Active Suspension Protection System for Flexible Joint Drain Pipes under Tunnel and Construction Method

Abstract

The present invention discloses an active suspension protection system and construction method for a flexible joint drainage pipe passing under a tunnel. The existing flexible joints of tunnel drainage pipes have poor deformation resistance, and the drainage pipes are prone to leakage, which endangers the underground environment. The present invention excavates a vertical shaft at the pipe joint, and a distribution beam is inserted into the groove excavated at the lower part of the drainage pipe joint; a wedge-shaped pad is arranged at the bottom of the drainage pipe, and an anti-slip baffle is arranged on the outer side of the pad; steel supports are arranged on the ground on both sides of the vertical shaft, and a suspension beam is erected thereon, and a jack is arranged on the suspension beam; a steel strand is wound around the distribution beam and a jack is inserted into it to ensure that the steel strand is in a tensioned state; direct vertical displacement monitoring points are arranged on the drainage pipes on both sides. When passing under the tunnel, the present invention eliminates settlement through dynamic fine-tuning of the tensioning jack according to real-time deformation monitoring data, thereby achieving safe and normal operation of the drainage pipe when passing under the tunnel.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel engineering, and in particular relates to an active suspension protection system and a construction method for a flexible joint drainage pipe passing under a tunnel. Background Art

[0002] During the construction of the tunnel project, the large-diameter drainage pipes laid in advance did not reserve conditions for future tunnel crossings, and the flexible joints of the drainage pipes had poor deformation resistance. In addition, the drainage network was built a long time ago and the structure was aging. The deformation of the stratum through which the tunnel passed could easily cause drainage pipe leakage, seriously affecting the normal life of residents, and sewage pipe leakage endangered the underground environment.

[0003] Conventional ground grouting reinforcement measures often affect the grouting range and reinforcement effect due to problems such as the difficulty in controlling the grouting angle and grouting pressure. In particular, excessive grouting pressure can easily lead to leakage or even damage of flexible joint drainage pipes. At the same time, it is difficult to lay direct vertical displacement monitoring points for buried drainage pipes. Summary of the invention

[0004] In order to make up for the shortcomings of the prior art, the present invention provides an active suspension protection system and construction method for a flexible joint drainage pipe passing under a tunnel. A working shaft is excavated at the joint of the flexible joint drainage pipe and an active suspension protection system is constructed to eliminate the settlement and deformation of the drainage pipe and achieve safe and normal operation of the drainage pipe when passing under the tunnel.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The active suspension protection system of the flexible joint drainage pipe under the tunnel is arranged in the working shaft. The working shaft is excavated at the location of the pipe joint. The protective wall of the working shaft is a zigzag cast-in-place concrete structure with unequal thickness, which is larger at the top and smaller at the bottom.

[0007] A distribution beam is installed in the groove dug at the bottom of the drainage pipe joint; a rubber plate is installed between the drainage pipe and the distribution beam; wedge-shaped pads are installed at both sides of the bottom of the drainage pipe, and an anti-skid baffle is installed outside the wedge-shaped pad, and the anti-skid baffle is welded to the top of the distribution beam;

[0008] Steel supports are arranged on the ground at both sides of the working shaft, a suspension beam is set up on the steel supports, two tensioning jacks are arranged on the suspension beam, and the tensioning jacks are connected to the oil pump; steel strands are respectively wound around both sides of the distribution beam and penetrated into the tensioning jacks, and the tensioning jacks ensure that the steel strands are in a tensioned state.

[0009] Specifically, the lap length of the upper and lower sections of the guard wall is not less than 50 mm, longitudinal steel bars and tie bars are arranged inside, and a plastic steel ladder is embedded in advance.

[0010] Specifically, a flood prevention retaining wall is arranged on the top of the retaining wall.

[0011] Specifically, when the step height of the plastic-steel ladder is greater than 3m, a protective cage is provided.

[0012] Specifically, direct vertical displacement monitoring points are arranged on the drainage pipes on both sides.

[0013] Specifically, the distribution beam is a three-piece structure, including three steel sections, upper and lower flange surfaces of the steel sections are respectively welded with steel tie plates, and ribs are welded at the web position of the steel sections.

[0014] Specifically, the steel support and the suspension beam are both double-jointed structures, and the structure is the same as the distribution beam structure.

[0015] A method for constructing an active suspension protection system for a flexible joint drainage pipe under a tunnel comprises the following steps:

[0016] Step 1: Determine the number of working shafts and locate the working shafts on site according to the degree and scope of the disturbance of the surrounding rock and soil and the surrounding environment caused by the tunnel construction;

[0017] Step 2: Level the site and dig a dewatering well for dewatering. The working shaft is operated by reverse digging. Excavation and wall pouring are carried out alternately. When pouring the wall, a plastic steel ladder is pre-buried;

[0018] Step 3: After the retaining wall reaches the designed strength, a groove is dug at the bottom of the drainage pipe joint, and the distribution beam is passed through. A rubber plate is arranged between the drainage pipe and the distribution beam; wedge-shaped pads are arranged on both sides of the bottom of the drainage pipe, and an anti-slip baffle is welded on the steel plate of the distribution beam as an anti-lateral displacement measure;

[0019] Step 4: Steel supports are set on the ground on both sides of the working shaft, suspension beams are set up on the steel supports, and two tensioning jacks are positioned and installed, and the tensioning jacks are connected to the oil pump;

[0020] Step 5: Wind the steel strands on both sides of the distribution beam and insert them into the tensioning jack, start the oil pump, and close the oil valve immediately when the tensioning jack piston starts and the oil pressure pointer flashes to ensure that the steel strands are in a taut state;

[0021] Step 6: Direct vertical displacement monitoring points are arranged on the drainage pipes on both sides of the flexible joint. When the tunnel passes under, the tensioning jack is used to dynamically fine-tune and eliminate settlement according to the real-time deformation monitoring data to ensure the normal use of the drainage pipes;

[0022] Step 7: After the tunnel is underpassed and the deformation of the drainage pipe is converged, use micro-expansive concrete to fill the gap between the distribution beam and the bottom of the working shaft, unload the tensioning jack and return the oil, remove the steel strands, suspension beams, supports and tensioning jacks; use low-grade plain concrete to backfill the working shaft below 3m below the ground, and use clay to backfill the range 3m below the ground.

[0023] Beneficial effects of the present invention:

[0024] 1) The present invention excavates a working shaft at the joint of the flexible joint drainage pipe, sets up distribution beams and suspension beam load-bearing components, sets up rubber plates, wooden wedge-shaped pads and anti-slip baffles, installs positioning tensioning jacks and steel strands, and constructs an active suspension flexible joint drainage pipe protection system. The drainage pipe settlement deformation is eliminated through dynamic regulation of the tensioning jack, and the safe and normal operation of the drainage pipe when the tunnel is passed under is realized;

[0025] 2) The invention is simple to construct. The steel, concrete, rubber sheet, steel strand, etc. involved are all conventionally used materials, and their design dimensions are conventional types, which are convenient for processing and manufacturing; the tensioning jacks and other auxiliary facilities are all conventional mechanical equipment;

[0026] 3) The present invention can ensure the safe and normal operation of the flexible joint drainage pipe when the tunnel is passing through through the tunnel through the active suspension protection system, effectively solving the problems of poor reinforcement effect and joint leakage caused by the difficult control of the setting angle and grouting pressure of the sleeve valve pipe or the steel flower pipe in conventional ground pre-grouting and tracking grouting, and at the same time overcomes the difficulty of laying direct vertical displacement monitoring points for the drainage pipe;

[0027] 4) The present invention has high economic and social benefits and has broad application prospects in urban rail transit, railways, highways and other projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic elevation diagram of the working shaft and active suspension protection device;

[0029] Figure 2 It is a plan view of the working shaft and active suspension protection device;

[0030] Figure 3 It is a schematic diagram of the cross section of the distribution beam, suspension beam and support composite steel;

[0031] In the figure, 1-drainage pipe, 2-working shaft, 3-protection wall, 4-flood retaining wall, 5-distribution beam, 6-rubber plate, 7-wedge pad, 8-anti-slip baffle, 9-steel strand, 10-suspension beam, 11-support, 12-tensioning jack, 13-direct vertical displacement monitoring point, 14-steel section, 15-steel tie plate, 16-rib plate. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with specific implementation modes.

[0033] like Figure 1 , Figure 2As shown, the present invention is arranged in a working shaft 2, the working shaft 2 is excavated at the position of the pipe joint, and the protective wall 3 of the working shaft 2 is a zigzag cast-in-place concrete structure with unequal thickness, which is larger at the top and smaller at the bottom;

[0034] In order to prevent water seepage at the joints of the retaining wall 3, the lap length of the upper and lower sections of the retaining wall 3 is not less than 50mm, and longitudinal steel bars and tie bars are set inside, and plastic steel ladders are embedded. The shaft concrete adopts micro-expansive concrete with expansion agent added; when the step height of the plastic steel ladder is greater than 3m, a cage is set; a flood-proof retaining wall 4 is set on the top of the retaining wall 3 to prevent flood water from backflowing into the working shaft 2;

[0035] A distribution beam 5 is passed through the groove dug at the lower part of the joint of the drainage pipe 1; a rubber plate 6 is arranged between the drainage pipe 1 and the distribution beam 5 to play an anti-skid and buffering role; wedge-shaped pads 7 are arranged on both sides of the bottom of the drainage pipe 1, and an anti-skid baffle 8 is arranged outside the wedge-shaped pad 7, and the anti-skid baffle 8 is welded to the top of the distribution beam 8 to prevent lateral movement; during the welding process, all welds are full welded;

[0036] Steel supports 11 are set on the ground at both sides of the working shaft 2, and suspension beams 10 are set on the steel supports 11. Two tensioning jacks 12 are set on the suspension beams 10, and the tensioning jacks 12 are connected to the oil pump; steel strands 9 are respectively wound around both sides of the distribution beam 5 and inserted into the tensioning jacks 12, and the tensioning jacks 12 ensure that the steel strands 9 are in a tensioned state.

[0037] Direct vertical displacement monitoring points 13 are arranged on the drainage pipes 1 on both sides. When the tunnel passes under, the tensioning jacks 12 can be used to dynamically fine-tune and eliminate settlement to meet the deformation requirements of the drainage pipes 1.

[0038] like Figure 3 As shown, the distribution beam 5 is a three-piece structure, including three steel sections 14, with steel plates 15 welded to the upper and lower flange surfaces of the steel section 14, and ribs 16 welded to the web position of the steel section 14; the steel support 11 and the suspension beam 10 are both double-piece structures, and the structure is the same as that of the distribution beam 5.

[0039] The method for constructing the active suspension protection system of the present invention comprises the following steps:

[0040] Step 1: According to the degree and scope of the disturbance of the surrounding rock and soil and the surrounding environment caused by the tunnel construction, determine the number of working shafts 2 and locate and stake out the positions of working shafts 2 on site;

[0041] Step 2: Level the site and install dewatering wells for dewatering operations. The working shaft 2 is constructed by the inverse excavation method. Excavation and pouring of the retaining wall 3 are carried out alternately. When pouring the retaining wall 3, a plastic-steel climbing ladder is embedded. Each section is taken as a construction cycle, that is, after excavating each section of soil, a section of concrete retaining wall 3 is immediately poured. The height of each section in general soil layers is 1m. When encountering local or flowing silt with a thickness not greater than 1.5m and possible earth and sand gushing, the height of each section of the retaining wall 3 can be reduced to 0.3 - 0.5m, and concrete is poured while excavating, inspecting, and following.

[0042] Step 3: After the retaining wall 3 reaches the design strength, excavate a trench under the joint of the drain pipe 1, lay the distribution beam 5 through it, and set a rubber plate 6 between the drain pipe 1 and the distribution beam 5; Wedge-shaped pads 7 are arranged on both sides of the bottom of the drain pipe 1, and an anti-slip baffle 8 is welded on the steel lacing plate 15 of the distribution beam 5 as an anti-side shift measure.

[0043] Step 4: Set steel supports 11 on the ground on both sides of the working shaft 2, erect a suspension beam 10 on the steel supports 11, and position and install two tension jacks 12, and connect the tension jacks 12 with an oil pump.

[0044] Step 5: Wind steel strands 9 on both sides of the distribution beam 5 and pass them through the tension jacks 12. Start the oil pump, and immediately close the fuel filling valve at the moment when the piston of the tension jack 12 starts, that is, when the oil pressure pointer flashes, to ensure that the steel strands 9 are in a tightened state.

[0045] Step 6: Respectively arrange direct vertical displacement monitoring points 13 on the drain pipes 1 on both sides of the flexible joint. When the tunnel passes under, according to the real-time deformation monitoring data, dynamically fine-tune through the tension jacks 12 to eliminate settlement and ensure the normal use of the drain pipes 1.

[0046] Step 7: After the tunnel passes under and the deformation of the drain pipe 1 converges, fill the gap between the distribution beam 5 and the bottom of the working shaft 2 with slightly expanded concrete. Unload and return the oil of the tension jacks 12, and remove the steel strands 9, suspension beam 10, supports 11, and tension jacks 12; The area below 3m on the ground of the working shaft 2 is backfilled with low-strength plain concrete, and the area within 3m below the ground is backfilled with clay.

[0047] In the description of the present invention, unless otherwise clearly specified and defined, the terms "set", "install", "connected", "connected", "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0048] The content of the present invention is not limited to the examples listed. Any equivalent transformation of the technical solution of the present invention made by those of ordinary skill in the art by reading the specification of the present invention is covered by the claims of the present invention.

Claims

1. An active suspension protection system for a flexible joint drainage pipe under a tunnel, characterized in that: It is arranged in the working shaft (2), and the working shaft (2) is excavated at the position of the pipe joint. The retaining wall (3) of the working shaft (2) is a cast-in-place concrete structure with a serrated unequal thickness that is larger at the top and smaller at the bottom; A distribution beam (5) is passed through a groove dug under the joint of the drain pipe (1); a rubber plate (6) is arranged between the drain pipe (1) and the distribution beam (5); wedge-shaped pads (7) are arranged on both sides of the bottom of the drain pipe (1), and an anti-slip baffle (8) is arranged outside the wedge-shaped pads (7), and the anti-slip baffle (8) is welded to the top of the distribution beam (5); Steel supports (11) are arranged on the ground on both sides of the working shaft (2), a suspension beam (10) is erected on the steel supports (11), two tension jacks (12) are arranged on the suspension beam (10), and the tension jacks (12) are connected to an oil pump; Steel strands (9) are wound around both sides of the distribution beam (5) and pass through the tension jacks (12), and the tension jacks (12) ensure that the steel strands (9) are in a tensioned state; Direct vertical displacement monitoring points (13) are arranged on both sides of the drain pipes (1).

2. The active suspension protection system for flexible joint drainage pipes under a tunnel according to claim 1, characterized in that: The overlapping length of the upper and lower sections of the retaining wall (3) is not less than 50 mm, and longitudinal and circumferential steel bars and tie bars are arranged inside, and a plastic-steel climbing ladder is embedded.

3. The active suspension protection system for the flexible joint drainage pipe under the tunnel according to claim 2, characterized in that: A flood control and drainage retaining wall (4) is arranged at the top of the retaining wall (3).

4. The active suspension protection system for the flexible joint drainage pipe under the tunnel according to claim 3, characterized in that: When the height of the ladder section of the plastic-steel climbing ladder is greater than 3 m, a protective cage is arranged.

5. The active suspension protection system for the flexible joint drainage pipe under the tunnel according to claim 4, characterized in that: The distribution beam (5) is a three-piece structure, including three sections of steel (14). Steel gusset plates (15) are welded to the upper and lower flange surfaces of the steel (14), and rib plates (16) are welded at the web positions of the steel (14).

6. The active suspension protection system for the flexible joint drainage pipe under the tunnel according to claim 5, characterized in that: Both the steel support (11) and the suspension beam (10) are double-piece structures, and the structure is the same as that of the distribution beam (5).

7. The construction method of the active suspension protection system for the flexible joint drainage pipe under the tunnel according to any one of claims 1-6, characterized in that: It includes the following steps: Step 1: Determine the number of working shafts (2) according to the degree and scope of the disturbance of the surrounding rock and soil mass and the impact on the surrounding environment during the construction of the tunnel project, and locate and loft the well positions of the working shafts (2) on site; Step 2: Level the site and install dewatering wells for dewatering operations. The working shaft (2) is constructed by the inverse construction method of digging holes, and the excavation and the pouring of the retaining wall (3) are carried out alternately. A plastic-steel climbing ladder is embedded when pouring the retaining wall (3); Step 3: After the retaining wall (3) reaches the design strength, dig a groove under the joint of the drain pipe (1), pass the distribution beam (5), and arrange a rubber plate (6) between the drain pipe (1) and the distribution beam (5); Wedge-shaped pads (7) are arranged on both sides of the bottom of the drain pipe (1), and an anti-slip baffle (8) is welded to the steel gusset plate (15) of the distribution beam (5) as an anti-side shift measure; Step 4: Arrange steel supports (11) on the ground on both sides of the working shaft (2), erect a suspension beam (10) on the steel supports (11), and position and install two tension jacks (12), and connect the tension jacks (12) to an oil pump; Step 5: Wind steel strands (9) around both sides of the distribution beam (5) and pass them through the tension jacks (12), start the oil pump, and immediately close the fuel filling valve at the moment when the piston of the tension jack (12) starts and the oil pressure pointer flashes, ensuring that the steel strands (9) are in a tensioned state; Step 6: Direct vertical displacement monitoring points (13) are arranged on the drainage pipes (1) on both sides of the flexible joint. When the tunnel is passing under, the tensioning jacks (12) are used to dynamically fine-tune and eliminate settlement according to the real-time deformation monitoring data, so as to ensure the normal use of the drainage pipes (1); Step 7: After the tunnel is completed and the deformation of the drainage pipe (1) is converged, the gap between the distribution beam (5) and the bottom of the working shaft (2) is filled with micro-expansive concrete, the tensioning jack (12) is unloaded and the oil is returned, and the steel strand (9), suspension beam (10), steel support (11) and tensioning jack (12) are removed; the working shaft (2) is backfilled with low-grade plain concrete below 3m of the ground, and the range below 3m of the ground is backfilled with clay.

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