Construction method for shield settlement control in complex urban environment crossing high-risk source

Abstract

The present application relates to a kind of complex city area environment crossing high-risk source shield settlement control construction method, comprising the following steps: sensor support drilling installation;Gravel backfill, shell material seal;Monitoring data acquisition, if exceeding early warning value, bridge jacking is carried out;First stage jacking;Second stage jacking;Third stage jacking.The present application installs various sensors in the recyclable support inside, and places sensor cable in the hollow pipe of support, which avoids cable breakage when recycling sensors, effectively saving monitoring cost.When jacking the dangerous bridge, first, use hydraulic jack to jacking independently on cap beam, then replace hydraulic jack and follow-up jack combination mode to jacking, finally, use new pile cap and steel pipe support to jacking in place, combination jacking is more secure, and the structure is stable, which solves the problem of construction limitation.

Description

Technical Field

[0001] This invention belongs to the field of shield tunnel construction, and in particular relates to a method for controlling the settlement of shield tunnels crossing high-risk sources in complex urban environments. Background Technology

[0002] With the rapid development of tunnel engineering, the number of tunnels constructed using the shield tunneling method is increasing year by year, especially large-diameter shields, which have become the current mainstream. As a new tunnel construction method, the shield tunneling method has advantages such as high construction efficiency, minimal disturbance, and strong adaptability to geological formations. However, the increase in shield diameter also leads to a geometric increase in construction difficulty. When shields cross rivers, railways, buildings, bridges, and complex geological formations, the resulting ground deformation can cause phenomena such as surface collapse, water seepage, and water inrush.

[0003] Therefore, how to reduce the impact of large-diameter shield tunneling on people's production and life when crossing high-risk sources, while reducing construction and maintenance costs and construction restrictions, is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for controlling the settlement of shield tunnels traversing high-risk sources in complex urban environments.

[0005] This method for controlling settlement of tunnel boring machines (TBMs) traversing high-risk sources in complex urban environments includes the following steps:

[0006] Step 1: After drilling holes in the ground of the monitoring section, place the sensor bracket inside;

[0007] Step 2: Backfill the borehole with sand and gravel, leaving a certain distance to seal the opening with casing material;

[0008] Step 3: When the ground monitoring data of the monitoring section exceeds the warning value, install suspended jacks and steel box blocks between the box girder and the cap girder to carry out the first stage of jacking.

[0009] Step 4: Remove the steel box pads, install the steel pipe support frame on the cap beam, and install hydraulic jacks and follow-up jacks on the steel pipe support frame to carry out the second stage of jacking.

[0010] Step 5: Construct the new foundation, remove the hydraulic jacks, build a steel pipe support frame on the new foundation and install hydraulic jacks. After the box girder is lifted into place synchronously, lock the hydraulic jacks and remove the following jacks. Then, construct the new piers and support system, and use hydraulic jacks to lower the box girder onto the new piers.

[0011] Preferably, the sensor bracket includes a conical tip, a hollow round rod, a circular hoop, a pull ring, a sensor cable hole, a pore water pressure sensor mounting hole, a horizontal earth pressure sensor mounting hole, and a vertical earth pressure sensor mounting hole. The pore water pressure sensor mounting hole, the horizontal earth pressure sensor mounting hole, and the vertical earth pressure sensor mounting hole are protruding and welded to the surface of the hollow round rod. Several hollow round rods are welded together by several circular hoops. The sensor cable is internally housed within the hollow round rod. The pull ring and the sensor cable hole are located at the top of the sensor bracket, and the conical tip is located at the bottom of the sensor bracket. In step one, the sensor bracket is welded, and the pore water pressure sensor, the horizontal earth pressure sensor, and the vertical earth pressure sensor are installed on the sensor bracket.

[0012] Preferably, in step one, mud slurry is used for drilling. When the lower end of the drill rod exceeds the installation position of the uppermost sensor among the pore water pressure sensor, horizontal earth pressure sensor, and vertical earth pressure sensor by a certain distance, casing material is injected until the slurry overflows at the borehole opening, and then the sensor bracket is placed in.

[0013] Preferably, in step three, a steel plate is installed on the top of the suspension jack, and the suspension jack and the steel box pad are symmetrically arranged along the center line of the box girder cross-section.

[0014] Preferably, in step four, the lower end of the steel pipe support frame is anchored to the cap beam by anchor bolts, and the steel pipe support frames are connected by tie rods. Hydraulic jacks and follower jacks are installed on the upper end of each steel pipe support frame, and steel plates are installed between the hydraulic jacks and follower jacks and the box girder. Two concrete limiting blocks are poured on each side of the box girder cross-section, and a limiting column is vertically slidably installed between the two limiting blocks on the same side. The top of the limiting column is fixedly connected to the bottom of the box girder, and a certain gap is reserved between the limiting blocks and the limiting columns to form a pull-out limiting device. When the box girder is lifted, the limiting column rises vertically between the two limiting blocks.

[0015] Preferably, in step five, the newly constructed pile foundation under the newly constructed pier adopts the low-clearance slope excavation and impact drilling pile supplementation technology, and the lower end of the steel pipe support frame is anchored to the newly constructed pier by anchor bolts.

[0016] Preferably, in step five, during the construction of the support system, a disc-lock bracket is set up on one side of the newly built pier as a temporary construction platform. The top of the disc-lock bracket is equipped with a disc-lock bracket top support. U-shaped channel steel is horizontally installed on the disc-lock bracket top support as a sliding guide rail. The bottom of the sliding trolley is locked in the U-shaped groove of the two sliding guide rails, allowing the sliding trolley to move freely horizontally. Then, a spherical support is placed on the sliding trolley, and the sliding trolley slides laterally to the top of the newly built pier. At the same time, a hand-operated hoist is used for fine adjustment to achieve precise positioning of the spherical support.

[0017] As a preferred method, after monitoring is completed, the sensor bracket is removed and retrieved. Specifically, a reaction frame is installed at the borehole opening, and a fixed pulley is installed at the top of the reaction frame. One end of the rope is connected to a pull ring, and the other end is passed around the fixed pulley. The rope is pulled by the tension to remove the sensor bracket.

[0018] The beneficial effects of this invention are:

[0019] 1) This invention adopts the three-stage jacking technology of the original bridge abutment 0# pier and the demolition of the existing bridge abutment to build new columns: originally, hydraulic jacks were used to lift the cap beam independently, then the hydraulic jacks and follow-up jacks were replaced to lift it in combination, and finally the newly built pile foundation and steel pipe support were used to lift it into place. The combined jacking is safer and the structure is more stable, which solves the problem of construction restrictions very well.

[0020] 2) This invention adopts a precise positioning and installation technology for spherical supports: two horizontal U-shaped channel steels are installed using a disc buckle bracket as sliding rails, and the spherical support is placed on the sliding trolley to the top of the pier. With the help of a hand-operated hoist for fine adjustment, the precise positioning and installation of the support replacement is achieved.

[0021] 3) This invention adopts integrated recyclable sensor intelligent monitoring technology: by installing various sensors inside a recyclable sensor bracket and embedding the sensor cables inside the hollow tube of the bracket, the sensor bracket is pulled out by ropes through a reaction frame equipped with fixed pulleys, avoiding the cables being torn when the sensors are recycled. The recycling and reuse of sensors effectively saves monitoring costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the sensor support structure;

[0023] Figure 2 This is a schematic diagram of the burial of ground sensors in the monitoring section;

[0024] Figure 3 This is a schematic diagram of the sensor bracket after drilling and installation;

[0025] Figure 4 This is a schematic diagram of sand and gravel backfilling;

[0026] Figure 5 This is a schematic diagram of the sensor bracket removal and recycling;

[0027] Figure 6 This is the elevation layout diagram of the jacks for pier #0 in the first phase;

[0028] Figure 7 This is the first phase 0# pier jack layout plan;

[0029] Figure 8 This is the elevation layout diagram of the jacks for pier #0 in the second phase;

[0030] Figure 9 This is the plan layout of the jacks for pier #0 in the second phase;

[0031] Figure 10 This is the elevation layout diagram of the jacks for pier #0 in the third phase;

[0032] Figure 11 This is the plan layout of the jacks for pier #0 in the third phase;

[0033] Figure 12 This is a schematic diagram showing the precise installation of the spherical support by sliding it into the top.

[0034] In the diagram: 1-Sensor bracket, 101-Conical tip, 102-Hollow rod, 103-Circular hoop, 104-Pull ring, 105-Sensor cable hole, 106-Pore water pressure sensor mounting hole, 107-Horizontal earth pressure sensor mounting hole, 108-Vertical earth pressure sensor mounting hole, 2-Pore water pressure sensor, 3-Horizontal earth pressure sensor, 4-Vertical earth pressure sensor, 5-Ground of monitoring section, 6-Pipe segment, 7-Mud, 8-Casing material, 9-Sensor cable, 10-Sand and gravel, 11-Acquisition system, 12-Reaction frame, 13-Fixed 14-Pulley, 15-Box girder, 16-Cap beam, 17-Suspension jack, 18-Steel box block, 19-Steel plate, 20-Support, 21-Pier column, 22-Pile cap, 23-Pile foundation, 24-Steel pipe support frame, 25-Hydraulic jack, 26-Following jack, 27-Limit stop block, 28-Limit column, 29-Anchor bolt, 30-Tie rod, 31-New pile cap, 32-New pier column, 33-New pile foundation, 34-Disc buckle bracket, 35-Disc buckle bracket top support, 36-Sliding guide rail, 37-Sliding trolley, 38-Spherical support. Detailed Implementation

[0035] The present invention will be further described below with reference to embodiments. The description of the embodiments below is only for the purpose of helping to understand the present invention. It should be noted that those skilled in the art can make several modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0036] Example 1

[0037] As one example, such as Figures 1 to 12 As shown, the present invention discloses a method for controlling settlement of shield tunneling in complex urban environments crossing high-risk sources, wherein the complex urban environment crossing high-risk sources refers to shield tunneling through bridge pile foundations, and includes the following steps:

[0038] like Figure 1 , Figure 2 , Figure 3As shown, in step one, the sensor bracket 1 is welded, and the pore water pressure sensor 2, horizontal earth pressure sensor 3, and vertical earth pressure sensor 4 are installed on the sensor bracket 1. These can also be replaced with other measuring elements such as displacement sensors as needed for monitoring. After drilling holes in the ground 5 of the monitoring section, the sensor bracket 1 is placed inside. The sensor bracket 1 includes a conical tip 101, a hollow round rod 102, a round hoop 103, a sensor cable hole 105, a pore water pressure sensor mounting hole 106, a horizontal earth pressure sensor mounting hole 107, and a vertical earth pressure sensor mounting hole 108. 08, wherein the pore water pressure sensor mounting hole 106, the horizontal earth pressure sensor mounting hole 107, and the vertical earth pressure sensor mounting hole 108 are protruding and welded to the surface of the hollow round rod 102. The four hollow round rods 102 are welded together by several round hoops 103. The sensor cable 9 is built into the hollow round rod 102. The sensor cable hole 105 is set at the top of the sensor bracket 1. The hole is drilled with mud 7 for wall protection. When the lower end of the drill rod exceeds the uppermost sensor embedding position by a certain distance, the casing material 8 is injected until the slurry overflows at the hole opening. Then the bracket with the sensor is placed in.

[0039] like Figure 4 As shown, in step two, the borehole is backfilled with sand and gravel 10, and a certain distance is reserved to seal it with casing material 8, and sufficient time is reserved for the casing material 8 to fully hydrate.

[0040] The shield tunnel passes through the strata for monitoring, and the acquisition system 11 collects data. Settlement monitoring points are set up on the ground. If the monitoring data is found to exceed the warning value, the bridge is lifted.

[0041] like Figure 6 , Figure 7 As shown, in step three, a suspension jack 17 and a steel box block 18 are installed between the box girder 15 and the cap beam 16 to carry out the first stage of lifting. A steel plate 19 is installed on the top of the suspension jack 17, and the suspension jack 17 and the steel box block 18 are symmetrically arranged along the center line of the cross-section of the box girder 15.

[0042] like Figure 8 , Figure 9 As shown, in step four, remove the steel box pad 18, install the steel pipe support frame 24 and the hydraulic jacks 25 and follower jacks 26 on it, and carry out the second stage of jacking. The lower end of the steel pipe support frame 24 is anchored to the cap beam 16 by anchor bolts 29. The steel pipe support frames 24 are connected by tie rods 30. The hydraulic jacks 25 and follower jacks 26 are installed on the upper end of each steel pipe support frame 25. A steel plate 19 is installed between the hydraulic jacks 25 and follower jacks 26 and the box beam 15.

[0043] like Figure 10 , Figure 11As shown, in step five, after the construction of the new pier cap 31 is completed, the original hydraulic jacks 25 are removed, a steel pipe support frame 24 is built on the new pier cap 31 and multiple hydraulic jacks 25 are installed. After the box girder 15 is lifted into place synchronously, the hydraulic jacks 25 are mechanically locked and the following jacks 26 are removed. Then the construction of the new pier column 32 and the support system is carried out. After the concrete strength of the new pier column 32 and the support pad stone reaches the design requirements, the beam is lowered onto the new pier column 32 to complete the lifting.

[0044] Example 2

[0045] As another embodiment, this embodiment two proposes a more specific method for controlling the settlement of shield tunnels traversing high-risk sources in complex urban environments, based on embodiment one.

[0046] In step four, two concrete limiting blocks 27 are poured on each side of the cross-section of the box girder 15. A limiting column 28 is vertically slidably installed between the two limiting blocks 27 on the same side. The top of the limiting column 28 is fixedly connected to the bottom of the box girder 15. A certain gap is reserved between the limiting blocks 27 and the limiting column 28 to form a pull-out limiting device. When the box girder 15 is lifted, the limiting column 28 rises vertically between the two limiting blocks 27.

[0047] In step five, the newly constructed pile foundation 33 under the newly constructed pier cap 31 adopts the low-clearance slope excavation impact drilling and pile supplementation technology, and the lower end of the steel pipe support frame 24 is anchored to the newly constructed pier cap 31 by anchor bolts 29.

[0048] like Figure 12 As shown, in step five, during the construction of the support system, a disc-lock bracket 34 is set up on one side of the newly built pier 32 as a temporary construction platform. Two horizontal U-shaped channel steels are installed on the top support 35 of the disc-lock bracket as sliding guide rails 36. The sliding trolley 37 is precisely locked in the U-shaped groove of the two sliding guide rails 36, allowing it to move freely horizontally. Then, the spherical support 38 is hoisted and placed on the sliding trolley 37 and slid laterally to the top of the pier. At the same time, a hand-operated hoist is used for fine-tuning to achieve precise positioning of the spherical support 38.

[0049] The sensor bracket 1 also includes a pull ring 104, which is disposed on the top of the sensor bracket 1, such as... Figure 5 As shown, in step five, after monitoring is completed, the sensor bracket 1 can be removed and retrieved. A reaction frame 12 is installed at the borehole opening, and a fixed pulley 13 is installed at the top of the reaction frame. One end of the rope is connected to the pull ring 104, and the other end is pulled by the tension 14 to pull the rope to remove the sensor bracket 1.

[0050] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 1 can be referred to each other, and will not be repeated in this application.

[0051] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

Claims

1. A method for controlling settlement of shield tunneling tunnels traversing high-risk sources in complex urban environments, characterized in that, Includes the following steps: Step 1: After drilling holes in the ground of the monitoring section, place the sensor bracket. The sensor bracket includes a conical tip, a hollow round rod, a hoop, a pull ring, a sensor cable hole, a pore water pressure sensor mounting hole, a horizontal earth pressure sensor mounting hole, and a vertical earth pressure sensor mounting hole. The pore water pressure sensor mounting hole, the horizontal earth pressure sensor mounting hole, and the vertical earth pressure sensor mounting hole are protruding and welded to the surface of the hollow round rod. Several hollow round rods are welded together by several hoops. The sensor cable is built into the hollow round rod. The pull ring and the sensor cable hole are located at the top of the sensor bracket, and the conical tip is located at the bottom of the sensor bracket. In Step 1, weld the sensor bracket and install the pore water pressure sensor, the horizontal earth pressure sensor, and the vertical earth pressure sensor on the sensor bracket. Drill the hole using mud wall protection. When the lower end of the drill rod exceeds the burial position of the uppermost sensor among the pore water pressure sensor, the horizontal earth pressure sensor, and the vertical earth pressure sensor by a certain distance, inject casing material until the slurry overflows at the borehole opening, and then place the sensor bracket. Step 2: Backfill the borehole with sand and gravel, leaving a certain distance to seal the opening with casing material; Step 3: When the ground monitoring data of the monitoring section exceeds the warning value, install suspended jacks and steel box blocks between the box girder and the cap girder to carry out the first stage of jacking. Step 4: Remove the steel box pads, install the steel pipe support frame on the cap beam, and install hydraulic jacks and follow-up jacks on the steel pipe support frame to carry out the second stage of jacking. Step 5: Construct the new foundation, remove the hydraulic jacks, build a steel pipe support frame on the new foundation and install hydraulic jacks. After the box girder is lifted into place synchronously, lock the hydraulic jacks and remove the following jacks. Then, construct the new piers and support system, and use hydraulic jacks to lower the box girder onto the new piers.

2. The method for controlling settlement of shield tunneling tunnels traversing high-risk sources in complex urban environments according to claim 1, characterized in that: In step three, a steel plate is installed on the top of the suspension jack, and the suspension jack and the steel box pad are symmetrically arranged along the center line of the box girder cross-section.

3. The method for controlling settlement of shield tunneling tunnels traversing high-risk sources in complex urban environments according to claim 1, characterized in that: In step four, the lower end of the steel pipe support frame is anchored to the cap beam by anchor bolts. The steel pipe support frames are connected by tie rods. Hydraulic jacks and follower jacks are installed on the upper end of each steel pipe support frame. Steel plates are installed between the hydraulic jacks and follower jacks and the box girder. Two concrete limit blocks are poured on each side of the box girder cross-section. Limit columns are vertically slidably installed between the two limit blocks on the same side. The top of the limit column is fixedly connected to the bottom of the box girder. A certain gap is reserved between the limit blocks and the limit columns to form a pull-out limit device. When the box girder is lifted, the limit columns rise vertically between the two limit blocks.

4. The method for controlling settlement of shield tunneling tunnels traversing high-risk sources in complex urban environments according to claim 1, characterized in that: In step five, the newly constructed pile foundation under the newly constructed pier adopts the low-clearance slope excavation and impact drilling pile supplementation technology, and the lower end of the steel pipe support frame is anchored to the newly constructed pier by anchor bolts.

5. The method for controlling settlement of shield tunneling tunnels traversing high-risk sources in complex urban environments according to claim 1, characterized in that: In step five, during the construction of the support system, a disc-lock scaffold is set up on one side of the newly built pier as a temporary construction platform. The top of the disc-lock scaffold is equipped with a disc-lock scaffold support. U-shaped channel steel is horizontally installed on the disc-lock scaffold support as a sliding guide rail. The bottom of the sliding trolley is locked in the U-shaped groove of the two sliding guide rails, allowing the sliding trolley to move freely horizontally. Then, a spherical support is placed on the sliding trolley. The sliding trolley slides laterally to the top of the newly built pier. At the same time, a hand-operated hoist is used for fine-tuning to achieve precise positioning of the spherical support.

6. The method for controlling settlement of shield tunneling tunnels traversing high-risk sources in complex urban environments according to claim 1, characterized in that: After monitoring is completed, the sensor bracket is removed and retrieved. Specifically, a reaction frame is installed at the borehole opening, and a fixed pulley is installed at the top of the reaction frame. One end of the rope is connected to a pull ring, and the other end is passed around the fixed pulley. The rope is pulled by the tension to remove the sensor bracket.

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