Jacking device for applying prestress to enclosure structure in foundation pit

Abstract

The utility model discloses a jacking device for applying prestress to an enclosure structure in a foundation pit. The pre-stress applying jacking device (1) comprises a loading base (11) and two diagonal bracing mechanisms (12), the inclined supporting mechanism is provided with a jacking output end, and the jacking output end can do telescopic action and can output jacking force; the two inclined strut mechanisms are respectively used as an upper inclined strut mechanism (128) and a lower inclined strut mechanism (129), the upper inclined strut mechanism is assembled on the loading base, and the lower inclined strut mechanism is assembled on the loading base; the loading base is assembled on the horizontal support close to the pit bottom; the lower inclined strut mechanism obliquely and downwards extends out of the top support output end to be supported at the position, close to the pit bottom, of the enclosure; an upper ring beam (28) is arranged at the position, close to the upper portion of the bottom support, of the enclosure, and the upper inclined supporting mechanism obliquely upwards extends out of the top support output end to be supported on the upper ring beam. The pre-stress applying jacking device can prevent the enclosure structure (2) from generating uncoordinated deformation.

Description

Technical Field

[0001] The utility model relates to the technical field of foundation pit engineering, in particular to a prestressed supporting device for applying prestress to a retaining structure in a foundation pit. Background Art

[0002] At present, a double-braced prestressed top support structure and prestressing method in the foundation pit have been developed. The concept is:

[0003] After the construction of the horizontal support near the pit bottom is completed, the prestressed top support device is immediately installed based on the horizontal support near the pit bottom, and the installation is completed before the subsequent lower level excavation operation. Then, the prestressed top support device is used to apply top support prestress to the enclosure structure;

[0004] The supporting output end of the lower oblique supporting mechanism provided in the prestressed supporting device can support the enclosure near the bottom of the pit obliquely downward, and can apply supporting prestress to the enclosure near the bottom of the pit;

[0005] In this way, the retaining wall near the bottom of the pit can be prestressed with top support at the first time, so that the displacement and deformation of the retaining wall near the bottom of the pit can be corrected in time, thereby improving the overall engineering quality of the foundation pit project.

[0006] The current problem is:

[0007] In the existing technical solution, the upper diagonal brace leans against the retaining structure in sections. If the retaining structure is a pile row, the prestressed reaction of the lower diagonal brace and the upper diagonal brace can easily cause uncoordinated deformation of the retaining structure. Summary of the Invention

[0008] The purpose of the utility model is to provide a prestressed supporting device for a retaining structure in a foundation pit, wherein the prestressed supporting device can avoid uncoordinated deformation of the retaining structure.

[0009] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0010] A device for applying prestressed support to a retaining structure in a foundation pit, the device comprising a loading base and two diagonal support mechanisms; the diagonal support mechanism has a support output end, which can perform telescopic movements; the two diagonal support mechanisms serve as an upper diagonal support mechanism and a lower diagonal support mechanism respectively, the upper diagonal support mechanism is assembled on the loading base, and the lower diagonal support mechanism is assembled on the loading base; the loading base is assembled on a horizontal support near the bottom of the pit; a lower ring beam is provided at the position of the retaining structure near the bottom of the pit, the lower diagonal support mechanism extends obliquely downward to support the support output end on the lower ring beam; an upper ring beam is provided at the upper part of the retaining structure near the bottom support, the upper diagonal support mechanism extends obliquely upward to support the support output end on the upper ring beam.

[0011] Furthermore, the upper ring beam and the lower ring beam are both concrete ring beams, and are both provided with hangers, which are used to fix the upper ring beam and the lower ring beam on the enclosure structure.

[0012] Furthermore, the upper ring beam and the lower ring beam are both concrete ring beams, and dowel bars are provided on both the upper ring beam and the lower ring beam. Both the upper ring beam and the lower ring beam are assembled on the enclosure structure through the dowel bars.

[0013] Furthermore, the upper ring beam and the lower ring beam are both prefabricated steel ring beams; the concrete protective layer on the surface of the enclosure structure is chiseled off to expose the steel bars inside it, and the upper ring beam and the lower ring beam are welded together with the steel bars inside the enclosure structure.

[0014] Furthermore, the loading base is assembled on a horizontal support near the pit bottom, and its specific structural form is: the loading base has a snap-fit ​​groove, and the snap-fit ​​groove of the loading base is snap-fitted and assembled on the edge of the horizontal support near the pit bottom.

[0015] Furthermore, the diagonal support mechanism includes a top support telescopic rod and an angle-adjusting telescopic rod; one end of the top support telescopic rod serves as the main body end, and the other end of the top support telescopic rod serves as the top support output end; the main body end of the top support telescopic rod is assembled on the loading base through an axle pin hinge mechanism, and the top support telescopic rod can swing up and down based on the loading base; the angle-adjusting telescopic rod is assembled based on the loading base, and a hoop is assembled at the telescopic end of the angle-adjusting telescopic rod, and the top support telescopic rod is assembled in the hoop, and the top support telescopic rod is connected to the telescopic end of the angle-adjusting telescopic rod through the hoop, and the telescopic action of the angle-adjusting telescopic rod can drive the top support telescopic rod to adjust the angle of the up and down swinging; the top support telescopic rod of the upper diagonal support mechanism is facing in an obliquely upward direction, and the top support telescopic rod of the lower diagonal support mechanism is facing in an obliquely downward direction.

[0016] Furthermore, the prestressed supporting device also includes a pulling rod; the pulling rod is arranged between the supporting telescopic rod of the upper diagonal supporting mechanism and the supporting telescopic rod of the lower diagonal supporting mechanism, and the pulling rod connects the two supporting telescopic rods.

[0017] Furthermore, the loading base is U-shaped.

[0018] Furthermore, the loading base is an embedded part.

[0019] Furthermore, the supporting telescopic rod is a hydraulic piston rod or a sleeve nesting mechanism.

[0020] Furthermore, the supporting output end of the diagonal supporting mechanism can output a supporting force.

[0021] Compared with the prior art, the prestressed support device of the present invention has the following advantages:

[0022] An upper ring beam is set at the upper part of the enclosure near the bottom support, and the jacking output end of the upper inclined support mechanism set in the prestressed jacking device applies a jacking force to the upper part of the enclosure near the bottom support through the upper ring beam. This can ensure that the enclosure structure is subjected to coordinated force and avoid uncoordinated deformation of the enclosure structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the structure of the prestressed supporting device of embodiment 1;

[0024] Figure 2 for Figure 1 Schematic diagram of the structure of the telescopic rod for adjusting the middle angle;

[0025] Figure 3 Schematic diagram of applying prestress to the enclosure structure by using a prestressed supporting device in Implementation Method 1;

[0026] Figure 4 Schematic diagram of the structure of the transverse supporting device in the prestressed supporting device of embodiment 1;

[0027] Figure 5 This is a schematic diagram of arranging a wooden box at the edge of the horizontal support structure in embodiment 1;

[0028] Figure 6 This is a schematic diagram of the prestressed top support device that is not removed after the lower level foundation pit structure is completed;

[0029] Figure 7 A schematic diagram of the removal of the prestressed top support device after the lower level foundation pit structure is completed;

[0030] Figure 8 Schematic diagram of the structure of the prestressed supporting device of embodiment 2;

[0031] Figure 9 Schematic diagram of applying prestress to the enclosure structure by using a prestressed supporting device in Implementation Method 2;

[0032] Figure 10 Schematic diagram of the structure of the prestressed supporting device of embodiment 3;

[0033] Figure 11 and Figure 12 This is a schematic diagram of a prestressed support device according to Embodiment 4 of the present invention.

[0034] Figure 11 The enclosure structure is a continuous wall enclosure structure.

[0035] Figure 12 The retaining structure is a pile retaining structure. DETAILED DESCRIPTION

[0036] First, in order to facilitate a clear and accurate description of the technical solution in the following text, the following definitions are made in advance:

[0037] Definition 1: The "current pit bottom" mentioned in this article refers to the pit bottom during the foundation pit construction excavation process. The "current pit bottom" is a dynamic concept. Wherever the foundation pit is excavated is the "current pit bottom".

[0038] Definition 2: The "designed pit bottom" mentioned in this article refers to the pit bottom designed for foundation pit engineering. The "designed pit bottom" is a static concept.

[0039] Definition 3: The "horizontal support near the pit bottom" mentioned in this article refers to the completed horizontal support structure closest to the current pit bottom within the foundation pit. This "horizontal support near the pit bottom" is a dynamic concept. For example, when the first layer of horizontal support structure is completed, it becomes the horizontal support near the pit bottom. When the second layer of horizontal support structure is completed, it becomes the horizontal support near the pit bottom, and the first layer of horizontal support structure no longer becomes the horizontal support near the pit bottom.

[0040] Definition 4: The "retaining structure near the pit bottom" mentioned in this document refers to the portion of the retaining structure closest to the current pit bottom. This "retaining structure near the pit bottom" is a dynamic concept that changes with the current pit bottom position. For example, when the "current pit bottom" is excavated to a depth of 1 meter, the portion of the retaining structure near that depth is considered the "retaining structure near the pit bottom."

[0041] Definition 5: The "upper portion of the retaining wall support" mentioned in this document refers to the portion of the retaining wall structure adjacent to and above the horizontal support near the pit bottom. This "upper portion of the retaining wall support" is a dynamic concept that changes with the horizontal support near the pit bottom.

[0042] Definition 6: The "enclosure support system" mentioned in this article is a broad concept, which summarizes all forms of "support structures" and their combinations for the enclosure structure in the foundation pit, such as "inclined upward support structure" and "horizontal support structure".

[0043] Definition 7: The "lower-level foundation pit structure" mentioned in this article refers to the deeper foundation pit structure to be constructed in the next phase of the foundation pit construction process. This "lower-level foundation pit structure" is a dynamic concept. For example, if the foundation pit is designed with two layers of horizontal support structures, after the first layer of horizontal support structures is constructed, the second layer of horizontal support structures to be constructed next is the lower-level foundation pit structure. After the second layer of horizontal support structures is constructed, the pit bottom structure to be constructed next is the lower-level foundation pit structure.

[0044] Definition 8: "Lower-level excavation" as used herein refers to the excavation required to create space for the deeper structures within the foundation pit before the next phase of construction. For example, if a foundation pit is designed with two horizontal support structures, after the first is completed, excavation is required to create space for the second. This excavation is called "lower-level excavation."

[0045] It should be noted that the present invention's prestressed support device for a retaining structure in a foundation pit is an improvement on a prestressed support device and prestressing method in a foundation pit. The following first introduces the prestressed support device and prestressing method in a foundation pit.

[0046] The following describes the concept of the prestressed support device in the foundation pit and the method of applying prestress using specific embodiments (embodiment 1 to embodiment 3):

[0047] Implementation method 1:

[0048] See also Figure 1 , this embodiment 1 provides a prestressed support device in a foundation pit, and the prestressed support device 1 mainly includes a loading base 11, a diagonal support mechanism 12 and a pulling rod 13.

[0049] The loading base 11 is in a horizontal "U" shape.

[0050] For the convenience of description

[0051] The inner concave portion of the U-shaped loading base 11 is called the clamping groove 111.

[0052] The upper surface of the loading base 11 is referred to as the upper seat surface 112.

[0053] The lower surface of the loading base 11 is referred to as the lower seat surface 113.

[0054] The outer bottom surface of the U-shaped loading base 11 is called the side seat surface 114.

[0055] The loading base 11 is used to be assembled with the horizontal support structure 3 (described in detail later).

[0056] It should be noted that the loading base 11 may also be an embedded part reserved on the ring beam.

[0057] The upper seat surface 112 and the lower seat surface 113 of the loading base 11 are both provided with a diagonal support mechanism 12, that is, two diagonal support mechanisms 12 are provided.

[0058] The diagonal support mechanism 12 provided on the upper seat surface 112 is referred to as an upper diagonal support mechanism 128.

[0059] The diagonal support mechanism 12 provided on the lower seat surface 113 is referred to as a lower diagonal support mechanism 129.

[0060] The upper diagonal support mechanism 128 and the lower diagonal support mechanism 129 have the same structure, but are arranged in different orientations;

[0061] In summary, the diagonal bracing mechanism 12 is disposed based on the upper seat surface 112 or the lower seat surface 113. The diagonal bracing mechanism 12 has a supporting output end that can extend and retract relative to the body of the diagonal bracing mechanism 12 and output a supporting force. In this way, the diagonal bracing mechanism 12 can apply a supporting force to the exterior (enclosing structure) based on the loading base 11, and the direction and angle of the applied supporting force are adjustable.

[0062] Specifically,

[0063] The diagonal support mechanism 12 mainly includes a top support rod 121 , a top support base 122 and an angle adjustment telescopic rod 124 .

[0064] The supporting base 122 is assembled on the upper seat surface 112 or the lower seat surface 113 of the loading base 11 through an axle pin hinge mechanism, so that the supporting rod 121 to be mentioned later can swing up and down based on the upper seat surface 112 or the lower seat surface 113 of the loading base 11.

[0065] One end of the support rod 121 serves as the assembly end, and the other end serves as the support output end (i.e., the support output end of the entire diagonal support mechanism 12). The assembly end of the support rod 121 is assembled with the support base 122, and the assembly point between the two adopts a sleeve-nested assembly method, which can also be regarded as a sleeve-nested assembly method. In other words, the assembly end of the support rod 121 and the support base 122 are assembled together through the sleeve-nested mechanism 123. In this way, the support rod 121 can perform telescopic movement relative to the support base 122 based on the sleeve-nested mechanism 123.

[0066] In addition, a driving telescopic cylinder of the prior art (which can be a hydraulic cylinder or an electric cylinder) is also provided in the sleeve nesting mechanism 123. The main body (cylinder body) of the driving telescopic cylinder is fixedly connected to the supporting base 122, and the telescopic end (cylinder head) of the driving telescopic cylinder is fixedly connected to the supporting rod 121. In this way, the driving telescopic cylinder can drive the supporting rod 121 to perform a telescopic action relative to the supporting base 122.

[0067] It should be noted that the rod body formed by the aforementioned support rod 121, support base 122, sleeve nesting mechanism 123, driving telescopic cylinder, etc. can be summarized as a support telescopic rod, which can perform telescopic movements and output support force to the outside. One end of the support telescopic rod serves as the main body end (equivalent to the support base 122), and the other end of the support telescopic rod serves as the support output end (equivalent to the support output end of the support rod 121). The main body end of the support telescopic rod is assembled on the upper seat surface 112 or the lower seat surface 113 of the loading base 11 through an axle pin hinge mechanism. In this way, the entire support telescopic rod can perform up and down swinging movements based on the upper seat surface 112 or the lower seat surface 113 of the loading base 11.

[0068] The supporting rod 121 mentioned below can be generally understood as the rod body of the supporting telescopic rod.

[0069] In addition, a supporting end 125 is provided at the supporting output end of the supporting rod 121 . The supporting end 125 is square-shaped and is used to directly lean against the enclosure structure 2 .

[0070] See also Figure 1 and Figure 2In order to adjust the swing angle of the supporting rod 121, an angle-adjusting telescopic rod 124 is provided for the supporting rod 121. One end of the main body of the angle-adjusting telescopic rod 124 is assembled and connected to the upper seat surface 112 or the lower seat surface 113 of the loading base 11. The telescopic end of the angle-adjusting telescopic rod 124 is equipped with a hoop 1241 via a pin hinge mechanism (not shown in the figure). The hoop 1241 can rotate based on the telescopic end of the angle-adjusting telescopic rod 124. The supporting rod 121 is assembled in the hoop 1241. In other words, the supporting rod 121 is assembled and connected to the telescopic end of the angle-adjusting telescopic rod 124 through the hoop 1241, and the supporting rod 121 can slide in the hoop 1241. In this way, the telescopic movement of the angle-adjusting telescopic rod 124 can drive the supporting rod 121 to adjust the upward and downward swing angle.

[0071] It should be noted that the angle-adjusting telescopic rod 124 can be a hydraulic cylinder telescopic rod or an electric cylinder telescopic rod.

[0072] At this point, the supporting rod 121 can output the supporting force based on the upper seat surface 112 or the lower seat surface 113 of the loading base 11, and can also adjust the angle of the up and down swing.

[0073] The supporting output end of the supporting rod 121 of the upper oblique supporting mechanism 128 provided on the upper seat surface 112 of the loading base 11 can support in an obliquely upward direction.

[0074] The supporting output end of the supporting rod 121 of the lower oblique supporting mechanism 129 provided on the lower seat surface 113 of the loading base 11 can support in an obliquely downward direction.

[0075] The prestressed supporting device of this embodiment is applied to the joint between the enclosure structure 2 and the horizontal supporting structure 3 .

[0076] The following first introduces the foundation pit engineering structure involved in this embodiment.

[0077] Those skilled in the art will understand that the overall engineering structure of the foundation pit mainly includes the enclosure structure 2 and the enclosure support system, and its specific structural configuration is as follows:

[0078] The enclosure structure 2 is constructed around the foundation pit, and the enclosure support system is usually arranged inside the foundation pit to support the enclosure structure 2. In this embodiment, the enclosure support system is mainly composed of several layers of horizontal support structures 3.

[0079] The several layers of horizontal support structures 3 are arranged on the inner side of the foundation pit, and the enclosure structure 2 is supported by these horizontal support structures 3; in this embodiment, the number of horizontal support structures 3 is three.

[0080] For each layer of the horizontal support structure 3 , a corresponding external ring beam 5 is provided on the enclosure structure 2 .

[0081] For each layer of horizontal support structure 3, a certain distance is left between its edge and the external ring beam 5 on the enclosure structure 2, that is, the two are separated. The separated part is specially used to set up a prestressed mechanism. The edge of the horizontal support structure 3 is connected to the external ring beam 5 through the set prestressed mechanism, and then connected to the enclosure structure 2 through the external ring beam 5, thereby forming support for the enclosure structure 2.

[0082] For the convenience of subsequent description, the spaced apart portion is referred to as a device assembly space.

[0083] It should be noted that, in other embodiments, if the external ring beam 5 is not provided on the enclosure structure 2 , the device assembly interval refers to the space between the edge of the horizontal support structure 3 and the enclosure structure 2 .

[0084] A plurality of buttresses 7 are provided at the device assembly intervals. These buttresses 7 are provided at the edge of the horizontal support structure 3 by being “cast together with the edge of the horizontal support structure 3 ”.

[0085] It should be noted that a pre-buried steel plate is embedded between the pier 7 and the retaining structure 2 or the external ring beam 5, which is only used to separate the connection between the pier 7 and the retaining structure 2 or the external ring beam 5, so as to form a gap during prestressed loading, and then grouting material is used to fill the gap tightly.

[0086] These numerous buttresses 7 are evenly and discretely arranged around the edge of the horizontal support structure 3. These buttresses 7 are spaced apart from the numerous prestressed support devices 1 described later. Each buttress 7 supports the external ring beam 5 at the edge of the horizontal support structure 3, essentially providing support for the enclosure structure 2 through the external ring beam 5.

[0087] It should be noted that the buttress 7 at this time only forms a "supporting posture" and is not in contact with the external ring beam 5, but the two are very close to each other, thus forming a "supporting posture".

[0088] Stiffening plates 4 and built-in ring beams 6 are provided at the edges of the horizontal support structure 3 to improve the structural strength of the edges of the horizontal support structure 3 .

[0089] It should be noted that the stiffening plate 4 can be replaced with an eight-shaped support.

[0090] In this embodiment, the enclosure structure 2 is a continuous wall enclosure structure 21 .

[0091] In addition, in order to conveniently detect the displacement and deformation of the enclosure structure 2 and obtain corresponding data, in this embodiment, an inclinometer 8 of the prior art is pre-buried inside the enclosure structure 2, and the displacement and deformation related data of the enclosure structure 2 can be detected and obtained through the inclinometer 8.

[0092] Those skilled in the art will appreciate that the above-mentioned foundation pit engineering structure is a structure of the prior art.

[0093] See also Figure 3 The specific installation and use method of the prestressed support device 1 is as follows:

[0094] Assemble the loading base 11 at the edge of the horizontal support structure 3 so that the clamping groove 111 of the loading base 11 is clamped at the edge of the horizontal support structure 3. For the upper diagonal support mechanism 128 and the lower diagonal support mechanism 129, control the angle adjustment telescopic rod 124 to extend and retract to adjust the angle of the top support rod 121. The top support output ends of the top support rods 121 of the two diagonal support mechanisms 12 are both tilted toward the enclosure structure 2, the top support rod 121 of the upper diagonal support mechanism 128 is tilted upward, and the top support rod 121 of the lower diagonal support mechanism 129 is tilted downward; then control the driving telescopic cylinder in the sleeve nesting mechanism 123 to drive the top support rod 121 to extend, so that the top support end 125 at the top support output end of the top support rod 121 is supported on the enclosure structure 2.

[0095] The supporting output end of the supporting rod 121 of the lower diagonal supporting mechanism 129 is tilted downward to support the enclosure structure 2, so that supporting prestress can be applied to the enclosure structure 2, and the supporting output end of the supporting rod 121 of the upper diagonal supporting mechanism 128 is tilted upward to support the enclosure structure 2, so that a downward supporting force can be applied to the edge of the horizontal supporting structure 3 based on the enclosure structure 2 to offset the reaction force generated by the supporting rod 121 of the lower diagonal supporting mechanism 129 on the horizontal supporting structure 3, thereby preventing the edge of the horizontal supporting structure 3 from deformation.

[0096] The greatest significance of the prestressed support device 1 of this embodiment is that it is applied to the horizontal support near the pit bottom, and based on the horizontal support near the pit bottom, prestressed support is applied to the surrounding area near the pit bottom.

[0097] Specifically,

[0098] A plurality of prestressed supporting devices 1 are set at the device assembly interval between the horizontal support near the pit bottom and the retaining structure 2, and are evenly and discretely arranged around the edge of the horizontal support near the pit bottom.

[0099] For each prestressed support device 1, the loading base 11 is snap-fitted and assembled on the edge of the horizontal support near the pit bottom, and the lower oblique support mechanism 129 is adjusted so that the support output end of its support rod 121 is obliquely downwardly supported at the position of the enclosure near the pit bottom, thereby applying support prestress to the enclosure near the pit bottom;

[0100] Adjust the upper diagonal support mechanism 128 so that the support output end of its support rod 121 is tilted upward to support the upper part of the enclosure near the bottom support, thereby offsetting the reaction force generated by the support rod 121 of the lower diagonal support mechanism 129 on the horizontal support near the bottom of the pit, thereby preventing the edge of the horizontal support near the bottom of the pit from deformation.

[0101] The prestressed supporting device 1 provided at the horizontal support near the bottom of the pit can apply supporting prestress to the part of the enclosure near the bottom of the pit before the lower level excavation operation, so that the displacement and deformation of the part of the enclosure near the bottom of the pit can be corrected in time at the first time, thereby improving the overall engineering quality of the foundation pit project.

[0102] In addition, for each prestressed supporting device 1, a pulling rod 13 is provided between the upper and lower supporting rods 121. The pulling rod 13 connects the two supporting rods 121, thereby preventing the supporting output end of the supporting rod 121 from slipping and falling off on the enclosure structure 2.

[0103] See also Figure 4 The prestressed supporting device of this embodiment further includes a transverse supporting device 14 , which is composed of a placement box 141 and a transverse supporting telescopic cylinder 142 .

[0104] The transverse supporting telescopic cylinder 142 can be a hydraulic cylinder or an electric cylinder. The transverse supporting telescopic cylinder 142 is placed in a placement box 141 , and four overlapping ends 1411 are symmetrically provided around the periphery of the placement box 141 .

[0105] The transverse supporting device 14 is entirely arranged on the side seat surface 114 of the loading base 11. When the prestressed supporting device 1 is installed at the junction of the enclosure structure 2 and the horizontal supporting structure 3, the transverse supporting device 14 is entirely located at the device assembly interval, and the overlapping ends 1411 of the placement box 141 are respectively overlapped on both sides of the device assembly interval, namely, on the upper seat surface 112 of the loading base 11, and on the external ring beam 5, so that the transverse supporting device 14 can be firmly placed in the device assembly interval.

[0106] The transverse supporting telescopic cylinder 142 in the transverse supporting device 14 is in a horizontal state, and one end of its main body (cylinder body) is against the side seat surface 114 of the loading base 11 through the wall panel of the placement box 141 (if there is no wall panel, it will be directly against it), and the telescopic end (cylinder head) of the transverse supporting telescopic cylinder 142 is supported on the external ring beam 5, that is, it is supported on the enclosure structure 2 through the external ring beam 5, so that, based on the edge of the horizontal supporting structure 3, the external ring beam 5 then applies transverse supporting prestress to the enclosure structure 2.

[0107] It should be noted that the transverse supporting device 14 is not necessary and can be provided as needed.

[0108] This embodiment also provides a method for applying prestress, which uses the above-mentioned prestressed supporting device to apply supporting prestress to the enclosure structure 2, especially to apply supporting prestress to the enclosure near the bottom of the pit.

[0109] The method for applying prestress comprises steps S1 to S3:

[0110] S1, construct a horizontal support structure 3 (horizontal support near the bottom of the pit) at the foundation pit construction location;

[0111] The constructed horizontal support structure 3 is as described above and will not be described in detail here.

[0112] See also Figure 5 It should be noted that when constructing the horizontal support structure 3, a wooden box 9 is installed in the soil at the predetermined installation location of the prestressed support device 1. The wooden box 9 is specifically installed below the horizontal support near the bottom of the pit.

[0113] The purpose of setting up the wooden box 9 is that when installing the loading base 11, there is still soil under the horizontal support structure 3, and there is no installation space at this time. During installation, the wooden box 9 can be taken out to reserve installation space for subsequent installation.

[0114] S2, after completing the construction of the horizontal support near the pit bottom in step S1, immediately start installing the previously mentioned prestressed top support device based on the horizontal support near the pit bottom, and complete the installation and setting before the subsequent lower-level excavation operation.

[0115] The specific installation structure of the prestressed support device has been described before and will not be repeated here.

[0116] S3, before the subsequent lower level excavation operation, the prestressed support device 1 is used to apply prestressed support to the enclosure structure 2.

[0117] The step S3 specifically includes S31 to S32;

[0118] S31 , applying transverse supporting prestress to the enclosure structure 2 using the transverse supporting device 14 in the prestressed supporting device 1 .

[0119] Specifically,

[0120] The transverse supporting device 14 applies transverse supporting prestress to the enclosure structure 2 based on the horizontal supporting structure 3; the telescopic end of the transverse supporting telescopic cylinder 142 in the transverse supporting device 14 is controlled to extend and retract, so that the telescopic end of the transverse supporting telescopic cylinder 142 serves as the supporting output end of the entire transverse supporting device 14 and extends horizontally and supports on the external ring beam 5. The supporting prestress applied by the transverse supporting device 14 acts on the enclosure structure 2 through the external ring beam 5.

[0121] The existing detection means are used to detect the deformation condition (deformation data) of the enclosure structure 2. According to the deformation condition of the enclosure structure 2 and in accordance with the design standards, the transverse supporting device 14 is controlled to apply appropriate supporting prestress to the enclosure structure 2 so that the deformation condition of the enclosure structure 2 meets the design standards.

[0122] Then, grouting material is poured at the position where a "supporting posture" is formed between the pier 7 and the external ring beam 5. After the grouting material is completely solidified, the pier 7 and the external ring beam 5 are truly connected together, and the pier 7 is truly based on the horizontal support structure 3 and applies transverse supporting prestress to the enclosure structure 2 through the external ring beam 5.

[0123] Finally, the entire transverse supporting device 14 is disassembled, and the pier 7 is used entirely to exert the role of applying transverse supporting prestress.

[0124] It should be noted that, in other embodiments, if the external ring beam 5 is not provided on the enclosure structure 2 , the supporting output end of the transverse supporting device 14 and the pier 7 are directly supported on the enclosure structure 2 .

[0125] S32: Apply oblique supporting prestress to the enclosure structure 2 using the oblique supporting mechanism 12 in the prestressed supporting device 1.

[0126] Specifically,

[0127] The top support output end of the lower oblique support mechanism 129 (that is, the top support output end of the top support rod 121) is adjusted to an azimuth angle obliquely downward toward the enclosure structure 2 (the enclosure near the bottom of the pit), and then the top support rod 121 is controlled and adjusted to extend and retract, so that the top support output end of the top support rod 121 extends obliquely downward and the top support end 125 on it rests against the enclosure structure 2 (the enclosure near the bottom of the pit), and the top support prestress applied by the lower oblique support mechanism 129 acts on the enclosure structure 2 (the enclosure near the bottom of the pit).

[0128] The existing detection means are used to detect the deformation condition (deformation data) of the retaining structure 2 (the retaining structure near the bottom of the pit). According to the deformation condition of the retaining structure 2 (the retaining structure near the bottom of the pit) and in accordance with the design standards, the lower diagonal bracing mechanism 129 is controlled to apply appropriate top support prestress to the retaining structure 2 (the retaining structure near the bottom of the pit) so that the deformation condition of the retaining structure 2 meets the design standards.

[0129] The supporting output end of the upper diagonal bracing mechanism 128 (i.e., the supporting output end of the supporting rod 121) is adjusted to an angle that is obliquely upward and toward the enclosure structure 2 (the upper portion of the enclosure near the bottom support). Then, the supporting rod 121 is controlled and adjusted to extend and retract, so that the supporting output end of the supporting rod 121 extends obliquely upward and the supporting end 125 on the supporting rod 121 abuts against the enclosure structure 2 (the upper portion of the enclosure near the bottom support). In this way, the reaction force generated by the lower diagonal bracing mechanism 129 on the horizontal supporting structure 3 can be offset, thereby preventing the edge portion of the horizontal supporting structure 3 from deforming.

[0130] After the prestressing method is implemented, the subsequent lower level excavation operation can be started.

[0131] It should be noted that, in this embodiment, a large number of inclinometers 8 (existing technology) are provided inside the retaining structure 2. These inclinometers 8 can detect the deformation of the retaining structure 2, including the deformation of the retaining structure near the bottom of the pit.

[0132] It should be noted that the prestressed supporting device and the prestressing method of this embodiment are not only implemented for one-layer horizontal supporting structure 3, but can also be implemented for multiple-layer horizontal supporting structures 3.

[0133] Whenever a layer of horizontal support near the bottom of the pit is completed, the above-mentioned prestressed support device and prestressing method can be used to apply support prestress to the retaining structure 2 based on the horizontal support near the bottom of the pit that has just been constructed, thereby ensuring that the retaining structure 2, especially the retaining structure near the bottom of the pit, can receive timely support prestressing.

[0134] It should be noted that after the construction of the lower level foundation pit structure is completed, the prestressed support device 1 can be retained without being removed. Figure 6 As shown, you can also choose to remove the prestressed support device 1, as shown in Figure 7 shown.

[0135] The main advantages of the prestressed support device and prestressing method of this embodiment are:

[0136] 1) After the construction of the horizontal support near the pit bottom is completed, the prestressed support device 1 is immediately installed based on the horizontal support near the pit bottom, and the installation is completed before the subsequent lower level excavation operation. Then, the prestressed support device 1 is used to apply prestress to the retaining structure 2;

[0137] The supporting output end of the lower oblique supporting mechanism 129 provided in the prestressed supporting device 1 can support obliquely downward at the position of the enclosure near the bottom of the pit, and can apply supporting prestress to the position of the enclosure near the bottom of the pit;

[0138] In this way, the retaining wall near the bottom of the pit can be prestressed with top support at the first time, so that the displacement and deformation of the retaining wall near the bottom of the pit can be corrected in time, thereby improving the overall engineering quality of the foundation pit project.

[0139] 2) The supporting output end of the upper diagonal supporting mechanism 128 provided in the prestressed supporting device 1 can support the upper part of the support near the bottom of the enclosure obliquely upward. The upper diagonal supporting mechanism 128 can apply a supporting force obliquely downward to the edge of the horizontal support near the bottom of the pit based on the enclosure structure 2 to offset the reaction force of the lower diagonal supporting mechanism 129, thereby preventing the edge of the horizontal support near the bottom of the pit from deformation;

[0140] 3) The prestressed supporting device is also provided with a transverse supporting device 14, which can apply transverse supporting prestress to the enclosure structure 2 based on the horizontal supporting structure 3, so that the displacement and deformation of the enclosure structure portion corresponding to the horizontal supporting structure 3 can be corrected in time.

[0141] Implementation 2:

[0142] See also Figures 8 and 9 , this embodiment 2 also provides a prestressed support device and a method for applying prestress, and the overall concept of the prestressed support device and the method for applying prestress is basically consistent with that of embodiment 1.

[0143] The main differences between the prestressed support device and the prestressing method of the second embodiment and those of the first embodiment are:

[0144] The retaining structure 2 of the foundation pit project is a pile retaining structure 22.

[0145] In order to adapt to this situation, the supporting end 125 provided on the supporting output end of the supporting rod 121 is wide-width, specifically, T-shaped.

[0146] Implementation 3:

[0147] See also Figure 10, this embodiment 3 also provides a prestressed support device and a method for applying prestress, and the overall concept of the prestressed support device and the method for applying prestress is basically consistent with that of embodiment 1.

[0148] The main differences between the prestressed support device and the prestressing method of the second embodiment and those of the first embodiment are:

[0149] A hydraulic piston rod 127 is used to replace the combination of the supporting rod 121, the supporting base 122, the sleeve nesting mechanism 123, the driving telescopic cylinder, etc., as another form of supporting telescopic rod.

[0150] The end of the outer arm of the hydraulic piston rod 127 is equivalent to the main body end of the supporting telescopic rod.

[0151] One end of the hydraulic piston rod 127 where the inner arm is located is equivalent to the supporting output end of the supporting telescopic rod.

[0152] In this way, the effect achieved is consistent with that of implementation mode 1.

[0153] The following provides a fourth embodiment to specifically illustrate the prestressed support device for the retaining structure in the foundation pit of the present invention:

[0154] Implementation 4:

[0155] This embodiment 4 provides a prestressed support device, which is improved based on the prestressed support device in the foundation pit and the prestressing method provided in embodiments 1 to 3.

[0156] Improvement 1:

[0157] See also Figure 11 ,and Figure 12 ,

[0158] A ring beam is provided at the top of the support near the bottom of the enclosure, and this ring beam is called an upper ring beam 28. A ring beam is also provided at the bottom of the enclosure near the pit, and this ring beam is called an lower ring beam 38.

[0159] Regarding the aforementioned "the supporting output end of the upper diagonal bracing mechanism 128 provided in the prestressed supporting device 1 is provided to support the upper portion of the enclosure near the bottom support obliquely upward," after the improvement, the supporting output end of the upper diagonal bracing mechanism 128 is supported on the upper ring beam 28 at the upper portion of the enclosure near the bottom support. In other words, the supporting output end of the upper diagonal bracing mechanism 128 applies a supporting force to the upper portion of the enclosure near the bottom support through the upper ring beam 28.

[0160] Regarding the previously mentioned "the supporting output end of the lower diagonal support mechanism 129 provided in the prestressed supporting device 1 is inclined downward to support the enclosure near the bottom of the pit", after the improvement, the supporting output end of the lower diagonal support mechanism 129 is supported on the lower ring beam 38 at the bottom of the pit. In other words, the supporting output end of the lower diagonal support mechanism 129 applies a supporting force to the enclosure near the bottom of the pit through the lower ring beam 38.

[0161] The upper ring beam 28 and the lower ring beam 38 are provided to ensure that the retaining structure 2 is subjected to coordinated forces and to avoid uncoordinated deformation of the retaining structure 2 .

[0162] In this embodiment, the upper ring beam 28 and the lower ring beam 38 are both prefabricated steel ring beams, but in other embodiments, they can be concrete ring beams.

[0163] If the upper ring beam 28 or the lower ring beam 38 is a concrete ring beam,

[0164] The upper ring beam 28 or the lower ring beam 38 can be provided with a hanging rod 29, and the upper ring beam 28 or the lower ring beam 38 can be fixed on the enclosure structure 2 (such as Figure 11 shown);

[0165] Inserted reinforcement may also be provided on the upper ring beam 28 or the lower ring beam 38 , and the upper ring beam 28 or the lower ring beam 38 may be assembled on the enclosure structure 2 through the inserted reinforcement.

[0166] If the upper ring beam 28 or the lower ring beam 38 is a prefabricated steel ring beam, the concrete protective layer on the surface of the retaining structure 2 can be chiseled off to expose the steel bars inside it, and then the upper ring beam 28 or the lower ring beam 38 can be welded together with the steel bars inside the retaining structure 2, thereby achieving the assembly and fixation of the upper ring beam 28 or the lower ring beam 38.

[0167] It should be noted that the upper ring beam 28 and the lower ring beam 38 can be regarded as components of the prestressed support device 1.

[0168] It should be noted that the prestressed support device can be used for the entire enclosure structure or for a partial enclosure structure.

[0169] The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for applying prestressed support to a retaining structure in a foundation pit, characterized by: The prestressed support device (1) comprises a loading base (11) and two diagonal support mechanisms (12); The diagonal support mechanism (12) has a top support output end, and the top support output end can perform a telescopic action; The two diagonal support mechanisms (12) serve as an upper diagonal support mechanism (128) and a lower diagonal support mechanism (129), respectively; the upper diagonal support mechanism (128) is assembled on a loading base (11), and the lower diagonal support mechanism (129) is assembled on a loading base (11); The loading base (11) is assembled on a horizontal support near the bottom of the pit; A lower ring beam (38) is provided near the bottom of the pit, and the lower oblique support mechanism (129) extends obliquely downward to support the output end of the support on the lower ring beam (38); An upper ring beam (28) is provided at the upper portion of the enclosure near the bottom support, and the upper oblique support mechanism (128) extends obliquely upwards and the top support output end is supported on the upper ring beam (28).

2. The device for applying prestressed support to the retaining structure in the foundation pit according to claim 1, characterized in that: The upper ring beam (28) and the lower ring beam (38) are both concrete ring beams, and are each provided with a hanging rod (29). The hanging rod (29) is used to fix the upper ring beam (28) and the lower ring beam (38) on the enclosure structure (2).

3. The device for applying prestressed support to the retaining structure in the foundation pit according to claim 1, characterized in that: The upper ring beam (28) and the lower ring beam (38) are both concrete ring beams, and dowel bars are provided on both the upper ring beam (28) and the lower ring beam (38). Both the upper ring beam (28) and the lower ring beam (38) are assembled on the enclosure structure (2) through the dowel bars.

4. The device for applying prestressed support to the retaining structure in the foundation pit according to claim 1, characterized in that: The upper ring beam (28) and the lower ring beam (38) are both prefabricated steel ring beams; the concrete protective layer on the surface of the enclosure structure (2) is chiseled off to expose the steel bars inside thereof, and the upper ring beam (28) and the lower ring beam (38) are welded together with the steel bars inside the enclosure structure (2).

5. The device for applying prestressed support to the retaining structure in the foundation pit according to claim 1, characterized in that: The loading base (11) is assembled on a horizontal support near the pit bottom, and its specific structural form is: the loading base (11) has a clamping groove (111), and the clamping groove (111) of the loading base (11) is clamped and assembled on the edge of the horizontal support near the pit bottom.

6. The device for applying prestressed support to the retaining structure in the foundation pit according to claim 1, characterized in that: The diagonal support mechanism (12) comprises a top support telescopic rod and an angle adjustment telescopic rod (124); One end of the supporting telescopic rod serves as the main body end, and the other end of the supporting telescopic rod serves as the supporting output end; The main body end of the supporting telescopic rod is assembled on the loading base (11) through an axle pin hinge mechanism, and the supporting telescopic rod can swing up and down based on the loading base (11); The angle-adjusting telescopic rod (124) is assembled based on the loading base (11); a hoop (1241) is assembled at the telescopic end of the angle-adjusting telescopic rod (124); the top-supporting telescopic rod is assembled in the hoop (1241); the top-supporting telescopic rod is connected to the telescopic end of the angle-adjusting telescopic rod (124) through the hoop (1241); the telescopic action of the angle-adjusting telescopic rod (124) can drive the top-supporting telescopic rod to adjust the angle of the up-and-down swing; The top supporting telescopic rod of the upper oblique supporting mechanism (128) faces an obliquely upward direction, and the top supporting telescopic rod of the lower oblique supporting mechanism (129) faces an obliquely downward direction.

7. The device for applying prestressed support to the retaining structure in the foundation pit according to claim 6, characterized in that: The prestressed supporting device (1) further comprises a pulling rod (13); the pulling rod (13) is arranged between the supporting telescopic rod of the upper diagonal supporting mechanism (128) and the supporting telescopic rod of the lower diagonal supporting mechanism (129), and the pulling rod (13) connects the two supporting telescopic rods.

8. The device for applying prestressed support to the retaining structure in the foundation pit according to claim 1, characterized in that: The loading base (11) is U-shaped.

9. The device for applying prestressed support to the retaining structure in the foundation pit according to claim 1, characterized in that: The loading base (11) is an embedded part.

10. The device for applying prestressed support to the retaining structure in the foundation pit according to claim 6, characterized in that: The supporting telescopic rod is a hydraulic piston rod (127) or a sleeve nesting mechanism.

11. The device for applying prestressed support to the retaining structure in the foundation pit according to claim 1, characterized in that: The supporting output end of the diagonal supporting mechanism (12) is capable of outputting a supporting force.

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