CN101761237B - Method for constructing isolation pile for shield tunnel to go through deformation control of buildings and structures at short distance - Google Patents

Abstract

The invention relates to an isolation pile construction method, in particular to an isolation pile construction method used for shield tunnel passing through historical ancient building deformation control at short distance, which is characterized in that it adopts casing type In the pile sinking and hole-forming step, the outer casing and the auger drill pipe located in the outer casing are sunk in the forward and reverse drilling mode with the full-rotary casing machine, wherein the outer casing rotates in the opposite direction and the auger Rotate to take out the soil in the outer casing, and use the outer casing to protect the wall, and assist the cement slurry and water glass double grout grouting between the piles, effectively control the settlement caused by the isolation pile construction process, and control the shield passing through the historical ancient buildings at close range The surface subsidence of time, and then protect the structural safety of historical buildings.

Description

Construction method of isolated piles for deformation control of shield tunnel passing through buildings at close range

technical field

The invention relates to a construction method of an isolation pile, in particular to an isolation pile construction method for controlling the settlement of a building when the shield tunnel passes through the building at a 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 at short distances to control deformation, improve the settlement problems caused by existing isolation pile construction methods, and cannot meet and protect historical ancient buildings with strict settlement requirements. building.

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 construction method of the isolated pile for the deformation control of the shield tunnel passing through the building in a short distance 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 shield tunnel passing through building deformation control at short distances as described above, 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 , the outer casing forms the retaining wall and assists the grouting of cement slurry and water glass.

In the isolation pile construction method for the shield tunnel passing through the deformation control of the building at a short distance as described above, in the step of sinking the pile and forming the hole, the full-rotation casing machine moves the center of the outer casing to the center of the pile to align the center of the outer casing with the full-turn After the verticality gauge of the casing machine adjusts the verticality of the outer casing, check the coincidence degree between the center of the outer casing and the center of the pile position again.

The above-mentioned isolation pile construction method for the shield tunnel passing through the building deformation control at a short distance is to pour a reinforced concrete force transmission platform with a thickness greater than 20 cm 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 at close range as described above, 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.

In the construction method of isolation piles for the shield tunnel passing through the building deformation control at short distances as described above, in the step of pouring concrete, a storage hopper is used for loading operations, and 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 concrete poured for the first time.

In the isolation pile construction method for the deformation control of the shield tunnel passing through the building at a short distance 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 the isolation of the deformation control of the building at a short distance The pile construction method can control the settlement when the shield tunnel passes through the ancient buildings at close range, and at the same time protect the safety of the ancient buildings, and for the unique soil layer of Shanghai, the shield tunnel passes through the historical buildings under harsh environmental conditions. The deformation control of the group is very effective.

Description of drawings

Fig. 1 is a flow diagram of a specific embodiment of the isolation pile construction method of the shield tunnel passing through the building deformation control at a short distance 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 deformation control of the shield tunnel passing through the building at a short distance provided by the present invention. The isolation pile construction method for the deformation control of the shield tunnel passing through the building at a short distance is used When the shield tunnel passes through at a short distance, the settlement is controlled to protect the historical buildings. The implementation steps of the isolation pile construction method of the shield tunnel passing through the building deformation control at a short distance include: pouring a reinforced concrete force transmission platform, and continuing to sink the pile to form a hole steps, and install reinforcement cages and pour concrete, performing auxiliary grouting measures.

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

In summary, in the isolation pile construction method for the shield tunnel passing through the deformation control of the building at a short distance in the present invention, the pile sinking method in which the outer sleeve and the auger rod rotate in the opposite direction is adopted, and the auger rod is used to rotate the soil and pass through the outer sleeve. The soil discharge hole on the top is discharged, and the outer casing and the auger pipe can be drilled to the pile bottom level synchronously. Among them, the way of rotating the soil can reduce the noise during the construction process and avoid the impact on the soil. In addition, the outer casing is used in the construction During the process, it can provide wall protection and isolate the disturbance of the surrounding soil during the construction process. At the same time, it can produce obvious outward extrusion, which reduces the loss of soil. It can also assist cement slurry and water glass grouting to achieve effective control and isolation. The settlement during the pile construction process can be isolated at the same time, and the settlement influence during the shield construction process can be isolated, so the isolation pile construction method of the present invention can control the deformation of the shield tunnel passing through the building at a short distance. Settlement, to protect the structural safety of ancient buildings, especially for Shanghai's unique soil.

Claims (6)

1. A shield tunnel passes through a construction method of isolated piles for deformation control of buildings at short distances, which is used to control settlement to protect historic buildings when passing through short distances in shield tunneling. It is characterized in that 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 center of the pile position 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.