Construction method of deep foundation pit excavation and grouting pre-reinforcement near operating sewage pipe

Abstract

The invention relates to a method for pre-reinforcement of deep foundation pit excavation and grouting near an operating sewage pipe. A newly added inner support device is developed, and a fixed frame is hung on an installed inner support I-beam. A rotating body and a telescopic rod are arranged at the lower end of the fixed frame, so as to solve the problem of positioning and temporary placement of the newly added inner support device and realize the multi-dimensional increase of the inner support; a dynamic balancing technology for the water level of the foundation pit is proposed, and a hydraulic sensor is pre-buried in a dewatering well in the pit to ensure that the water level in the foundation pit is maintained within a certain range, thereby improving the safety of the foundation pit excavation construction; a locally added support structure is developed, and the problem of locally adding inner support is solved by arranging precast concrete piers, thereby improving the stability of the supporting structure; a lateral grouting technology is proposed, and lateral grouting holes are arranged on newly added columns and steel sheet piles to realize multi-angle grouting, make up for the deficiency of vertical grouting, and enhance the stability of the soil around the sewage pipe.

Description

Technical Field

[0001] The invention belongs to the field of foundation pit excavation and sewage pipe reinforcement adjacent to an operating sewage pipe, and in particular relates to a deep foundation pit excavation grouting pre-reinforcement construction method adjacent to an operating sewage pipe. Background Art

[0002] With the acceleration of urbanization, the number and scale of construction projects are gradually increasing due to the needs of urban construction and people's lives, which has directly led to the aggravation of the land shortage. In order to alleviate this situation, in addition to increasing the height and expanding the ground use space, the construction of engineering projects also takes into account the application of underground parts, such as the construction of large underground parking lots, underground shopping malls and other underground construction projects. There are multiple operating sewage pipes outside the excavation range of underground urban foundation pits, and the pipes adopt PCCP structure and pressure and non-pressure design.

[0003] According to the relevant specifications, the allowable deformation value of flexible pipes should meet the following requirements: For metal pipes with rigid materials such as cement mortar as anti-corrosion lining, the maximum vertical deformation under combined action should not exceed 0.02-0.03D0. The land disturbance caused by foundation pit excavation increases the settlement of sewage pipes. For sewage pipes with high settlement requirements, it is necessary to reinforce the operating pipes.

[0004] In view of this, in order to solve a series of problems arising from the pre-reinforcement construction of deep foundation pit excavation and grouting near the operating sewage pipe, it is urgent to invent a simple and effective pre-reinforcement construction method of deep foundation pit excavation and grouting near the operating sewage pipe to improve the safety of construction, especially for the excavation construction of sewage pipes and foundation pits near the operating sewage pipes, which has the advantages of significantly saving construction costs, speeding up construction progress and improving construction safety performance. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a deep foundation pit excavation grouting pre-reinforcement construction method adjacent to an operating sewage pipe.

[0006] This method of pre-reinforcement construction of deep foundation pit excavation and grouting near the operating sewage pipe includes the following steps:

[0007] S1. Strengthen the foundation pit by adding new internal support devices to the support system in the foundation pit, or by setting up a local additional support structure under the surrounding purlin to temporarily increase the support for the foundation pit;

[0008] S2. Strengthen the foundation pit diagonal bracing: set up new columns and adjustable steel diagonal bracing inside the steel sheet piles, and adjust the diagonal bracing angle of the steel support through the flexible parts;

[0009] S3. Sewage pipe repair: Use pipeline mortar quick caulking device to repair sewage pipe. The arc steel formwork is installed through the formwork installation bracket and then fixed through the formwork fixing frame. Grouting is performed on the outer side of the arc steel formwork.

[0010] S4. Grouting reinforcement of soil around sewage pipes: adopt lateral grouting of foundation pit, set lateral grouting holes and grouting pipes through the newly added columns and steel sheet piles, and set grouting body at the bottom of sewage pipe outside the foundation pit.

[0011] Preferably, in step S1: when the groundwater in the foundation pit needs to be maintained at a certain horizontal line, an inner dewatering well is set in the foundation pit, and an outer dewatering well is set outside the foundation pit. The inner dewatering well and the outer dewatering well are connected by water pipes, and a hydraulic sensor is pre-buried in the inner dewatering well.

[0012] Preferably, steel sheet piles are provided on the inner side of the foundation pit, and a support system is arranged between the steel pipe piles. The support system includes inner supporting I-beams and surrounding purlins, and a bottom plate is provided under the surrounding purlins.

[0013] Preferably, in step S1: a newly added internal support device includes a rotating body, a fixed frame, an automatic hydraulic telescopic rod and an internal support mounting body, the fixed frame is hung on the internal support I-beam, the connecting rod is arranged on the internal support I-beam, fastening bolts are arranged on both sides of the fixing part, and the fixing part is fixed by the fastening bolts, a rotating body is arranged at the lower end of the fixing part, an automatic hydraulic telescopic body is bolted under the fixing part, a special-shaped telescopic rod is arranged at the lower end of the automatic hydraulic telescopic body, and the internal support mounting body is arranged at one end of the special-shaped telescopic rod.

[0014] Preferably, in step S1: a locally added bracing structure includes a U-shaped connector and a precast concrete pier, a U-shaped connector is arranged below the purlin, the U-shaped connector opening is upwardly fixedly connected to one end of a support rod, the other end of the support rod is supported on the precast concrete pier, a pad is arranged on the precast concrete pier, a reserved hole is arranged on the precast concrete pier, a special-shaped embedded part is arranged on the bottom plate, the precast concrete pier is fixed to the bottom plate by a combination of a fixing rod and a standardized steel bar, the combined fixing rod passes through the reserved hole, and both ends of the combined fixing rod and the standardized steel bar are bolted to the special-shaped embedded parts respectively.

[0015] Preferably, in step S2: the adjustable steel diagonal brace includes a steel support and a channel steel, an additional column is arranged on the inner side of the steel sheet pile, a sleeve is arranged on the steel sheet pile, a triangular support is arranged on the column, a supporting platform is arranged on the triangular support, a reserved groove is arranged on the supporting platform, a special-shaped pad is arranged on the supporting platform, the steel support passes through the reserved groove, one end of the steel support is fixed to the special-shaped pad by a U-shaped hoop, one end of the steel support is connected with a flexible piece, the flexible piece is inserted into the channel steel, a thruster is arranged in the channel steel, and the thruster is respectively connected to the angle steel and the flexible piece.

[0016] Preferably, in step S3: when leakage occurs in the connection seam of the sewage pipe, a pipe mortar rapid caulking device is used for construction, and the pipe mortar rapid caulking device includes an arc-shaped steel formwork, a formwork mounting bracket and a formwork fixing bracket, the arc-shaped steel formwork includes two standard sections, and the arc-shaped steel formwork fits the inner wall of the sewage pipe; the formwork mounting bracket includes a lower cross bar, a scissors brace, an upper cross bar, a platform plate, a diagonal brace and a second platform, four telescopic rods are arranged on the formwork mounting bracket, and the telescopic rods support the arc-shaped steel formwork; the formwork fixing bracket includes a base, a stable diagonal brace, a horizontal telescopic fastening rod and a vertical telescopic fastening rod, a grouting hole is arranged at the bottom of the arc-shaped steel formwork, and a leakage hole is arranged at the top of the arc-shaped steel formwork, and when repairing the leakage, grouting is performed from the grouting hole until the mortar flows out of the leakage hole.

[0017] Preferably, in step S4: a sewage pipe is provided outside the foundation pit, a grouting body is provided at the bottom of the sewage pipe, lateral grouting holes are provided on the newly added columns and steel sheet piles, and a grouting pipe is provided in the lateral grouting hole.

[0018] A grouting pre-reinforcement system for deep foundation pit excavation near an operating sewage pipe is obtained by any of the methods described above.

[0019] The beneficial effects of the present invention are:

[0020] 1) The present invention develops a new internal support device, in which a fixed frame is hung on the installed internal support I-beam, and a rotating body and a telescopic rod are arranged at the lower end of the fixed frame, which solves the problem of positioning and temporary placement of the new internal support device and realizes multi-dimensional increase of internal support.

[0021] 2) The present invention proposes a dynamic balancing technology for foundation pit water level. Hydraulic sensors are pre-buried in the dewatering well in the pit to ensure that the water level in the foundation pit is maintained within a certain range, thereby improving the safety of foundation pit excavation construction.

[0022] 3) The present invention has developed a locally added bracing structure, which solves the problem of locally adding internal supports by setting precast concrete piers and improves the stability of the supporting structure.

[0023] 4) The present invention proposes a lateral grouting technology, in which lateral grouting holes are set on newly added columns and steel sheet piles, to achieve multi-angle grouting, make up for the shortcomings of vertical grouting, and enhance the stability of the soil around the sewage pipe.

[0024] 5) The present invention has developed a pipeline mortar rapid grouting device, which installs and fixes the arc steel template through a template installation bracket and a template fixing frame. The bottom and top of the arc steel template are respectively provided with grouting holes and leakage holes, which solves the problem of repairing pipe joints and speeds up the pipeline grouting construction.

[0025] 6) The present invention has developed an adjustable steel diagonal brace structure. The adjustable steel diagonal brace is provided with a movable part and a jack, which realizes the adjustability of the diagonal brace jacking force and solves the problem of steel diagonal brace support. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the plan layout of the sewage pipe and foundation pit of the present invention;

[0027] Figure 2 It is a schematic diagram of the newly added inner support installation device of the present invention;

[0028] Figure 3 This is a schematic diagram of the dynamic balance of the foundation pit water level of the present invention;

[0029] Figure 4 This is a schematic diagram of a partially added bracing structure of the present invention;

[0030] Figure 5 It is a schematic diagram of the precast concrete pier of the present invention;

[0031] Figure 6 It is a schematic diagram of the adjustable steel diagonal brace structure of the present invention;

[0032] Figure 7 yes Figure 6 A magnified view of the structure in the middle A area;

[0033] Figure 8 Schematic diagram of the template installation bracket of the present invention;

[0034] Fig. 9 It is a schematic diagram of the template fixing frame of the present invention.

[0035] Among them: 1-sewage pipe, 2-grouting hole, 3-support system, 4-steel sheet pile, 5-new internal support device, 6-special-shaped lifting and retracting rod, 7-rotating body, 8-connecting rod, 9-fastening bolt, 10-internal support I-beam, 11-fixed frame, 12-automatic hydraulic telescopic body, 13-internal support installation body, 14-outside pit dewatering well, 15-water pipe, 16-inside pit dewatering well, 17-base, 18-stable diagonal brace, 19-connecting seam, 20-leakage hole, 21-vertical telescopic fastening rod, 22-arc steel formwork, 23-horizontal telescopic fastening rod, 24-grouting hole, 25-diagonal brace, 26-second platform, 27-platform plate, 28-upper cross bar, 29-formwork installation bracket , 30-telescopic rod, 31-scissors support, 32-lower cross bar, 33-purlin, 34-support rod, 35-U-shaped connector, 36-bottom plate, 37-special-shaped embedded parts, 38-standardized steel bars, 39-precast concrete pier, 40-reserved hole, 41-grouting body, 42-lateral grouting hole, 43-new column, 44-grouting pipe, 45-special-shaped pad, 46-U-shaped hoop, 47-steel support, 48-reserved groove, 49-support platform, 50-sleeve, 51-triangular support, 52-angle steel, 53-thruster, 54-hydraulic sensor, 55-pad, 56-combined fixing rod, 57-slip piece, 58-channel steel, 59-template fixing frame. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0037] Embodiment 1

[0038] As an example, Figures 1 to 9 As shown, this deep foundation pit excavation grouting pre-reinforcement system near the operating sewage pipe is characterized by: including a newly added internal support installation device, a dynamic balance technology for the foundation pit water level, a locally added support structure, an adjustable steel inclined support, a grouting reinforcement technology, a pipe mortar rapid caulking device, etc.

[0039] like Figure 1 As shown, the foundation pit is supported by steel sheet piles 4 on all sides, a support system 3 is arranged between the steel pipe piles 4, and a new internal support device 5 is arranged on the support system 3.

[0040] like Figure 2 As shown, the newly added inner support device 5 is composed of a rotating body 7, a fixing frame 11, an automatic hydraulic telescopic rod 12, an inner support installation body 13, etc. The fixing frame 11 is suspended on the inner support I-beam 10, and the connecting rod 8 is arranged on the inner support I-beam 10. Fastening bolts 9 are arranged on both sides of the fixing member 11, and the fixing member 11 is fixed by tightening the fastening bolts 9. The rotating body 7 is arranged at the lower end of the fixing member 11, and the automatic hydraulic telescopic body 12 is bolted under the fixing member 11. The special-shaped telescopic rod 6 is arranged at the lower end of the automatic hydraulic telescopic body 12, and the inner support installation body 13 is arranged at one end of the special-shaped telescopic rod 6.

[0041] like Figure 3 As shown, an in-pit dewatering well 16 is arranged in the foundation pit, and an out-pit dewatering well 14 is arranged outside the foundation pit. The dewatering wells are connected by a water pipe 15, and a hydraulic sensor 54 is pre-buried in the in-pit dewatering well 16.

[0042] like Figure 4 , 5 As shown, a U-shaped connector 35 is arranged below the purlin 33, the opening of the U-shaped connector 35 faces upward, one end of the support rod 34 is fixed to the U-shaped connector 35, and the other end of the support rod 34 is tightened by a precast concrete pier 39, a pad 55 is arranged on the precast concrete pier 39, a reserved hole 40 is arranged on the precast concrete pier 39, and a special-shaped embedded part 37 is arranged on the bottom plate 36. The precast concrete pier 39 is fixed by a combination fixing rod 56 and a shaped steel bar 38, the combination fixing rod 56 passes through the reserved hole 40, and the two ends of the combination fixing rod 56 and the shaped steel bar 38 are bolted to the special-shaped embedded part 37 respectively.

[0043] like Figure 6 As shown, the steel sheet pile 4 is newly provided with a column 43, a sleeve 50 is arranged on the steel sheet pile 4, a triangular support member 51 is arranged on the column 43, a support platform 49 is arranged on the triangular support member 51, a reserved groove 48 is arranged on the support platform 49, a special-shaped pad 45 is arranged on the support platform 49, a steel support 47 passes through the reserved groove 48, one end of the steel support 47 is fixed on the special-shaped pad 45 through a U-shaped hoop 46, one end of the steel support 47 is connected to a movable member 57, the movable member 57 is inserted into a channel steel 58, a pusher 53 is arranged in the channel steel 58, and the pusher is respectively connected to the angle steel 52 and the movable member 57.

[0044] like Figure 6 As shown, a sewage pipe 1 is provided outside the foundation pit, a grouting body 41 is provided at the bottom of the sewage pipe 1, lateral grouting holes 42 are provided on the columns 43 and the steel sheet piles 4, and a grouting pipe 44 is provided in the lateral grouting hole 42.

[0045] like Figure 7 , 8 As shown, the arc steel formwork 22 is divided into two standard sections, and the arc steel formwork 22 is close to the sewage pipe 1; the formwork installation bracket 29 is composed of a lower cross bar 32, a scissors brace 31, an upper cross bar 28, a platform plate 27, a diagonal brace 25, and a second platform 26. Four telescopic rods 30 are arranged on the formwork installation bracket 59, and the telescopic rods 30 press the arc steel formwork 22 tightly; the formwork fixing frame 59 is welded by a base 17, a stable diagonal brace 18, a horizontal telescopic fastening rod 23, a vertical telescopic fastening rod 21, etc., a slurry leakage hole 24 is arranged at the bottom of the arc steel formwork 22, and a slurry leakage hole 20 is arranged at the top of the arc steel formwork 22.

[0046] Embodiment 2

[0047] As another embodiment, this embodiment 2 is proposed on the basis of the embodiment 1, and the deep foundation pit excavation grouting pre-reinforcement construction method near the operating sewage pipe includes the following steps:

[0048] S1, foundation pit bracing reinforcement; a new internal bracing device 5 is provided on the support system 3 in the foundation pit, or a local additional bracing structure is provided under the surrounding purlin 33 to temporarily increase the bracing reinforcement of the foundation pit;

[0049] S2, foundation pit diagonal bracing reinforcement; additional columns 43 and adjustable steel diagonal bracing are provided inside the steel sheet pile 4, and the diagonal bracing angle of the steel support 47 is adjusted by the movable member 57;

[0050] S3, sewage pipe repair; using the pipeline mortar rapid caulking device to repair the sewage pipe, the arc steel template 22 is installed through the template mounting bracket 29, and then fixed by the template fixing frame 59, and grouting is performed on the outer side of the arc steel template 22;

[0051] S4. Grouting reinforcement of soil around the sewage pipe: adopt lateral grouting of the foundation pit, set lateral grouting holes 42 through the newly added columns 43 and steel sheet piles 4, and set grouting pipes 44, and set a grouting body 41 at the bottom of the sewage pipe 1 outside the foundation pit.

[0052] It should be noted that the parts in this embodiment that are the same or similar to those in the first embodiment can be referenced to each other and will not be described in detail in this application.

[0053] Embodiment 3

[0054] As another embodiment, this embodiment 3 proposes, based on the embodiment 2, a method for pre-reinforcement construction of deep foundation pit excavation and grouting near an operating sewage pipe, specifically:

[0055] S1. Strengthen the foundation pit support; Figures 2 to 5 As shown, when the groundwater of the foundation pit needs to be kept at a certain horizontal line during the construction process, an in-pit dewatering well 16 is set in the foundation pit, and an out-pit dewatering well 14 is set outside the foundation pit. The dewatering wells are connected by a water pipe 15, and a hydraulic sensor 54 is pre-buried in the in-pit dewatering well 16. When temporarily adding support reinforcement to the foundation pit, the following two schemes can be adopted. Scheme 1: The newly added internal support device 5 is composed of a rotating body 7, a fixed frame 11, an automatic hydraulic telescopic rod 12, an internal support installation body 13, etc. The fixed frame 11 is suspended on the internal support I-beam 10, and the connecting rod 8 is set on the internal support I-beam 10. Fastening bolts 9 are set on both sides of the fixing member 11, and are fixed by tightening the fastening bolts 9. A rotating body 7 is set at the lower end of the fixing member 11, and an automatic hydraulic telescopic body 12 is bolted below the fixing member 11. A special-shaped telescopic rod 6 is set at the lower end of the automatic hydraulic telescopic body 12, and an internal support installation body 13 is set at one end of the special-shaped telescopic rod 6. Solution 2: A U-shaped connector 35 is provided below the purlin 33, the opening of the U-shaped connector 35 faces upward, one end of the support rod 34 is fixed to the U-shaped connector 35, and the other end of the support rod 34 is tightened by the precast concrete pier 39, a pad 55 is provided on the precast concrete pier 39, a reserved hole 40 is provided on the precast concrete pier 39, and a special-shaped embedded part 37 is provided on the bottom plate 36. The precast concrete pier 39 is fixed by a combined fixing rod 56 and a shaped steel bar 38, the combined fixing rod 56 passes through the reserved hole 40, and both ends of the combined fixing rod 56 and the shaped steel bar 38 are bolted to the special-shaped embedded parts 37 respectively.

[0056] S2, foundation pit diagonal bracing reinforcement; Figure 6 and Figure 7As shown, a new column 43 is added to the steel sheet pile 4, a sleeve 50 is arranged on the steel sheet pile 4, a triangular support member 51 is arranged on the column 43, a support platform 49 is arranged on the triangular support member 51, a reserved groove 48 is arranged on the support platform 49, a special-shaped pad 45 is arranged on the support platform 49, a steel support 47 passes through the reserved groove 48, one end of the steel support 47 is fixed to the special-shaped pad 45 by a U-shaped hoop 46, one end of the steel support 47 is connected to a movable member 57, the movable member 57 is inserted into a channel steel 58, a pusher 53 is arranged in the channel steel 58, and the pusher is respectively connected to the angle steel 52 and the movable member 57.

[0057] S3. Seal the sewage pipe. The construction work requires the cooperation of the pump station, which will lower the water level. Each team will seal the overflow of the sewage system and inspect the upstream pipeline. Ventilate the pipeline, and organize personnel to enter the pipeline after the gas test is qualified.

[0058] Sewage pipe repair; Figure 8 and Fig. 9 As shown, when leakage occurs in the connection seam of the sewage pipe, a pipe mortar rapid caulking device is used for construction. The arc steel template 22 is divided into two standard sections, and the arc steel template 22 is close to the sewage pipe 1; the template installation bracket 29 is composed of a lower cross bar 32, a scissors brace 31, an upper cross bar 28, a platform plate 27, a diagonal brace 25, and a second platform 26. Four telescopic rods 30 are arranged on the template installation bracket 59, and the telescopic rods 30 are pressed against the arc steel template 22; the template fixing frame 59 is welded by a base 17, a stable diagonal brace 18, a horizontal telescopic fastening rod 23, a vertical telescopic fastening rod 21, etc., and a leakage hole 24 is arranged at the bottom of the arc steel template 22, and a leakage hole 20 is arranged at the top of the arc steel template 22.

[0059] S4. Grouting reinforcement of soil around sewage pipe: The soil around sewage pipe can be reinforced by lateral grouting of foundation pit and ground grouting. Lateral grouting of foundation pit: A sewage pipe 1 is arranged outside the foundation pit, a grouting body 41 is arranged at the bottom of the sewage pipe 1, lateral grouting holes 42 are arranged on the columns 43 and the steel sheet piles 4, and a grouting pipe 44 is arranged in the lateral grouting hole 42.

[0060] It should be noted that the parts in this embodiment that are the same or similar to those in the first embodiment can be referenced to each other and will not be described in detail in this application.

[0061] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

Claims

1. A method for pre-reinforcement of deep foundation pit excavation and grouting near an operating sewage pipe, characterized in that: The following steps are involved: S1. Pit support reinforcement; steel sheet piles are arranged on the inner side of the pit, and a support system is arranged between the steel pipe piles. The support system includes inner support I-beams and surrounding purlins, and a bottom plate is arranged under the surrounding purlins; a new inner support device is arranged on the support system in the pit; the new inner support device includes a rotating body, a fixed frame, an automatic hydraulic telescopic rod and an inner support installation body, the fixed frame is hung on the inner support I-beam, the connecting rod is arranged on the inner support I-beam, fastening bolts are arranged on both sides of the fixing part, and the fixing part is fixed by fastening bolts, a rotating body is arranged at the lower end of the fixing part, an automatic hydraulic telescopic body is bolted under the fixing part, a special-shaped telescopic rod is arranged at the lower end of the automatic hydraulic telescopic body, and an inner support installation body is arranged at one end of the special-shaped telescopic rod; S2. Strengthen the foundation pit diagonal brace; set up new columns and adjustable steel diagonal braces on the inner side of the steel sheet piles, and adjust the diagonal brace angle of the steel support through the flexible piece; the adjustable steel diagonal brace includes a steel support and a channel steel, a new column is set up on the inner side of the steel sheet pile, a sleeve is set on the steel sheet pile, a triangular support is set on the column, a support platform is set on the triangular support, a reserved groove is set on the support platform, a special-shaped pad is set on the support platform, the steel support passes through the reserved groove, one end of the steel support is fixed to the special-shaped pad through a U-shaped hoop, one end of the steel support is connected with a flexible piece, the flexible piece is inserted into the channel steel, a jack is set in the channel steel, and the jack is connected to the angle steel and the flexible piece respectively; S3. Sewage pipe repair: Use pipeline mortar quick caulking device to repair sewage pipe. The arc steel formwork is installed through the formwork installation bracket and then fixed through the formwork fixing frame. Grouting is performed on the outer side of the arc steel formwork. S4. Grouting reinforcement of soil around sewage pipes: adopt lateral grouting of foundation pit, set lateral grouting holes and grouting pipes through the newly added columns and steel sheet piles, and set grouting body at the bottom of sewage pipe outside the foundation pit.

2. The method for pre-reinforcement of deep foundation pit excavation and grouting near an operating sewage pipe according to claim 1 is characterized in that: In step S1: when the groundwater in the foundation pit needs to be kept at a certain horizontal line, an inner dewatering well is set in the foundation pit, and an outer dewatering well is set outside the foundation pit. The inner dewatering well and the outer dewatering well are connected by a water pipe, and a hydraulic sensor is pre-buried in the inner dewatering well.

3. The method for pre-reinforcement of deep foundation pit excavation and grouting near an operating sewage pipe according to claim 1 is characterized in that: In step S3: when leakage occurs in the connection seam of the sewage pipe, a pipe mortar rapid caulking device is used for construction. The pipe mortar rapid caulking device includes an arc-shaped steel formwork, a formwork mounting bracket and a formwork fixing bracket. The arc-shaped steel formwork includes two standard sections, and the arc-shaped steel formwork fits the inner wall of the sewage pipe; the formwork mounting bracket includes a lower cross bar, a scissors brace, an upper cross bar, a platform plate, a diagonal brace and a second platform. Four telescopic rods are arranged on the formwork mounting bracket, and the telescopic rods support the arc-shaped steel formwork; the formwork fixing bracket includes a base, a stable diagonal brace, a horizontal telescopic fastening rod and a vertical telescopic fastening rod. Grouting holes are arranged at the bottom of the arc-shaped steel formwork, and a leakage hole is arranged at the top of the arc-shaped steel formwork. When repairing the leakage, grouting is performed from the grouting holes until mortar flows out of the leakage hole.

4. The method for pre-reinforcement of deep foundation pit excavation and grouting near an operating sewage pipe according to claim 1 is characterized in that: In step S4: a sewage pipe is provided outside the foundation pit, a grouting body is provided at the bottom of the sewage pipe, lateral grouting holes are provided on the newly added columns and steel sheet piles, and a grouting pipe is provided in the lateral grouting hole.

5. The deep foundation pit excavation grouting pre-reinforcement system near the operating sewage pipe is characterized by: Obtained by the method described in any one of claims 1 to 4.

Images