Construction device and construction method for safe construction of underground structures

Abstract

The present invention discloses a construction device and a construction method for safe construction of underground structures, wherein the construction device comprises a foundation pit support assembly, wherein the foundation pit support assembly comprises a plurality of support plates, wherein the support plates comprise a plurality of enclosures and a plurality of retaining plates; the enclosures are hollow plate-like structures; the enclosures comprise an outer plate for connecting with the foundation pit and an inner plate close to the center of the foundation pit, wherein a plurality of connecting holes are provided on the outer plate; a drainage port is provided on the inner plate; a grouting pipe is provided in the gap between any two adjacent retaining plates, wherein the outlet end of the grouting hole faces the side of the grouting pipe away from the enclosure. The construction method is based on the construction device. The device and method provided by the present scheme can not only provide support for the foundation pit construction to facilitate construction safety, but also partially or completely fill the voids caused by the foundation pit construction to the soil layer at the edge of the foundation pit after the foundation pit construction is completed, thereby facilitating the stability of the strata around the foundation pit.

Description

Technical Field

[0001] The present invention relates to the technical field of underground engineering construction, and in particular to a construction device and a construction method for safe construction of underground structures. Background Art

[0002] The foundation pit generally refers to the earth pit excavated at the design location of the building foundation according to the building base elevation and foundation plane size. For the foundation pit construction, the foundation pit support device is a temporary structure and a safety protection structure to prevent collapse during the foundation pit construction process. At the same time, during the foundation pit excavation and construction process, it is necessary to consider the precipitation of the foundation pit.

[0003] The strata of sandy pebble geology are generally loose and rich in water. When constructing foundation pits in water-rich sandy pebble strata close to important buildings, special attention should be paid to the impact of ground precipitation on the surrounding environment. Therefore, in the existing construction, there are a series of problems in the construction process of deep foundation pits in sandy pebble strata (excavation depth exceeds 5 meters (including 5 meters), or the depth does not exceed 5 meters, but the geological conditions, surrounding environment and underground pipelines are particularly complex), such as great construction difficulty and great impact on the surrounding environment.

[0004] In the existing technology, the commonly used support methods in soft soil areas are bored interlocking piles and underground continuous walls. The research on dewatering optimization and risk control of deep foundation pits in water-rich sand and gravel formations is of great significance to underground building construction. Summary of the invention

[0005] In response to the above-mentioned technical problem of conducting research on optimization and risk control of dewatering of deep foundation pits in water-rich sand and gravel strata, which is of great significance to underground building construction, the present invention provides a construction device and a construction method for safe construction of underground structures. The device and method provided in this scheme can not only provide support for foundation pit construction to facilitate construction safety, but also partially or completely fill the voids caused by foundation pit construction in the soil layer at the edge of the foundation pit after the foundation pit construction is completed, which is beneficial to the stability of the strata around the foundation pit.

[0006] The construction device and construction method for safe construction of underground structures provided by the present invention solve the problem through the following technical points: the construction device for safe construction of underground structures comprises a foundation pit support assembly, the foundation pit support assembly comprises a plurality of support plates arranged in sequence along the circumferential direction of the foundation pit, the support plates comprise a plurality of enclosure plates and a plurality of retaining plates;

[0007] The retaining plates are arranged at intervals along the circumferential direction of the foundation pit, and a panel is arranged between any two adjacent retaining plates, and the outer side of each panel is pressed against the inner side of the corresponding two retaining plates;

[0008] The enclosure is a hollow plate-like structure;

[0009] The enclosure plate includes an outer plate for connecting with the foundation pit and an inner plate close to the center of the foundation pit, the outer plate is provided with a plurality of connecting holes penetrating the inner and outer sides of the outer plate; the inner plate is provided with a drainage port penetrating the inner and outer sides of the inner plate;

[0010] A vertically arranged grouting pipe is arranged in the gap between any two adjacent retaining plates. The grouting pipe is provided with a plurality of grouting holes arranged along the axial direction of the grouting pipe, and the outlet end of the grouting hole faces the side of the grouting pipe away from the enclosure plate.

[0011] This plan aims to solve the problems of great construction difficulty and easy impact on the surrounding environment during the construction of foundation pits in sandy and gravel formations, especially deep foundation pits. The above plan is provided based on the characteristics of sandy and gravel formations that are usually rich in water and very prone to collapse. When this plan is used, the following operation methods are used to provide safety protection support for the construction of several structures, provide foundation pit dewatering conditions, and improve the stability of the bottom layer around the foundation pit after the foundation pit is constructed:

[0012] S1. Complete the installation of the enclosure, retaining plate and grouting pipe on the edge of the foundation pit, and use the device to provide support for the wall of the foundation pit. In this step, the enclosure and retaining plate are used as retaining walls on the support. By fitting to the inner wall of the foundation pit, the purpose of avoiding collapse accidents caused by excavation of the foundation pit is achieved. In specific application, since both ends of each retaining plate are supported on the enclosure at the corresponding position in the circumferential direction of the foundation pit, a support frame is used to provide support and constraint for the enclosure in the radial direction of the foundation pit.

[0013] S2. During the foundation pit construction process, the connecting holes and drain outlets on the enclosure are used to achieve foundation pit dewatering. In this step, in order to solve the problem that the sand and gravel geology is not convenient for setting well point dewatering during the construction of underground structures, connecting holes and drain outlets are opened on the enclosure as a component of the retaining wall to achieve foundation pit dewatering. In the specific structural design, the enclosure is set as a hollow structure, aiming to consider: the connecting holes are actually the water inlet holes on the enclosure, and the drain outlets are actually the water outlet holes on the enclosure. The design of the above water inlet holes should actually be considered to be set as many as possible and the coverage area should be as large as possible. In this way, the problem that water from the stratum is introduced into the enclosure from the local area of ​​the enclosure, resulting in the formation of large-area holes in the local area of ​​the stratum due to the erosion of the water body, can be solved to a certain extent. After the water enters the enclosure, it gathers inside the enclosure and is then discharged from the drain outlet, which can facilitate the collection and extraction of water from the enclosure. Therefore, in specific application, it is set to have connecting holes covering the entire surface of the outer plate.

[0014] S3. After the foundation pit construction is completed, the grouting pipe is used to inject grouting material into the outside of the grouting pipe, and during the curing process of the grouting material, the enclosure is used as a template for supporting the grouting pipe. By adopting this solution, the grouting pipe can be used to fill the cavities on the wall of the foundation pit that are inevitably formed due to the dewatering of the foundation pit. By increasing the density of the wall of the foundation pit, the stability of the strata around the foundation pit can be achieved.

[0015] When this solution is used in practice, the enclosure can be made of multiple plates spliced ​​together. For example, according to the internal design, for a solution without a filter, six flat plates can be welded. For a solution that includes a filter and requires maintenance of the filter, one of the flat plates can be bolted to the adjacent plate.

[0016] Further technical solutions are:

[0017] In order to use this device to form a complete protection for the foundation pit wall, it is set as follows: the enclosure and the retaining plate form a cylindrical structure, and a vertically arranged sealing strip is arranged between each enclosure and the retaining plate in contact with it. With this solution, the sealing strip is used to limit the flow path of the foundation pit dewatering to passing through the enclosure. In this way, it is convenient for technicians in this field to obtain a balance point in well point dewatering and control of the flow rate of well point dewatering: that is, to meet the dewatering needs and also meet the consideration of the safety of the surrounding bottom layer, such as by controlling the water outflow of the drain outlet to achieve the above purpose.

[0018] In order to facilitate the collection of water outflow from the enclosure and the control of the above balance point, it is set as follows: a water tank fixed to the inner plate is provided on the inner side of the bottom of each enclosure, and the outlet end of the drain port is located in the water tank;

[0019] The fluid conductance of the drain outlets on each enclosure is adjustable.

[0020] As a specific solution for adjusting the fluid conductivity of the drain outlet, it is set as follows: the number of drain outlets on each enclosure is multiple, and the blocking state of some or all drain outlets on each enclosure is adjustable. This solution forms the enclosure water flow adjustment through multiple drain outlets, and the specific adjustment method is to block some drain outlets. In specific application, if the foundation pit drainage does not meet the safety requirements, the above-mentioned state of blocking all drain outlets can be adopted.

[0021] As described above, in the specific implementation of this scheme, in order to achieve multi-gradient adjustable drainage flow of the enclosure through the drainage outlet, it is preferably set to have as many drainage outlets as possible. At the same time, considering the water conduction capacity of the outer plate of the enclosure to the edge of the foundation pit, to avoid the concentrated water conduction causing excessively large local holes in the foundation pit to expand the impact of the foundation pit excavation on the bottom layer, it is preferably adopted that the connecting holes are evenly distributed on the entire surface of the outer plate as a drainage outlet blocking solution, which is set as follows: it also includes a filter screen arranged in the hollow space of each enclosure, and in the plate thickness direction of the enclosure, the filter screen divides the hollow space into an outer cavity and an inner cavity, the outer cavity is the cavity between the filter screen and the outer plate, and the inner cavity is the cavity between the filter screen and the inner plate;

[0022] It also includes a mud discharge port connected to the bottom side of the enclosure, with the inlet end connected to the inner cavity;

[0023] It also includes a water injection port connected to the enclosure, with the outlet end connected to the inner cavity;

[0024] The mud discharge port and water injection port are both provided with a cut-off device for controlling their respective on-off states. In this scheme, the filter net is used as a filtering component between the connecting hole and the drain port to avoid the drain port being blocked due to the introduction of sand, mud, etc. into the enclosure in a short period of time due to the large number of connecting holes; it is configured to include the mud discharge port and the water injection port, aiming to achieve: regularly or when necessary, inject cleaning water through the water injection port to clean the outer cavity, and then discharge it from the mud discharge port; it is configured to also include a cut-off device, aiming to achieve the cut-off of the mud discharge port when it is not necessary, and the fluid is only enriched in the water tank and pumped out by a general pump body; the position limitation of the above mud discharge port and water injection port is intended to cover the entire filtering surface of the filter net as much as possible through the above cleaning water; the setting of the above cut-off device is not only intended to achieve the above flow limiting purpose, but also to use the outer cavity as a temporary storage space for sand and mud entering the enclosure, such as using the sand and mud accumulated in the outer cavity at a certain time interval to judge the impact of the precipitation flow on the safety of the formation at this time.

[0025] As a technical solution to solve the blockage of the connecting hole by introducing pressurized gas into the hollow space of the enclosure when each drain outlet is closed and the cut-off device is turned off, it is configured as follows: each drain outlet is matched with a plug, and also includes a connecting pipe connected to the enclosure, and the outlet end of which is connected to the hollow space.

[0026] As a technical solution to facilitate the installation and cleaning and maintenance of the filter during use: the connection between the filter and the enclosure is achieved in the following manner: the connection between the filter and the enclosure is achieved in the following manner: the remaining four faces of the enclosure are respectively the upper end face, the lower end face, the left end face and the right end face, and any one of the remaining four faces is bolted to the enclosure;

[0027] Two chute grooves in a positive relationship are arranged on the wall surface of the hollow space of the enclosure, and the filter screen is clamped in the hollow space through the chute grooves;

[0028] The starting end of the chute is directly opposite to the surface connected to the enclosure by bolts. With this solution, after the surface connected to the enclosure by bolts is disassembled, the filter screen can be disassembled or installed by pulling and inserting operations.

[0029] It also includes a support plate arranged in the inner cavity, and the filter screen is supported on the support plate as a surface of the inner cavity boundary.

[0030] As a technical solution to facilitate the restraint of the enclosure at the edge of the foundation pit, it is configured as follows: it also includes a support frame for supporting the enclosure, the support frame includes a vertical pole and a plurality of cross bars arranged along the axis direction of the vertical pole, the cross bars serve as support members between the vertical pole and the inner side of each enclosure, and the length of the cross bars is adjustable; as a specific solution in which the length of the cross bars is adjustable and easy to adjust, the cross bars include a threaded barrel and a threaded rod connected in series, the threaded barrel is threadedly connected to the threaded rod and is coaxial, the threaded barrel is connected to the vertical pole, and a pad is provided between the end of the threaded rod and the inner side of the enclosure;

[0031] The backing plate comprises: a first plate body which is a steel plate, a second plate body which is a plastic plate or a graphite plate, and a third plate body which is a steel plate, wherein the first plate body is fixedly connected to the threaded rod, the second plate body is clamped between the first plate body and the third plate body, and the outer side of the third plate body is in contact with the inner side of the enclosure plate. The structure of this solution is simple, and the second plate body serves as a wear-reducing plate between the first plate body and the third plate body, so as to facilitate the relative rotation of the first plate body and the third plate body;

[0032] As a technical solution for balancing the forces on both sides of the vertical pole to stabilize the position of the vertical pole in space, so that the support frame is a split structure, the support frame is convenient for position transfer and storage, and the position of the cross bar can be conveniently adjusted according to specific support needs, it is set to: also include a sleeve mounted on the vertical pole and capable of sliding along the axis of the vertical pole, each sleeve is fixed with two cross bars, and the cross bars on each sleeve are linearly symmetrical with respect to the axis of the sleeve;

[0033] The number of the panels is an even number and the panels are evenly distributed in a ring relative to the axis of the vertical pole, and the ends of the cross bars on each sleeve act on the panels on the corresponding sides of the vertical pole;

[0034] The locking device is also included for locking the position of the sleeve on the axis of the crossbar. In the above specific structural design, it is set as follows: the number of the enclosure plates is an even number and they are evenly distributed in the circumferential direction of the vertical pole. As for the force on the vertical pole, since the thrusts from the horizontal bars on different sides are in opposite directions, the assembly composed of the sleeve and the crossbar can effectively optimize the force on the vertical pole and improve the stability of the support frame.

[0035] The sleeve is arranged to slide along the axis of the vertical pole, and a detachable lifting ring is arranged at the upper end of the vertical pole. The arrangement of the support frame and the assembly of the device can be carried out to obtain a safe and reliable construction plan under the condition of economic rationality and easy operation through the following operations:

[0036] D1. Complete the installation of all sleeves on the vertical poles, and the sleeves are stacked at the bottom of the vertical poles;

[0037] Complete the installation of the enclosure on the side of the support frame, and make the enclosure and the inner side of the retaining plate stick to each other;

[0038] Complete the installation of the lifting ring on the top of the pole;

[0039] D2. Adjust the length of the cross bars on both sides of the lowest sleeve so that both ends of the cross bars form a supporting relationship with the corresponding side panels. By using the above supporting relationship, the position of the vertical pole in space can be constrained and the strength state of the vertical pole can be maintained;

[0040] D3. Use the lifting tool hung on the lifting ring to lift the crossbar on the upper sleeve of the lowest sleeve in turn, so that the corresponding sleeve moves to the required vertical pole axis position along with the crossbar on it;

[0041] The specific lifting is as follows: the top sleeve is lifted first and after the axis position is determined, the length of the cross bar is adjusted to constrain the corresponding side panel, and then one of them is fixed on the vertical pole through the corresponding locking device. Then, in the arrangement order of the sleeves, the position of each sleeve on the vertical pole is adjusted from top to bottom, the length of the cross bar is adjusted to constrain the panel and the position is fixed on the vertical pole.

[0042] The lifting ring is detachable, so that the vertical pole can be erected at the installation position in the form of a bare pole first, and then the sleeves are installed from the upper end of the vertical pole, and then the lifting ring is installed to provide a lifting point located at the top of the vertical pole for each sleeve.

[0043] In the specific structural limitation and operation mode, the cross bar on the lowest sleeve can be used to realize the use of the enclosure to form an anti-falling constraint for the supporting state of the vertical pole. In this way, when the subsequent sleeve is lifted, the vertical pole can be kept in a relatively stable state until all sleeve positions are adjusted. For example, the sleeve and cross bar assembly can be lifted by a hand hoist or an electric hoist, so that the anti-falling constraint of the vertical pole and the subsequent lifting are easy to operate and economical. In order to fix the position of the sleeve, a number of pin holes corresponding to the number of sleeves can be set in the axial direction of the vertical pole. According to the installation requirements of the specific sleeve, the pin holes at the corresponding position can be selected so that the sleeve and the vertical pole form a pin connection relationship to achieve the fixing purpose.

[0044] This solution also provides a specific construction method, which is based on the device described in any one of the above, and is implemented by the following steps:

[0045] S1, completing the installation of the enclosure, retaining plate and grouting pipe on the edge of the foundation pit, and using the device to provide support for the wall surface of the foundation pit;

[0046] S2. During the foundation pit construction process, the connecting holes and drainage holes on the enclosure are used to achieve foundation pit dewatering;

[0047] S3. After the foundation pit construction is completed, the grouting pipe is used to inject grouting material into the outside of the grouting pipe, and during the curing process of the grouting material, the enclosure is used as a template for supporting the grouting pipe.

[0048] In specific application, it is preferred to set up multiple grouting pipes between each retaining plate. For the same grouting area, multiple grouting pipes can reduce the inner diameter of a single grouting pipe to improve the compressive capacity of the grouting pipe to obtain a better grouting effect. At the same time, for the purpose of using the enclosure to achieve precipitation, multiple grouting pipes can also cover as large a drainage area of ​​the foundation pit wall as possible for achieving precipitation.

[0049] Furthermore, the grouting pipes between the retaining plates form a grouting area. To facilitate the structural stability of the grouting area, it is preferably arranged that each grouting area is provided with a steel mesh serving as a steel skeleton for the grouting material, such that a concrete retaining wall including a steel skeleton is ultimately formed through grouting.

[0050] The present invention has the following beneficial effects:

[0051] This plan aims to solve the problems of great construction difficulty and easy impact on the surrounding environment during the construction of foundation pits in sandy and gravel formations, especially deep foundation pits. The above plan is provided based on the characteristics of sandy and gravel formations that are usually rich in water and very prone to collapse. When this plan is used, the following operation methods are used to provide safety protection support for the construction of several structures, provide foundation pit dewatering conditions, and improve the stability of the bottom layer around the foundation pit after the foundation pit is constructed:

[0052] S1. Complete the installation of the enclosure, retaining plate and grouting pipe on the edge of the foundation pit, and use the device to provide support for the wall of the foundation pit. In this step, the enclosure and retaining plate are used as retaining walls on the support. By fitting to the inner wall of the foundation pit, the purpose of avoiding collapse accidents caused by excavation of the foundation pit is achieved. In specific application, since both ends of each retaining plate are supported on the enclosure at the corresponding position in the circumferential direction of the foundation pit, a support frame is used to provide support and constraint for the enclosure in the radial direction of the foundation pit.

[0053] S2. During the foundation pit construction process, the connecting holes and drain outlets on the enclosure are used to achieve foundation pit dewatering. In this step, in order to solve the problem that the sand and gravel geology is not convenient for setting well point dewatering during the construction of underground structures, connecting holes and drain outlets are opened on the enclosure as a component of the retaining wall to achieve foundation pit dewatering. In the specific structural design, the enclosure is set as a hollow structure, aiming to consider: the connecting holes are actually the water inlet holes on the enclosure, and the drain outlets are actually the water outlet holes on the enclosure. The design of the above water inlet holes should actually be considered to be set as many as possible and the coverage area should be as large as possible. In this way, the problem that water from the stratum is introduced into the enclosure from the local area of ​​the enclosure, resulting in the formation of large-area holes in the local area of ​​the stratum due to the erosion of the water body, can be solved to a certain extent. After the water enters the enclosure, it gathers inside the enclosure and is then discharged from the drain outlet, which can facilitate the collection and extraction of water from the enclosure. Therefore, in specific application, it is set to have connecting holes covering the entire surface of the outer plate.

[0054] S3. After the foundation pit construction is completed, the grouting pipe is used to inject grouting material into the outside of the grouting pipe, and during the curing process of the grouting material, the enclosure is used as a template for supporting the grouting pipe. By adopting this solution, the grouting pipe can be used to fill the cavities on the wall of the foundation pit that are inevitably formed due to the dewatering of the foundation pit. By increasing the density of the wall of the foundation pit, the stability of the strata around the foundation pit can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a front view of a specific embodiment of the construction device for safe construction of underground structures according to the present invention and a partial structural schematic diagram, which is used to reflect the matching relationship between the support frame and the enclosure;

[0056] Figure 2 It is a partial schematic diagram of a specific embodiment of the construction device for safe construction of underground structures according to the present invention, and the schematic diagram is used to reflect the structural composition of the enclosure part;

[0057] Figure 3 It is a top view of a specific embodiment of the construction device for safe construction of underground structures according to the present invention;

[0058] Figure 4 It is a structural schematic diagram of a grouting pipe in a specific embodiment of the construction device for safe construction of underground structures described in the present invention.

[0059] The reference numerals in the figure are: 1. enclosure, 2. cross bar, 3. vertical bar, 4. threaded tube, 5. threaded rod, 6. pad, 7. mud discharge port, 8. connecting pipe, 9. water injection port, 10. grouting pipe, 101. grouting hole, 11. steel mesh, 12. water tank, 13. drain outlet, 14. plug, 15. connecting hole, 16. filter screen, 17. support plate, 18. lifting ring, 19. pin hole, 20. sleeve, 21. retaining board. DETAILED DESCRIPTION

[0060] The present invention will be further described in detail below in conjunction with the embodiments, but the structure of the present invention is not limited to the following embodiments.

[0061] Embodiment 1:

[0062] like Figures 1 to 4 As shown, a construction device for safe construction of underground structures includes a foundation pit support assembly, wherein the foundation pit support assembly includes a plurality of support plates arranged in sequence along the circumferential direction of the foundation pit, and the support plates include a plurality of enclosure plates 1 and a plurality of retaining plates 21;

[0063] The retaining plates 21 are arranged at intervals along the circumferential direction of the foundation pit, and a panel 1 is arranged between any two adjacent retaining plates 21, and the outer sides of each panel 1 are pressed against the inner sides of the corresponding two retaining plates 21;

[0064] The enclosure 1 is a hollow plate-like structure;

[0065] The enclosure 1 includes an outer plate for connecting with the foundation pit and an inner plate close to the center of the foundation pit. The outer plate is provided with a plurality of connecting holes 15 penetrating the inner and outer sides of the outer plate; the inner plate is provided with a drainage port 13 penetrating the inner and outer sides of the inner plate;

[0066] A vertically arranged grouting pipe 10 is provided in the gap between any two adjacent retaining plates 21 , and the grouting pipe 10 is provided with a plurality of grouting holes 101 arranged along the axial direction of the grouting pipe 10 , and the outlet end of the grouting hole 101 faces the side of the grouting pipe 10 away from the enclosure 1 .

[0067] This plan aims to solve the problems of great construction difficulty and easy impact on the surrounding environment during the construction of foundation pits in sandy and gravel formations, especially deep foundation pits. The above plan is provided based on the characteristics of sandy and gravel formations that are usually rich in water and very prone to collapse. When this plan is used, the following operation methods are used to provide safety protection support for the construction of several structures, provide foundation pit dewatering conditions, and improve the stability of the bottom layer around the foundation pit after the foundation pit is constructed:

[0068] S1. Complete the installation of the enclosure 1, retaining plate 21 and grouting pipe 10 on the edge of the foundation pit, and use the device to provide support for the wall of the foundation pit. In this step, the enclosure 1 and retaining plate 21 are used as retaining walls on the support, and are attached to the inner wall of the foundation pit to achieve the purpose of avoiding collapse accidents caused by excavation of the foundation pit. In specific use, since both ends of each retaining plate 21 are supported on the enclosure 1 at the corresponding position in the circumferential direction of the foundation pit, a support frame is used to provide support and constraint for the enclosure 1 in the radial direction of the foundation pit.

[0069] S2. During the foundation pit construction process, the connecting holes 15 and the drain outlets 13 on the enclosure 1 are used to achieve foundation pit dewatering. In this step, in view of the problem that the sandy gravel geology is not convenient for setting well point dewatering during the construction of underground structures, connecting holes 15 and drain outlets 13 are opened on the enclosure 1 as a component of the retaining wall to achieve foundation pit dewatering. In the specific structural design, the enclosure 1 is set as a hollow structure, aiming to consider: the connecting holes 15 are actually the water inlet holes on the enclosure 1, and the drain outlets 13 are actually the water outlet holes on the enclosure 1. The design of the above water inlet holes should actually be considered to be set as many as possible and the coverage area is as large as possible. In this way, the problem that the water from the stratum is introduced into the enclosure 1 from the local area of ​​the enclosure 1, resulting in the formation of large-area holes in the local area of ​​the stratum due to the scouring of the water body, can be solved to a certain extent. After the water enters the enclosure 1, it gathers inside the enclosure 1 and is then discharged from the drain outlet 13, which can facilitate the collection and extraction of the water from the enclosure 1. Therefore, in specific application, the connecting holes 15 are set to cover the entire surface of the outer plate.

[0070] S3. After the foundation pit construction is completed, the grouting pipe 10 is used to inject grouting material into the outside of the grouting pipe 10, and during the curing process of the grouting material, the enclosure 1 is used as a template for supporting the grouting pipe 10. By adopting this solution, the grouting pipe 10 can be used to fill the cavities on the wall of the foundation pit that are inevitably formed due to the dewatering of the foundation pit. By increasing the density of the wall of the foundation pit, the purpose of stabilizing the strata around the foundation pit is achieved.

[0071] When this solution is used in practice, the enclosure 1 can be made of multiple plates spliced ​​together. For example, according to the internal design, for a solution without a filter screen 16, six flat plates can be welded. For a solution that includes a filter screen 16 and requires maintenance of the filter screen 16, one of the flat plates can be bolted to the plate connected to it.

[0072] Embodiment 2:

[0073] like Figures 1 to 4As shown, this embodiment is further limited on the basis of embodiment 1: in order to use this device to form a complete protection for the foundation pit wall, it is set as follows: the enclosure 1 and the retaining plate 21 form a cylindrical structure, and a vertically arranged sealing strip is arranged between each enclosure 1 and the retaining plate 21 in contact therewith. By adopting this scheme, the sealing strip is used to make the flow path of the foundation pit dewatering limited to passing through the enclosure 1, so that, for example, in terms of well point dewatering and controlling the flow rate of well point dewatering, it is convenient for technical personnel in this field to obtain a balance point: that is, to meet the dewatering needs and also meet the consideration of the safety of the surrounding bottom layer, such as by controlling the water outflow of the drain outlet 13, the above purpose is achieved.

[0074] In order to facilitate the collection of water from the enclosure 1 and the control of the above balance point, it is set as follows: a water tank 12 fixed to the inner plate is provided on the inner side of the bottom of each enclosure 1, and the outlet end of the drain port 13 is located in the water tank 12;

[0075] The fluid conductance of the drainage openings 13 on each enclosure 1 is adjustable.

[0076] As a specific solution for adjusting the fluid conductivity of the drain outlet 13, it is set as follows: the number of drain outlets 13 on each enclosure 1 is multiple, and on each enclosure 1, the blocking state of some or all of the drain outlets 13 is adjustable. This solution forms the water flow adjustment of the enclosure 1 through multiple drain outlets 13, and the specific adjustment method adopts the method of blocking some of the drain outlets 13. In specific application, if the foundation pit drainage does not meet the safety requirements, the state of all the drain outlets 13 being blocked as above can be adopted.

[0077] As described above, in the specific implementation of this scheme, in order to achieve the multi-gradient adjustable drainage flow of the enclosure 1 through the drainage outlet 13, it is preferably set to have as many drainage outlets 13 as possible. At the same time, considering the water conduction capacity of the outer plate of the enclosure 1 to the edge of the foundation pit, to avoid the concentrated water conduction causing the local holes of the foundation pit to be too large and the impact of the foundation pit excavation on the bottom layer to be expanded, it is preferably adopted that the connecting holes 15 are evenly distributed on the entire surface of the outer plate as a solution for preventing the drainage outlet 13 from being blocked, and it is set as follows: it also includes a filter screen 16 arranged in the hollow space of each enclosure 1, and in the plate thickness direction of the enclosure 1, the filter screen 16 divides the hollow space into an outer cavity and an inner cavity, the outer cavity is the cavity between the filter screen 16 and the outer plate, and the inner cavity is the cavity between the filter screen 16 and the inner plate;

[0078] It also includes a mud discharge port 7 connected to the bottom side of the enclosure 1, with the inlet end connected to the inner cavity;

[0079] It also includes a water injection port 9 connected to the enclosure 1, with the outlet end connected to the inner cavity;

[0080] The mud outlet 7 and the water injection port 9 are both provided with a cut-off device for controlling the on-off state of each. In this scheme, the filter screen 16 is used as a filtering component between the connecting hole 15 and the drain port 13 to prevent the drain port 13 from being blocked due to the large number of connecting holes 15 and the introduction of sand, mud, etc. into the enclosure 1 in a short period of time; the mud outlet 7 and the water injection port 9 are provided to achieve: regularly or when necessary, the cleaning water is injected through the water injection port 9 to clean the outer cavity, and then discharged from the mud outlet 7; the cut-off device is provided to achieve the cut-off of the mud outlet 7 when it is not necessary, and the fluid is only enriched in the water tank 12 and pumped out by a general pump body; the position of the mud outlet 7 and the water injection port 9 is limited to cover the entire filtering surface of the filter screen 16 as much as possible through the cleaning water; the setting of the cut-off device is not only intended to achieve the above flow limit purpose, but also to use the outer cavity as a temporary storage space for sand and mud entering the enclosure 1, such as using the sand and mud accumulated in the outer cavity at a certain time interval to judge the impact of the precipitation flow on the safety of the formation.

[0081] As a technical solution for solving the blockage of the connecting hole 15 by introducing pressurized gas into the hollow space of the enclosure 1 when each drain outlet 13 is closed and the shut-off device is turned off, it is configured as follows: each drain outlet 13 is matched with a plug 14, and also includes a connecting pipe 8 connected to the enclosure 1, and the outlet end of which is connected to the hollow space.

[0082] As a technical solution to facilitate the installation and cleaning and maintenance of the filter 16 during use: the connection between the filter 16 and the enclosure 1 is achieved in the following manner: the connection between the filter 16 and the enclosure 1 is achieved in the following manner: the remaining four faces of the enclosure 1 are respectively the upper end face, the lower end face, the left end face and the right end face, and any one of the remaining four faces is bolted to the enclosure 1;

[0083] Two chute grooves in a positive relationship are arranged on the wall surface of the hollow space of the enclosure 1, and the filter screen 16 is clamped in the hollow space through the chute grooves;

[0084] The starting end of the chute is directly opposite to the surface bolted to the enclosure 1. With this solution, after the surface bolted to the enclosure 1 is detached, the filter 16 can be disassembled or installed by pulling and inserting operations.

[0085] It also includes a support plate 17 disposed in the inner cavity, and the filter screen 16 is supported on the support plate 17 as a surface of the inner cavity boundary.

[0086] In specific applications, it is preferably configured that multiple grouting pipes 10 are provided between each retaining plate 21. For the same grouting area, multiple grouting pipes 10 can reduce the inner diameter of a single grouting pipe 10 to enhance the compressive strength of the grouting pipe 10, so as to obtain a better grouting effect. At the same time, for the purpose of achieving precipitation using the enclosure 1, multiple grouting pipes 10 can also cover as large a drainage area of ​​the foundation pit wall as possible for achieving precipitation.

[0087] Furthermore, the grouting pipes 10 between each retaining plate 21 form a grouting area. To facilitate the structural stability of the grouting area, it is preferably arranged that each grouting area is provided with a steel mesh 11 serving as a steel skeleton for the grouting material, such that a concrete retaining wall including a steel skeleton is ultimately formed through grouting.

[0088] Embodiment 3:

[0089] like Figures 1 to 4 As shown, this embodiment is further limited on the basis of embodiment 1.

[0090] As a technical solution to facilitate the completion of the constraint of the enclosure 1 on the edge of the foundation pit, it is configured as follows: it also includes a support frame for supporting the enclosure 1, the support frame includes a vertical pole 3 and a plurality of cross bars 2 arranged along the axial direction of the vertical pole 3, the cross bars 2 serve as support members between the vertical pole 3 and the inner side of each enclosure 1, and the length of the cross bars 2 is adjustable; as a specific solution in which the length of the cross bar 2 is adjustable and easy to adjust, the cross bar 2 includes a threaded barrel 4 and a threaded rod 5 connected in series, the threaded barrel 4 is threadedly connected to the threaded rod 5 and is coaxial, the threaded barrel 4 is connected to the vertical pole 3, and a pad 6 is provided between the end of the threaded rod 5 and the inner side of the enclosure 1;

[0091] The pad 6 includes: a first plate body which is a steel plate, a second plate body which is a plastic plate or a graphite plate, and a third plate body which is a steel plate. The first plate body is fixedly connected to the threaded rod 5, the second plate body is clamped between the first plate body and the third plate body, and the outer side of the third plate body is in contact with the inner side of the enclosure 1. This solution has a simple structure. The second plate body serves as a wear-reducing plate between the first plate body and the third plate body, so as to facilitate the relative rotation of the first plate body and the third plate body.

[0092] As a technical solution for balancing the forces on both sides of the vertical pole 3 to stabilize the position of the vertical pole 3 in space, so that the support frame is a split structure, the support frame position is convenient for transfer and storage, and the position of the cross bar 2 can be conveniently adjusted according to specific support needs, it is set as follows: it also includes a sleeve 20 sleeved on the vertical pole 3 and capable of sliding along the axis of the vertical pole 3, each sleeve 20 is fixed with two cross bars 2, and the cross bars 2 on each sleeve 20 are linearly symmetrical with respect to the axis of the sleeve 20;

[0093] The number of the panels 1 is an even number and the panels 1 are evenly distributed in a ring relative to the axis of the vertical pole 3, and the ends of the cross bars 2 on each sleeve 20 act on the panels 1 on the corresponding side of the vertical pole 3;

[0094] It also includes a locking device for locking the sleeve 20 on the axis of the crossbar 2. In the above specific structural design, it is set as follows: the number of the enclosure plates 1 is an even number and they are evenly distributed in the circumferential direction of the vertical pole 3. As for the force on the vertical pole 3, since the thrust directions of the horizontal poles 2 from different sides are opposite, the assembly composed of the sleeve 20 and the crossbar 2 can effectively optimize the force on the vertical pole 3 and improve the stability of the support frame.

[0095] The sleeve 20 is configured to slide along the axis of the vertical pole 3. If a detachable lifting ring 18 is provided at the upper end of the vertical pole 3, the setting of the support frame and the assembly of the device can be conveniently performed through the following operations to obtain a safe and reliable construction plan under the condition of economic rationality and easy operation:

[0096] D1. Complete the installation of all sleeves 20 on the vertical pole 3, and the sleeves 20 are stacked at the bottom of the vertical pole 3;

[0097] Complete the installation of the enclosure 1 on the side of the support frame, and make the enclosure 1 abut against the inner side of the retaining plate 21;

[0098] Complete the installation of the lifting ring 18 on the top of the vertical pole 3;

[0099] D2. Adjust the length of the cross bars 2 on both sides of the bottom sleeve 20 so that both ends of the cross bars 2 form a supporting relationship with the corresponding side panels 1. By using the above supporting relationship, the position of the vertical pole 3 in space can be constrained and the strength state of the vertical pole 3 can be maintained;

[0100] D3, using the lifting tool hung on the lifting ring 18, lift the crossbar 2 on the upper sleeve 20 of the lowest sleeve 20 in turn, so that the corresponding sleeve 20 moves with the crossbar 2 thereon to the required axis position of the vertical pole 3;

[0101] The specific lifting is as follows: the top sleeve 20 is lifted first and after the axis position is determined, the length of the cross bar 2 is adjusted to constrain the corresponding side panel 1, and then one of them is fixed on the vertical pole 3 through the corresponding locking device. Then, in the arrangement order of the sleeves 20, the position adjustment of each sleeve 20 on the vertical pole 3, the length of the cross bar 2 is adjusted to constrain the panel 1 and the position is fixed on the vertical pole 3 from top to bottom.

[0102] The lifting ring 18 is detachable, so that the vertical pole 3 can be erected at the installation position in the form of a bare pole first, and then the sleeves 20 are installed from the upper end of the vertical pole 3, and then the lifting ring 18 is installed to provide a lifting point at the top of the vertical pole 3 for each sleeve 20.

[0103] In the specific structural limitation and operation mode, the cross bar 2 on the lowest sleeve 20 can be used to form an anti-falling constraint for the support state of the vertical pole 3 by using the enclosure 1. In this way, when the subsequent sleeve 20 is lifted, the vertical pole 3 can be in a relatively stable state until all the sleeves 20 are adjusted in position. For example, the sleeve 20 and the cross bar 2 assembly can be lifted by a hand winch or an electric winch, so that the anti-falling constraint of the vertical pole 3 and the subsequent lifting are easy to operate and economical. In order to fix the position of the sleeve 20, a number of pin holes 19 corresponding to the number of sleeves 20 can be set in the axial direction of the vertical pole 3. According to the installation requirements of the specific sleeve 20, the pin holes 19 at the corresponding position are selected so that the sleeve 20 and the vertical pole 3 form a pin connection relationship to achieve the fixing purpose.

[0104] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific embodiments of the present invention are limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, other embodiments obtained without departing from the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction device for safe construction of underground structures, comprising a foundation pit support assembly, wherein the foundation pit support assembly comprises a plurality of support plates arranged in sequence along the circumferential direction of the foundation pit, characterized in that: The supporting plate comprises a plurality of enclosure plates (1) and a plurality of retaining plates (21); The retaining plates (21) are arranged at intervals along the circumferential direction of the foundation pit, and a panel (1) is provided between any two adjacent retaining plates (21), and the outer sides of each panel (1) are pressed against the inner sides of the corresponding two retaining plates (21); The enclosure plate (1) is a hollow plate-like structure; The enclosure plate (1) comprises an outer plate for connecting with the foundation pit and an inner plate close to the center of the foundation pit, the outer plate is provided with a plurality of connecting holes (15) penetrating the inner and outer sides of the outer plate; the inner plate is provided with a drainage port (13) penetrating the inner and outer sides of the inner plate; A vertically arranged grouting pipe (10) is provided in the gap between any two adjacent retaining plates (21), the grouting pipe (10) being provided with a plurality of grouting holes (101) arranged along the axial direction of the grouting pipe (10), and the outlet ends of the grouting holes (101) are oriented toward a side of the grouting pipe (10) away from the enclosure plate (1); A water trough (12) fixed to the inner side plate is provided on the inner side of the bottom of each enclosure (1), and the outlet end of the drainage port (13) is located in the water trough (12); The fluid conductance of the drainage opening (13) on each enclosure (1) is adjustable; It also includes a filter screen (16) arranged in the hollow space of each enclosure (1), wherein in the thickness direction of the enclosure (1), the filter screen (16) divides the hollow space into an outer cavity and an inner cavity, the outer cavity being the cavity between the filter screen (16) and the outer plate, and the inner cavity being the cavity between the filter screen (16) and the inner plate; It also includes a mud discharge port (7) connected to the bottom side of the enclosure (1) and having an inlet end connected to the inner cavity; It also includes a water injection port (9) connected to the enclosure (1) and having an outlet end connected to the inner cavity; The mud discharge port (7) and the water injection port (9) are both provided with a cut-off device for controlling the on-off state of each. It also comprises a support frame for supporting the enclosure (1), the support frame comprising a vertical pole (3) and a plurality of cross bars (2) arranged along the axis direction of the vertical pole (3), the cross bars (2) serving as support members between the vertical pole (3) and the inner side of each enclosure (1), and the length of the cross bars (2) is adjustable; the cross bars (2) comprise a threaded barrel (4) and a threaded rod (5) connected in series, the threaded barrel (4) and the threaded rod (5) being threadedly connected and coaxial, the threaded barrel (4) being connected to the vertical pole (3), and a pad (6) being provided between the end of the threaded rod (5) and the inner side of the enclosure (1); The backing plate (6) comprises: a first plate body made of steel plate, a second plate body made of plastic plate or graphite plate, and a third plate body made of steel plate, the first plate body being fixedly connected to the threaded rod (5), the second plate body being clamped between the first plate body and the third plate body, and the outer side of the third plate body being in contact with the inner side of the enclosure plate (1); It also includes a sleeve (20) sleeved on the vertical rod (3) and capable of sliding along the axis of the vertical rod (3), each sleeve (20) being fixed with two cross bars (2), and the cross bars (2) on each sleeve (20) are linearly symmetrical with respect to the axis of the sleeve; The number of the enclosure plates (1) is an even number and the enclosure plates (1) are evenly distributed in a ring relative to the axis of the vertical pole (3), and the ends of the cross bars (2) on each sleeve (20) act on the enclosure plates (1) on the corresponding sides of the vertical pole (3); It also includes a locking device for locking the position of the sleeve on the axis of the cross bar (2).

2. The construction device for safe construction of underground structures according to claim 1, characterized in that: The enclosure (1) and the retaining plate (21) form a cylindrical structure, and a vertically arranged sealing strip is provided between each enclosure (1) and the retaining plate (21) in contact therewith.

3. The construction device for safe construction of underground structures according to claim 1, characterized in that: The number of drainage openings (13) on each enclosure (1) is multiple, and the blocking state of some or all of the drainage openings (13) on each enclosure (1) is adjustable.

4. The construction device for safe construction of underground structures according to claim 1, characterized in that: Each drainage outlet (13) is matched with a plug (14), and also includes a connecting pipe (8) connected to the enclosure (1) and having an outlet end communicating with the hollow space.

5. The construction device for safe construction of underground structures according to claim 1, characterized in that: The connection between the filter screen (16) and the enclosure (1) is achieved in the following manner: the remaining four faces of the enclosure (1) are respectively an upper end face, a lower end face, a left end face and a right end face, and any one of the remaining four faces is bolted to the enclosure (1); Two slide grooves in a positively opposed relationship are arranged on the wall surface of the hollow space of the enclosure (1), and the filter screen (16) is clamped in the hollow space through the slide grooves; The starting end of the slide groove faces the surface of the enclosure plate (1) that is bolted thereto.

6. The construction device for safe construction of underground structures according to claim 1, characterized in that: It also includes a support plate (17) arranged in the inner cavity, and the filter screen (16) is supported on the support plate (17) as a surface of the inner cavity boundary.

7. A construction method for safe construction of underground structures, characterized in that: The method is based on the device described in any one of claims 1 to 6, and the method is implemented by the following steps: S1, completing the installation of the enclosure plate (1), the retaining plate (21) and the grouting pipe (10) on the edge of the foundation pit, and using the device to provide support for the wall surface of the foundation pit; S2. During the foundation pit construction process, the connecting holes (15) and the drainage holes (13) on the enclosure (1) are used to achieve foundation pit dewatering; S3. After the foundation pit construction is completed, the grouting pipe (10) is used to inject grouting material into the outside of the grouting pipe (10), and during the curing process of the grouting material, the enclosure (1) is used as a template for supporting the grouting pipe (10).

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