Construction method and device for long-distance large-diameter pipeline trench dewatering

Abstract

The application relates to a long-distance large-diameter pipeline trench dewatering construction method and device, and belongs to the technical field of foundation pit excavation dewatering. The device comprises a PVC pipe body, a pipe joint assembly and a geotextile screen. The PVC pipe body is provided with a drilling hole at a 20cm interval along the length direction. The drilling holes are arranged at intervals in the circumferential direction. An anti-blocking head is arranged in the drilling hole. The pipe joint assembly is used for connecting adjacent PVC pipe bodies. The pipe joint assembly comprises a front butt joint ring, a rear butt joint ring, a hinged base, a winding ring and a micro-bias adjusting mechanism. The front butt joint ring and the rear butt joint ring are both hinged on the hinged base. The hinged base is provided with a plug body. A butt joint corrugated pipe is connected on the relative ring surface between the front butt joint ring and the rear butt joint ring. The device can directly realize the on-site rapid splicing and assembly of the pipe body and the geotextile screen. During the splicing process, the adjusting device can be used for the inclination setting of the butt joint angle, so that the water seepage pumping can be carried out at a certain inclination angle as a whole, and the rapid drainage is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of foundation pit excavation and drainage, in particular to a long-distance large-diameter pipeline trench dewatering construction method and device. BACKGROUND

[0002] When the water pipeline foundation pit excavation passes through reservoirs and small ponds and other areas, the high groundwater level around the construction area will cause seepage and other conditions after the foundation pit is excavated. During the open excavation construction process, the foundation pit is often waterlogged due to the influence of rainfall factors. After excavation, the construction of concrete base pouring, pipeline installation, pipeline joint processing, corrosion prevention, and cathodic protection will cause the foundation pit to be exposed for a long time. The seepage and waterlogging of the foundation pit will have a serious impact on the excavation foundation surface. After the foundation surface is soaked, the bearing capacity of the foundation is difficult to meet the design requirements, and the foundation surface cannot be used for the next step of construction. The construction will cause disturbance to the foundation surface, resulting in insufficient bearing capacity. The waterlogged state brings great inconvenience to the work in the foundation pit and seriously delays the construction period. The conventional method of using open ditch drainage will narrow the working surface of the foundation pit, change the original shape of the foundation pit, and is not conducive to subsequent pipeline installation and trench backfill work. In addition, the water seepage state will cause hidden dangers such as pipe bottom cavities if backfilled recklessly, and the quality cannot be guaranteed. During the construction process, the seepage of the slope will affect the stability of the deep foundation pit slope, causing safety hazards such as collapse and landslide.

[0003] Therefore, according to the safety and quality requirements of pipeline construction, there is an urgent need for a long-distance large-diameter pipeline trench dewatering construction method and device to solve the problem of seepage and waterlogging of long-distance large-diameter pipeline trench dewatering in low-lying areas near reservoirs and ponds. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a long-distance large-diameter pipeline trench dewatering construction method and device to maximize the reduction of foundation pit seepage and waterlogging, reduce the impact on pipeline installation, trench backfill, and slope stability, and ensure the safety of the construction process and the dryness of the foundation surface to ensure that the bearing capacity of the foundation meets the requirements.

[0005] The technical problem to be solved by the present application is solved by the following technical solution, which discloses a long-distance large-diameter pipeline trench dewatering construction method and device, comprising the following steps,

[0006] Step S1, according to the geological conditions, artificial and / or small mechanical excavation at the bottom of the foundation pit both sides of the 30 cm wide, 50 cm deep trench, slope setting with the foundation plane consistent with the slope, for providing installation space for the pipeline; Step S2, select DN150 mm PVC pipe body, and in the pipe according to 20 cm spacing for drilling, drilling in the hole after the plug anti-clogging head, used to prevent the filling of the soil after being blocked; Step S3, select the geotextile to wrap the PVC pipe in step S2, the adjacent pipe material wrapped with pipe joint assembly butt joint and placed in the trench, pipe joint assembly for the adjacent pipe body tilt butt joint and geotextile tensioning construction; Step S4, the pipe section installed in step S3 laying 20 to 40 mm thick gravel layer and leveling, until the completion of the specified pipe section of the overall landfill construction; Step S5, the end of the foundation pit of the buried pipe section in step S4 is excavated 2x2x2m specification of the water collection well, used to collect the buried pipe in the blind ditch on both sides of the foundation pit to collect the effluent; Step S6, the water collection well is pumped to the three-stage sedimentation tank system outside the foundation pit and then flows into the surrounding river system, completing the trench dewatering and drainage process.

[0007] Further, the step S3 includes first wrapping the PVC pipe into the ring of the pipe joint assembly, then locking and wrapping the front corner of the geotextile on the ring by sewing, and then wrapping the other end of the PVC pipe into the ring, locking and wrapping the rear corner of the geotextile on the ring by sewing, until the geotextile is completely wrapped and fixed by sewing at both ends.

[0008] Further, the step S3 includes adjusting the inclination angle of the pipe joint assembly after butt joint and placing in the trench, so that the pipe section has a certain overall inclination for water seepage and diversion in the entire water seepage section.

[0009] Further, the step S4 includes first laying the gravel with a diameter close to the pipe hole diameter when laying the gravel layer on the installed pipe section.

[0010] The application also discloses a long-distance large-diameter pipeline trench dewatering construction device, which comprises a PVC pipe body, a pipe joint assembly and a geotextile filter screen, drilling holes are arranged at intervals of 20 cm along the length direction of the PVC pipe body, the drilling holes are arranged at intervals along the circumference direction, a plug is arranged in the drilling hole, the pipe joint assembly is used for connecting adjacent PVC pipe bodies, the pipe joint assembly comprises a front butt joint ring, a rear butt joint ring, a hinged base, a winding ring and a slight deviation adjusting mechanism, the front butt joint ring and the rear butt joint ring are both hinged to the hinged base, the hinged base is provided with a plug body, a butt joint corrugated pipe is connected to the relative ring surface between the front butt joint ring and the rear butt joint ring, the outer side end surfaces of the front butt joint ring and the rear butt joint ring are both rotationally connected with the winding ring, the edge of the winding ring is provided with a threading hole used for connecting the geotextile filter screen, the slight deviation adjusting mechanism is connected between the front butt joint ring and the rear butt joint ring, and the PVC pipe body, the pipe joint assembly and the geotextile filter screen are integrally assembled and buried in the excavation groove to realize water seepage section water pumping and drainage and then water pumping to a three-stage settlement tank system for settlement and discharge.

[0011] Further, the anti-blocking head comprises a center pipe, a plug cylinder and a plug pressing plate, the plug cylinder is fixedly sleeved on the upper part of the center pipe, the plug pressing plate is fixedly sleeved on the middle part of the center pipe, a plurality of mud separation plates are fixedly sleeved on the bottom part of the center pipe, the side wall of the center pipe between the mud separation plates is provided with a water permeable hole, the bottom end of the mud separation plate is encapsulated in the bottom end of the center pipe and is provided with a mud separation column on the lower side, and the bottom end of the mud separation plate is provided with a through mesh.

[0012] Further, the slight deviation adjusting mechanism comprises a slight deviation plate, an end plate, an adjusting nut and a support connecting column, the top end of the front butt joint ring and the rear butt joint ring is hingedly connected with the slight deviation plate, the slight deviation plate is inserted with the support connecting column, the support connecting column is provided with an external thread, the two ends of the support connecting column are provided with the end plate, the end plate is connected with a compression spring, the end plate is connected with the adjacent slight deviation plate through the compression spring, and the adjusting nut top-presses the slight deviation plate to the end plate direction through screw action to realize slight deviation adjustment.

[0013] Further, the three-stage settlement tank system comprises a first settlement tank, a second settlement tank and a third settlement tank, the first settlement tank, the second settlement tank and the third settlement tank are sequentially adjacent and are poured through a concrete cushion layer, a first filter screen cylinder is arranged between the first settlement tank and the second settlement tank, a second filter screen cylinder is arranged between the second settlement tank and the third settlement tank, the first settlement tank is provided with an upper water inlet, and the third settlement tank is provided with a water outlet on the upper part.

[0014] Further, the first filter screen cylinder is embedded and fixed at the left middle height of the partition wall between the first settlement tank and the second settlement tank, the second filter screen cylinder is embedded and fixed at the right upper height of the partition wall between the second settlement tank and the third settlement tank, and the first settlement tank, the second settlement tank and the third settlement tank are all provided with a mud pumping system for settlement regeneration.

[0015] Compared with the prior art, the present application has the following advantages:

[0016] (1) The present application can directly realize the on-site rapid splicing and assembly of the pipe body and the geotechnical filter screen, and the abutment angle can be inclinedly set through the adjusting device during splicing, so that the water seepage pumping can be performed at a certain inclined angle as a whole, which is beneficial to rapid drainage.

[0017] (2) The present application utilizes the geotechnical filter screen to wrap the continuous PVC pipe body, and the pipe body can be quickly sleeved and uniformly wrapped through the rotation of the ring body, thereby improving the operation convenience; the geotechnical filter screen can effectively filter out the silt in the blind ditch into the pipe, thereby saving labor; the sleeving and wrapping are performed in a modularized segmented manner, thereby improving the overall construction efficiency.

[0018] (3) The present application improves the regeneration efficiency of the sedimentation tank through the structural design of the sedimentation tank system, reduces the decline of the sedimentation capacity caused by the large amount of soil settlement, and can automatically remove the silt. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a sectional structure schematic view of the PVC pipe body 1 of the present application;

[0020] Figure 2 is a sectional structure schematic view of the PVC pipe body 1 of the present application; Figure 1 is a partial enlarged view of the A position in

[0021] Figure 3 is an installation structure schematic view of the pipe joint assembly 2 and the geotechnical filter screen 3 on the PVC pipe body 1;

[0022] Figure 4 is a partial enlarged view of the B position in Figure 3

[0023] Figure 5 is a structure schematic view of the three-stage sedimentation tank system 4;

[0024] 1-PVC pipe body, 11-anti-blocking head, 111-center pipe, 111a-mud separation plate, 111b-mud separation column, 112-cylinder body, 113-plug pressing plate, 2-pipe joint assembly, 21-front abutment ring, 22-rear abutment ring, 23-hinged base, 231-insertion nail body, 24-encircling ring, 241-threading hole, 25-micro-offset adjusting mechanism, 251-micro-offset plate, 252-end plate, 252a-spring pressing plate, 253-adjusting nut, 254-supporting connecting column, 26-abutment corrugated pipe, 3-geotechnical filter screen, 4-three-stage sedimentation tank system, 41-first sedimentation tank, 42-second sedimentation tank, 43-third sedimentation tank, 44-first filter screen cylinder, 45-second filter screen cylinder, 46-concrete cushion layer, 47-mud pumping system. DETAILED DESCRIPTION

[0025] As​Figures 1-5 As shown, the present application provides a long-distance large-diameter pipeline trench dewatering construction device, which specifically comprises a PVC pipe body 1, a pipe joint assembly 2 and a geotextile filter 3, the PVC pipe body 1 is provided with a drill hole at an interval of 20 cm along the length direction, the drill holes are arranged at intervals in the circumferential direction, a plug is installed in the drill hole, specifically, the plug comprises a center pipe 111, a plug cylinder 112 and a plug pressing plate 113, the plug cylinder 112 is fixedly sleeved on the upper part of the center pipe 111, the plug cylinder 112 is used for plugging in the drill hole, and a rubber protrusion is arranged at the top end of the plug cylinder 112 to prevent slipping, the plug pressing plate 113 is fixedly sleeved on the middle part of the center pipe 111, a plurality of mud separation plates 111a are fixedly sleeved at the bottom of the center pipe 111, the side wall of the center pipe 111 between the mud separation plates 111a is provided with a water permeable hole, the bottom mud separation plate 111a is encapsulated at the bottom end of the center pipe 111 and is provided with a mud separation column 111b at the lower side, and the bottom mud separation plate 111a is provided with a through mesh. Through the arrangement of the mud separation plates 111a and the mud separation columns 111b, the water seepage after the pipe body is buried can be absorbed without setting an internal filter, the drill holes of the pipe body are prevented from being blocked by objects such as mud and sand, sufficient water permeable gaps are ensured, the water seepage and absorption effect is improved, and at the same time, the high protrusion on the inner side of the pipe body can also prevent a part of the mud water from blocking the pores, thereby achieving the anti-blocking effect in the pipe.

[0026] The pipe joint assembly 2 is further described below, the pipe joint assembly 2 is used for connecting adjacent PVC pipe bodies 1, and the pipe joint assembly 2 comprises a front butt joint ring 21, a rear butt joint ring 22, a hinged base 23, a winding ring 24 and a slight deviation adjusting mechanism 25, the front butt joint ring 21 and the rear butt joint ring 22 are both hinged on the hinged base 23, the hinged base 23 is provided with a plug body 231, a butt joint corrugated pipe 26 is connected on the relative ring surface between the front butt joint ring 21 and the rear butt joint ring 22, the outer side end surface of the front butt joint ring 21 and the rear butt joint ring 22 is both rotationally connected with the winding ring 24, the edge of the winding ring 24 is provided with a threading hole 241 for sewing the geotextile filter 3, the slight deviation adjusting mechanism 25 is connected between the front butt joint ring 21 and the rear butt joint ring 22, the slight deviation adjusting mechanism 25 comprises a slight deviation plate 251, an end plate 252, an adjusting nut 253 and a support connecting column 254, the top end of the front butt joint ring 21 and the rear butt joint ring 22 is both hinged with the slight deviation plate 251, the slight deviation plate 251 is inserted with the support connecting column 254, the support connecting column 254 is provided with external threads, the two ends of the support connecting column 254 are provided with the end plate 252, the end plate 252 is connected with a compression spring 252a, the end plate 252 is connected with the adjacent slight deviation plate 251 through the compression spring 252a, and the adjusting nut 253 top-presses the slight deviation plate 251 to the end plate 252 direction for slight deviation adjustment through the screw action.

[0027] The PVC pipe body 1, the pipe joint assembly 2 and the geotechnical filter screen 3 are integrally assembled and buried in the excavation groove to realize water seepage section drainage and then are pumped to the three-stage settlement tank system 4 for settlement and discharge. The three-stage settlement tank system 4 comprises a first settlement tank 41, a second settlement tank 42 and a third settlement tank 43, the first settlement tank 41, the second settlement tank 42 and the third settlement tank 43 are sequentially adjacent and are poured by a concrete cushion 46, a first filter screen cylinder 44 is arranged between the first settlement tank 41 and the second settlement tank 42, a second filter screen cylinder 45 is arranged between the second settlement tank 42 and the third settlement tank 43, the first settlement tank 41 is provided with an upper water inlet, and the third settlement tank 43 is provided with a water outlet at the upper portion. The first filter screen cylinder 44 is embedded and fixed at the left middle height of the partition wall between the first settlement tank 41 and the second settlement tank 42, the second filter screen cylinder 45 is embedded and fixed at the right upper height of the partition wall between the second settlement tank 42 and the third settlement tank 43, and the first settlement tank 41, the second settlement tank 42 and the third settlement tank 43 are all provided with a mud pumping system 47 for settlement regeneration. Figure 5 As shown in the figure, (1) is a top view, and (2) is a side view, by arranging three-stage settlement, the three-stage settlement tank system 4 has the advantage of high regeneration efficiency, the three-stage settlement tank system 4 is provided with the mud pumping system 47, the regeneration efficiency of the settlement tank is improved, the decline of the settlement capacity caused by a large amount of soil settlement is reduced, and the process of automatically removing the silt in the tank can be realized.

[0028] In order to further illustrate the specific construction method of the above device, a long-distance large-diameter pipe trench dewatering construction method is provided, which comprises the following steps,

[0029] Step S1: according to the geological conditions, manually and / or by small machinery, a 30cm-wide and 50cm-deep trench is excavated on both sides of the foundation pit bottom, and the slope is set to be consistent with the slope of the building base surface, so as to provide space for installing the pipe;

[0030] Step S2: select a DN150mm PVC pipe body 1, and drill holes on the pipe body at an interval of 20cm, and then insert the anti-blocking head 11 into the holes to prevent the pipe body from being blocked by the soil after being filled;

[0031] Step S3: select a geotechnical filter screen 3 to wrap the PVC pipe body 1 in step S2, abut and connect the adjacent pipe bodies with the pipe joint assembly 2, and place them into the excavation groove, the pipe joint assembly 2 is used for abutting and connecting the inclined pipe body and tensioning the geotechnical filter screen 3, this step includes the following steps: first, insert one end of the PVC pipe body 1 into the winding ring 24 of the pipe joint assembly 2, then sew and lock one corner of the front part of the geotechnical filter screen 3 to the winding ring 24 by the needle and wind it, then insert the other end of the PVC pipe body 1 into the winding ring 24, and then sew and lock one corner of the rear part of the geotechnical filter screen 3 to the winding ring 24 by the needle and wind it, until the geotechnical filter screen 3 is completely wound, and then fix the two ends by the needle.

[0032] Step S4, laying 20 to 40 mm thick gravel layer on the pipe segment installed in step S3 and leveling, until the specified pipe segment overall landfill construction is completed, also including the process of laying gravel close to the pipe body drilling diameter size when laying gravel on the installed pipe segment;

[0033] Step S5, excavating a 2x2x2m specification catch basin at the end of the foundation pit of the buried pipe segment of step S4, for collecting the mud water flowing out of the buried pipe body in the blind ditch on both sides of the foundation pit;

[0034] Step S6, pumping the catch basin to the three-stage settlement tank system 4 outside the foundation pit, and then flowing into the surrounding river system, completing the trench dewatering and drainage process.

[0035] In addition, the above step S3 also includes adjusting the inclination of the pipe joint assembly 2 after being connected and placed in the excavation groove, and setting the inclination angle of the pipe joint assembly 2 through the micro-bias adjustment mechanism 25, so that the pipe segment has a certain overall inclination for water seepage and diversion in the entire water seepage section.

[0036] The large-diameter laying pipe of the foundation pit construction in the application generally has a diameter of 2.8m and 2.2m, and the weight is 25t to 45t according to different wall thicknesses. Therefore, it is very important to meet the foundation bearing capacity index. If the bearing capacity is insufficient, the load after pipe installation will be too heavy, the foundation will collapse, and the installed pipe will be dislocated, etc. It is necessary to re-pull the pipe, process the foundation again, and then reinstall, which causes huge amount of human and machine costs. Therefore, in order to ensure the quality of the foundation pit, the foundation pit drainage is needed. According to the safety and quality requirements of the pipeline construction, the traditional artificial excavation drainage ditch method is cancelled in the low-lying and near-reservoir pond areas of the buried pipe segment.

[0037] The application reduces the seepage and water accumulation of the foundation pit to the greatest extent, reduces the influence on the pipe installation, trench backfill and slope stability, and ensures the safety of the foundation pit and the dryness of the foundation surface during construction, and ensures that the foundation bearing capacity meets the requirements.

[0038] The above only describes the preferred embodiments of the application and is not intended to limit the application. For those skilled in the art, the application can have various changes and modifications. Any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A method for dewatering a long distance and large diameter pipeline trench, characterized by: It comprises the following steps, Step S1, according to the geological conditions, artificial and / or small mechanical excavation at both sides of the bottom of the foundation pit groove 30cm wide, 50cm deep, slope setting with the foundation plane slope consistent, for providing the space for installation of pipeline; Step S2, select DN150mm PVC pipe body, and drill holes on the pipe according to 20cm interval, after drilling, plug the anti-clogging head in the hole, for preventing the soil from being blocked after landfill; Step S3, select the geotechnical filter screen to wrap the PVC pipe body in step S2, and the adjacent pipe materials wrapped by single geotechnical filter screen are connected by pipe joint assembly and placed in the excavation groove, the pipe joint assembly is used for connecting the pipe body and the geotechnical filter screen, and the pipe joint assembly is used for connecting the pipe body and the geotechnical filter screen. The pipe joint assembly comprises a front connecting ring, a rear connecting ring, a hinged base, a winding ring and a micro-bias adjusting mechanism, the front connecting ring and the rear connecting ring are hinged on the hinged base, the hinged base is provided with a plug body, the relative ring surface between the front connecting ring and the rear connecting ring is connected with a connecting corrugated pipe, the outer side end surface of the front connecting ring and the rear connecting ring is rotatably connected with the winding ring, the edge of the winding ring is provided with a threading hole for sewing the geotechnical filter screen, and the micro-bias adjusting mechanism is connected between the front connecting ring and the rear connecting ring; Step S4, laying 20 to 40mm thick gravel layer on the pipe segment installed in step S3 and leveling, until the specified pipe segment is completed; Step S5, excavating a water collecting well with a size of 2x2x2m at the end of the foundation pit of the buried pipe segment in step S4, for collecting the mud water flowing out of the buried pipe in the blind ditch on both sides of the foundation pit; Step S6, the water collecting well is pumped to the three-stage sedimentation tank system outside the foundation pit, and then flows into the surrounding river system for sedimentation, and the trench dewatering and drainage process is completed.

2. The long-distance large-diameter pipeline trench dewatering construction method according to claim 1, characterized by: The step S3 comprises the following steps: first, the one end of the PVC pipe body is sleeved into the winding ring of the pipe joint assembly, then the front corner of the geotechnical filter screen is sewn and locked to the winding ring by the needle and is wound, then the other end of the PVC pipe body is also sleeved into the winding ring, and then the rear corner of the geotechnical filter screen is sewn and locked to the winding ring by the needle and is wound, until the geotechnical filter screen is completely wound, and then the two ends are fixed by the needle.

3. The long-distance large-diameter pipeline trench dewatering construction method according to claim 2, characterized by: The step S3 comprises the following steps: after the pipe joint assembly is connected and placed in the excavation groove, the micro-bias adjusting mechanism of the pipe joint assembly is used to set the inclination angle, so that the pipe segment can be used for water seepage and diversion in the whole water seepage section with a certain overall inclination.

4. The long-distance large-diameter pipeline trench dewatering construction method according to claim 1, characterized by: The step S4 comprises the following steps: when the gravel layer is laid on the installed pipe segment, the gravel with a size close to the diameter of the pipe body is first laid.

5. The long-distance large-diameter pipe trench dewatering construction device for implementing the construction method according to claim 1, characterized in that: The PVC pipe body, the pipe joint assembly and the geotechnical filter screen are provided, the PVC pipe body is provided with a drill hole at an interval of 20cm along the length direction, the drill hole is arranged at an interval along the circumference, the drill hole is plugged with an anti-clogging head, the pipe joint assembly is used for connecting adjacent PVC pipe bodies, and the PVC pipe body, the pipe joint assembly and the geotechnical filter screen are integrally assembled and buried in the excavation groove to realize water seepage and drainage in the water seepage section, and then are pumped to the three-stage sedimentation tank system through the water collecting well for sedimentation and discharge.

6. The long-distance large-diameter pipeline trench dewatering construction apparatus according to claim 5, characterized by: The anti-blocking head comprises a center pipe, a plug barrel and a plug pressing plate, the plug barrel is fixedly sleeved on the upper part of the center pipe, the plug pressing plate is fixedly sleeved on the middle part of the center pipe, a plurality of mud isolation plates are horizontally and spacedly arranged on the bottom of the center pipe, the side wall of the center pipe between the mud isolation plates is provided with water permeable holes, the bottom mud isolation plate is encapsulated on the bottom end of the center pipe and is provided with a mud isolation column on the lower side, and the bottom mud isolation plate is provided with a through mesh.

7. The long-distance large-diameter pipeline trench dewatering construction apparatus according to claim 5, characterized by: The micro-bias adjusting mechanism comprises micro-bias plates, end plates, adjusting nuts and support connecting columns, the front and rear butt rings are both hinged with the micro-bias plates at the top ends, the micro-bias plates are inserted with the support connecting columns, the support connecting columns are provided with external threads, the support connecting columns are provided with the end plates at both ends, the end plates are connected with compression springs, the end plates are connected with adjacent micro-bias plates through the compression springs, and the adjusting nuts top-press the micro-bias plates to the end plates in the direction of micro-bias adjustment through screw action.

8. The long-distance large-diameter pipeline trench dewatering construction apparatus according to claim 5, characterized by: The three-stage sedimentation tank system comprises a first sedimentation tank, a second sedimentation tank and a third sedimentation tank, the first sedimentation tank, the second sedimentation tank and the third sedimentation tank are sequentially adjacent and are poured through a concrete cushion layer, a first filter screen cylinder is arranged between the first sedimentation tank and the second sedimentation tank, a second filter screen cylinder is arranged between the second sedimentation tank and the third sedimentation tank, the first sedimentation tank is provided with an upper water inlet, and the third sedimentation tank is provided with a water outlet at the upper part.

9. The long-distance large-diameter pipeline trench dewatering construction apparatus according to claim 8, characterized by: The first filter screen cylinder is embedded and fixed at the left middle height of the partition wall between the first sedimentation tank and the second sedimentation tank, the second filter screen cylinder is embedded and fixed at the right upper height of the partition wall between the second sedimentation tank and the third sedimentation tank, and the first sedimentation tank, the second sedimentation tank and the third sedimentation tank are all provided with a mud pumping system for sedimentation regeneration.

Images