CN110528516B

CN110528516B - Device and method for enhancing stability of steel casing during hole forming construction

Info

Publication number: CN110528516B
Application number: CN201910827613.5A
Authority: CN
Inventors: 徐新战; 梁亦邱; 张陈
Original assignee: Zhejiang Yitong Special Foundation Engineering Co ltd
Current assignee: Zhejiang Yitong Special Foundation Engineering Co ltd
Priority date: 2019-09-03
Filing date: 2019-09-03
Publication date: 2021-01-15
Anticipated expiration: 2039-09-03
Also published as: CN110528516A

Abstract

The invention discloses a device and a method for strengthening the stability of a steel casing during pore-forming construction, wherein the device comprises the steel casing, a plurality of grouting guide pipes for grouting cement slurry into a soil body are welded on the outer side wall of the steel casing, and a plurality of slurry conveying holes with different heights are arranged on each grouting guide pipe; the device also comprises a plurality of slurry conveying branch pipes which are used for communicating the openings on the grouting guide pipes; each grouting guide pipe is provided with a pressure sensor for measuring the stress at the bottom of the grouting guide pipe; the device also comprises a plurality of rope wheels with adjustable paying-off lengths, which are in one-to-one correspondence with the grouting guide pipes, wherein a steel wire rope is led out of each rope wheel, and the tail end of each steel wire rope is provided with a plug used for falling into the corresponding grouting guide pipe so as to control the grouting height of the grouting guide pipe; the key point of the method is that the paying-off length of each rope wheel is set in a compensation mode according to the reading of the pressure sensor of each grouting guide pipe, and then different reinforcement heights are obtained. The device and the method can avoid the transverse and vertical displacement of the steel casing.

Description

Device and method for enhancing stability of steel casing during hole forming construction

Technical Field

The invention relates to the technical field of pile foundation pore-forming construction, in particular to a device and a method for enhancing the stability of a steel casing during pore-forming construction.

Background

With the development of economy in China, the number of large-scale municipal public works such as large bridges, large wind power, large cross-river and cross-sea tunnels and the like is increasing day by day. Above-mentioned project all can relate to the pore-forming construction of engineering pile foundation, and during engineering pile foundation pore-forming construction, often need predetermine the steel and protect a section of thick bamboo, is about being about to put into the soil body and steel protects a section of thick bamboo top 30cm by static pressure stake machine or vibration hammer etc. and expose ground to play location pile foundation center, dado and prevent the hole of collapsing, stabilize downthehole mud liquid level height, prevent that ground foreign matter from falling into effects such as drill way.

The steel casing retaining wall in the prior art during pore-forming construction has the following defects: because the steel casing has a great self weight, the steel casing has great dependence on the stability of a soil body with a holding force at the bottom end, and the soil body is difficult to avoid having nonuniformity, namely the soil body strength and the bearing capacity at different circumferential positions of the steel casing are different, and moreover, the vibration is severe when a drill bit drills, the vibration can cause the stability of the soil body at the bottom opening of the casing to be poor, and particularly when the drill bit passes through the bottom opening of the steel casing, the soil body around the bottom opening is strongly washed and disturbed; the above factors can cause the steel casing to simultaneously generate horizontal and vertical displacement, so that the pile position of the drilling machine is misaligned, the drill bit is drilled downwards and interferes with the steel casing to cause damage to the drill bit and the steel casing, even the drill bit cannot continue to drill, or even if the steel casing is drilled downwards and the bottom opening of the steel casing is tapped, the drill bit cannot be pulled out due to the horizontal and vertical displacement of the steel casing. Once the accident happens, a large amount of manpower, material resources and financial resources are wasted to be processed.

Disclosure of Invention

The invention aims to solve the technical problem of providing a device for enhancing the stability of a steel pile casing during hole forming construction, which can avoid the transverse and vertical displacement of the steel pile casing.

The invention provides a device for strengthening the stability of a steel casing during pore-forming construction, which comprises the steel casing, wherein a plurality of grouting guide pipes for grouting cement slurry into a soil body are welded on the outer side wall of the steel casing, and a plurality of grout conveying holes with different heights are arranged on each grouting guide pipe; the device also comprises a plurality of slurry conveying branch pipes which are used for communicating the openings on the grouting guide pipes; each grouting guide pipe is provided with a pressure sensor for measuring the stress at the bottom of the grouting guide pipe; the device also comprises a plurality of rope wheels with adjustable paying-off lengths, which are in one-to-one correspondence with the grouting guide pipes, wherein a steel wire rope is led out of each rope wheel, and the tail end of each steel wire rope is provided with a plug which is used for falling into the corresponding grouting guide pipe so as to control the grouting height of the grouting guide pipe.

Compared with the prior art, the device for enhancing the stability of the steel casing during hole forming construction has the following advantages.

Firstly, after the main body part of the steel casing sinks into the soil body, cement paste is injected into the soil body around the steel casing through each slurry conveying branch pipe, each grouting guide pipe and each slurry conveying hole, and after the cement paste is bonded and initially solidified, the soil body around the steel casing is reinforced, so that the steel casing and the soil body around the steel casing form a large cement reinforced body together, the strength bearing capacity and other holding performances of the soil body around the steel casing are improved, and the probability of occurrence of transverse and vertical displacement is reduced; the defects that the pile position is inaccurate, the drill bit and the steel casing are interfered and damaged, and the drill bit cannot be drilled down or pulled up are avoided; and, because all set up pressure sensor on each slip casting pipe, can judge the holding power performance of the soil body of the different circumferential positions of steel casing according to its reading, and the pertinence compensates, through controlling unwrapping wire length, with the lower limit position of injecing the end cap in each slip casting pipe, the jam prevents the thick liquid to continue to descend, and then make each different circumferential position obtain with the identical reinforcement height of unwrapping wire length, make along each node bearing capacity of steel casing circumference even, the further probability that horizontal displacement or vertical uneven settlement take place that reduces of utmost point pertinence. The accidents are basically avoided, and the manpower, material resources and financial resources are greatly saved.

Preferably, a solid rod for filling the pipe cavity to prevent soil from entering is arranged in each grouting guide pipe; therefore, when the steel casing is effectively prevented from sinking, the soil body blocks each grouting guide pipe, and smooth grouting is guaranteed.

Preferably, the bottom of the grouting guide pipe is a sharp part, and the sharp part is low inside and high outside, so that sinking resistance of the bottom end of the grouting guide pipe can be reduced, and sinking efficiency of the grouting guide pipe can be improved.

Preferably, the top of each solid rod is provided with an end head which is used for being clamped outside the upper opening of the corresponding grouting guide pipe, the upper end of each grouting guide pipe is provided with an external thread, an internal thread sleeve is screwed on the external thread, the end head is accommodated in the internal thread sleeve, the top of the internal thread sleeve is provided with a radially inward convex compression ring, and the pressure sensor is positioned between the compression ring and the end head; the design has several advantages, the assembly is convenient and quick, and the pressure sensor can be placed after the solid rod is inserted and the end is clamped, and then the pressure sensor is screwed into the internal thread sleeve; the pressure sensor is protected inside the grouting guide pipe and is not directly ground with the soil body sand stone at the bottom, so that the service life of the pressure sensor is guaranteed; in addition, in the process that the internal thread sleeve and the compression ring sink integrally along with the steel casing, the end head can be pressed down, so that the pressure sensor can truly reflect the stress at the bottom of the grouting guide pipe, namely the bottom of the solid rod, and reasonably reflect the soil layer holding capacity below the circumferential node, and the soil layer holding capacity serves as a basis for adjusting the reinforcement heights of different circumferential nodes in the later period; finally, the device dismantles the process also very conveniently, only needs to unscrew the internal thread sleeve, just can conveniently take out pressure sensor, and convenient reading, and the process of taking out the solid pole is also convenient and fast.

As a preferable selection of the rope pulley pay-off device, each rope pulley can be rotatably arranged on a wheel carrier, the wheel carrier and the rope pulley are both provided with insertion holes, and a bolt which passes through two through holes to lock the corner of the rope pulley is arranged between the rope pulley and the wheel carrier; therefore, workers manually pay off the cable, draw the bolt away and rotate the rope wheel for different circles, and the paying-off length of the cable can be freely adjusted according to the bottom holding force condition of each circumferential node.

Still further preferably, the device is further provided with a main controller, each rope pulley is provided with an electric motor, an output shaft of each electric motor is connected with the rope pulley, the electric motors are in signal connection with the main controller, and all the pressure sensors are also in signal connection with the main controller; like this, realized full automatization regulation and control, each pressure sensor sends the main control unit with the pressure value is automatic, converts out the holding power performance of each circumference node by main control unit to compensation is made to the pertinence, converts out the reinforcement height and the unwrapping wire length that each circumference node corresponds, with the number of rotations of the motor that control each circumference node corresponds, finally realizes full automatization and adjusts.

Preferably, the bottom end of the grouting guide pipe is flush with the bottom end of the steel casing, and a lower opening is formed in the bottom end of the grouting guide pipe; because the steel protects a section of thick bamboo and relies on very greatly to the stability of its bottom holding power soil body, and when the drill bit passes through steel protects a section of thick bamboo end opening, erode and the disturbance is also especially strong to the peripheral soil body of end opening, like this, can directly carry out the slip casting to the soil body of steel protects a section of thick bamboo bottom, directly improves the holding power performance of bottom soil body, the solution that immediately shows up that the node position intensity bearing capacity is not enough leads to inhomogeneous settlement and displacement problem.

The invention aims to solve another technical problem of providing a method for enhancing the stability of a steel pile casing during hole forming construction, which can avoid the occurrence of horizontal and vertical displacement of the steel pile casing.

The invention provides a technical scheme for enhancing the stability of a steel pile casing during hole forming construction, which comprises the following steps:

a. welding each grouting guide pipe on the outer side wall of the steel casing, putting a solid rod into each grouting guide pipe, clamping the end of each solid rod at the upper opening of the corresponding grouting guide pipe, placing a pressure sensor on the top surface of each end, and screwing an internal thread sleeve on the external thread at the upper end of each grouting guide pipe;

b. sinking the main body part of the steel casing into the soil body by using a vibration hammer or a static pile press; in the process, the pressing ring of the internal thread sleeve presses down the end head and the solid rod through the pressure sensors, and each pressure sensor can measure the soil resistance borne by the bottom end of each grouting guide pipe;

c. loosening each internal thread sleeve, taking away the pressure sensor, and drawing out the solid rod from the grouting guide pipe; at the moment, the readings of each pressure sensor are manually collected, or each pressure sensor reports the readings to the main controller;

d. according to the reading of the pressure sensor of each grouting guide pipe, the paying-off length of each rope wheel is set in a compensation mode, the paying-off length is shorter when the reading is larger, and the paying-off length is larger when the reading is smaller; and the plugs corresponding to the rope wheels are placed into the corresponding grouting guide pipes;

e. an upper opening of each grouting guide pipe is butted with one slurry conveying branch pipe, and the grouting guide pipes are synchronously grouted with cement slurry; the cement paste impacts the plugs downwards, corresponding steel wire ropes are straightened, the cement paste overflows from all the slurry conveying holes higher than the plugs, the cement paste is bonded and reinforced with the surrounding soil body, different reinforcement heights are formed at all the nodes along the circumferential direction of the steel casing, and the reinforcement heights of all the circumferential nodes are matched with the paying-off lengths of all the plugs one by one.

The reinforcing method has the advantages that: cement paste is injected into soil bodies around the steel casing to reinforce the soil bodies around the steel casing, so that the holding performance of the steel casing is improved, and the probability of occurrence of transverse and vertical displacement is reduced; moreover, the holding force performance of different circumferential nodes of the steel casing is judged according to the reading of each grouting conduit pressure sensor, the compensation is carried out in a targeted manner, different reinforcement heights of each node are formed by controlling the paying-off length, the holding force of each circumferential node is uniform, and the probability of horizontal or vertical uneven settlement is further reduced; the pressure sensor is convenient and quick to assemble, and is not directly ground with the soil body gravel at the bottom, so that the service life of the pressure sensor is guaranteed; moreover, when the steel casing sinks, the pressure ring presses the end downwards, so that the pressure sensor can truly and accurately reflect the stress at the bottom of the solid rod and reasonably reflect the bearing performance of the soil layer below the circumferential node; finally, the lower opening at the bottom end of the grouting guide pipe can directly perform grouting on the soil body at the bottom of the steel casing, so that the holding performance of the soil body at the bottom is directly improved, and the effect is obvious.

Drawings

FIG. 1 is a structural schematic diagram of a grouting state of a measuring device of the device for reinforcing the stability of the steel casing during hole forming construction.

FIG. 2 is a schematic structural diagram of the device for reinforcing the stability of the steel pile casing during the sinking process in the hole forming construction process.

Fig. 3 is a partially enlarged structural view of a grouting guide pipe of the device for reinforcing the stability of a steel casing during hole forming construction according to the invention.

FIG. 4 is a schematic side sectional view of a preferred pressure sensor mounting arrangement of the apparatus for reinforcing steel casing stability during hole forming operations of the present invention.

Fig. 5 is an enlarged structural view of a sheave of the apparatus for reinforcing the stability of a steel casing in a boring process according to the present invention.

The device comprises a steel casing 1, a grouting guide pipe 2, a grouting hole 3, a grouting branch pipe 4, a grouting branch pipe 5, a pressure sensor 6, a rope pulley 7, a steel wire rope 8, a plug 9, a solid rod 10, a tip 11, an internal thread sleeve 12, a pressing ring 13, a wheel carrier 14, a bolt 15, a joint 16, a grouting main pipe 17, a slurry pump 18, a stirring tank 19 and a wire casing.

Detailed Description

The invention is further described with reference to the following figures and specific examples.

As shown in fig. 1, 2, 3, 4 and 5, the device for enhancing the stability of the steel casing during hole forming construction comprises the steel casing 1, wherein a plurality of grouting guide pipes 2 for grouting soil are welded on the outer side wall of the steel casing 1. Each grouting guide pipe 2 is provided with a plurality of slurry conveying holes 3 with different heights, the slurry conveying holes 3 on each grouting guide pipe 2 are distributed downwards in a winding way in a spiral line, and the circumferential distance between every two adjacent slurry conveying holes 3 is 120 degrees.

The device also comprises a plurality of slurry conveying branch pipes 4 which are used for communicating the openings on the grouting guide pipes 2; specifically, during grouting, the outlet of each slurry conveying branch pipe 4 is connected with the upper opening of a grouting guide pipe 2 through a connector 15, the inlets of all the slurry conveying branch pipes 4 are communicated with a slurry conveying main pipe 16, a slurry pump 17 is arranged on the slurry conveying main pipe 16, and the slurry pump 17 is communicated with a stirring pool 18 for storing cement slurry.

The bottom end of each grouting guide pipe 2 is flush with the bottom end of the steel casing 1, and a lower opening is formed in the bottom end of each grouting guide pipe 2. The bottom of each grouting guide pipe 2 is a sharp part, and the sharp part is radially low inside and high outside along the steel casing 1. Each grouting guide pipe 2 is internally provided with a solid rod 9 for filling the pipe cavity and preventing soil from entering.

Each grouting guide pipe 2 is provided with a pressure sensor 5 for measuring the stress on the bottom of the grouting guide pipe 2. In the embodiment, the pressure sensor 5 is preferably mounted in a structure that the top of each solid rod 9 is provided with an end 10 for being clamped outside the opening of the corresponding grouting guide pipe 2, the upper end of each grouting guide pipe 2 is provided with an external thread, and the external thread section at the upper end of each grouting guide pipe 2 is smaller in external diameter than the normal section at the middle lower part of the grouting guide pipe 2; the external thread section is screwed with an internal thread sleeve 11, an end head 10 is accommodated in the internal thread sleeve 11, a radial inward convex pressing ring 12 is arranged at the top of the internal thread sleeve 11, and the pressure sensor 5 is positioned between the pressing ring 12 and the end head 10.

The device also comprises a plurality of rope wheels 6 with adjustable paying-off lengths, which are in one-to-one correspondence with the grouting guide pipes 2, wherein a steel wire rope 7 is led out of each rope wheel 6, and the tail end of each steel wire rope 7 is provided with a plug 8 which is used for falling into the corresponding grouting guide pipe 2 so as to control the grouting height of the grouting guide pipe 2. A wire groove 19 is reserved at the top of the pipe wall of each grouting guide pipe 2, and when grouting is carried out, the joint 15 of the slurry conveying branch pipe 4 is screwed with the internal thread of the opening on the grouting guide pipe 2, the steel wire rope 7 penetrates through the pipe wall of the grouting guide pipe 2 through the wire groove 19 to enter the pipe cavity. Of course, after the grouting guide pipe 2 is opened and screwed into the connector 15, the wire groove 19 becomes a wire hole, and at this time, an elastic sleeve can be sleeved on the steel wire rope 7 to block the wire hole, so as to realize sealing.

In the present embodiment, the wire releasing device of the sheave 6 is preferably manually operated, and has a structure in which: each rope wheel 6 is rotatably arranged on a wheel frame 13, the wheel frames 13 and the rope wheels 6 are provided with insertion holes, and a bolt 14 which passes through two through holes to lock the rotation angle of the rope wheels 6 is arranged between the rope wheels 6 and the wheel frames 13.

Of course, the paying-off device of the rope pulley 6 of the present application can also be selected to be automatic, i.e. each rope pulley 6 is provided with an electric motor, and the output shaft of the electric motor is connected with the rope pulley 6.

This a device for strengthening steel protects a stability still is equipped with main control unit like PLC control chip, this motor and main control unit signal connection, and all pressure sensor 5 also with main control unit signal connection.

As shown in fig. 1, 2, 3, 4 and 5, the method for reinforcing the stability of the steel casing during the hole forming construction of the invention comprises the following steps.

a. Uniformly welding each grouting guide pipe 2 on the outer side wall of the steel casing 1 along the circumferential direction, putting a solid rod 9 into each grouting guide pipe 2, clamping an end 10 of each solid rod 9 at the upper opening of the corresponding grouting guide pipe 2, placing a pressure sensor 5 on the top surface of each end 10, and screwing an internal thread sleeve 11 on the external thread at the upper end of each grouting guide pipe 2; the pressure sensor 5 is trapped between the pressure ring 12 of the internally threaded sleeve 11 and the end 10 of the solid rod 9.

b. Sinking the main body part of the steel casing 1 into the soil body by using a vibration hammer or a static pile press; in the process, the pressing ring 12 of the internal thread sleeve 11 presses down the end 10 and the solid rod 9 through the pressure sensors 5, and each pressure sensor 5 can measure soil resistance on the bottom end of each grouting guide pipe 2, more precisely on the bottom end of the solid rod 9.

c. Unscrewing each internally threaded sleeve 11, taking away the pressure sensor 5 and extracting the solid rod 9 from the grouting guide pipe 2; at this time, the readings of the pressure sensors 5 are manually collected, or the readings of the pressure sensors 5 are automatically reported to the main controller.

d. According to the reading of the pressure sensor 5 of each grouting guide pipe 2, the paying-off length of each rope wheel 6 is set in a compensation mode, the larger the reading is, the shorter the paying-off length is, and the smaller the reading is, the larger the paying-off length is; and the plugs 8 corresponding to the rope wheels 6 are placed into the corresponding grouting guide pipes 2.

The pay-off length is set in a compensation mode in the step, the pay-off length is a processing idea, the specific conversion relation between the reading of the pressure sensor 5 and the pay-off length can be automatically adjusted and summarized by field construction personnel through experience, and the overall compensation idea that the reinforcement height with strong holding force is small and the reinforcement length with weak holding force is large can be met.

e. An upper opening of each grouting guide pipe 2 is butted with one slurry conveying branch pipe 4, and grouting slurry is synchronously poured into each grouting guide pipe 2; the cement paste impacts the plug 8 downwards, the corresponding steel wire rope 7 is straightened, the cement paste overflows from each slurry conveying hole 3 higher than the plug 8, the cement paste is bonded and reinforced with the surrounding soil body, different reinforcing heights are formed at each node along the circumferential direction of the steel protective cylinder 1, and the reinforcing heights of the circumferential nodes are matched with the paying-off lengths of the plugs 8 one by one.

Claims

1. The utility model provides a be used for strengthening steel when pore-forming construction and protect a device of stability, it includes that steel protects a section of thick bamboo (1), its characterized in that: a plurality of grouting guide pipes (2) for grouting cement slurry to a soil body are welded on the outer side wall of the steel casing (1), and a plurality of slurry conveying holes (3) with different heights are formed in each grouting guide pipe (2); the device also comprises a plurality of slurry conveying branch pipes (4) which are used for communicating the openings on the grouting guide pipes (2); each grouting guide pipe (2) is provided with a pressure sensor (5) for measuring the stress of the bottom of the grouting guide pipe (2); the device also comprises a plurality of rope wheels (6) with adjustable paying-off lengths, which are in one-to-one correspondence with the grouting guide pipes (2), wherein a steel wire rope (7) is led out of each rope wheel (6), and the tail end of each steel wire rope (7) is provided with a plug (8) which is used for dropping into the corresponding grouting guide pipe (2) to control the grouting height of the grouting guide pipe (2);

a solid rod (9) for filling the pipe cavity and preventing soil from entering is arranged in each grouting guide pipe (2);

every solid core rod (9) top is equipped with and is used for card end (10) outside corresponding slip casting pipe (2) upper shed, is equipped with the external screw thread on every slip casting pipe (2), closes internal thread sleeve (11) on this external screw thread soon, and in internal thread sleeve (11) was held in end (10), and internal thread sleeve (11) top was equipped with radial protruding clamping ring (12) inwards, and pressure sensor (5) are located between clamping ring (12) and end (10).

2. The device for reinforcing the stability of the steel pile casing during pore-forming construction according to claim 1, characterized in that: the bottom of the grouting guide pipe (2) is a sharp part, and the inside of the sharp part is low and the outside is high.

3. The device for reinforcing the stability of the steel pile casing during pore-forming construction according to claim 1, characterized in that: each rope wheel (6) can be rotatably arranged on a wheel frame (13), the wheel frames (13) and the rope wheels (6) are respectively provided with a jack, and a bolt (14) which penetrates through the two through holes to lock the rotation angle of the rope wheels (6) is arranged between the rope wheels (6) and the wheel frames (13).

4. The device for reinforcing the stability of the steel pile casing during pore-forming construction according to claim 1, characterized in that: the device is also provided with a main controller, each rope wheel (6) is provided with an electric motor, the output shaft of the electric motor is connected with the rope wheel (6), the electric motor is in signal connection with the main controller, and all the pressure sensors (5) are also in signal connection with the main controller.

5. The device for reinforcing the stability of the steel pile casing during pore-forming construction according to claim 1, characterized in that: the bottom end of the grouting guide pipe (2) is flush with the bottom end of the steel casing (1), and the bottom end of the grouting guide pipe (2) is provided with a lower opening.

6. A method for strengthening the stability of a steel pile casing during pore-forming construction is characterized in that: the method comprises the following steps:

a. welding each grouting guide pipe (2) on the outer side wall of a steel casing (1), putting a solid rod (9) into each grouting guide pipe (2), clamping an end head (10) of each solid rod (9) at the upper opening of the corresponding grouting guide pipe (2), placing a pressure sensor (5) on the top surface of each end head (10), and screwing an internal thread sleeve (11) on the external thread at the upper end of each grouting guide pipe (2);

b. sinking the main body part of the steel casing (1) into the soil body by using a vibration hammer or a static pile press; in the process, the compression ring (12) of the internal thread sleeve (11) presses down the end (10) and the solid rod (9) through the pressure sensors (5), and each pressure sensor (5) can measure soil resistance borne by the bottom end of each grouting guide pipe (2);

c. loosening each internal thread sleeve (11), taking away the pressure sensor (5), and drawing out the solid rod (9) from the grouting guide pipe (2); reading numbers of the pressure sensors (5) are collected manually, or the reading numbers are reported to the main controller by the pressure sensors (5);

d. according to the reading of the pressure sensor (5) of each grouting guide pipe (2), the paying-off length of each rope wheel (6) is set in a compensation mode, the paying-off length is shorter when the reading is larger, and the paying-off length is larger when the reading is smaller; and the plugs (8) corresponding to the rope wheels (6) are placed into the corresponding grouting guide pipes (2);

e. an upper opening of each grouting guide pipe (2) is butted with one slurry conveying branch pipe (4), and grouting slurry is synchronously poured into each grouting guide pipe (2); the plug (8) is impacted downwards by cement paste, the corresponding steel wire rope (7) is tightened, the cement paste overflows from each slurry conveying hole (3) higher than the plug (8), the cement paste is bonded and reinforced with a surrounding soil body, different reinforcing heights are formed along each circumferential node of the steel protective cylinder (1), and the reinforcing heights of the circumferential nodes are matched with the paying-off lengths of the plugs (8) one by one.