CN112144537A - Self-anchoring type flower steel pipe supporting device and anchoring construction method thereof - Google Patents

Abstract

The invention discloses a self-anchoring type flower steel pipe supporting device and an anchoring construction method thereof, and belongs to the technical field of foundation pit supporting. The invention relates to a self-anchored flower steel pipe supporting device, which comprises a flower steel pipe, a grouting pipe and anchor bars, wherein the surface of the flower steel pipe is provided with through holes for slurry to pass through, the anchor bars are movably arranged in the through holes, one end of each anchor bar is positioned in the flower steel pipe, the other end of each anchor bar extends out of the flower steel pipe, the grouting pipe is sleeved in the flower steel pipe and can freely move along the length direction of the flower steel pipe, and the surface of the grouting pipe is provided with sawteeth which are distributed at intervals along the length direction of the grouting pipe and are matched with the anchor bars. The device can be widely applied to excavation and support construction of the deep foundation pit under geological conditions such as a sand soil layer, a flowing soil layer and the like, plays a very important role in stabilizing the foundation pit, can be repeatedly used, is energy-saving and environment-friendly, and meets the requirement of sustainable development.

Description

Self-anchoring type flower steel pipe supporting device and anchoring construction method thereof

Technical Field

The invention belongs to the technical field of foundation pit supporting, and particularly relates to a self-anchored flower steel pipe supporting device and an anchoring construction method thereof, which are suitable for deep foundation pit excavation supporting construction in municipal administration, house construction and the like.

Background

In the construction process of modern municipal engineering, house engineering and the like, the situation that the difference between the site geological condition and the prior investigation is large sometimes occurs, so that the design scheme cannot be implemented. Wherein, the weak surrounding rock is a rock mass which is frequently encountered in municipal and building engineering. The weak surrounding rock has poor self-stability, so the settlement and large deformation of the surrounding rock need to be controlled in the construction process to ensure the construction safety.

The anchor bolt support is a reinforcing support mode adopted in surface engineering such as side slopes, rock-soil deep foundation pits and the like and underground chamber construction such as tunnels, stopes and the like. At present, a large number of engineering practices show that the anchor pipe is driven into the weak surrounding rock and grouting is carried out, so that the anchor pipe can generate a good supporting effect on the weak surrounding rock, and the settlement and large deformation of the surrounding rock are controlled to ensure the construction safety. The anchor rod has the advantages of good supporting effect, material saving, low cost and contribution to mechanical operation. Meanwhile, the method has the advantages of simple construction process, high construction speed, small occupied construction clearance and the like, and can meet the construction requirement of the weak surrounding rock engineering for quick construction, so that the method for supporting the weak surrounding rock by adopting the anchor pipe is widely applied.

For example, the application with chinese patent application No. 2017200579916 discloses a bolting structure with a bolt sleeve, which includes a bolt with a bolt sleeve, the bolt with the bolt sleeve includes a bolt sleeve and a bolt body; the anchor rod body is a hollow tubular body, a plurality of grout outlet holes are formed in the hollow tubular body, and the anchor rod sleeve is sleeved in the middle of the anchor rod body; when the anchor rod is in use, the anchor rod body is used for penetrating through the pit wall of the foundation pit and is obliquely arranged in the side slope of the foundation pit, cement slurry is poured into the anchor rod body, and part of the cement slurry is extruded out of the slurry outlet hole, so that the cement slurry is filled between the drilled hole and the rock mass, and the anchor rod with the anchor rod sleeve is tightly occluded with the rock mass to form an anchor rod supporting structure.

However, in the stratum such as sand layer, flowing soil layer, above-mentioned traditional anchor bolt supporting construction anchor power will descend by a wide margin, and the anchor effect is relatively poor, and in addition the flow of soil layer, probably can lose the anchor effect. Meanwhile, when the traditional anchor rod supports the foundation pit soil layer, the supporting area of the soil layer is small, so that the stability of the anchor rod on the foundation pit support is relatively poor.

Through search, chinese patent application No. 2018107043326 discloses an M-level supporting anchor pipe, which includes: the flower steel tube, M level support exhibition wall group interval in proper order sets up on the flower steel tube, and at least two in arbitrary level support exhibition wall group support the exhibition wall all with flower steel tube rotation connection, and M is not less than 2 integer. The unfolding wall opening rod is used for moving in the flower steel pipe and pushing the at least two supporting unfolding walls to rotate from a folded state embedded in the flower steel pipe to an unfolded state positioned outside the flower steel pipe relative to the flower steel pipe; wherein, N level supports the exhibition wall group and is in the state of expanding, and N is the positive integer that is not more than M. The application can improve the stability of the anchor pipe fixed in the weak surrounding rock to a certain extent, but cannot play a powerful anchoring role in a popular sand layer or a quicksand layer.

In order to solve the problems, the invention provides a self-anchored flower steel pipe which can be widely applied to excavation and support construction of deep foundation pits of sand layers and soil shifting layers, has a very important effect on the stability of the foundation pits, can be repeatedly used, is energy-saving and environment-friendly, and meets the requirements of sustainable development.

Disclosure of Invention

1. Problems to be solved

Aiming at the defects of relatively poor anchoring effect and relatively poor supporting stability of the existing anchor rod supporting structure to a foundation pit, the invention provides a self-anchoring type flower steel pipe supporting device and an anchoring construction method thereof. The self-anchored flower steel pipe structure can effectively improve the anchoring effect, has better supporting stability of the foundation pit, and can be widely applied to the excavation supporting construction of deep foundation pits of sand soil layers and soil flowing layers.

2. Technical scheme

In order to solve the problems, the technical scheme adopted by the invention is as follows:

the invention relates to a self-anchoring type flower steel pipe supporting device which comprises a flower steel pipe, a grouting pipe and anchor bars, wherein through holes for slurry to pass through are formed in the surface of the flower steel pipe, the anchor bars are movably arranged in the through holes, one end of each anchor bar is positioned in the flower steel pipe, the other end of each anchor bar extends out of the flower steel pipe, the grouting pipe is sleeved in the flower steel pipe and can freely move along the length direction of the flower steel pipe, and sawteeth which are distributed at intervals along the length direction of the grouting pipe and are matched with the anchor bars are arranged on the surface of the grouting pipe.

Furthermore, the anchor bar is composed of an anchoring section, a connecting section and a bearing section

And in the structure, the bearing section pushes the anchor bars to move under the thrust action of the sawteeth on the surface of the grouting pipe, so that the anchoring section is anchored with the weak surrounding rock.

Furthermore, the grouting pipe comprises a sleeve which is sleeved outside the grouting pipe and can freely move along the length direction of the patterned steel pipe.

Furthermore, the surface of the grouting pipe is provided with a plurality of saw teeth which are uniformly distributed at intervals along the circumferential direction, the interval distance between every two adjacent saw teeth in the same saw tooth is 20-30cm, and the width of each saw tooth is 20-30 cm.

Furthermore, the sawtooth is cast iron sawtooth, and its width is 20cm, and slip casting pipe surface is equipped with 3 even symmetric distributions's sawtooth.

Furthermore, the sleeve is made of a PVC pipe, and the thickness of the PVC pipe is 3-5 mm.

Furthermore, the flower steel pipe is in a cylindrical hollow pipe structure, one end of the flower steel pipe is processed into a conical structure, and the conical angle is 105-120 degrees.

Furthermore, the other end of the flower steel pipe, which is opposite to the conical structure, is provided with a plugging cap, the plugging cap is made of rubber, and the thickness of the plugging cap is 3-5 mm.

The anchoring construction method of the self-anchoring type flower steel pipe supporting device comprises the following steps:

firstly, punching holes in a sand layer by using an anchor rod machine according to the spacing and the angle designed by a drawing, and then punching a self-anchored flower steel pipe supporting device into the holes;

pushing the grouting pipe, and pushing the anchor bars to slide outwards along the through holes on the surface of the steel pipe under the action of the sawteeth on the surface of the grouting pipe and the anchor bar bearing section, so that the anchoring sections of the anchor bars are anchored in the soil;

step three, when the anchoring section of the anchor bar is anchored into the soil layer and the grouting pipe is basically not stressed, sleeving the sleeve outside the grouting pipe, and completely separating the anchor bar from the grouting pipe under the action of the sleeve;

grouting the whole device through a central hole of a grouting pipe, installing a plugging cap after grouting is finished, and performing pressure supplementing and compacting after installation is finished;

and fifthly, finally, drawing out the grouting pipe for the next anchoring construction to be recycled.

Furthermore, during grouting, grouting is carried out according to the principle of first small pressure and then pressurization, the small pressure value is 0.01-0.02MPa, the pressurized pressure value is 0.04-0.06MPa, pressure supplement is carried out in a constant pressure mode after installation is finished, and the pressure is controlled to be 0.04-0.06MPa and is kept for 20-30 s.

3. Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention relates to a self-anchoring type flower steel pipe supporting device which comprises a flower steel pipe, a grouting pipe and anchor bars, wherein the anchor bars are pushed to move into soil along through holes in the surface of the flower steel pipe by sawteeth in the surface of the grouting pipe, so that the anchor bars are in contact with the soil body in the largest area to increase friction resistance, then slurry is diffused through the through holes in the flower steel pipe, and after the slurry is solidified, the flower steel pipe, the anchor bars and the surrounding soil layer form a whole to increase the integrity, thereby achieving the effect of enhancing the anchoring.

(2) According to the self-anchored flower steel pipe supporting device, the structure and distribution of the anchor bars are optimized, so that the stability of anchoring between the supporting device and surrounding soil is further improved. Meanwhile, the supporting device can be directly driven into the soil layer without the help of the hole guiding construction of other external hole guiding equipment, so that the construction period is greatly shortened, and the construction efficiency is improved.

(3) According to the self-anchored flower steel pipe supporting device, the grouting pipe has multiple purposes, and on one hand, the grouting pipe serves as a stress device and pushes anchor bars to enable the anchor bars to be embedded into a soil layer to the maximum extent, so that the anchoring effect and the structural stability of the whole supporting structure are enhanced; on the other hand, as a grouting pipeline of the patterned steel pipe, the whole device can be directly grouted and reinforced through a central pipeline of the grouting pipe; meanwhile, after the slurry is solidified, the grouting pipe can be directly pulled out and installed in the next patterned steel pipe for repeated use, so that the construction cost is reduced.

(4) According to the self-anchored flower steel pipe supporting device, the sleeve is arranged outside the grouting pipe, the anchor bars can be supported and fixed on one side through the arrangement of the sleeve, the structural stability of the supporting device is guaranteed, the anchor bars are prevented from moving and shaking in the grouting process and the subsequent grouting pipe drawing process, the grouting pipe can be protected, and the grouting pipe and sawteeth on the surface of the grouting pipe are prevented from being influenced by slurry.

(5) According to the anchoring construction method of the self-anchoring type flower steel pipe supporting device, the flower steel pipe, the grout and the anchor bars are integrated into a whole in three positions, and the structure of the flower steel pipe is optimized, so that the anchoring effect and the supporting stability of the whole supporting device can be effectively improved. The supporting device for the deformed steel pipe is used for anchoring construction, and a specific anchoring construction process, particularly a grouting process, is optimized, so that the supporting effect on a weak foundation can be further ensured, and the stability and the firmness of a supporting structure are improved.

Drawings

FIG. 1 is a schematic plan view of a self-anchored lattice steel pipe support device according to the present invention;

FIG. 2 is a schematic side view of the self-anchoring lattice steel pipe support apparatus of the present invention;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 1;

FIG. 4 is a state diagram (one) of the self-anchoring lattice steel pipe supporting apparatus of the present invention;

FIG. 5 is a view showing the state of the self-anchoring lattice steel pipe supporting apparatus of the present invention;

FIG. 6 is a schematic view of the final state of the self-anchoring lattice steel pipe supporting device of the present invention;

fig. 7 is a schematic structural view of the anchor bar.

In the figure: 1. a flower steel pipe; 101. perforating; 2. a grouting pipe; 201. saw teeth; 3. anchoring ribs; 301. an anchoring section; 302. a connecting section; 303. a bearing section; 4. a sleeve; 5. and (6) plugging the cap.

Detailed Description

The invention is further described with reference to specific examples.

Example 1

With reference to fig. 1-3, the self-anchored flower-shaped steel pipe supporting device of this embodiment includes a flower-shaped steel pipe 1, a grouting pipe 2 and an anchor bar 3, wherein a through hole 101 for allowing a slurry to pass through is formed in the surface of the flower-shaped steel pipe 1, the anchor bar 3 is movably installed in the through hole 101, one end of the anchor bar is located inside the flower-shaped steel pipe 1, the other end of the anchor bar extends out of the flower-shaped steel pipe 1, the grouting pipe 2 is sleeved inside the flower-shaped steel pipe 1 and can freely move along the length direction of the flower-shaped steel pipe 1, and saw teeth 201 which are distributed at intervals along the length direction of the grouting pipe 2 and are matched with the anchor bar 3 are.

As shown in fig. 7, the anchor bar 3 is composed of an anchoring section 301, a connecting section 302 and a bearing section 303

In the structural model, the force bearing section 303 pushes the anchor bars 3 to move under the thrust action of the sawteeth 201 on the surface of the grouting pipe 2, so that the anchoring section 301 is anchored with the weak surrounding rock. Specifically, promote slip casting pipe 2, make the dowel move in to soil along the perforation on colored steel pipe surface through its surperficial sawtooth and dowel steel bearing section 303's interact, anchor section 301 inserts in soil to make dowel steel 3 and the biggest area contact of soil body increase frictional force resistance, and then improve strutting arrangement's anchor effect and structural stability, and optimize through 3 structures to the dowel steel and be favorable to further guaranteeing strutting arrangement and the stability and the fastness of soft foundation support on every side. In the embodiment, the grouting pipe 2 is arranged to serve as a stress device to push the anchor bars so that the anchor bars are embedded into the soil layer to the maximum extent; on the other hand, the grouting pipe can be directly used as a grouting pipeline of the flower steel pipe 12, grouting and reinforcing the whole device by the central hole; meanwhile, after the slurry is solidified, the grouting pipe 2 can be directly pulled out and installed in the next patterned steel pipe 1 for repeated use, so that the construction cost is reduced.

In addition, the present embodiment further comprises a sleeve 4, wherein the sleeve 4 is sleeved outside the grouting pipe 2 and can freely move along the length direction of the patterned steel pipe 1. Can support fixedly to dowel bar 2 through setting up of sleeve pipe 4 on the one hand, be favorable to guaranteeing strutting arrangement's structural stability to be convenient for take out slip casting pipe 2, prevent that slip casting in-process and follow-up slip casting pipe 2 from taking out in-process dowel bar 3 and taking place to remove and rock, on the other hand can also protect slip casting pipe 2, prevents that the sawtooth on slip casting pipe 2 and its surface from being influenced by the thick liquid.

Example 2

The self-anchored flower steel tube supporting device of this embodiment has a structure substantially the same as that of embodiment 1, and the difference is mainly that: in the embodiment, a plurality of saw teeth 201 are uniformly distributed on the surface of the grouting pipe 2 along the circumferential direction, a plurality of anchor bars 3 corresponding to the saw teeth 201 are arranged on the surface of the steel pipe, the spacing distance between adjacent saw teeth in the same saw tooth 201 is 20-30cm, and the width of each saw tooth is 20-30cm, so that the supporting effect on the surrounding foundation is further ensured. Specifically, sawtooth 201 is the cast iron sawtooth in this embodiment, and its width is 20cm, and slip casting pipe 2 surface is equipped with 3 sawtooth 201 of even symmetric distribution, and after the anchor bar anchor, three anchor bar 3 is evenly arranged on a circumference, and mutual central angle is 120 to can further increase the reverse claw of colored steel pipe and close the ability, improve the tensile strength of colored steel pipe 1 to peripheral soil. In the embodiment, one end of the flower steel tube 1 is provided with a plugging cap 5, and the plugging cap 5 is made of rubber and has a thickness of 3-5 mm.

The anchoring construction method of the self-anchoring type flower steel pipe supporting device comprises the following steps:

firstly, punching holes in a sand layer by using an anchor rod machine according to the distance and the angle designed by a drawing, and then punching the self-anchored flower-shaped steel pipe supporting device into the holes, wherein the initial state of the self-anchored flower-shaped steel pipe supporting device when the self-anchored flower-shaped steel pipe supporting device is punched into the holes is shown in figure 4.

Pushing the grouting pipe 2, pushing the anchor bars 3 to slide outwards along the through holes 101 in the surface of the figured steel pipe 1 under the action of the sawteeth 201 in the surface of the grouting pipe 2 and the anchor bar bearing section 303, and completely anchoring the anchoring sections 301 of the anchor bars 3 into soil, as shown in fig. 5;

step three, as shown in fig. 6, when the anchoring section 301 of the anchor bar 3 is anchored into the soil layer and the grouting pipe 2 is basically not stressed (because the grouting pipe 2 can be subjected to the resistance of sandy soil in the process of pushing the anchor bar 3 to extend upwards into the sandy soil layer, after one side of the anchor bar 3, namely the anchoring section 301, is parallel to the grouting pipe 2, the grouting pipe 2 is pushed to be free from the resistance transmitted by the anchor bar 3, and at this time, the anchor bar 3 is ensured to be successfully anchored into the soil layer), the sleeve 4 is sleeved outside the grouting pipe 2, and the anchor bar 3 and the grouting pipe 2 are completely separated under the action of the sleeve 4;

grouting the whole device through a central hole of the grouting pipe 2, installing a plugging cap 5 after grouting is finished, and performing pressure supplementing and compacting after installation is finished;

and step five, finally, the grouting pipe 2 is drawn out for the next anchoring construction to be recycled.

During grouting, the grouting is carried out according to the principle of first small pressure and then pressurization, the small pressure value is 0.01-0.02MPa, the pressurized pressure value is 0.04-0.06MPa, pressure supplement is carried out in a constant pressure mode after the installation is finished, the pressure is kept at 0.04-0.06MPa, and the pressure is kept for 20-30 s.

Example 3

The self-anchored flower steel tube supporting device of this embodiment has a structure substantially the same as that of embodiment 2, and the difference mainly lies in that: the casing 4 of the embodiment is a PVC pipe, the thickness of the PVC pipe is 3-5mm, the flower steel pipe 1 is a cylindrical hollow pipe structure, the other end of the flower steel pipe opposite to the plugging cap is processed into a conical structure, the cone angle is 105-120 degrees, therefore, the supporting device of the embodiment can be directly driven into a soil layer without the need of hole guiding construction of other external hole guiding equipment, the construction period is greatly shortened, and the construction efficiency is improved (the specific principle is that the soil layer in the advancing direction is stirred through the cone angle, and then the anchoring hole opening is expanded through the anchoring bar again, so that the whole device can be conveniently driven into the soil layer). The inner diameter and the thickness of the figured steel pipe 1 are determined according to the design requirements of drawings, if no relevant design instruction exists in the drawings, the inner diameter is 3-5cm, and the thickness is 5-8 mm.

Claims (10)

1. The utility model provides a from anchor formula flower steel pipe supporting device which characterized in that: including flower steel pipe (1), slip casting pipe (2) and dowel (3), wherein, the surface machining of flower steel pipe (1) has perforation (101) that supply thick liquids to pass through, but dowel (3) movable mounting is in perforation (101), and its one end is located flower steel pipe (1) inside, and its other end stretches out to flower steel pipe (1) outside, slip casting pipe (2) suit is inside and can follow flower steel pipe (1) length direction free movement in flower steel pipe (1), slip casting pipe (2) surface be equipped with along its length direction interval distribution and with dowel (3) matched with sawtooth (201).

2. A self-anchoring flower-shaped steel pipe supporting device according to claim 1, wherein: the anchor bar (3) consists of an anchoring section (301), a connecting section (302) and a force bearing section (303)

The anchor bar is of a structural structure, and the bearing section (303) pushes the anchor bars (3) to move under the thrust action of the sawteeth (201) on the surface of the grouting pipe (2), so that the anchoring section (301) is anchored with the weak surrounding rock.

3. A self-anchoring flower-shaped steel pipe supporting device according to claim 2, wherein: the grouting device is characterized by further comprising a sleeve (4), wherein the sleeve (4) is sleeved outside the grouting pipe (2) and can freely move along the length direction of the patterned steel pipe (1).

4. A self-anchoring flower-shaped steel pipe supporting device according to claim 3, wherein: the surface of the grouting pipe (2) is provided with a plurality of saw teeth (201) which are distributed at even intervals along the circumferential direction, the interval distance between adjacent saw teeth in the same saw tooth (201) is 20-30cm, and the width of each saw tooth is 20-30 cm.

5. A self-anchoring flower-shaped steel pipe supporting device according to claim 4, wherein: the sawtooth (201) are cast iron sawteeth, the width of the sawtooth is 20cm, and 3 saw teeth (201) which are uniformly and symmetrically distributed are arranged on the surface of the grouting pipe (2).

6. A self-anchoring flower steel pipe support device according to any one of claims 3 to 5, wherein: the sleeve (4) is a PVC pipe, and the thickness of the PVC pipe is 3-5 mm.

7. A self-anchoring flower steel pipe support device according to any one of claims 1 to 5, wherein: the flower steel pipe (1) is of a cylindrical hollow pipe structure, one end of the flower steel pipe is processed into a conical structure, and the cone angle is 105-120 degrees.

8. A self-anchoring flower-shaped steel pipe supporting device according to claim 7, wherein: the other end of the flower steel pipe (1) opposite to the conical structure is provided with a plugging cap (5), the plugging cap (5) is made of rubber, and the thickness of the plugging cap is 3-5 mm.

9. An anchoring construction method of a self-anchored flower-shaped steel pipe supporting device as claimed in any one of claims 1 to 8, comprising the steps of:

firstly, punching holes in a sand layer by using an anchor rod machine according to the spacing and the angle designed by a drawing, and then punching a self-anchored flower steel pipe supporting device into the holes;

pushing the grouting pipe (2), pushing the anchor bars (3) to slide outwards along the through holes (101) in the surface of the figured steel pipe (1) under the action of the sawteeth (201) in the surface of the grouting pipe (2) and the anchor bar bearing section (303), and anchoring the anchoring sections (301) of the anchor bars (3) into soil;

thirdly, when the anchoring section (301) of the anchor bar (3) is anchored in the soil layer and the grouting pipe (2) is basically not stressed, namely the anchoring section (301) is parallel to the grouting pipe (2), sleeving the sleeve (4) outside the grouting pipe (2), and completely separating the anchor bar (3) from the grouting pipe (2) under the action of the sleeve (4);

grouting the whole device through a central hole of the grouting pipe (2), installing a plugging cap (5) after grouting is finished, and performing pressure compensation and compaction after installation;

and step five, finally, the grouting pipe (2) is drawn out for the next anchoring construction to be recycled.

10. The anchor construction method of a self-anchored flower steel pipe support device according to claim 9, characterized in that: during grouting, the grouting is carried out according to the principle of first small pressure and then pressurization, the pressure value of the small pressure is 0.01-0.02MPa, the pressure value after pressurization is 0.04-0.06MPa, pressure compensation is carried out in a constant pressure mode after installation is finished, and the pressure is kept at 0.04-0.06MPa and is kept for 20-30 s.

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