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CN-121976554-A - Open caisson structure and construction method thereof

CN121976554ACN 121976554 ACN121976554 ACN 121976554ACN-121976554-A

Abstract

The application provides a sunk well structure, which comprises a first section well wall and a height-connecting well wall which are connected in sequence along the vertical direction, wherein the first section well wall comprises a well shaft, a counter-force beam at the lower side of the well shaft and a blade foot at the lower side of the counter-force beam, the lower end of the well shaft is provided with an operation hole for accommodating a sinking mechanism, an axial hole is formed in the counter-force beam along the axial direction, an anchor rod of a pull-out-resistant anchor rod can freely pass through the axial hole upwards and then is connected to the sinking mechanism, and the sinking mechanism can provide counter force through an anchor rod body to push the first section well wall to move downwards relative to the anchor rod body so as to push the first section well wall to sink in an underground soil body. According to the application, a part of the first section of well wall is used as the counter-force beam, the sinking mechanism is arranged in the operation hole, the defect caused by frequent installation and dismantling of the counter-force beam when load is applied to the top of each well wall is avoided, and when the uppermost side of the well wall is sunk to the designed height-connecting position, the next section of well wall can be installed by only suspending sinking of the well wall, so that the construction efficiency is effectively improved.

Inventors

  • LI RENMIN
  • LIU XIAOBO

Assignees

  • 江苏东合南岩土科技股份有限公司

Dates

Publication Date
20260505
Application Date
20251226

Claims (10)

  1. 1. A sunk well structure is characterized by comprising at least two sections of well walls which are connected together in sequence along the vertical direction, wherein the well wall at the lowest side is called a first section of well wall, the rest of well walls are called a high-joint well wall, the first section of well wall comprises a well shaft, an annular counter-force beam formed at the lower side of the well shaft and a blade foot formed at the lower side of the counter-force beam, the outer wall of the counter-force beam radially outwards exceeds the outer wall of the well shaft when being observed along the axial direction of the first section of well wall, the outer wall of the counter-force beam radially outwards exceeds the outer wall of any high-joint well wall, an operation hole is formed at the lower end of the well shaft, a sinking mechanism is located in the operation hole, an axial hole is formed in the counter-force beam along the axial direction, an anchor body of an anti-pulling anchor rod can upwards freely penetrate through the axial hole and then is connected to a sinking mechanism, and the sinking mechanism can provide counter force through the anchor body to push the first section of well wall to downwards move relative to the anchor body, so that the first section of well wall is pushed to sink in an underground soil body.
  2. 2. The open caisson structure according to claim 1, wherein the open caisson structure is formed, An inner sleeve is lined in the axial hole, and the anchor rod body freely penetrates through the back of the inner sleeve and is connected to the sinking mechanism.
  3. 3. The open caisson structure according to claim 1, wherein the open caisson structure is formed, The well bore of the first section well wall is provided with a grouting pipe, the grouting pipe penetrates through the well bore along the radial direction, thixotropic slurry can be injected into a gap between the first section well wall and an external soil body through the grouting pipe, and cement mortar can be injected into the gap between the first section well wall and the soil body on the outer wall through the grouting pipe after all the well walls are submerged, so that the thixotropic slurry is replaced.
  4. 4. The open caisson structure according to claim 1, wherein the open caisson structure is formed, An outer baffle is mounted on the outer wall of the shaft and seals the outer end of the working hole.
  5. 5. The open caisson structure according to claim 1, wherein the open caisson structure is formed, The anchor rod body of the anti-pulling anchor rod is steel stranded wires or finish rolling threaded steel, when the anchor rod body is steel stranded wires, the sinking mechanism is a hollow hydraulic jack, and when the anchor rod body is finish rolling threaded steel, the sinking mechanism is a hollow hydraulic jack or finish rolling nut.
  6. 6. The open caisson structure according to claim 1, wherein the open caisson structure is formed, When the first section of well wall is sunk to a set depth, the anchor rod body is locked in the working hole through the lockset, and then is poured in the working hole through concrete or grouting materials.
  7. 7. A method of constructing an open caisson structure according to any one of claims 1-6, characterized in that it comprises the steps of: (1) Constructing an anti-pulling anchor rod at a set position of the ground, then installing a first section of well wall on the ground, enabling the upper end of the anchor rod body of the anti-pulling anchor rod to penetrate through the axial hole upwards and then extend into the operation hole, and installing a sinking mechanism on the anchor rod body; (2) The method comprises the steps of excavating earthwork of a foundation pit in a well, synchronously starting a sinking mechanism, enabling the sinking mechanism to downwards move along an anchor rod body, driving a first section of well wall to sink until the first section of well wall is sunk to a designed height-connecting position, suspending the sinking mechanism, and enabling the first section of well wall to suspend sinking; (3) The second section of well wall is arranged on the first section of well wall, the earth excavation of the foundation pit in the well is continuously carried out, the sinking mechanism is started, the first section of well wall is continuously sunk, the second section of well wall is synchronously driven to synchronously sink until reaching the designed height connection position again, the sinking mechanism is suspended, and the first section of well wall and the second section of well wall are temporarily sunk; (4) And (3) repeating the step until the sinking of the open caisson structure is completed.
  8. 8. The construction method according to claim 7, wherein, In the sinking process of the first section of well wall, thixotropic slurry is injected into a gap between the first section of well wall and an external underground soil body through a grouting pipe, and after the sinking of the whole open caisson structure is completed, cement mortar is injected to the outer side of the open caisson structure through the grouting pipe, so that the thixotropic slurry is replaced.
  9. 9. The construction method according to claim 7, wherein, The height of the cutting edge foot is 2.5-4 meters, in the sinking process of the first section of well wall, the bottom surface of the foundation pit in the well is higher than the lower end surface of the cutting edge foot, and the distance from the bottom surface of the foundation pit in the well to the lower end surface of the cutting edge foot is 20-50% of the height of the cutting edge foot until the first section of well wall is sunk to a set elevation, and then the foundation pit in the well is excavated to a set depth.
  10. 10. The construction method according to claim 7, wherein, The inner wall of the shaft or the counter-force beam is provided with a hydraulic station, a first hydraulic inlet pipe of the hydraulic station is communicated with a second hydraulic outlet pipe of the sinking mechanism, the first hydraulic outlet pipe of the hydraulic station is communicated with the second hydraulic inlet pipe of the sinking mechanism, and after the sinking of the whole sinking well structure is completed, the anchor rod body is locked in the operation hole through a lock, and the sinking mechanism and the hydraulic station are removed.

Description

Open caisson structure and construction method thereof Technical Field The invention belongs to the field of underground structure construction, and particularly relates to an open caisson structure and a construction method thereof. Background The open caisson construction method is a common underground deep foundation construction method and is widely applied to projects such as pump stations, bridge pier bases, shield working wells and the like. The open caisson mode only depends on two methods of open caisson dead weight and external counterforce, when sinking by the open caisson dead weight, after the earthwork at the bottom of the open caisson is excavated, the open caisson can overcome the side friction resistance of the well wall and the resistance at the lower end of the blade foot by the dead weight to sink, and in the sinking process, the attitude control of the open caisson is difficult, the open caisson is easy to suddenly sink or incline, and the open caisson is sensitive to geological conditions. The open caisson construction method with external counterforce is that under the action of external force, the open caisson is sunk in soil body, after the earthwork in the open caisson is excavated, the open caisson is sunk again, and the sinking of the open caisson and the excavation of the earthwork are alternately carried out until the sinking of the open caisson is completed. The additional counter force mode can directly place the weight at the top of the open caisson, and the weight of the weight and the dead weight of the open caisson are utilized to sink. In the open caisson construction method adopting external counterforce, the counterforce beam is required to be erected at the top of the uppermost shaft wall in each sinking of the open caisson, the counterforce beam is removed after the open caisson is sunk to a set height connection position, the next shaft wall can be installed, and after the installation of the next shaft wall is completed, the counterforce beam is required to be erected at the top of the newly installed shaft wall again, so that the construction process is complicated, and the construction efficiency is affected. Therefore, the construction method for sinking the open caisson is improved to improve the construction efficiency of the open caisson, and the open caisson construction is still a problem. Disclosure of Invention In order to improve the construction efficiency of the open caisson, the application firstly provides an open caisson structure, which comprises at least two sections of well walls which are connected together in sequence along the vertical direction, wherein the well wall at the lowest side is called a head well wall, the rest well walls are called a high well wall, the head well wall comprises a well shaft, an annular counter-force beam formed at the lower side of the well shaft and a blade foot formed at the lower side of the counter-force beam, the outer wall of the counter-force beam extends outwards beyond the outer wall of the well shaft along the axial direction of the head well wall in a radial direction, the outer wall of the counter-force beam extends outwards beyond the outer wall of any high well wall in a radial direction, an operation hole is formed at the lower end of the well shaft, a sinking mechanism is positioned in the operation hole, an axial hole is formed in the counter-force beam along the axial direction, an anchor rod of an anti-pulling anchor rod can freely pass through the axial hole upwards and then be connected to the sinking mechanism, and the sinking mechanism can provide counter force through the anchor rod body to push the head well wall to move downwards relative to the anchor rod body, so that the head well wall is pushed to sink in an underground soil body. In the radial direction, the outer wall of the counterforce beam extends outwards by 0.25-0.5m compared with the outer wall of the shaft. In the application, the operation hole is arranged in the well wall of the first-section well wall, the anchor rod body of the anchor rod is connected to the sinking mechanism arranged in the operation hole, the sinking mechanism and the anchor rod are utilized to drive the first-section well wall to sink, and the outer wall of the counter-force beam radially outwards exceeds the outer wall of the well shaft, so that an upward step surface is formed between the counter-force beam and the outer wall of the well shaft, thereby reducing the friction force between the underground soil body and the rest of the well wall, and enabling the enterprise well wall to sink synchronously with the first-section well wall under the self-weight operation. Because the part of the first section of well wall is used as the counter-force beam, and the sinking mechanism is arranged in the operation hole, the defect caused by frequent installation and dismantling of the counter-force beam when the load is applied to the top of each well wall is