Rectangular working well with preset pipe jacking hole and sliding back wall in water-rich stratum and construction method thereof

Abstract

A construction method of a rectangular working well includes steps of: (I) designing functional requirements for the rectangular working well; (II) constructing a caisson of an enclosing structure of the rectangular working well; (III) constructing an edge protector; (IV) excavating earthwork of the rectangular working well; (V) forming a back cover for the rectangular working well, and pre-embedding a sliding track, a pull ring and a back wall anchor; (VI) installing a ladder for entering the rectangular working well; (VII) preventing joint leakage; (VIII) installing a water-proof pressure plate at an entrance of the preset pipe jacking hole; (IX) constructing the sliding back wall; (X) lifting the sandwich concrete slab wall at a top of the preset pipe jacking hole; and (XI) performing pipe jacking. The structure system constructed by the present invention has many advantages such as clear function, safety, quickness, and flexible design.

Claims

1. A construction method of a rectangular working well with a preset pipe jacking hole and a sliding back wall in a water-rich stratum, comprising steps of: (I) designing functional requirements for the rectangular working well, comprising steps of: (1) collecting relevant data to determine a plane size, a depth, and a treatment method of a working well back cover, so as to satisfy well operation requirements; (2) determining a height and a diameter of the preset pipe jacking hole according to a position, a diameter, a material and a connection method of a proposed pipeline, wherein a quantity of the preset pip jacking hole is at least one; and (3) calculating and drawing a structure of the rectangular working well: using comparative calculation analysis of a rod system element method and numerical simulation to obtain an optimal supporting structure composition of the rectangular working well, and then drawing to complete functional requirement design for the rectangular working well; (II) constructing a caisson of an enclosing structure of the rectangular working well, comprising steps of: (1) preparing before construction of the caisson: comprising site leveling, laying out, excavating earth of a first layer, compacting a foundation, leveling and laying out, inspecting lines, laying a sand cushion, forming cutting edge formwork, binding steel bars, forming well body formwork, pouring concrete, curing, and demoulding; (2) constructing the caisson by sections: comprising preparing, installing a vertical transportation machinery and drainage pumps, observing, correcting, sinking to a designed elevation by sections, and verifying the elevation; (3) setting a thin-walled plain concrete cavity along a vertical axis where the preset pipe jacking hole is located during pouring the caisson by sections, and inserting a sandwich concrete slab wall into the thin-walled plain concrete cavity; and (4) using reinforced concrete or steel members as a material of the enclosing structure of the rectangular working well, and performing anticorrosive measures; (III) constructing an edge protector: setting embedded parts during construction the caisson of the enclosing structure of the rectangular working well, and connecting the edge protector and the embedded parts by bolts; (IV) excavating earthwork of the rectangular working well: during construction of the caisson, directly excavating the earthwork above water, and excavating the earthwork below the water by high-pressure water gun loosening, hydraulic grabbing or reverse circulation pumping; (V) forming a back cover for the rectangular working well, and pre-embedding a sliding track, a pull ring and a back wall anchor: in order to meet needs of subsequent construction, using concrete to treat the back cover of the rectangular working well; using plain concrete for anti-floating stability before connecting a caisson wall with reinforced concrete; simultaneously pre-embedding the sliding track, the pull ring and the back wall anchor during pouring the reinforced concrete back cover; (VI) installing a ladder for entering the rectangular working well: according to needs of subsequent maintenance, designing the ladder which is installed on an internal wall of the rectangular working well by planting bars; (VII) preventing joint leakage: using a polymer material for leakage control at joints of the rectangular working well and side walls of the caisson of the enclosing structure; (VIII) installing a water-proof pressure plate at an entrance of the preset pipe jacking hole: fixing the water-proof pressure plate at the entrance through expansion bolts according to a position of the preset pipe jacking hole; (IX) constructing the sliding back wall: according to a calculation result of a pipe jacking thrust, hoisting a prefabricated back wall, and fixing the back wall by the back wall anchor; installing a pull rod between the back wall anchor and the pull ring; for different pipe jacking positions, adjusting a position of the sliding back wall through the pull rod and starting pipe jacking again after fixing; (X) lifting the sandwich concrete slab wall at a top of the preset pipe jacking hole: lifting the sandwich concrete slab wall to form the thin-walled plain concrete cavity at the preset pipe jacking hole, so as to reduce a resistance when a pipe jacking machinery passes through the preset pipe jacking hole; and (XI) performing pipe jacking: after the pipe jacking machinery is installed in place, continuously passing through the thin-walled plain concrete cavity at the preset pipe jacking hole under a hydraulic jacking thrust for normal pipe jacking construction.

2. A rectangular working well with a preset pipe jacking hole and a sliding back wall in a water-rich stratum, comprising: the rectangular working well (1), wherein an enclosing structure of the rectangular working well (1) is a caisson (4), a back cover (2) is provided at a bottom of the rectangular working well (1), and the preset jacking hole (3) is provided inside the rectangular working well (1) and near the bottom; the sliding back wall (14) is provided opposite to the preset jacking hole (3), a thin-walled plain concrete cavity (16) is provided in the caisson (4) along a vertical axis of the preset jacking hole (3), and a sandwich concrete panel wall (5) is inserted into the thin-walled plain concrete cavity (16).

3. The rectangular working well, as recited in claim 2, wherein a water-proof pressure plate (13) is fixed at an entrance of the preset pipe jacking hole (3) by expansion bolts.

4. The rectangular working well, as recited in claim 2, wherein a pipe jacking machinery (17) is provided in the rectangular working well (1); the pipe jacking machinery (17) is docked with a pipe jacking (18) in a thrust direction, and the pipe jacking machinery (17) pushes the pipe jacking (18) toward the preset pipe jacking hole (3).

5. The rectangular working well, as recited in claim 2, wherein a polymer material (12) is used for leakage control at joints between the back cover (2) and the caisson (4) as well as joints at side walls of the caisson (4).

6. The rectangular working well, as recited in claim 2, wherein a connector is pre-embedded on the caisson (4); an edge protector (6) is connected to a top end of the caisson (4), and the edge protector (6) is connected to the pre-embedded connector by bolts.

7. The rectangular working well, as recited in claim 2, wherein a ladder (11) is installed on an internal wall of the rectangular working well (1) through planting bars.

8. The rectangular working well, as recited in claim 2, wherein a sliding track (8) and a pull ring (9) are pre-embedded on the back cover (2); the sliding back wall (14) cooperates with the sliding track (8); the sliding back wall (14) is connected to a pull rod (15) through an anchor (10), and an end portion of the pull rod (15) is connected to the pull ring (9).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG. 1 is a perspective view of the present invention;

[0040] FIG. 2 is a functional structure view of a rectangular working well according to the present invention;

[0041] FIG. 3 is a plan layout of the rectangular working well according to the present invention;

[0042] FIG. 4 is a structural view of a caisson and a sandwich concrete slab wall according to the present invention;

[0043] FIG. 5 is a sectional structure view of the rectangular working well according to the present invention.

[0044] FIG. 6 is an enlarged view of a caisson structure of the present invention;

[0045] FIG. 7 is a structure view of a water-proof pressure plate according to the present invention;

[0046] FIG. 8 is a structure view of a sliding track of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0047] A construction method of a rectangular working well with a preset pipe jacking hole and a sliding back wall in a water-rich stratum, comprising steps of: first designing functional requirements for the rectangular working well; constructing a maintenance structure and a temporary protector in sequence; excavating earthwork of the rectangular working well; forming a back cover for the rectangular working well, and pre-embedding a sliding track, a pull ring and a back wall anchor; installing a ladder for entering the rectangular working well; preventing joint leakage; installing a water-proof pressure plate at an entrance of the preset pipe jacking hole; constructing the sliding back wall; then using a hydraulic jacking thrust of pipe jacking equipment to penetrate a thin-walled plain concrete cavity formed by lifting a sandwich concrete slab wall to safely perform pipe jacking, thereby complete construction of the rectangular working well with the preset pipe jacking hole and the sliding back wall in a water-rich stratum. Specifically, the construction method comprises steps of:

[0048] (I) designing functional requirements for the rectangular working well, comprising steps of:

[0049] (1) collecting relevant data to determine a plane size, a depth, and a treatment method of a working well back cover, so as to satisfy well operation requirements;

[0050] (2) determining a height and a diameter of the preset pipe jacking hole according to a position, a diameter, a material and a connection method of a proposed pipeline, wherein a quantity of the preset pip jacking hole is at least one; and

[0051] (3) calculating and drawing a structure of the rectangular working well: using comparative calculation analysis of a rod system element method and numerical simulation to obtain an optimal supporting structure composition of the rectangular working well, and then drawing to complete functional requirement design for the rectangular working well;

[0052] (II) constructing a caisson of an enclosing structure of the rectangular working well, comprising steps of:

[0053] (1) preparing before construction of the caisson: comprising site leveling, laying out, excavating earth of a first layer, compacting a foundation, leveling and laying out, inspecting lines, laying a sand cushion, forming cutting edge formwork, binding steel bars, forming well body formwork, pouring concrete, curing, and demoulding;

[0054] (2) constructing the caisson by sections: comprising preparing, installing a vertical transportation machinery and drainage pumps, observing, correcting, sinking to a designed elevation by sections, and verifying the elevation;

[0055] (3) setting a thin-walled plain concrete cavity along a vertical axis where the preset pipe jacking hole is located during pouring the caisson by sections, and inserting a sandwich concrete slab wall into the thin-walled plain concrete cavity; and

[0056] (4) using reinforced concrete or steel members as a material of the enclosing structure of the rectangular working well, and performing anticorrosive measures;

[0057] (III) constructing an edge protector: setting embedded parts during construction the caisson of the enclosing structure of the rectangular working well, and connecting the edge protector and the embedded parts by bolts;

[0058] (IV) excavating earthwork of the rectangular working well: during construction of the caisson, directly excavating the earthwork above water, and excavating the earthwork below the water by high-pressure water gun loosening, hydraulic grabbing or reverse circulation pumping;

[0059] (V) forming a back cover for the rectangular working well, and pre-embedding a sliding track, a pull ring and a back wall anchor: in order to meet needs of subsequent construction, using concrete to treat the back cover of the rectangular working well; using plain concrete for anti-floating stability before connecting a caisson wall with reinforced concrete; simultaneously pre-embedding the sliding track, the pull ring and the back wall anchor during pouring the reinforced concrete back cover;

[0060] (VI) installing a ladder for entering the rectangular working well: according to needs of subsequent maintenance, designing the ladder which is installed on an internal wall of the rectangular working well by planting bars;

[0061] (VII) preventing joint leakage: using a polymer material for leakage control at joints of the rectangular working well and side walls of the caisson of the enclosing structure;

[0062] (VIII) installing a water-proof pressure plate at an entrance of the preset pipe jacking hole: fixing the water-proof pressure plate at the entrance through expansion bolts according to a position of the preset pipe jacking hole;

[0063] (IX) constructing the sliding back wall: according to a calculation result of a pipe jacking thrust, hoisting a prefabricated back wall, and fixing the back wall by the back wall anchor; installing a pull rod between the back wall anchor and the pull ring; for different pipe jacking positions, adjusting a position of the sliding back wall through the pull rod and starting pipe jacking again after fixing;

[0064] (X) lifting the sandwich concrete slab wall at a top of the preset pipe jacking hole: lifting the sandwich concrete slab wall to form the thin-walled plain concrete cavity at the preset pipe jacking hole, so as to reduce a resistance when a pipe jacking machinery passes through the preset pipe jacking hole; and

[0065] (XI) performing pipe jacking: after the pipe jacking machinery is installed in place, continuously passing through the thin-walled plain concrete cavity at the preset pipe jacking hole under a hydraulic jacking thrust for normal pipe jacking construction.

[0066] Mechanical requirements of two construction processes are both considered, and forces and structural functions of excavation support and pipe jacking calculated construction are considered simultaneously to avoid conflicts between excavation support and pipe jacking during construction.

[0067] A rectangular working well with a preset pipe jacking hole and a sliding back wall in a water-rich stratum comprises: the rectangular working well 1, wherein an enclosing structure of the rectangular working well 1 is a caisson 4, wherein a material of the enclosing structure is generally reinforced concrete. When steel members are used as the enclosing structure of the rectangular working well, anticorrosive measures should be taken in the water-rich stratum. A back cover 2 is provided at a bottom of the rectangular working well 1, and the preset jacking hole 3 is provided inside the rectangular working well 1 and near the bottom, wherein a position of the preset pipe jacking hole 3 is a position where a pipe jack is about to jack; the sliding back wall 14 is provided opposite to the preset jacking hole 3, a thin-walled plain concrete cavity 16 is provided in the caisson 4 along a vertical axis of the preset jacking hole 3, and a sandwich concrete panel wall 5 is inserted into the thin-walled plain concrete cavity 16. A pipe jacking machinery 17 is provided in the rectangular working well 1: the pipe jacking machinery 17 is docked with a pipe jacking 18 in a thrust direction, and the pipe jacking machinery 17 pushes the pipe jacking 18 toward the preset pipe jacking hole 3.

[0068] During pipe jacking, the sandwich concrete slab wall 5 is lifted, and the thin-walled plain concrete cavity 16 at the preset pipe jacking hole 3 is penetrated by a hydraulic jacking thrust for pipe jacking. The sandwich concrete slab wall 5 is inserted into the thin-walled plain concrete cavity 16 in the caisson. When the pipe jacking is not performed, the sandwich concrete slab wall 5 is applicable as a part of the enclosing structure of the rectangular working well. For pipe jacking, the sandwich concrete slab wall 5 is lifted, and the thin-walled plain concrete cavity 16 is easily penetrated by the jacking thrust of the pipe jacking machinery, which facilitates the pipe jacking. Conventional working wells are all concrete structures, which is difficult to drill by a water drill, wherein a concrete surface must be secondary removed. During a removing process, safety hazards such as collapse and subsidence are likely to appear on the ground. After the sandwich concrete slab wall 5 is lifted, thin walls of the thin-walled plain concrete cavity 16 can be easily penetrated, and the pipe jacking can be directly performed to avoid secondary destruction.

[0069] A sliding track 8 and a pull ring 9 are pre-embedded on the back cover 2; the sliding back wall 14 cooperates with the sliding track 8; the sliding back wall 14 is connected to a pull rod 15 through an anchor 10, and an end portion of the pull rod 15 is connected to the pull ring 9. When a pipe jacking device is pushed into the pipe jacking, a back of the pipe jacking device bears all the horizontal jacking thrust of the pipe jacking process. As a result, it is necessary to pour a concrete back wall at the back of the pipe jacking device in time to distribute the jacking thrust evenly on the back wall. The pour-in-place back wall is a one-time wall surface and requires setting period and curing time, which prolongs the construction period. After the pipe jacking, the back wall needs to be removed. However, in the present application, the sliding back wall 14 is a prefabricated part. During construction, the sliding back wall 14 is hoisted into the rectangular working well 1 and fixed by an anchor. When the rectangular working well 1 has multiple pipe jacking positions, a position of the sliding back wall 14 can be adjusted by the pull rod and the pipe jacking can be started again after fixing.

[0070] A ladder 11 is installed on an internal wall of the rectangular working well 1 through planting bars to facilitate subsequent use of the rectangular pipe jacking well.

[0071] A water-proof pressure plate 13 is fixed at an entrance of the preset pipe jacking hole 3 by expansion bolts. A polymer material 12 is used for leakage control at joints between the back cover 2 and the caisson 4 as well as joints at side walls of the caisson 4. Especially in water-rich stratum, it is possible to prevent permanent working wells from seeping water from holes and joints after long-term use.

[0072] A connector is pre-embedded on the caisson 4; an edge protector 6 is connected to a top end of the caisson 4, and the edge protector 6 is connected to the pre-embedded connector by bolts.

[0073] The present invention innovatively adopts a combined enclosing structure of the caisson, the sandwich concrete slab wall at the preset pipe jacking hole and the sliding back wall for advanced support of the rectangular working well. The present invention innovates the construction process and structural design, and uses the hydraulic jacking thrust of the pipe jacking equipment to directly penetrate the thin-walled plain concrete cavity formed after lifting the sandwich concrete slab wall, so as to realize the safe and rapid forming of the preset pipe jacking hole. It is the first time to use the sliding back wall to meet subsequent construction requirements of single-well repeated pipe jacking, which can save investment and speed up the construction progress. According to the present invention, the rectangular working well with the preset pipe jacking hole and the sliding back wall in the water-rich stratum has many advantages such as clear function, safety, quickness, and flexible design. In particular, it overcomes the safety hazards such as water gushing and sand gushing during penetrating well walls by the pipe jacking in the water-rich stratum, which provides a new set of working well design and construction technology for non-excavation construction of underground pipelines for water conservancy, municipal, thermal, communication and other infrastructure. The present invention not only changes the conventional post-drilling construction method and avoids risks thereof, but also creatively proposes and adopts a synchronous design of the preset pipe jacking hole and the rectangular working well, enabling hydraulically penetrating the thin-walled plain concrete cavity with the help of the pipe jacking equipment.

[0074] The above are only the preferred embodiments of the present invention. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the overall concept of the present invention. These modifications and improvements should also fall into the protection scope of the present invention.