CN116607809A - Automatic underpinning and resetting device for pier assembly and construction method thereof - Google Patents

Abstract

The invention relates to the technical field of civil engineering reinforcement underpinning and transformation, in particular to an automatic underpinning and resetting device for a pier assembly and a construction method thereof, wherein the automatic underpinning and resetting device comprises a plurality of groups of upper steel corbels and lower steel corbels which are respectively connected to an underpinned pier, and a lifting support column is fixed between each group of upper steel corbels and each group of lower steel corbels by using cantilever bolts; the hydraulic pressure gauge is connected with the automatic pressure maintaining water supply device. Compared with the prior art, the invention has the advantages that: the underpinning sedimentation regulation displacement monitoring is converted into pressure monitoring, so that the influence of the environment is smaller; the joint surface of the underpinning bracket and the underpinned pier column introduces the latest second-order tooth contact interface, so that the shearing and sliding resistance is greatly improved; the liquid bags are adopted for automatically maintaining pressure and supplying water, so that the risk of oil leakage and pollution is low, and the long-term use cost is low; each pillar pier realizes double insurance of liquid sac bearing and peripheral lifting temporary support bearing; the device simple structure, it is convenient to assemble, and the efficiency of construction is high, and the security is high.

Description

A column pier assembly type automatic underpinning reset device and its construction method

technical field

The invention relates to the technical field of civil engineering reinforcement and underpinning transformation, in particular to an assembled type automatic underpinning reset device for a column pier and a construction method thereof.

Background technique

Structural underpinning is a technology that changes the load transmission route of engineering structures. With the development of my country's construction industry from the stage of large-scale new construction to the stage of both new construction and reinforcement and reconstruction, and the vigorous development of urban renewal and construction activities, existing engineering structure reinforcement, displacement, large space renovation, underground space development, tunnel crossing Projects such as pile foundation buildings are increasing day by day. In the above projects, column pier underpinning is a key engineering technology widely used.

The column pier underpinning technology usually transfers the vertical load originally transmitted from the column pier to the foundation to a system consisting of underpinning nodes and supporting supports, jacks, etc. During the underpinning process, after the underpinning node and the support under the node are completed, the column pier often needs to be cut and separated from the foundation, so as to realize the transformation of unloading and load transmission path.

Scholars and engineers at home and abroad have done a lot of research on column pier underpinning, and have designed a variety of underpinning joint forms, the most common of which is the column-holding beam + beam-column contact interface embedding mode. This form of underpinning joints requires wet operations such as pouring concrete, followed by maintenance, and the construction period is relatively long. Therefore, institutions such as Hohai University have designed prestressed concrete assembly type and steel structure assembly type pier underpinning joints, conducted experimental research, and carried out engineering pilot applications. These studies did not consider the subsidence difference factor at the same time.

In order to control the uneven settlement of the underpinning structure and ensure the safety of the superstructure, based on the concept of active underpinning, Shanghai Tianyan Building Displacement Engineering Co., Ltd. proposed the idea of superimposing vertical jacks in the mobile support. However, the assembly units of these prefabricated underpinning nodes are relatively large, the construction is difficult, and the scale needs to be customized. The adaptability to the shape of the column section is poor, which greatly increases the project cost. Therefore, a new type of assembled underpinning node with simple structure and operation should be further developed.

When there is synchronous integrated underpinning of multi-column piers, the automatic adjustment of settlement difference in active underpinning projects often adopts PLC (logic programming controller) system, which consumes high standby energy and costs, especially when underpinning pier When the quantity of the underpinning structure is small and the stress period of the underpinning structure is long, the cost performance difference is more obvious. Therefore, a new type of automatic control system for settlement difference with low cost and simple structure should be developed.

The commonly used temporary supports in the structural underpinning system are steel columns, hydraulic jacks, etc., supplemented by the use of displacement sensors to monitor the settlement, and after feedback, instructions are issued to adjust the height of the temporary supports. But at the construction site, the displacement sensor is easily affected by the environment, so the settlement control effect is poor.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, and provide a pier-assembled automatic underpinning reset device and its construction method with simple structure, convenient construction, high efficiency and low pollution.

In order to achieve the above purpose, an assembly-type automatic underpinning and reset device for pier is designed, which includes several sets of upper steel corbels and lower steel corbels. The upper steel corbels and lower steel corbels are connected to the underpinned pier. A lifting support column is fixed with a cantilever bolt between the upper steel corbel and the lower steel corbel; it also includes a liquid bag, which is set in the middle of the underpinned pier after cutting, and the liquid bag and pressure gauge and automatic pressure maintaining The water supply device is connected to each other, and the outer periphery of the liquid bag is assembled into a whole with a casing restrained by a hoop.

Preferably, several sets of upper steel corbels and lower steel corbels are fixed to the underpinned pier by corbel shear bolts and steel plates with second-order teeth, and then pulled by several groups of Hualan screws hooked on the anchor rings of the steel corbels. tight.

Preferably, the upper steel corbel or the lower steel corbel is composed of an H-shaped steel with unequal lengths on the flange, a steel plate with second-order teeth, and a fabricated stiffener. The side connected by the steel plate with second-order teeth and the H-shaped steel is a vertical plane. The contact surface with the column surface is a toothed surface, which is provided with a first-order large tooth and several groups of second-order small teeth; there are reserved grooves on the upper and lower flanges on both sides of the web for installing stiffeners. There are several sets of anchor rings welded on both sides from top to bottom on the outside of the plate near the edge.

Preferably, the lifting support column is composed of a steel spiral core barrel and a steel spiral sleeve, the two are nested together through a turnbuckle, and the upper end plate of the steel spiral core barrel is suspended on the lower flange of the upper steel corbel through support suspension bolts , The lower part of the steel spiral sleeve is provided with a loading rod hole, which penetrates into the loading rod.

Preferably, the assembled casing is composed of a set of L-shaped steel guard plate units, two upper and lower semicircular notches are provided on both sides, and a plurality of rubber protrusions are provided on the outside of the riser from top to bottom, and the whole set of L-shaped Two steel guard plate units contact to form a closed casing, the inner periphery of the casing and the surface of the underpinned pier are not in contact, and the upper part of the rubber protrusion is a ferrule.

A construction method of a pier assembly type automatic underpinning reset device, the method is specifically as follows:

1) Cutting lines are placed within the design height of the column pier underpinning, and the distance between the cutting lines matches the height of the liquid bag;

2) Grind the surface of the column pier at the upper and lower adjacent parts outside the excised area of the column pier, and the shape is basically consistent with the shape of the steel plate with second-order teeth in the steel corbel;

3) Apply cement mortar, and the mortar strength is not lower than the concrete strength of the pier;

4) Install the upper and lower steel corbels, fix them with expansion bolts or anchor bolts, and keep the lower surface level;

5) Install Hualan screws, tighten them, and assemble the upper and lower steel corbels into two underpinning platforms; 6) Install lifting support columns between each set of upper and lower steel corbels, and use suspension bolts for the upper end plate Hang on the lower part of the upper steel corbel, and insert the loading rods into the loading rod holes of the steel spiral sleeve one by one to adjust the height until the top is tight;

7) Insert the static cutting wire saw through the gap of the support column to cut the column pier; after cutting, put the hoop with matching size, which can be temporarily fixed in the reserved section at the upper and lower ends of the column pier;

8) Select a liquid bladder that matches the size of the pier, place it in the area where the pier is removed, and then connect the pressure gauge, water supply and drainage valve, and pressure-maintaining water supply device;

9) Water-filled pressure test: Install a displacement gauge between the upper and lower column ends, then fill the high-pressure liquid bag with water and pressurize until the upper column end shows signs of upward movement, and then release the pressure;

10) Weighing and pressure measurement: unscrew the surrounding lifting support columns, the upper column has signs of sinking, pressurize the liquid bladder to supply water, push the upper column end back to the original elevation, then this pressure is the water pressure maintenance target value,

11) Casing installation: first place the pre-installed ferrules along the pier of the underpinned pier for a week, adjacent to each other. Large downward force of the hoop, after the rubber protrusion is deformed, the lower hoop can pass through the rubber protrusion of this layer, so that a hoop is installed on the upper part of each layer corresponding to the rubber protrusion; continue to squeeze the hoop to the rubber protrusion, and when the hoop Stop squeezing the ferrule when you feel tight;

12) Re-tighten all supports, and the equipment is in an automatic standby state.

Preferably, the method also includes state adjustment of the lifting support column:

1) In the condition of subsidence or shutdown of the underpinned column, the standby state of the lifting support column is to tighten the upper and lower steel corbels. When the column subsides, the water pressure measured by the pressure gauge decreases, and the pressure maintaining water supply device automatically adjusts Supply water to ensure that the upper column returns to the original elevation state, and then adjust the lifting support column one by one to make it stretch to the top tight state;

2) In the condition of subsidence and uplift of the underpinned column, the standby state of the lifting support column is the unstressed state.

Compared with the prior art, the present invention has the advantages of:

1. Convert the displacement monitoring of underpinning settlement regulation to pressure monitoring that is less affected by the environment;

2. On the connection surface between the underpinning corbel and the underpinned pier column, the latest second-order tooth contact interface is introduced, and the anti-shear slipping ability is greatly improved;

3. The liquid bladder is used to automatically maintain the pressure for water supply, which effectively solves the problems of high oil leakage pollution risk and high long-term use cost of the PLC system;

4. Each column pier realizes the dual insurance of liquid bag bearing and peripheral lifting temporary support bearing;

5. The device has simple structure, convenient assembly, high construction efficiency and high safety.

Description of drawings

Fig. 1 is the elevation view of the system installation state of the reset device provided by the present invention;

Fig. 2 is the installation sectional view of the corbel of reset device provided by the present invention;

Fig. 3 is the elevation view of the corbel structure of the reset device provided by the present invention;

Fig. 4 is an enlarged view of the lifting support of the reset device provided by the present invention;

Fig. 5 is a cross-sectional view of the installation of the casing liquid bag of the reset device provided by the present invention;

Fig. 6 is an elevation view of the casing wall unit of the reset device provided by the present invention.

In the picture:

1. Underpinned column pier; 2. Upper steel corbel; 3. Lower steel corbel; 4. Lifting support column; 5. Casing; 6. High pressure liquid bag; 7. Pressure gauge; ;9, Hualan screws; 10, corbel shear bolts; 11, support suspension bolts; 12, hoops;

2-1, H-shaped steel with unequal length of flange; 2-2, steel plate with second-order teeth; 2-3, first-order large teeth; 2-4, second-order small teeth; 2-5, first bolt hole; 2 -6, anchor ring; 2-7, reserved groove; 2-8, assembled stiffener; 2-9, second bolt hole;

4-1. Steel spiral core barrel; 4-2. Steel spiral sleeve; 4-3. Bolt hole 3; 4-4. Loading rod hole; 4-5. Loading rod;

5-1, L-shaped steel guard plate unit; 5-2, semicircular notch; 5-3, rubber protrusion.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing, and the structure and principle of the present invention are very clear to those skilled in the art. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As shown in Figure 1, the present invention discloses an assembled automatic underpinning reset device for pier, including several sets of upper steel corbels, lower steel corbels, lifting support columns, assembled casings, high-pressure liquid bladders, pressure gauges , Automatic pressure maintaining water supply device.

Several sets of upper steel corbels and lower steel corbels are fixed on the underpinned pier by corbel shear bolts and steel plates with second-order teeth, and then tensioned by several sets of Hualan screws hooked on the anchor rings of the steel corbels. A lifting support column is fixed with cantilever bolts between each group of upper steel corbels and lower steel corbels. The lifting support column is composed of a steel spiral core barrel and a steel spiral sleeve. The two are nested together through a turnbuckle. The steel spiral The upper end plate of the core barrel is suspended on the lower flange of the upper steel corbel through the supporting suspension bolts. The lower part of the steel spiral sleeve is provided with a loading rod hole, which penetrates the loading rod and rotates the loading rod until it is tightened. It is easy to achieve height adjustment. Adjustment.

The upper steel corbel or the lower steel corbel is composed of an H-shaped steel with unequal length of the flange, a steel plate with second-order teeth, and a fabricated stiffener. The side of the steel plate with second-order teeth connected to the H-shaped steel is a vertical plane, and The contact surface is a toothed surface, with a first-order large tooth and several groups of second-order small teeth; there are reserved grooves on the upper and lower flanges on both sides of the web for installing stiffeners, and the outer side of the web is close to Several sets of anchor rings are welded on both sides of the edge from top to bottom.

The main function of the anchor ring is that when a group of steel corbels are assembled, the two can be connected by Hualan screws, and the Hualan screws can be tightened to apply prestress to the group of supporting corbels, thereby increasing the force of the steel corbels. time stability and reliability. The contact surface between the steel corbel and the underpinned pier has introduced the latest scientific research results, and the force transmission performance of the second-order tooth contact interface is better.

Helical nesting device to adjust the support height is a mature technology, but due to the existence of hydraulic jacks, it is rarely used in engineering sites. However, when a hydraulic jack is used as a temporary support, the equipment is affected by leakage and is prone to pressure drop. Moreover, synchronous starting of multiple jacks often requires the use of a PLC synchronous displacement control system.

In order to ensure that the steel corbel has a sufficient contact area with the column surface, the surface of the column pier is firstly ground on the upper and lower adjacent parts outside the excised area of the column pier. 2-3mm back cement mortar to ensure that the contact surface is dense, and the strength of the mortar is not lower than the concrete strength of the pier.

After the temporary support is tightened, the pier is cut; the matching high-pressure liquid bag is selected according to the size of the cut section, and installed in the space after the partial resection of the pier, and the periphery is basically the same as the outer edge line of the pier.

The liquid bag is set in the middle of the underpinned pier after cutting. The liquid bag is connected with the pressure gauge and the automatic pressure maintaining water supply device.

The prefabricated casing is composed of a set of L-shaped steel guard plate units, with upper and lower semicircular notches on both sides, and multiple rubber protrusions on the outside of the vertical plate from top to bottom, and the whole set of L-shaped steel guard plates Two units contact to form a closed casing, the inner diameter of which is 10-20mm larger than the diameter of the pier to be replaced, and the height extends upwards and downwards at the cutting area of the pier by no less than 50mm; No contact, the minimum gap is not less than 2mm, the upper part of the rubber convex is a ferrule, and the outer diameter of the figure surrounded by the rubber convex vertices of the same elevation is more than 2mm larger than the inner diameter of the ferrule.

The setting of the casing is mainly to avoid large deformation of the liquid bag around the periphery, resulting in failure to control the vertical displacement. The semicircular notch is a reserved pipeline opening, and two adjacent L-shaped guard plate units are spliced to form a round hole; the connecting pipe of the pressure-maintaining water supply equipment is connected to the liquid bag through this pipeline opening.

The size and shape of the casing unit shall take into account the cross-sectional shape of the pier. After the column is cut off, several hoops are inserted before the liquid bag is installed. After the airbag is restarted, the casing can be assembled. When assembling, first place the pre-installed ferrule and place the casing unit along the underpinned pier for a week, next to each other, and then put the placed ferrule under it. When it reaches the rubber protrusion, it encounters obstacles, and increases the downward sleeve. After the rubber convex is deformed, the hoop below can pass through the rubber convex of this layer. A ferrule is installed on the corresponding rubber convex upper part of each layer like this. Continue to squeeze the ferrule toward the rubber protrusion, and stop squeezing the ferrule when the ferrule feels tight.

Water filling pressure test: Install a displacement gauge with an accuracy of not less than 0.1mm between the upper and lower column ends, then fill the high-pressure liquid bladder with water and pressurize until the upper column end shows signs of upward movement, check for water leakage, pressure gauges, valves, etc. Whether the state is normal; after that, the pressure is relieved, and the pressure relief range is not less than 20% of the pressure test.

Weighing and pressure measurement: Unscrew the surrounding lifting support columns 4, the upper column has signs of sinking, and the maximum sinking is not more than 1mm; pressurize the liquid bladder to supply water, push the upper column end back to the original elevation, then this pressure is the water pressure. pressure to maintain the target value.

The construction method of pier assembly type automatic underpinning reset device is characterized in that the method is as follows:

1) Cutting lines are placed within the design height of the column pier underpinning, and the distance between the cutting lines matches the height of the liquid bag;

2) Grind the surface of the column pier at the upper and lower adjacent parts outside the excised area of the column pier, and the shape is basically consistent with the shape of the steel plate with second-order teeth in the steel corbel;

3) Apply cement mortar, and the mortar strength is not lower than the concrete strength of the pier;

4) Install the upper and lower steel corbels, fix them with expansion bolts or anchor bolts, and keep the lower surface level;

5) Install Hualan screws, tighten them, and assemble the upper and lower steel corbels into two underpinning platforms;

6) Install lifting support columns between each group of upper and lower steel corbels, and the upper end plate is suspended on the lower part of the upper steel corbel with suspension bolts, and insert the loading rods into the loading rod holes of the steel spiral sleeve one by one to adjust the height , until the top is tight;

7) Insert the static cutting wire saw through the gap of the support column to cut the column pier; after cutting, put the hoop with matching size, which can be temporarily fixed in the reserved section at the upper and lower ends of the column pier;

8) Select a liquid bladder that matches the size of the pier, place it in the area where the pier is removed, and then connect the pressure gauge, water supply and drainage valve, and pressure-maintaining water supply device;

9) Water filling pressure test: Install a displacement gauge with an accuracy of not less than 0.1mm between the upper and lower column ends, then fill the high-pressure liquid bladder with water and pressurize until the upper column end shows signs of upward movement, and check for water leakage, pressure gauges, and valves Wait until the working state is normal, and then release the pressure, and the pressure relief range is not less than 20% of the pressure test;

10) Weighing and pressure measurement: unscrew the surrounding lifting support columns, the upper column has signs of sinking, the maximum sinking is not more than 1mm, pressurize the liquid bag to supply water, push the upper column end back to the original elevation, then the pressure is The water pressure maintains the target value,

11) Casing installation: first place the pre-installed ferrules along the pier of the underpinned pier for a week, adjacent to each other. Large downward force of the hoop, after the rubber protrusion is deformed, the lower hoop can pass through the rubber protrusion of this layer, so that a hoop is installed on the upper part of each layer corresponding to the rubber protrusion; continue to squeeze the hoop to the rubber protrusion, and when the hoop Stop squeezing the ferrule when you feel tight;

12) Re-tighten all supports, and the equipment is in an automatic standby state.

There are also state settings for the lifting support column to adapt to two different working conditions, namely, the subsidence or shutdown condition of the underpinned column and the subsidence and uplift condition of the underpinned column.

1) During the subsidence of the underpinned column or the shutdown condition, the standby state of the lifting support column is to tighten the upper and lower steel corbels. When the column subsides, the water pressure measured by the pressure gauge decreases, and the pressure maintaining water supply device automatically adjusts the water supply to ensure that the upper column returns to the original elevation state, and then adjusts the lifting support columns one by one to make them stretch to the top tight state. 2) In the subsidence and uplift working condition of the underpinned column, the standby state of the lifting support column 4 is the unstressed state, and the lower end plate of the steel spiral sleeve is 1-2mm away from the top flange plate of the lower corbel.

The test data of the pressure gauge is archived in real time for future reference, and the monitoring personnel set up regular inspections of the pressure change records, with an interval of no more than 24 hours.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Anyone familiar with the technical field within the technical scope disclosed in the present invention, according to the technical scheme of the present invention and the novel Ideas plus equivalent replacements or changes shall fall within the protection scope of the present invention.

Claims (7)

1. An assembled automatic underpinning reset device for a column pier, comprising several sets of upper steel corbels and lower steel corbels, the upper steel corbels and lower steel corbels are connected to the underpinned column pier, and it is characterized in that each group A lifting support column is fixed with cantilever bolts between the upper steel corbel and the lower steel corbel; it also includes A liquid bag, the liquid bag is arranged in the middle of the underpinned pier after cutting, the liquid bag is connected with the pressure gauge and the automatic pressure maintaining water supply device, and the outer casing of the liquid bag is assembled into a whole with a casing constrained by a hoop. 2. An assembled automatic underpinning reset device for pier as claimed in claim 1, characterized in that said several groups of upper steel corbels and lower steel corbels are fixed by corbel shear bolts and steel plates with second-order teeth to the underpinned pier, and then tightened by several sets of Hualan screws hooked on the anchor rings of the steel corbels. 3. A pier assembly type automatic underpinning reset device as claimed in claim 1, characterized in that the upper steel corbel or the lower steel corbel is made of an H-shaped steel with unequal length of the flange and a steel plate with second-order teeth. 1. Composed of assembled stiffeners, the side of the connection between the steel plate with second-order teeth and the H-shaped steel is a vertical plane, and the contact surface with the column surface is a toothed surface, with a first-order large tooth and several groups of second-order small teeth; web There are reserved grooves on the upper and lower flanges on both sides to install stiffeners, and several groups of anchor rings are welded from top to bottom on the outer side of the web near the edge. 4. An assembly-type automatic underpinning reset device for pier as claimed in claim 1, characterized in that the lifting support column is composed of a steel spiral core barrel and a steel spiral sleeve, and the two are nested together by a turnbuckle , the upper end plate of the steel spiral core barrel is suspended on the lower flange of the upper steel corbel through support suspension bolts, and the lower part of the steel spiral sleeve is provided with a loading rod hole, which penetrates into the loading rod. 5. An assembled automatic underpinning reset device for pier as claimed in claim 1, characterized in that the assembled casing is composed of a group of L-shaped steel guard plate units, and both sides are equipped with upper and lower There are two semicircular gaps, and there are multiple rubber protrusions on the outer side of the riser from top to bottom. The whole set of L-shaped steel guard plate units are in contact with each other to form a closed casing. The upper part of the rubber protrusion is a ferrule. 6. A construction method employing an assembled automatic underpinning reset device for pier as claimed in any one of claims 1-5, characterized in that the method is as follows: 1) Cutting lines are placed within the design height of the column pier underpinning, and the distance between the cutting lines matches the height of the liquid bag; 2) Grind the surface of the column pier at the upper and lower adjacent parts outside the excised area of the column pier, and the shape is basically consistent with the shape of the steel plate with second-order teeth in the steel corbel; 3) Apply cement mortar, and the mortar strength is not lower than the concrete strength of the pier; 4) Install the upper and lower steel corbels, fix them with expansion bolts or anchor bolts, and keep the lower surface level; 5) Install Hualan screws, tighten them, and assemble the upper and lower steel corbels into two underpinning platforms; 6) Install lifting support columns between each group of upper and lower steel corbels, and the upper end plate is suspended on the lower part of the upper steel corbel with suspension bolts, and insert the loading rods into the loading rod holes of the steel spiral sleeve one by one to adjust the height , until the top is tight; 7) Insert the static cutting wire saw through the gap of the support column to cut the column pier; after cutting, put the hoop with matching size, which can be temporarily fixed in the reserved section at the upper and lower ends of the column pier; 8) Select a liquid bladder that matches the size of the pier, place it in the area where the pier is removed, and then connect the pressure gauge, water supply and drainage valve, and pressure-maintaining water supply device; 9) Water-filled pressure test: Install a displacement gauge between the upper and lower column ends, then fill the high-pressure liquid bag with water and pressurize until the upper column end shows signs of upward movement, and then release the pressure; 10) Weighing and pressure measurement: unscrew the surrounding lifting support columns, the upper column has signs of sinking, pressurize the liquid bladder to supply water, push the upper column end back to the original elevation, then this pressure is the water pressure maintenance target value, 11) Casing installation: first place the pre-installed ferrules along the pier of the underpinned pier for a week, adjacent to each other. Large downward force of the hoop, after the rubber protrusion is deformed, the lower hoop can pass through the rubber protrusion of this layer, so that a hoop is installed on the upper part of each layer corresponding to the rubber protrusion; continue to squeeze the hoop to the rubber protrusion, and when the hoop When you feel tight, stop squeezing the ferrule; 12) Re-tighten all supports, and the equipment is in an automatic standby state. 7. A construction method as claimed in claim 6, characterized in that the method also includes state adjustment of the lifting support column: 1) In the condition of subsidence or shutdown of the underpinned column, the standby state of the lifting support column is to tighten the upper and lower steel corbels. When the column subsides, the water pressure measured by the pressure gauge decreases, and the pressure maintaining water supply device automatically adjusts Supply water to ensure that the upper column returns to the original elevation state, and then adjust the lifting support column one by one to make it stretch to the top tight state; 2) In the condition of subsidence and uplift of the underpinned column, the standby state of the lifting support column is the unstressed state.