CN101761237A - Method for constructing isolation pile for shield tunnel to go through deformation control of buildings and structures at short distance - Google Patents

Abstract

The present invention relates to a construction method of isolation piles, especially to a construction method of isolation piles used for the deformation control of shield tunnels passing through buildings (structures) at short distances for the deformation control of shield tunnels passing through historical buildings at short distances. Using casing-type pile sinking to form holes, the outer casing and the auger drill pipe located in the outer casing are respectively sunk in the drilling method of forward and reverse rotation with a full-rotary casing machine, wherein the outer casing rotates in the opposite direction, The auger drill pipe rotates forward to take out the soil in the outer casing, and the outer casing acts as a wall protection, and assists the grouting between the cement slurry and the water glass double grout pile, effectively controlling the settlement caused by the construction of the isolation pile, and controlling the close distance of the shield. Through the surface settlement of historical ancient buildings, the structural safety of historical ancient buildings can be protected.

Description

Construction method of isolated piles for deformation control of shield tunnel passing through buildings (structures) in short distance

technical field

The invention relates to an isolation pile construction method, in particular to an isolation pile construction method for controlling the settlement of buildings when the shield tunnel passes through the building (structure) at short distance.

Background technique

Due to the complexity of shield tunneling construction technology, the surface settlement of the soil layer above the shield cannot be completely eliminated at present. Especially for historical buildings with high historical value, weak foundation and extremely fragile structure near the shield tunnel construction site, the settlement effect caused by shield tunnel construction will deeply damage the structure of historical ancient buildings. Advanced airtight shield technology still cannot completely eliminate surface subsidence.

At present, most of the simple construction and low cost mixing isolation piles and ordinary cast-in-situ piles are used to block the disturbance of the foundation of historical ancient buildings when the shield tunnel passes through in a short distance by means of isolation, and reduce surface settlement to protect ancient buildings. Structure.

The Chinese patent with the application number 200610029159.1 "Construction Method of Isolation Pile for Key Building Protection" discloses a kind of isolation row pile that can form a wall, and can provide water isolation, effectively protect key buildings, and passed Before the construction of the project on the side of the key protected building, the deep mixing pile is used to reinforce the soil as an isolated retaining wall to solve the loss of groundwater on the side adjacent to the key protected building.

Another Chinese patent application No. 200610116618.X "Construction method for double-circle shield passing through buildings or structures at short distances" discloses a construction protection technology when shields pass through buildings or structures at short distances. The method of setting ordinary isolation piles and controlling the construction technical parameters of the shield tunnel can reduce the impact on adjacent buildings, but the specific construction method of the isolation piles has not been disclosed.

Both of the above two construction methods reduce the impact on adjacent buildings during the construction of the control project, but they do not fully consider the impact or risk on adjacent buildings during the construction of the isolation pile itself.

In fact, for the construction of ordinary isolated piles, for historical buildings with strict settlement requirements, there are factors such as high filling rate of concrete pouring (there is a risk of hole collapse in the process), large disturbance to the soil during construction, and low strength. It will cause large land subsidence and endanger the structural safety of important historical buildings.

Contents of the invention

The technical problem to be solved by the present invention is to provide a construction method of isolation piles for shield tunnels to pass through buildings (structures) in a short distance to control the deformation, improve the settlement problem caused by the existing isolation pile construction methods, which cannot meet and protect the settlement requirements Harsh historic buildings.

The technical solution of the present invention is: it is used to control the settlement to protect historical ancient buildings when the shield tunnel passes through in a short distance, and it is characterized in that the shield tunnel passes through the isolation of the deformation control of the building (structure) in a short distance. The pile construction method includes the following steps:

Pour reinforced concrete force transmission platform, pour a layer of reinforced concrete force transmission platform according to the construction work surface, and reserve a perforation hole with a diameter larger than the diameter of the isolation pile at the pile position to be drilled;

In the pile drilling step, a full-rotary casing machine is used to respectively sink an outer casing and an auger drill rod inside the outer casing into the pile position. The rotation direction of the outer casing is opposite to that of the auger rod, and additional Connect the outer casing and the auger pipe until the design elevation is reached, then lift the auger pipe, take out the remaining soil in the outer casing, and remove the virtual soil in the outer casing to ensure that the soil at the bottom of the isolation pile is the original soil layer;

To install the reinforcement cage, slowly lift the reinforcement cage manufactured according to the design requirements with two-point double hooks, gradually lower the point and adjust the orientation of the reinforcement cage, and tie a measuring rope before the reinforcement cage is in place to monitor whether the reinforcement cage is floating;

Concrete is poured, and the first concrete pouring is carried out after the concrete pipe is placed. After the first concrete drop is completed, the pipe pulling machine is used to pull the pipe, and check whether the outer pipe is pulled out smoothly and whether the steel cage is floating. After the outer casing is completely pulled out, supplementary irrigation shall be carried out as required, and the concrete conduit shall be removed after the filling is completed; and auxiliary grouting measures shall be taken to complete the grouting hole forming operation between the isolation piles before the shield tunneling. According to the shield tunneling The monitoring situation during the propulsion process is followed by grouting.

In the isolation pile construction method for the shield tunnel passing through the deformation control of the building (structure) at a short distance as described above, the outer casing rotates in the opposite direction, the auger rod rotates forward and takes out the soil in the outer casing, so that the soil is removed from the outer casing. The soil discharge hole is discharged, and the outer casing forms a retaining wall and assists the grouting of cement slurry and water glass.

In the isolation pile construction method for shield tunnel passing through buildings (structures) at short distances to control deformation as described above, in the step of sinking piles to form holes, the full-rotary casing machine is moved to align the center of the outer casing with the center of the pile position , after adjusting the verticality of the outer casing with the vertical instrument of the full-turn casing machine, check the coincidence degree between the center of the outer casing and the pile as the center again.

The above-mentioned isolation pile construction method for shield tunnel passing through buildings (structures) at short distances for deformation control is to pour a reinforced concrete force transmission platform with a thickness greater than 20 centimeters in the pouring of the reinforced concrete force transmission platform.

In the isolation pile construction method for the deformation control of the shield tunnel passing through the building (structure) at short distances as described above, in the step of installing the reinforcement cage, the reinforcement cage is provided with positioning rollers, and the bottom of the reinforcement cage is provided with a horizontal anti-floating steel plate.

As mentioned above, the construction method of isolation piles for shield tunnel passing through buildings (structures) at short distances to control the deformation, in the step of pouring concrete, the loading operation is carried out with a storage hopper, and the plug of the storage hopper is made of a circular steel plate and thin Wire rope suspension, and the amount of the first feeding is greater than the amount of concrete poured for the first time.

The isolation pile construction method for the shield tunnel passing through the building (structure) at a short distance to control the deformation as described above, in the isolation pile construction method, the hole forming sequence of the isolation pile adopts the method of jumping and opening holes.

The advantages of the present invention are: in the pile sinking hole forming step, a special casing method is adopted, that is, the rotation direction of the outer casing and the auger rod is opposite, and the pile sinking method in which the auger rod rotates to take soil, so that the outer casing and the auger The rods are drilled synchronously to the pile bottom elevation, and the method of rotating the soil can reduce the noise during the construction process and avoid the impact on the soil. Among them, the outer casing can provide the function of protecting the wall and isolate the disturbance of the surrounding soil during the construction process. It has an obvious outward extrusion effect to reduce soil loss, further assists cement slurry and water glass grouting, and effectively controls the settlement during the construction of the isolation pile. Therefore, the shield tunnel of the present invention passes through buildings (structures) at close distances. The construction method of isolation piles with deformation control can control the settlement of shield tunnels when they pass through ancient buildings at close range, and at the same time protect the safety of ancient buildings. , which is very effective for deformation control of historical buildings.

Description of drawings

Fig. 1 is a schematic flow chart of a specific embodiment of the isolation pile construction method for shield tunnel passing through buildings (structures) for deformation control at short distances according to the present invention.

Detailed ways

As shown in Figure 1, it discloses a schematic flow chart of the isolation pile construction method for the shield tunnel passing through the deformation control of the building (structure) at a short distance provided by the present invention. The isolation pile construction method is used to control the settlement to protect historical buildings when the shield tunnel passes through at a short distance. The implementation steps of the isolation pile construction method for the shield tunnel passing through the building (structure) deformation control at a short distance include: The reinforced concrete force transmission platform is poured, followed by the pile sinking to form the hole, and the reinforcement cage is installed and the concrete is poured, and the auxiliary grouting measures are carried out.

In the step of pouring the reinforced concrete force transmission platform, according to the actual construction work surface, pour a layer of reinforced concrete force transmission platform with a thickness greater than 20 cm, and reserve on the reinforced concrete force transmission platform at the pile position to be drilled. A perforation with a diameter larger than the diameter of the isolation pile, wherein the diameter of the perforation is 2 cm larger than the diameter of the isolation pile. The reinforced concrete force transmission platform forms a guide wall and can ensure the verticality of the subsequent hole formation.

In the step of sinking piles to form holes, move a full-rotary casing machine so that the center of the outer casing on the full-rotary casing machine is aligned with the center of the pile position, and adjust the outer casing with the vertical instrument of the full-rotary casing machine After the verticality, check the coincidence degree of the center of the outer casing and the pile as the center again, and then use the full-rotary casing machine to respectively sink the outer casing and the auger pipe in the outer casing in a rotating manner, and the outer casing and the auger The rotation direction of the drill pipe is opposite, and the outer casing and the auger pipe are connected according to the design requirements, and the auger pipe is lifted up to the design elevation, and the remaining soil in the outer casing is brought out, and the virtual soil in the outer casing is removed to ensure that the isolation pile The soil at the bottom is the original soil layer, in which the outer casing rotates in reverse, the auger rod rotates forward and takes out the soil in the outer casing, so that the soil is discharged from the soil discharge hole on the outer casing, and the outer casing forms a retaining wall and assists the cement slurry Grouting with water glass, in addition, the soil level inside the outer casing is always 3-5 meters higher than the bottom elevation of the outer casing to prevent piping, and according to geological conditions, the depth of the outer casing can be 1 meter deeper than the actual pile to prevent Soil piping occurs, and real-time monitoring is required during construction to determine whether the type of soil layer is consistent with the geological data.

In the step of installing the reinforcement cage, the manufacture of the reinforcement cage is in accordance with the design requirements. There are positioning rollers around the reinforcement cage, and a horizontal anti-floating steel plate at the bottom of the reinforcement cage. The completed reinforcement cage will be hoisted slowly with two-point double hooks. Gradually lower the reinforcement cage to prevent deformation of the reinforcement cage. During the lowering process, gradually adjust the direction of the reinforcement cage, and tie the measuring rope before the reinforcement cage is in place, so as to ensure the accurate positioning of the reinforcement cage and monitor whether the reinforcement cage is floating.

In the step of pouring concrete, the first concrete pouring is carried out after the concrete pipe is placed, and the pipe pulling operation is carried out after the first concrete drop is completed. Whether it is floating or not, when the steel cage is floating, it will carry out back pressure treatment, and the lifting amount will be controlled at 10-20 cm. In the step of concrete, a storage hopper is used for feeding operations, the plug of the storage hopper is made of a circular steel plate and suspended by a thin steel wire rope, and the amount of the first feeding is greater than the amount of the first poured concrete.

In the step of auxiliary grouting measures, the grouting holes between the isolation piles are completed before the shield tunneling, and the tracking grouting is carried out according to the monitoring situation during the shield tunneling.

In the isolation pile construction method of the shield tunnel passing through the deformation control of the building (structure) at a short distance of the present invention, the hole forming sequence of the isolation pile adopts the method of jumping out of the hole, for example, the construction pile number sequence of the hole forming sequence is 1- 7-12..., the adjacent construction pile number 2-8-13... will be constructed after the strength reaches a certain level.

In summary, in the isolation pile construction method of the shield tunnel passing through the deformation control of the building (structure) at a short distance, the pile sinking method in which the outer sleeve and the auger rod are rotated in the opposite direction is adopted, and the auger rod is rotated to take soil And it is discharged through the drainage hole on the outer casing, and the outer casing and the auger pipe can be drilled to the pile bottom level synchronously. Among them, the method of rotating soil can reduce the noise during construction and avoid the impact on the soil. In addition, During the construction process, the outer casing can provide wall protection, isolate the disturbance of the surrounding soil during the construction process, and at the same time produce an obvious outward extrusion effect, which reduces the loss of soil, and can also assist cement slurry and water glass grouting, To effectively control the settlement during the construction of the isolation pile, and at the same time isolate the influence of settlement during the construction of the shield tunnel, so the isolation pile construction method of the present invention can control the deformation of the shield tunnel passing through the building (structure) at a short distance. Settlement when passing through ancient buildings at close range during construction, to protect the structural safety of ancient buildings, especially suitable for Shanghai's unique soil layers.

Claims (7)

1. A shield tunnel passes through an isolation pile construction method for the deformation control of buildings (structures) at short distances, it is used for shield tunneling when passing at short distances, and controls settlement to protect historic buildings. It is characterized in that the The method includes the following steps: Pour reinforced concrete force transmission platform, pour a layer of reinforced concrete force transmission platform according to the construction work surface, and reserve a perforation hole with a diameter larger than the diameter of the isolation pile at the pile position to be drilled; In the pile drilling step, a full-rotary casing machine is used to respectively sink an outer casing and an auger drill rod inside the outer casing into the pile position. The rotation direction of the outer casing is opposite to that of the auger rod, and additional Connect the outer casing and the auger pipe until the design elevation is reached, then lift the auger pipe, take out the remaining soil in the outer casing, and remove the virtual soil in the outer casing to ensure that the soil at the bottom of the isolation pile is the original soil layer; To install the reinforcement cage, slowly lift the reinforcement cage manufactured according to the design requirements with two-point double hooks, gradually lower the point and adjust the orientation of the reinforcement cage, and tie a measuring rope before the reinforcement cage is in place to monitor whether the reinforcement cage is floating; Concrete is poured, and the first concrete pouring is carried out after the concrete pipe is placed. After the first concrete drop is completed, the pipe pulling machine is used to pull the pipe, and check whether the outer pipe is pulled out smoothly and whether the steel cage is floating. After the outer casing is completely pulled out, supplementary irrigation will be carried out as required, and the concrete conduit will be removed after the irrigation is completed; and Auxiliary grouting measures, complete the grouting hole forming operation between the isolated piles before the shield tunneling, and track the grouting according to the monitoring situation during the shield tunneling. 2. The method according to claim 1, characterized in that: the outer casing rotates in reverse, the auger rod rotates forward and takes out the soil in the outer casing, so that the soil is discharged from the soil discharge hole on the outer casing, and the outer casing forms a retaining wall And auxiliary cement slurry and water glass grouting. 3. The method according to claim 1 or 2, characterized in that: in the step of sinking piles and forming holes, the full-rotary casing machine moves the center of the outer casing to align with the center of the pile position, and the full-rotary casing machine After adjusting the verticality of the outer casing with the vertical instrument, check the coincidence degree between the center of the outer casing and the pile as the center again. 4. The method according to claim 3, characterized in that: in pouring the reinforced concrete force transmission platform, the reinforced concrete force transmission platform with a thickness greater than 20 cm is poured. 5. The method according to claim 4, characterized in that: in the step of installing the reinforcement cage, positioning rollers are provided on the reinforcement cage, and a horizontal anti-floating steel plate is provided at the bottom of the reinforcement cage. 6. The method according to claim 5, characterized in that: in the step of pouring concrete, the loading operation is carried out with a storage hopper, the plug of the storage hopper adopts a circular steel plate and is suspended with a thin steel wire rope, and the first loading The amount is greater than the amount of concrete poured for the first time. 7. The method according to claim 6, characterized in that: in the construction method, the hole forming sequence of the isolation piles adopts the method of jumping and opening holes.

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