on the near-pit-bottom horizontal support; a lower bearing seat is arranged at a near-pit-bottom part of the enclosure, and an upper bearing seat is arranged at an upper part of the enclosure near the bottom support; the lower telescopic roof support mechanism can swing to an angle that the roof support end thereof is obliquely downward directed to the lower bearing seat, the roof support end of the lower telescopic roof support mechanism can be obliquely extended downward and supported on the lower bearing seat; the upper telescopic roof support mechanism can swing to an angle that the roof support end thereof is obliquely upward directed to the upper bearing seat, and the roof support end of the upper telescopic roof support mechanism can be obliquely extended upward and supported on the upper bearing seat; the active control system further comprises a grouting bag, and the grouting bag is arranged between the enclosure and the peripheral engineering structure.

[0009] Further, the active control system further comprises an inclinometer, and the inclinometer is arranged on the periphery of the enclosure or in the body of the enclosure.

[0010] Further, the active control system further comprises a displacement monitoring device, and the displacement monitoring device is arranged on the peripheral engineering structure.

[0011] Further, the active control system further comprises a pull rod, the two ends of the pull rod are connected with the upper telescopic roof support mechanism and the lower telescopic roof support mechanism respectively, and the pull rod binds the upper telescopic roof support mechanism and the lower telescopic roof support mechanism together.

[0012] Further, the two ends of the pull rod are connected with the upper telescopic roof support mechanism and the lower telescopic roof support mechanism respectively, and the connection mode is welding connection or lock buckle connection.

[0013] Compared with the prior art, the active control system has the beneficial effects that:

[0014] The grouting bag is arranged between the enclosure and the peripheral engineering structure, the grouting bag can be segmented grouted according to the displacement deformation condition of the peripheral engineering structure, the deformation of the peripheral engineering structure is controlled through soil extrusion by grouting, the influence of the foundation pit engineering on the peripheral engineering structure is prevented, and the deformation of the peripheral engineering structure is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a first schematic view of the double-brace prestressed roof support structure in the foundation pit of the embodiment 1, and the view is a side view.

[0016] Figure 2 Figure 2 is a second schematic view of the double-strut prestressed top support structure in the foundation pit of Embodiment 1, which is a plan view of the near-pit-bottom horizontal support;

[0017] Figure 3 Figure 3 is a third schematic view of the double-strut prestressed top support structure in the foundation pit of Embodiment 1, which is a schematic view of the assembly connection of the double- telescopic top support assembly and the near-pit-bottom horizontal support;

[0018] Figure 4 Figure 4 is a schematic view of the prestressed top support structure applied to the enclosure structure in Embodiment 1, which shows the case of removing the soil near the enclosure near-pit-bottom part;

[0019] Figure 5 Figure 5 is a schematic view of the active control system based on Embodiment 2 of the utility model. DETAILED DESCRIPTION

[0020] First, in order to facilitate the clear and accurate description of the technical solutions in the following, the following definitions are made in advance:

[0021] Definition 1: The "current pit bottom" referred to in this paper is the pit bottom in the process of foundation pit construction and excavation, which is a dynamic concept. Where the foundation pit is excavated, where is the "current pit bottom".

[0022] Definition 2: The "design pit bottom" referred to in this paper is the pit bottom designed in the foundation pit engineering, which is a static concept.

[0023] Definition 3: The "enclosure near-pit-bottom part" referred to in this paper is the part near the current pit bottom of the enclosure structure (such as the part indicated by arrow B in the figure). Figure 1 The "enclosure near-pit-bottom part" is a dynamic concept, which changes with the position of the current pit bottom. For example, when the "current pit bottom" is excavated to a depth of 1 meter, the part near the 1-meter depth of the enclosure structure is the "enclosure near-pit-bottom part".

[0024] Definition 4: The "near-pit-bottom horizontal support" referred to in this paper is the horizontal support structure closest to the current pit bottom that has been built in the foundation pit. The "near-pit-bottom horizontal support" is a dynamic concept. For example, when the first layer of horizontal support structure is completed, the first layer of horizontal support structure is the near-pit-bottom horizontal support, and when the second layer of horizontal support structure is completed, the second layer of horizontal support structure is the near-pit-bottom horizontal support.

[0025] Definition 5: The "near-bottom support upper part" mentioned herein refers to the part of the retaining structure near the near-pit-bottom horizontal support and above the near-pit-bottom horizontal support (as indicated by arrow A). Figure 1

[0026] Definition 6: The "retaining support system" mentioned herein is a broad concept and is a generalization of all forms of "support structures" and their combinations for the retaining structure in the foundation pit, such as "inclined upward support structures", "horizontal support structures".

[0027] Definition 7: The "lower-level foundation pit structure" mentioned herein refers to the deeper foundation pit structure to be constructed in the next stage during the construction of the foundation pit project. The "lower-level foundation pit structure" is a dynamic concept. For example, when the first layer of horizontal support structure is constructed, the second layer of horizontal support structure to be constructed is the lower-level foundation pit structure, and when the second layer of horizontal support structure is constructed, the foundation pit bottom structure to be constructed is the lower-level foundation pit structure.

[0028] Definition 8: The "lower-level excavation operation" mentioned herein refers to the need to excavate soil downward in the foundation pit to create a construction space for the deeper foundation pit structure before the next stage of construction of the deeper foundation pit structure during the construction of the foundation pit project. The excavation operation during this period is called "lower-level excavation operation". For example, when the first layer of horizontal support structure is constructed, the second layer of horizontal support structure to be constructed is the lower-level excavation operation.

[0029] It should be noted that the foundation pit deformation active control system of the utility model is improved based on a double-brace prestressed top support structure and a prestress application method in the foundation pit. The double-brace prestressed top support structure and the prestress application method in the foundation pit will be introduced first.

[0030] The main idea of the double-brace prestressed top support structure and the prestress application method in the foundation pit is as follows:

[0031] Based on the near-pit-bottom horizontal support 41, a downward inclined support component is arranged towards the foundation pit retaining structure, and the downward inclined support component is supported at the near-pit-bottom part of the retaining structure. Then, a top support force applying mechanism is arranged for the downward inclined support component, and the top support force applying mechanism can drive the downward inclined support component to apply top support prestress to the near-pit-bottom part of the retaining structure.

[0032] ​The main idea of the technical solution is as described above, so that the prestress can be applied to the bottom part of the enclosure before the lower level foundation pit structure is completed, so that corresponding measures can be taken to the displacement deformation of the bottom part of the enclosure, thereby improving the overall engineering quality of the foundation pit project.

[0033] The concept of the double-braced prestressed top support structure and the prestress application method in the foundation pit will be further described below with specific examples (Example 1):

[0034] Example 1:

[0035] Referring to Figure 1 , the foundation pit engineering structure involved in this embodiment will be introduced first.

[0036] As can be understood by those skilled in the art, the overall engineering structure of the foundation pit mainly includes the enclosure structure 6 and the enclosure support system, and the specific structure is set as follows:

[0037] The enclosure structure 6 is constructed on the periphery of the foundation pit, and the enclosure support system is usually arranged inside the foundation pit and is used to support the enclosure structure 6.

[0038] In this embodiment, the enclosure support system is mainly composed of several layers of horizontal support structures 4, which are arranged inside the foundation pit and support the enclosure structure 6. In this embodiment, the number of horizontal support structures 4 is three. For each layer of horizontal support structure 4, a corresponding enclosure purlin 7 is arranged on the enclosure structure 6. Except that the enclosure purlin 7 arranged for the top horizontal support structure 4 is at the top end of the enclosure structure 6, the remaining enclosure purlins 7 are arranged on the free side of the enclosure structure 6. The upper two horizontal support structures 4 in the foundation pit are connected together with the enclosure structure 6 through the enclosure purlin 7, thereby forming a support for the enclosure structure 6. The third layer of horizontal support structure 4, i.e. the near-bottom horizontal support 41, has a certain interval distance between its edge part and the enclosure purlin 7, that is, they are spaced apart. This spaced-apart part is specially used to set a prestress mechanism, and the edge part of the near-bottom horizontal support 41 is connected together with the enclosure purlin 7 through the prestress mechanism, and then connected together with the enclosure structure 6 through the enclosure purlin 7, thereby forming a support for the enclosure structure 6.

[0039] For the convenience of subsequent description, the spaced-apart part is referred to as a device assembly interval.

[0040] It should be noted that in other embodiments, if no enclosure purlin 7 is arranged on the enclosure structure 6, then the device assembly interval refers to the spacing between the edge part of the near-bottom horizontal support 41 and the enclosure structure 6.

[0041] In the embodiment, the enclosure support system further comprises a plurality of anti-pulling piles 5 which are fixedly arranged in the foundation pit, and then the aforementioned several layers of horizontal support structures 4 are connected with the anti-pulling piles 5 (the connection between the upper two layers of horizontal support structures 4 and the anti-pulling piles 5 is not shown in the figure), and the anti-pulling piles 5 provide vertical support for the horizontal support structures 4.

[0042] In the embodiment, the edge part of the near-foundation-bottom horizontal support 41 is provided with a ring beam 3 which is connected with a plurality of anti-pulling piles 5, and the anti-pulling piles 5 provide vertical support, especially downward support, for the edge part of the near-foundation-bottom horizontal support 41, which provides a strong force basis for the double-stretching and retracting top support assembly 9 to be mentioned later.

[0043] In addition, in order to conveniently detect the displacement deformation of the enclosure 6 and obtain corresponding data, in the embodiment, a inclinometer (prior art) is embedded in the interior of the enclosure 6, and the displacement deformation related data of the enclosure 6 can be detected and obtained through the inclinometer.

[0044] Those skilled in the art can understand that the foundation pit engineering structure described above is a prior art structure.

[0045] Referring to Figures 1 to 3 , on the basis of the foundation pit engineering structure of the embodiment, a prestressed top support structure is further arranged, and the prestressed top support structure mainly comprises two substructures, namely a transverse prestressed top support substructure and an inclined prestressed top support substructure.

[0046] The transverse prestressed top support substructure is used to apply transverse top support prestress to the enclosure 6 based on the near-foundation-bottom horizontal support 41.

[0047] The inclined prestressed top support substructure is used to apply inclined top support prestress to the near-foundation-bottom part of the enclosure based on the near-foundation-bottom horizontal support 41, so as to prevent displacement deformation of the near-foundation-bottom part of the enclosure at the first time.

[0048] The transverse prestressed top support substructure comprises a plurality of cantilever piers 8.

[0049] The cantilever piers 8 are arranged at the edge part of the near-foundation-bottom horizontal support 41 (i.e. at the ring beam 3) in a manner of being "cast and formed together with the edge part of the horizontal support structure 4", the plurality of cantilever piers 8 are arranged at the device assembly intervals, i.e. between the edge part of the near-foundation-bottom horizontal support 41 and the enclosure rafter 7, and are uniformly and discretely arranged around the edge part of the near-foundation-bottom horizontal support 41. The plurality of cantilever piers 8 are arranged at intervals with the plurality of double-stretching and retracting top support assemblies 9 to be mentioned later.

[0050] Each outrigger 8 forms a jacking state with the surrounding purlin 7 based on the edge of the near-bottom horizontal support 41, that is, the surrounding purlin 7 forms a jacking state with the surrounding structure 6.

[0051] It should be noted that the outrigger 8 at this time only forms a "jacking state", and it does not contact the surrounding purlin 7, but is very close to it, thereby forming a "jacking state".

[0052] Referring to Figure 2 For each outrigger 8,

[0053] A groove is provided on the side of the outrigger 8 facing the surrounding structure 6, and the groove opening faces the surrounding structure 6. For the sake of convenience, this groove is referred to as a jack receiving groove, and the jack receiving groove is used to accommodate a jack 81.

[0054] Specifically,

[0055] When it is necessary to permanently "apply lateral jacking prestress to the surrounding structure 6 based on the near-bottom horizontal support 41", a jack 81 is accommodated in the jack receiving groove of the outrigger 8, the body of the jack 81 abuts against the outrigger 8, and then the jacking end of the jack 81 is jacked against the surrounding purlin 7, thereby applying a large lateral jacking prestress to the surrounding structure 6 through the surrounding purlin 7, so that the device assembly interval is slightly larger, and then the position where the "jacking state" is formed between the outrigger 8 and the surrounding purlin 7 is grouted with adhesive grout. After the adhesive grout is completely cured, the outrigger 8 and the surrounding purlin 7 are truly connected together, and the outrigger 8 truly applies lateral jacking prestress to the surrounding structure 6 based on the near-bottom horizontal support 41 and through the surrounding purlin 7. At this time, the jack 81 can be disassembled.

[0056] It should be noted that in other embodiments, if the surrounding purlin 7 is not provided on the surrounding structure 6, then the outrigger 8 and the jack 81 are directly jacked against the surrounding structure 6 when the lateral jacking prestress is applied to the surrounding structure 6. For example, when the surrounding structure 6 is a continuous wall surrounding structure, the surrounding purlin 7 does not need to be provided.

[0057] The inclined prestress jacking substructure mainly includes a plurality of double-elastic jacking assemblies 9, and the lower segmented elastic steel pipe 911 therein corresponds to the inclined downward support component.

[0058] The plurality of double-elastic jacking assemblies 9 are arranged at the device assembly interval mentioned earlier and are uniformly and discretely arranged around the edge of the near-bottom horizontal support 41.

[0059] The double-elastic jacking assembly 9 includes a jacking base 913 and two segmented elastic steel pipes, and the two segmented elastic steel pipes,

[0060] a lower telescopic section steel pipe as a lower telescopic section steel pipe 911,

[0061] a lower telescopic section steel pipe as a lower telescopic section steel pipe 911,

[0062] The lower telescopic section steel pipe 911 and the upper telescopic section steel pipe 912 are identical in terms of monomer structure.

[0063] Referring to Figure 3 For each telescopic section steel pipe, the telescopic section steel pipe is two-segmented. For the convenience of description, one segment is referred to as a body segment, and one end of the body segment is referred to as a body end; the other segment is referred to as a jacking segment, and one end of the jacking segment is referred to as a jacking end.

[0064] A telescopic hydraulic cylinder 917 is arranged in the telescopic section steel pipe, the body (cylinder body) of the telescopic hydraulic cylinder 917 is connected to the body segment of the telescopic section steel pipe by a flange connection (or welding), and the telescopic end (cylinder head) of the telescopic hydraulic cylinder 917 is connected to the jacking segment of the telescopic section steel pipe by a flange connection (or welding). In this way, the telescopic hydraulic cylinder 917 can drive the telescopic section steel pipe to perform telescopic action.

[0065] In summary, the telescopic hydraulic cylinder 917 is arranged in the telescopic section steel pipe as a telescopic driving device, and the telescopic section steel pipe can exert jacking force under the driving of the telescopic driving device.

[0066] The telescopic section steel pipe can be understood as a telescopic jacking mechanism, and other forms of telescopic jacking mechanisms can be used to replace the telescopic section steel pipe in other embodiments.

[0067] In summary, the telescopic jacking mechanism should have a telescopic jacking end, which corresponds to the jacking end of the telescopic section steel pipe, and the body of the telescopic jacking mechanism corresponds to the body end of the telescopic section steel pipe.

[0068] The lower telescopic section steel pipe 911 can be summarized as a lower telescopic jacking mechanism, and the body of the lower telescopic jacking mechanism corresponds to the body end of the lower telescopic section steel pipe 911.

[0069] The upper telescopic section steel pipe 912 can be summarized as an upper telescopic jacking mechanism, and the body of the upper telescopic jacking mechanism corresponds to the body end of the upper telescopic section steel pipe 912.

[0070] For each telescopic jacking assembly 9,

[0071] The jacking base 913 is mounted on the edge portion of the near-bunker bottom horizontal support 41, specifically on the end face of the edge portion of the near-bunker bottom horizontal support 41.

[0072] The body end of the lower segmented telescopic steel pipe 911 and the upper segmented telescopic steel pipe 912 are assembled with the jacking base 913 through a quick detachable shaft pin mechanism. In this way, the lower segmented telescopic steel pipe 911 and the upper segmented telescopic steel pipe 912 can swing up and down (or rotate at a certain angle around the body end) based on the edge of the near-pit-bottom horizontal support 41.

[0073] The installed double telescopic jacking assembly 9, in which the lower segmented telescopic steel pipe 911 is located below the upper segmented telescopic steel pipe 912, or the upper segmented telescopic steel pipe 912 is located above the lower segmented telescopic steel pipe 911, in this way, the upper segmented telescopic steel pipe 912 mainly swings up and down above, and the lower segmented telescopic steel pipe 911 mainly swings up and down below.

[0074] It should be noted that the jacking base 913 is not necessary, in other embodiments, the lower segmented telescopic steel pipe 911 and the upper segmented telescopic steel pipe 912 can also be assembled with the edge of the near-pit-bottom horizontal support 41 through a shaft pin mechanism, as long as it can swing up and down based on the edge of the near-pit-bottom horizontal support 41.

[0075] Referring to Figure 1 For all double telescopic jacking assemblies 9, two ring beams are fixedly arranged on the enclosure 6, one of which is a lower force bearing 921 and the other is an upper force bearing 922.

[0076] The lower force bearing 921 is arranged at the near-pit-bottom part of the enclosure, and has an upwardly inclined force bearing surface for bearing the jacking of the lower segmented telescopic steel pipe 911.

[0077] The upper force bearing 922 is arranged at the upper part of the near-pit-bottom support of the enclosure, and has a downwardly inclined force bearing surface for bearing the jacking of the upper segmented telescopic steel pipe 912.

[0078] The lower segmented telescopic steel pipe 911 can swing downward to a direction angle of "the jacking end of the lower segmented telescopic steel pipe 911 being inclined downward toward the force bearing surface of the lower force bearing 921", then control the telescopic hydraulic cylinder 917 to drive the lower segmented telescopic steel pipe 911 to elongate until the jacking end of the lower segmented telescopic steel pipe 911 is inclined downward and abuts against the force bearing surface of the lower force bearing 921, then continue to control the lower segmented telescopic steel pipe 911 to elongate, which can achieve the effect of "applying jacking prestress to the near-pit-bottom part of the enclosure based on the near-pit-bottom horizontal support 41".

[0079] The upper subsection telescopic steel pipe 912 can be swung upward to an azimuth angle of "the top bracing end of the upper subsection telescopic steel pipe 912 being obliquely upward toward the bearing surface of the upper bearing seat 922", and then the telescopic hydraulic cylinder 917 is controlled to drive the upper subsection telescopic steel pipe 912 to elongate until the top bracing end of the upper subsection telescopic steel pipe 912 is obliquely upward and abuts against the top bracing on the bearing surface of the upper bearing seat 922, and then the elongation of the upper subsection telescopic steel pipe 912 is continued, so that the effect of "applying an obliquely downward top bracing force to the edge part of the near-pit-bottom horizontal support 41 based on the enclosure 6 to counteract the reaction force of the lower subsection telescopic steel pipe 911, so as to prevent the edge part of the near-pit-bottom horizontal support 41 from deforming" can be achieved.

[0080] The embodiment also provides a method for applying prestress to an enclosure in a foundation pit, which is used to achieve "applying top bracing prestress to the enclosure 6", and in particular to achieve "applying top bracing prestress to the enclosure near the pit bottom". In essence, the method for applying prestress is to use the concept of the prestressed top bracing structure described above to achieve "applying top bracing prestress to the enclosure 6".

[0081] Specifically, the method for applying prestress of the embodiment includes:

[0082] S1, constructing the near-pit-bottom horizontal support 41 at the foundation pit construction position.

[0083] It should be noted that the near-pit-bottom horizontal support 41 is constructed based on the uplift pile 5 that is pre-constructed in the foundation pit.

[0084] The constructed near-pit-bottom horizontal support 41 is as described above, and will not be repeated here.

[0085] S2, immediately after the construction of the near-pit-bottom horizontal support 41 in step S1 is completed, the prestressed top bracing structure is constructed based on the near-pit-bottom horizontal support 41, and the construction of the prestressed top bracing structure is completed before the subsequent lower-layer earth excavation operation.

[0086] The constructed prestressed top bracing structure is as described above, and will not be repeated here.

[0087] Referring to Figure 4 It should be noted that when constructing the obliquely prestressed top bracing substructure, the soil near the enclosure near the pit bottom needs to be removed by excavating the soil at the enclosure near the pit bottom, and the purpose of this is to

[0088] On the one hand, it is to be able to construct and set the lower bearing seat 921 at the enclosure near the pit bottom,

[0089] Another aspect is to provide operation space for "swinging the lower segment telescopic steel pipe 911 downward to the bearing surface of the lower bearing seat 921, and then making the top support end of the lower segment telescopic steel pipe 911 abut against the bearing surface of the lower bearing seat 921".

[0090] It should be noted that the "excavation at the position of the surrounding structure near the pit bottom" is not within the scope of the "lower tier excavation operation".

[0091] S3, applying top support prestress to the surrounding structure 6 by using the constructed prestressed top support structure.

[0092] The step S3 specifically includes S31 to S32.

[0093] S31, applying lateral top support prestress to the surrounding structure 6 by using the lateral prestressed top support substructure;

[0094] Specifically, a jack 81 is arranged in the jack accommodating groove of the outrigger 8, the body of the jack 81 abuts against the outrigger 8, and then the top support end of the jack 81 is controlled to extend laterally and abut against the surrounding purlin 7, and the top support prestress applied by the jack 81 is applied to the surrounding structure 6 through the surrounding purlin 7.

[0095] The deformation condition (deformation data) of the surrounding structure 6 is detected by using the detection means of the prior art, and according to the deformation condition of the surrounding structure 6 and the design standard, the jack 81 is controlled to apply appropriate top support prestress to the surrounding structure 6, so that the deformation condition of the surrounding structure 6 meets the design standard, and then the adhesive grout is poured at the position between the outrigger 8 and the surrounding purlin 7, and after the adhesive grout is completely set, the outrigger 8 and the surrounding purlin 7 are truly connected together, and the outrigger 8 truly supports the surrounding structure 6 based on the near-pit-bottom horizontal support 41 and applies lateral top support prestress to the surrounding structure 6 through the surrounding purlin 7.

[0096] Finally, the jack 81 is disassembled, and the outrigger 8 fully plays a role of applying lateral top support prestress.

[0097] It should be noted that in other embodiments, if the surrounding purlin 7 is not arranged on the surrounding structure 6, then the top support end of the jack 81 and the outrigger 8 directly abut against the surrounding structure 6.

[0098] S32, applying top support prestress to the surrounding structure near the pit bottom by using the inclined prestressed top support substructure.

[0099] Specifically,

[0100] Swing the lower subsection telescopic steel pipe 911 downward to a position angle of "the bracing end of the lower subsection telescopic steel pipe 911 is obliquely downward toward the bearing surface of the lower bearing seat 921", and then control and adjust the telescopic extension of the lower subsection telescopic steel pipe 911, so that the bracing end of the lower subsection telescopic steel pipe 911 is obliquely extended downward and abuts against the bearing surface of the lower bearing seat 921, and the bracing prestress exerted by the lower subsection telescopic steel pipe 911 is applied to the surrounding near-pit bottom part through the lower bearing seat 921.

[0101] The deformation condition (deformation data) of the surrounding near-pit bottom part is detected by using the detection means of the prior art, and the deformation condition of the surrounding near-pit bottom part is controlled to meet the design standard according to the deformation condition of the surrounding near-pit bottom part and the design standard, so that the lower subsection telescopic steel pipe 911 exerts appropriate bracing prestress on the surrounding near-pit bottom part, and the deformation condition of the surrounding near-pit bottom part meets the design standard.

[0102] Swing the upper subsection telescopic steel pipe 912 upward to a position angle of "the bracing end of the upper subsection telescopic steel pipe 912 is obliquely upward toward the bearing surface of the upper bearing seat 922", and then control and adjust the telescopic extension of the upper subsection telescopic steel pipe 912, so that the bracing end of the upper subsection telescopic steel pipe 912 is obliquely extended upward and abuts against the bearing surface of the upper bearing seat 922.

[0103] After the prestress exerting method is implemented, the lower layer earth excavation operation can be started.

[0104] It should be noted that in the present embodiment, a plurality of inclinometers (prior art) are arranged inside the support structure 6, and the deformation condition of the support structure 6, including the deformation condition of the surrounding near-pit bottom part, can be detected by the inclinometers.

[0105] It should be noted that the prestress bracing structure and the prestress exerting method of the present embodiment can be implemented not only for one layer of horizontal support structure 4, but also for multiple layers of horizontal support structure 4.

[0106] An embodiment 2 is provided below to specifically describe the foundation pit deformation active control system of the present application.

[0107] Embodiment 2:

[0108] The present embodiment 2 provides an active control system, which is improved based on the double-bracing prestress bracing structure and the prestress exerting method provided in the embodiment 1.

[0109] It should be noted that the foundation pit involved in the present embodiment is located beside a tunnel, and the construction process of the foundation pit will inevitably affect the tunnel beside it, causing deformation of the tunnel.

[0110] Referring to Figure 5 and comparing Figure 1The active control system of the second embodiment is improved as compared with the first embodiment as follows:

[0111] Improvement 1:

[0112] A plurality of grouting bags 61 are arranged on the periphery of the enclosure 6 (prior art), and the grouting bags 61 are arranged at positions close to the enclosure 6 between the enclosure 6 and the tunnel.

[0113] During the construction of the foundation pit project, the grouting bags 61 can be grouted in sections according to the displacement and deformation of the tunnel, so that the displacement of the tunnel is controlled by grouting and soil compaction, thereby protecting the tunnel and preventing the foundation pit project from affecting the tunnel.

[0114] It should be noted that in order to realize grouting into the grouting bag 61, a grouting machine is arranged for each grouting bag 61.

[0115] The bag of the grouting bag 61 can be geotextile, acrylic, polyester, etc.

[0116] The material of the grouting pipe of the grouting bag 61 can be steel, pvc or other materials.

[0117] Improvement 2:

[0118] A plurality of inclinometers 31 are arranged on the enclosure 6 to monitor the deformation of the enclosure 6.

[0119] In this embodiment, the inclinometer 31 is arranged on the periphery of the enclosure 6, and in other embodiments, the inclinometer 31 can also be embedded in the body of the enclosure 6.

[0120] Improvement 3:

[0121] A plurality of displacement monitoring devices 71 are arranged on the tunnel to monitor the deformation of the tunnel.

[0122] Improvement 4:

[0123] A pull rod 51 is arranged between the upper sectional telescopic steel pipe 912 and the lower sectional telescopic steel pipe 911, and the two ends of the pull rod 51 are connected to the upper sectional telescopic steel pipe 912 and the lower sectional telescopic steel pipe 911, respectively, and the connection mode can be welding connection or lock buckle connection. The function of the pull rod 51 is to bind the upper sectional telescopic steel pipe 912 and the lower sectional telescopic steel pipe 911 together to ensure that they do not split, thereby ensuring the stable bracing effect on the enclosure 6 (especially on the part close to the bottom of the foundation pit).

[0124] It should be noted that in other embodiments, the tunnel can be summarized as a peripheral engineering structure, such as a pipeline structure, a civil air defense project, or even another foundation pit project.

[0125] It should be noted that the active control system can be applied to the whole enclosure, or can be applied to the local enclosure.

[0126] The active control system of the embodiment 2 has the following main advantages:

[0127] 1) The grouting bag 61 is arranged between the enclosure 6 and the tunnel, and the grouting bag 61 is divided into sections and grouted according to the displacement and deformation condition of the tunnel, so that the displacement and deformation of the tunnel are controlled by grouting and soil compaction, the influence of the foundation pit engineering on the tunnel is prevented, and the deformation of the tunnel is avoided.

[0128] In addition, the active control system of the embodiment 2 has the following other advantages:

[0129] 2) The inclinometer 31 is arranged for the enclosure 6, and the displacement monitoring device 71 is arranged for the tunnel to monitor the deformation condition of the tunnel, so that the force of the top support pre-stress applied to the position near the bottom of the foundation pit can be controlled according to the monitoring data of the inclinometer 31 and the displacement monitoring device 71,

[0130] and,

[0131] the grouting amount of the grouting bag 61,

[0132] so as to dynamically and actively control the displacement and deformation of the enclosure 6 and the tunnel.

[0133] 3) The pull rod 51 binds the upper sectionally telescopic steel pipe 912 and the lower sectionally telescopic steel pipe 911 together to ensure that the two pipes will not be split, so as to ensure the stable top support effect on the enclosure 6 (especially on the position near the bottom of the foundation pit).

[0134] The above is only a preferred embodiment of the utility model, and is not used to limit the protection scope of the utility model, therefore, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A foundation pit deformation active control system, characterized in that: The active control system comprises a double telescopic roof support assembly (9), The double telescopic roof support assembly (9) comprises an upper telescopic roof support mechanism and a lower telescopic roof support mechanism, Both the upper telescopic roof support mechanism and the lower telescopic roof support mechanism have a telescopic roof support end; The body of the upper telescopic roof support mechanism is assembled and connected with the near-pit-bottom horizontal support (41) through a shaft pin mechanism, The body of the lower telescopic roof support mechanism is assembled and connected with the near-pit-bottom horizontal support (41) through a shaft pin mechanism, Both the upper telescopic roof support mechanism and the lower telescopic roof support mechanism can swing up and down based on the near-pit-bottom horizontal support (41); A lower force bearing (921) is arranged at the surrounding near-pit-bottom part, and an upper force bearing (922) is arranged at the upper part of the surrounding near-pit-bottom support; The lower telescopic roof support mechanism can swing to an angle in which the roof support end thereof is obliquely downward directed to the lower force bearing (921), and the roof support end of the lower telescopic roof support mechanism can be obliquely extended downward and supported on the lower force bearing (921); The upper telescopic roof support mechanism can swing to an angle in which the roof support end thereof is obliquely upward directed to the upper force bearing (922), and the roof support end of the upper telescopic roof support mechanism can be obliquely extended upward and supported on the upper force bearing (922); The active control system further comprises a grouting bag (61), which is arranged between the surrounding structure (6) and the peripheral engineering structure.

2. The foundation deformation active control system according to claim 1, characterized in that: The active control system further comprises an inclinometer (31), which is arranged on the periphery of the surrounding structure (6) or in the body of the surrounding structure (6).

3. The foundation deformation active control system according to claim 2, characterized in that: The active control system further comprises a displacement monitoring device (71), which is arranged on the peripheral engineering structure.

4. The foundation deformation active control system according to claim 1, characterized in that: The active control system further comprises a pull rod (51), which is arranged between the upper telescopic roof support mechanism and the lower telescopic roof support mechanism, and the two ends of the pull rod (51) are connected together with the upper telescopic roof support mechanism and the lower telescopic roof support mechanism, respectively, so as to bind the upper telescopic roof support mechanism and the lower telescopic roof support mechanism together.

5. The foundation deformation active control system according to claim 4, wherein: The two ends of the pull rod (51) are connected together with the upper telescopic roof support mechanism and the lower telescopic roof support mechanism, respectively, and the connection mode adopted is welding connection or lock buckle connection.

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