A foundation pit excavation support device and method

Abstract

The present invention discloses a foundation pit excavation support device and method, which relates to the technical field of foundation pit construction auxiliary devices, including a concrete pile wall, a steel connection mechanism, a purlin connection mechanism, a first connection part, and a second connection part. The first connection part and the second connection part have opposite surfaces each provided with an inclined surface. The first connection part and the second connection part are detachably connected by a plurality of bolt mechanisms, and the bolt mechanisms can rotate at any angle on the first connection part and the second connection part. In the present invention, the gravity of the purlin acts on the first connection part and the second connection part, so that the inclined surfaces on the first connection part and the second connection part slide relative to each other, thereby converting the gravity of the purlin into a lateral support force on the steel connection mechanism and a longitudinal shear force acting on the bolt mechanism. Compared with the prior art, the longitudinal shear force acting on the bolt mechanism is reduced, thereby avoiding the problem of reduced support effect due to bolt deformation.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit construction auxiliary devices, and in particular to a foundation pit excavation support device and method. Background Art

[0002] Urban road water supply pipelines are an important part of urban infrastructure. They carry the task of transporting a variety of fluid media necessary for urban operations. The excavation and support of urban road pipeline foundation pits are important links in municipal engineering. The quality and safety of their construction are directly related to the stability of urban infrastructure and the safety of residents' lives. In recent years, with the development of urban construction, urban underground space has also been gradually developed and utilized, which has made the volume and depth of foundation pit excavation larger and larger. Deep foundation pit excavation construction should minimize the deformation of the soil caused by foundation pit excavation and reduce the impact on the surrounding environment. When excavating deep foundation pits, support devices are needed to support the soil of the foundation pit to prevent soil collapse.

[0003] The foundation pit excavation support device currently used is mainly to pour concrete on the foundation pit soil wall to form a concrete pile wall (or pile-board retaining wall), and then use steel and purlins to support the concrete pile wall laterally. The steel is installed laterally on the surface of the concrete pile wall, and then the purlins squeeze the steel laterally to generate support force for the steel. The connection surface between the steel and the purlins is often connected by bolts. Due to the large deadweight of the purlin, under the action of gravity, the shear force formed by the gravity due to the deadweight of the purlin is usually large. During long-term use, the bolts are prone to deformation, which in turn affects the support effect of the purlin on the steel. Summary of the invention

[0004] The object of the present invention is to provide a foundation pit excavation support device and method to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A foundation pit excavation support device, comprising:

[0007] Concrete pile wall cast on the side wall of foundation pit soil;

[0008] A steel connection mechanism installed in the concrete pile wall;

[0009] A purlin connection mechanism detachably connected to the steel connection mechanism, wherein a first connection portion is fixedly connected to one side of the purlin connection mechanism facing the center of the foundation pit;

[0010] A purlin is arranged in a foundation pit, and a second connecting part is fixedly connected to each of the two ends of the purlin, the first connecting part and the second connecting part are arranged correspondingly and the opposite surfaces of the two are abutted, the opposite surfaces of the first connecting part and the second connecting part are respectively provided with an inclined surface, and the inclined surfaces on the first connecting part and the second connecting part are arranged correspondingly, the first connecting part and the second connecting part are detachably connected by a plurality of bolt mechanisms, and the bolt mechanisms on the first connecting part and the second connecting part can be rotated at any angle.

[0011] Through the above technical solution, the gravity of the purlin acts on the first connecting part and the second connecting part, causing the inclined surfaces on the first connecting part and the second connecting part to slide relative to each other, thereby converting the gravity of the purlin into a lateral support force on the steel connection mechanism and a longitudinal shear force acting on the bolt mechanism. Compared with the prior art, the longitudinal shear force acting on the bolt mechanism is reduced, thereby avoiding the problem of reduced support effect due to bolt deformation.

[0012] Furthermore, the steel section connection mechanism includes a fixing part pre-embedded in the concrete pile wall, the fixing part is detachably connected to a movable part, the movable part is detachably connected to a steel section abutment plate on a side away from the fixing part, the lower outer wall of the steel section abutment plate is fixedly connected to a supporting steel plate, the surface of the steel section abutment plate is welded with steel, and the lower side of the steel section abuts against the top surface of the supporting steel plate.

[0013] Through the above technical solution, the abutting surfaces of the steel sections are against each other, and the supporting force of the purlin acting on the steel sections will be transmitted from the movable parts to the fixed parts, thereby supporting the foundation pit.

[0014] Furthermore, the purlin connection mechanism includes a connecting steel plate fixedly connected to the outer wall of the steel section facing away from the movable part, a connecting section is welded to the outer wall of the connecting steel plate facing away from the steel section, and the first connecting part is fixedly connected to one end of the connecting section away from the connecting steel plate.

[0015] Through the above technical solution, the extrusion pressure of the purlin on the second connection part acts on the steel section via the second connection part, the first connection part, the connection section and the connection steel plate in sequence, thereby enabling the steel section to support the foundation pit.

[0016] Furthermore, the bolt mechanism includes a plurality of ball heads rotatably embedded in the first connecting part and the second connecting part, and a spherical groove for the ball head to engage is provided in the first connecting part and the second connecting part, and the inner diameter of the spherical groove is larger than the outer diameter of the ball head, and the ball head is universally rotatable in the spherical groove, and a protrusion is fixed to the outer wall of the ball head, and a bolt mounting hole penetrating the ball head is provided on the surface of the protrusion, and a bolt pair is installed in two opposite bolt mounting holes on the first connecting part and the second connecting part, and a clearance groove for the bolt pair to pass freely is also provided on the surface of the first connecting part and the second connecting part.

[0017] Through the above technical solution, the two ball heads are locked by the bolt pair, so that the inclined surfaces of the first connecting part and the second connecting part can be offset against each other. In addition, the inner diameter of the spherical slot is larger than the outer diameter of the ball head. At the same time, since the ball head can rotate in the spherical slot, when the inclined surface of the first connecting part and the inclined surface of the second connecting part slide relative to each other, the ball head can drive the bolt pair to rotate to a certain extent, thereby reducing the longitudinal shear force acting on the bolt pair.

[0018] Furthermore, the outer wall of the ball head is provided with a deformation seam which passes through the protrusion.

[0019] Through the above technical solution, when the deadweight of the surrounding purlin is large and the longitudinal shear force acting on the bolt pair is large, the ball head can produce elastic contraction deformation, so that the rotation amplitude of the bolt pair can be increased, thereby reducing the longitudinal shear force it is subjected to.

[0020] Furthermore, a positioning portion is fixedly connected to the inclined surface on the second connecting portion, and a positioning groove for the positioning portion to engage is formed on the inclined surface on the first connecting portion, and the positioning portion is vertically and freely slidable in the positioning groove.

[0021] Through the above technical solution, after the first connecting part and the second connecting part are assembled, it can be ensured that the inclined surfaces of the two are parallel and abut against each other, which is convenient for the installation of the surrounding purlin.

[0022] Furthermore, a conical section is coaxially fixed to an end face of one side of the movable part adjacent to the fixed part, and an outer diameter of the conical section decreases successively in a direction away from the movable part. A conical hole for the conical section to engage is provided on the end face of the fixed part, and a plurality of notched grooves penetrating the conical hole are provided on the periphery of the fixed part. A plurality of screw mounting holes are provided on an end face of the movable part exposed from the conical hole, and a screw is installed in the screw mounting hole, and one end of the screw passing through the screw mounting hole is threadedly penetrated into the fixed part.

[0023] Through the above technical solution, when the lateral force of the surrounding purlin on the movable part is large, the lateral force will drive the cone section to slide in the cone hole, and cause the fixing part to produce a certain degree of elastic expansion deformation, so that the fixing part produces a longitudinal force on the concrete pile wall, thereby avoiding excessive lateral extrusion pressure on the concrete pile wall by the fixing part, which may cause cracks in the concrete pile wall.

[0024] Furthermore, a glue storage cavity connected to the tapered hole is provided in the fixing component, a plurality of fluid channels connected to the glue storage cavity and the notch groove are provided in the fixing component, an extrusion portion is fixedly connected to the end face of the tapered section, and the extrusion portion is engaged with the glue storage cavity and can slide freely.

[0025] Through the above technical scheme, when the lateral force of the surrounding purlin on the movable part is large, the sliding stroke of the cone section in the cone hole is large, which leads to a large elastic expansion amplitude of the fixing part, and the fixing part may cause extrusion cracks on the concrete pile wall. Therefore, when the cone section slides in the cone hole, the extrusion part will squeeze the epoxy resin glue in the glue storage cavity, and then squeeze the epoxy resin glue into the notch groove, so that the epoxy resin glue can fill the cracks in the concrete pile wall corresponding to the notch groove to prevent water seepage.

[0026] Furthermore, an end surface of the movable part is provided with an injection port for use with the glue storage cavity.

[0027] Through the above technical solution, epoxy resin glue can be injected into the glue storage cavity through the injection port.

[0028] A foundation pit excavation support method, applied to the foundation pit excavation support device as described above, comprises:

[0029] Concrete pile walls are poured on the side walls of the foundation pit soil, and the steel connection mechanism is pre-buried and installed in the concrete pile walls;

[0030] Then connect the enclosure purlin connection mechanism to the steel connection mechanism. After installation, hoist the enclosure purlin on the foundation pit, and detachably connect the second connection part and the first connection part through a bolt mechanism, so that the inclined surface on the second connection part and the inclined surface on the first connection part are in a state of abutment.

[0031] Under the action of the deadweight of the purlin, the gravity of the purlin will generate a lateral clamping force on the steel connection mechanism and a longitudinal shear force acting on the bolt mechanism, thereby supporting the steel connection mechanism.

[0032] Through the above technical solution, the longitudinal shear force on the bolts is reduced to prevent the support effect on the foundation pit from being reduced.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. In the present invention, the gravity of the purlin acts on the first connection part and the second connection part, so that the inclined surfaces on the first connection part and the second connection part slide relative to each other, thereby converting the gravity of the purlin into a transverse support force on the steel connection mechanism and a longitudinal shear force acting on the bolt mechanism. Compared with the prior art, the longitudinal shear force acting on the bolt mechanism is reduced, thereby avoiding the problem of reduced support effect caused by bolt deformation;

[0035] 2. In the present invention, when the lateral force of the surrounding purlin on the movable part is large, the lateral force will drive the cone section to slide in the cone hole, and cause the fixing part to produce a certain range of elastic expansion deformation, so that the fixing part produces a longitudinal force on the concrete pile wall, thereby preventing the fixing part from producing too large a lateral extrusion force on the concrete pile wall, thereby causing cracks in the concrete pile wall;

[0036] 3. In the present invention, when the lateral force of the surrounding purlin on the movable part is large, the sliding stroke of the cone section in the cone hole is large, which leads to a large elastic expansion amplitude of the fixing part. The fixing part may cause extrusion cracks on the concrete pile wall. Therefore, when the cone section slides in the cone hole, the extrusion part will squeeze the epoxy resin glue in the glue storage cavity, and then squeeze the epoxy resin glue into the notch groove, so that the epoxy resin glue can fill the cracks in the concrete pile wall corresponding to the notch groove to prevent water seepage. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the overall structure of a foundation pit excavation support device in the present invention;

[0038] Figure 2 for Figure 1 The schematic diagram of the position relationship after the concrete pile wall is omitted;

[0039] Figure 3 It is a schematic diagram of the positional relationship of the surrounding purlin, the first connecting part and the second connecting part after being assembled in the present invention;

[0040] Figure 4 for Figure 3 A schematic diagram of the positional relationship from another perspective;

[0041] Figure 5 for Figure 4 Schematic diagram of the positional relationship after the middle part of the structure is cut open;

[0042] Figure 6 for Figure 5 A magnified schematic diagram of the local structure at point A;

[0043] Figure 7 It is a schematic diagram of the positional relationship between the ball head and the bolt pair after assembly in the present invention;

[0044] Figure 8It is a schematic diagram of the positional relationship between the fixed part and the movable part after assembly in the present invention;

[0045] Fig. 9 for Figure 8 Schematic diagram of the explosion decomposition of the structure in the middle;

[0046] Fig.10 for Figure 8 Schematic diagram of the positional relationship after the middle part of the structure is cut open;

[0047] Fig.11 It is a structural schematic diagram of the fixing member in the present invention;

[0048] Fig.12 for Fig.11 Schematic diagram of the positional relationship after cutting open from the first perspective;

[0049] Fig.13 for Fig.11 Schematic diagram of the positional relationship after cutting open from the second perspective.

[0050] In the figure, the description of each figure mark is as follows: 1, concrete pile wall; 2, fixing piece; 3, steel abutment plate; 4, connecting section; 5, first connecting part; 6, second connecting part; 7, surrounding purlin; 8, steel; 9, supporting steel plate; 10, connecting steel plate; 11, inclined surface; 12, movable part; 13, glue storage cavity; 14, positioning part; 15, positioning groove; 16, air avoidance groove; 17, ball head; 18, spherical card groove; 19, bolt pair; 20, deformation joint; 21, protrusion; 22, notch groove; 23, screw mounting hole; 24, screw; 25, tapered hole; 26, tapered section; 27, first fluid cavity; 28, injection port; 29, second fluid cavity; 30, overflow cavity; 31, extrusion part. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] See also Figure 1 - Fig.13The present invention provides a technical solution: a foundation pit excavation support device, comprising a concrete pile wall 1, the concrete pile wall 1 is cast on the four side walls of the foundation pit soil, and the casting method of the concrete pile wall 1 is the existing technology. A fixing part 2 is pre-embedded and installed in the concrete pile wall 1, and the outer contour of the fixing part 2 is cylindrical. The axial direction of the fixing part 2 is parallel to the thickness direction of the concrete pile wall 1, and the end surface of the fixing part 2 on one side facing the outer side of the concrete pile wall 1 is coaxially opened with a conical hole 25 in the form of a blind hole (combined with Figure 1 and Fig. 9 ), the inner diameter of the tapered hole 25 increases in sequence in the direction away from the fixing member 2, and a tapered section 26 is mounted in the tapered hole 25, and one end of the tapered section 26 exposed from the tapered hole 25 is fixedly connected with the movable member 12 in an integral manner, and the outer diameter of the tapered section 26 is adapted to the inner diameter of the tapered hole 25, and the end surface of the movable member 12 away from the fixing member 2 is connected with a steel abutment plate 3 by screws, and the lower outer wall of the steel abutment plate 3 is fixedly connected with a support steel plate 9 (such as Figure 4 As shown), a profiled steel 8 is welded on the surface of the profiled steel abutment plate 3, the lower side of the profiled steel 8 abuts against the top surface of the supporting steel plate 9, the length dimension of the profiled steel 8 is adapted to the lateral length dimension of the side wall of the foundation pit, a connecting steel plate 10 is welded on the outer wall of the side of the profiled steel 8 facing away from the movable part 12, a connecting section 4 is welded on the outer wall of the side of the connecting steel plate 10 facing away from the profiled steel 8, and a first connecting portion 5 is fixedly connected to the connecting section 4 on the side facing the center of the foundation pit;

[0053] A plurality of purlins 7 are arranged in the foundation pit, and the two ends of the purlins 7 in the length direction correspond to the steel sections 8 on both sides of the foundation pit respectively. A second connecting portion 6 is welded to each of the two ends in the length direction of the purlin 7, and the second connecting portion 6 is arranged correspondingly to the first connecting portion 5. The first connecting portion 5 and the second connecting portion 6 have inclined surfaces 11 on the opposite surfaces, and the inclined surfaces 11 on the two are arranged correspondingly, so that the inclined surface 11 on the first connecting portion 5 is parallel to the inclined surface 11 on the second connecting portion 6, and a spherical groove 18 (such as Figure 6As shown in the figure, a ball head 17 is universally rotatably embedded in the spherical slot 18, and a protrusion 21 is symmetrically fixed to the periphery of the ball head 17 along its center, and a bolt mounting hole penetrating the ball head 17 is coaxially opened on the protrusion 21, and a bolt pair 19 is commonly installed in the two corresponding bolt mounting holes on the first connecting part 5 and the second connecting part 6, and the two ball heads 17 on the first connecting part 5 and the second connecting part 6 are connected by the bolt pair 19, so that the surrounding purlin 7 and the connecting section 4 can be detachably connected together. Furthermore, the inner diameter of the spherical slot 18 is slightly larger than the outer diameter of the ball head 17, so that when the first connecting part When the inclined surface 11 on the first connecting portion 5 and the inclined surface 11 on the second connecting portion 6 slide relative to each other, the ball head 17 will rotate in the spherical groove 18 (the rotation amplitude is relatively small), and the ball head 17 will drive the bolt pair 19 to deflect up and down, thereby causing the axis of the bolt pair 19 to deflect up and down. In this way, when the gravity generated by the deadweight of the surrounding purlin 7 acts on the bolt pair 19, the longitudinal shear force on the bolt pair 19 is the longitudinal component of the gravity of the surrounding purlin 7, and the lateral component of the gravity of the surrounding purlin 7 will act on the steel section 8 in turn through the second connecting portion 6 and the first connecting portion 5, thereby tightening the steel section 8, thereby being able to tighten the soil side wall of the foundation pit. Compared with the prior art, since the gravity of the surrounding purlin 7 can act on the soil side wall of the foundation pit, the supporting force on the soil side wall of the foundation pit is relatively large. In addition, the surfaces of the first connecting part 5 and the second connecting part 6 are provided with an escape groove 16 for the bolt pair 19 to pass freely. Furthermore, the outer wall of the ball head 17 is provided with a deformation joint 20 that penetrates the protruding part 21. By setting the deformation joint 20, when the self-weight of the surrounding purlin 7 is large and the longitudinal shear force acting on the bolt pair 19 is large, the ball head 17 can produce elastic contraction deformation, so that the rotation amplitude of the bolt pair 19 can be increased, thereby reducing the longitudinal shear force it is subjected to. Shear force, the inclined surface 11 on the second connecting part 6 is fixedly connected with the positioning part 14, and the inclined surface 11 on the first connecting part 5 is provided with a positioning groove 15 for the positioning part 14 to engage, and the positioning part 14 slides vertically and freely in the positioning groove 15. When assembling the purlin 7, first pre-assemble the purlin 7 and the first connecting part 5, and insert the positioning part 14 into the positioning groove 15, so that the inclined surfaces 11 on the first connecting part 5 and the second connecting part 6 can be in a parallel state. After pre-assembling the purlin 7 and the first connecting part 5, the pre-assembled purlin 7 and the first connecting part 5 are hoisted into the foundation pit, and the connecting steel plate 10 and the steel section 8 on the first connecting part 5 are welded.

[0054] The fixing member 2 is provided with a plurality of notched grooves 22 penetrating the tapered hole 25 on its periphery, a plurality of screw mounting holes 23 are provided on one end surface of the movable member 12 exposed from the tapered hole 25, a screw 24 is installed in the screw mounting hole 23, one end of the screw 24 passing through the screw mounting hole 23 is threadedly penetrated into the fixing member 2, the screw mounting hole 23 comprises a countersunk hole and a through hole, the screw head of the screw 24 is engaged in the countersunk hole, and the depth dimension of the countersunk hole is greater than the axial length dimension of the screw head, the threaded portion of the screw 24 passes through the screw mounting hole 23 and is threadedly connected with the fixing member 2, so that the movable member 12 can be installed on the fixing member 2 by means of the screw 24, a glue storage cavity 13 communicating with the tapered hole 25 is provided in the fixing member 2, a plurality of fluid channels communicating with the glue storage cavity 13 and the notched groove 22 are provided in the fixing member 2, specifically, the fluid channel comprises a first fluid cavity 27 (such as a first fluid cavity 27) provided in the fixing member 2 Fig.13 As shown), there are multiple first fluid chambers 27, and the length direction of the first fluid chamber 27 is perpendicular to the axial direction of the fixing member 2. A second fluid chamber 29 is also opened in the fixing member 2, and the length direction of the second fluid chamber 29 is parallel to the axial direction of the fixing member 2. In addition, an annular overflow chamber 30 is coaxially opened in the fixing member 2, and the overflow chamber 30 is connected with multiple notch grooves 22 and the second fluid chamber 29. An extrusion portion 31 is fixedly connected to the end face of the cone section 26, and the extrusion portion 31 is engaged with the glue storage chamber 13 and slides freely. An injection port 28 is provided on the end face of the movable member 12 for use with the glue storage chamber 13, and a wire plug is provided at the mouth of the injection port 28 (not shown in the figure).

[0055] Working principle of the present invention:

[0056] A concrete pile wall 1 is cast on the soil side wall of the foundation pit by the prior art, and a fixing member 2 is embedded in the concrete pile wall 1. The movable member 12 is installed on the fixing member 2 by means of screws 24, that is, the cone section 26 is clamped and installed in the cone hole 25 of the fixing member 2. At this time, the fixing member 2 does not produce elastic expansion deformation;

[0057] First, the purlin 7 and the first connecting part 5 are pre-assembled, that is, the purlin 7 is lifted by the lifting equipment, and the positioning part 14 on the second connecting part 6 is inserted into the positioning groove 15 of the first connecting part 5, so as to align the first connecting part 5 and the second connecting part 6, and make the inclined surface 11 on the first connecting part 5 and the inclined surface 11 on the second connecting part 6 parallel, and then the bolt pair 19 is passed through the ball heads 17 of the first connecting part 5 and the second connecting part 6, and the first connecting part 5 and the second connecting part 6 are tightly connected together, so as to complete the pre-assembly of the purlin 7 and the first connecting part 5, and then the purlin 7 is lifted into the foundation pit by the lifting equipment, and the connecting steel plate 10 on the first connecting part 5 is placed on the supporting steel plate 9, and then the connecting steel plate 10 is welded to the section steel 8. The weight of the purlin 7 is large, so that the gravity of the purlin 7 will make the inclined surfaces on the first connecting part 5 and the second connecting part 6 The surface 11 of the second connecting part 6 slides relative to the surface 11 of the first connecting part 5, that is, the surrounding purlin 7 moves downward slightly, and the inclined surface 11 on the second connecting part 6 slides on the inclined surface 11 on the first connecting part 5. The lateral component of the gravity of the surrounding purlin 7 will act on the first connecting part 5, and then act on the movable part 12 by the second connecting part 6, the connecting section 4, the steel section 8, and the steel section abutment plate 3 in sequence, so that the tapered section 26 of the movable part 12 slides in the tapered hole 25 of the fixing part 2. During the sliding process, the tapered section 26 exerts a squeezing force on the inner wall of the tapered hole 25, thereby causing the movable part 12 to produce elastic expansion deformation along its radial outer side, so that the movable part 12 can be securely clamped and installed in the concrete pile wall 1. Since the concrete pile wall 1 has resistance to the elastic expansion deformation of the movable part 12 after solidification, the movable part 12 will not produce a large degree of elastic expansion deformation when the lateral force of the surrounding purlin 7 on the movable part 12 is not large.

[0058] When the deadweight of the purlin 7 is large, the inclined surface 11 of the second connection part 6 will slide on the inclined surface 11 of the first connection part 5, and the ball head 17 on the first connection part 5 and / or the second connection part 6 will produce elastic contraction deformation, thereby causing the bolt pair 19 to swing upward as a whole. The bolt pair 19 always exerts a pulling force on the two ball heads 17 to keep the first connection part 5 and the second connection part 6 in a state where the inclined surfaces 11 are against each other. Since the bolt pair 19 swings, the longitudinal shear force acting on the bolt pair 19 is small, and the bolt pair 19 is not easy to produce shear deformation;

[0059] In addition, due to the large deadweight of the surrounding purlin 7, the sliding stroke of the cone section 26 in the cone hole 25 is large, and the elastic expansion deformation of the fixing member 2 is large, which may cause the expanded part of the fixing member 2 to exert a large extrusion force on the concrete pile wall 1 (the concrete pile wall 1 is generally made of C20 concrete, and its strength grade is not high), and the squeezed part of the concrete pile wall 1 is prone to cracks and water seepage. Therefore, when the sliding stroke of the cone section 26 in the cone hole 25 is large, the squeezing part 31 will squeeze the epoxy resin glue in the glue storage chamber 13, so that the epoxy resin glue enters the second fluid chamber 29 from the first fluid chamber 27, and then flows out from the overflow. The liquid in the cavity 30 flows out to the notch groove 22, and then is squeezed by the notch groove 22 to the crack part (the part of the fixing part 2 corresponding to the edge of the notch groove 22 exerts a greater local squeezing force on the concrete pile wall 1, so the crack generally corresponds to the edge of the notch groove 22). The epoxy resin glue can fill the gap in the crack part to prevent water from seeping into the fixing part 2 to cause rust or cause external rainwater to enter the gap in the crack part. When installing the fixing part 2 and the movable part 12, the movable part 12 is installed in the fixing part 2 by means of screws 24, and then an injection device is used to squeeze the epoxy resin glue to the injection port 28 and enter the glue storage cavity 13 for storage. After the injection is completed, the injection port 28 is closed with a screw plug.

[0060] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A foundation pit excavation support device, characterized in that: include: Concrete pile wall cast on the side wall of foundation pit soil; A steel connection mechanism installed in the concrete pile wall; A purlin connection mechanism detachably connected to the steel connection mechanism, wherein a first connection portion is fixedly connected to one side of the purlin connection mechanism facing the center of the foundation pit; A purlin arranged in a foundation pit, wherein the two ends of the purlin are respectively fixedly connected with a second connection part, the first connection part and the second connection part are arranged correspondingly and the opposite surfaces of the two are abutted, the opposite surfaces of the first connection part and the second connection part are respectively provided with an inclined surface, the inclined surfaces on the first connection part and the second connection part are arranged correspondingly, the first connection part and the second connection part are detachably connected by a plurality of bolt mechanisms, and the bolt mechanisms on the first connection part and the second connection part can be rotated at any angle; The steel connection mechanism comprises a fixing part pre-buried and installed in the concrete pile wall, the fixing part is detachably connected to a movable part, a side of the movable part away from the fixing part is detachably connected to a steel abutment plate, a lower outer wall of the steel abutment plate is fixedly connected to a support steel plate, a steel abutment plate surface is welded with a steel, and the lower side of the steel abutment plate abuts against the top surface of the support steel plate; The bolt mechanism includes a plurality of ball heads rotatably embedded in the first connecting part and the second connecting part. The first connecting part and the second connecting part are provided with spherical grooves for the ball heads to engage with. The inner diameter of the spherical groove is larger than the outer diameter of the ball head. The ball head is universally rotatable in the spherical groove. A protrusion is fixed to the outer wall of the ball head. A bolt mounting hole penetrating the ball head is provided on the surface of the protrusion. A bolt pair is installed in two opposite bolt mounting holes on the first connecting part and the second connecting part. A clearance groove is also provided on the surface of the first connecting part and the second connecting part for the bolt pair to pass freely.

2. The foundation pit excavation support device according to claim 1, characterized in that: The purlin connection mechanism includes a connecting steel plate fixedly connected to the outer wall of the steel section facing away from the movable part, a connecting section is welded to the outer wall of the connecting steel plate facing away from the steel section, and the first connecting part is fixedly connected to one end of the connecting section away from the connecting steel plate.

3. The foundation pit excavation support device according to claim 1, characterized in that: The outer wall of the ball head is provided with a deformation seam which penetrates through the protrusion.

4. The foundation pit excavation support device according to claim 1, characterized in that: The inclined surface on the second connecting portion is fixedly connected with a positioning portion, and the inclined surface on the first connecting portion is provided with a positioning groove for the positioning portion to engage with, and the positioning portion is vertically and freely slidable in the positioning groove.

5. The foundation pit excavation support device according to claim 1, characterized in that: A conical section is coaxially fixed to an end face of one side of the movable part adjacent to the fixed part, and the outer diameter of the conical section decreases successively in the direction away from the movable part. A conical hole for the conical section to engage is provided on the end face of the fixed part, and a plurality of notched grooves penetrating the conical hole are provided on the periphery of the fixed part. A plurality of screw mounting holes are provided on an end face of the movable part exposed from the conical hole, and a screw is installed in the screw mounting hole, and one end of the screw passing through the screw mounting hole is threadedly penetrated into the fixed part.

6. The foundation pit excavation support device according to claim 5, characterized in that: The fixing member is provided with a glue storage cavity connected with the tapered hole, and a plurality of fluid channels connected with the glue storage cavity and the notch groove are provided in the fixing member. The end surface of the tapered section is fixed with an extrusion portion, which is engaged with the glue storage cavity and can slide freely.

7. The foundation pit excavation support device according to claim 6, characterized in that: The end surface of the movable part is provided with an injection port used in conjunction with the glue storage cavity.

8. A foundation pit excavation support method, applied to the foundation pit excavation support device according to any one of claims 1 to 7, characterized in that: include: Concrete pile walls are poured on the side walls of the foundation pit soil, and the steel connection mechanism is pre-buried and installed in the concrete pile walls; Then connect the enclosure purlin connection mechanism to the steel connection mechanism. After installation, hoist the enclosure purlin on the foundation pit, and detachably connect the second connection part and the first connection part through a bolt mechanism, so that the inclined surface on the second connection part and the inclined surface on the first connection part are in a state of abutment. Under the action of the deadweight of the purlin, the gravity of the purlin will generate a lateral clamping force on the steel connection mechanism and a longitudinal shear force acting on the bolt mechanism, thereby supporting the steel connection mechanism.

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