CN210459233U

CN210459233U - Pile anchor foundation pit supporting structure for soft soil area

Info

Publication number: CN210459233U
Application number: CN201921218196.6U
Authority: CN
Inventors: 李小园; 蒋美恋; 郭泽旭; 刘明泉; 刘畅; 莫奎; 陈少波; 潘隆
Original assignee: Hainan Pengyue Survey Design And Research Co Ltd
Current assignee: Pengyue Surveying Co ltd
Priority date: 2019-07-31
Filing date: 2019-07-31
Publication date: 2020-05-05
Anticipated expiration: 2029-07-31

Abstract

The utility model discloses a weak soil area is with stake anchor foundation ditch supporting construction, including drilling bored concrete pile and a plurality of prestressing force enlarged footing anchor rope that is parallel to each other, every prestressing force enlarged footing anchor rope slope sets up and is fixed at the outer soil body of drilling bored concrete pile and foundation ditch, prestressing force enlarged footing anchor rope includes the sleeve pipe, the steel strand wires free end, ordinary anchor end and enlarged footing anchor end, the steel strand wires free end is pre-buried to have the sleeve pipe, the steel strand wires free end passes through anchor backing plate and ground tackle to be fixed on the waist rail or the hat beam of drilling bored concrete pile, ordinary anchor end diameter is 500mm, enlarged footing anchor end diameter is 800mm, enlarged footing anchor end stretches into the silt layer in the soil body. The cast-in-situ bored pile and the prestressed expanded head anchor cable are used for supporting together to actively reinforce the rock-soil body, and the deformation of the foundation pit is effectively controlled through the prestress implementation; effectively increase the frictional resistance between the soil body and the poured concrete, shorten the length of prestressing force enlarged head anchor rope, reduce the construction degree of difficulty.

Description

Pile anchor foundation pit supporting structure for soft soil area

Technical Field

The utility model relates to a civil engineering excavation supporting field especially relates to a weak soil area is with stake anchor underground structure.

Background

The thick-layer soft soil in Hainan province is widely distributed, and has poor engineering geological properties, which are mainly characterized by high content of private soil minerals, loose structure, high pore ratio and water content, low strength, high compressibility and easy generation of flow deformation. The design and construction of the foundation pit support in the soft soil area are more difficult than those of the common rock-soil area, the deformation control is difficult, and the problems of support structure failure, foundation pit slope instability, seepage deformation, ground settlement, ground subsidence, pit bottom uplift, inrush and other engineering geology problems often occur in the foundation pit construction. The traditional pile anchor support is adopted, the frictional resistance of the anchoring section of an anchor rod in the stratum is often insufficient due to poor geological conditions, the length of the anchoring section needs to be twenty-thirty meters or even longer, the construction difficulty is increased, particularly for the problem of hole forming and diameter reducing in a soft soil area, a large-diameter anchoring body cannot be formed by adopting the existing prestress enlarged head anchor cable, hole collapse is easily caused due to improper construction, water and soil loss is even caused, the potential safety hazard problems such as peripheral road pipelines are influenced, and in addition, the soft soil is easy to gush water, so that the foundation pit support deformation is caused.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a soft soil area is with stake anchor underground structure, including bored concrete pile and prestressing force enlarged footing anchor rope, every prestressing force enlarged footing anchor rope stretches into bored concrete pile and the outer soil body internal fixation of foundation ditch with 45 slopes, prestressing force enlarged footing anchor rope includes sleeve pipe, steel strand wires free end, ordinary anchor end and enlarged footing anchor end, and the steel strand wires free end is pre-buried to have the sleeve pipe, and the steel strand wires free end passes through anchor backing plate and ground tackle to be fixed on the waist rail or the hat beam of bored concrete pile, and ordinary anchor end diameter is 500mm, and enlarged footing anchor end diameter is 800mm, and enlarged footing anchor end stretches into the silt layer in the soil body.

Preferably, the cast-in-situ bored pile is formed by longitudinally and alternately pouring longitudinal bars, stiffening bars, spiral stirrups and concrete.

Preferably, a waterproof curtain is arranged on one side, close to the soil body, of the cast-in-situ bored pile, and the height of the cast-in-situ bored pile is larger than that of the waterproof curtain, so that a waterproof structure of the side wall of the digging face is formed.

Preferably, the side of the cast-in-situ bored pile, which is far away from the soil body, is sprayed with a concrete layer, and a drainage ditch is arranged at the bottom of the foundation pit corresponding to the concrete layer, so that a water stop structure at the bottom of the foundation pit is formed.

Preferably, the common anchoring end is 6m in length, and the enlarged head anchoring end is 5m in length.

Preferably, the soil body is a miscellaneous fill soil layer, a mucky soil layer, a cohesive soil layer and a silt layer from top to bottom in sequence.

Adopt the utility model provides a pile anchor underground structure for weak soil area utilizes bored concrete pile and enlarged footing prestressing force enlarged footing anchor rope to strut jointly, and the ground body is consolidated in the initiative, implements the effective control foundation ditch through the prestressing force and warp. Furthermore, by increasing the contact area between the poured concrete of the prestress expansion head anchor cable and the soil body, the frictional resistance between the soil body and the poured concrete is effectively increased, the length of the prestress expansion head anchor cable is shortened, and the construction difficulty is reduced. Further, the shear strength of foundation soil outside the foundation pit is utilized, the anchoring force of the prestressed expanded-head anchor cable is increased, and horizontal resistance is provided, so that the anti-overturning capacity of the cast-in-situ bored pile structure is enhanced, further, a water stopping part is arranged on the side wall of the excavation surface and the bottom of the foundation pit, water is drained in time, and the foundation pit support deformation caused by water burst of soft soil is prevented.

Drawings

Fig. 1 is a schematic view of a pile anchor foundation pit supporting structure for a soft soil area of the utility model;

fig. 2 is a schematic diagram of a large prestressed enlarged head anchor cable 3 in fig. 1;

FIG. 3 is a schematic view of the cast-in-situ bored pile of FIG. 1;

fig. 4 is a schematic cross-sectional view of the cast-in-situ bored pile of fig. 3.

Detailed Description

The principles and features of the present invention are described below in conjunction with the following drawings, the examples given are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

Referring to fig. 1 and 2, a pile anchor foundation pit supporting structure for soft soil area, including drilling bored concrete pile 1 and 3 prestressing force enlarged footing anchor ropes 3 that are parallel to each other, drilling bored concrete pile 1 is equipped with water-stop curtain 2 towards soil body 4 one side, drilling bored concrete pile 1 highly is greater than water-stop curtain 2, form and dig a lateral wall stagnant water structure, the opposite side sprays to concrete layer 6, the foundation pit bottom that concrete layer 6 corresponds is equipped with escape canal 7, form foundation pit bottom stagnant water structure, be convenient for in time the drainage. The prestressed enlarged head anchor cable 3 is obliquely arranged at an angle of 45 degrees between the bored pile 1 and a soil body outside a foundation pit, the soil body 4 is sequentially provided with a miscellaneous fill layer, a mucky soil layer, a cohesive soil layer and a silt layer from top to bottom, the prestressed enlarged head anchor cable 3 comprises a PVC sleeve 33, a steel strand free end 34, a common anchoring end 34 and an enlarged head anchoring end 35, the PVC sleeve 33 is embedded in the steel strand free end 34, the steel strand free end 34 is 5m, the steel strand free end is fixed on the waist beam 5 or the crown beam 10 through an anchor backing plate 32 and an OVM15-3\4 anchor 31, the diameter of the common anchoring end 34 is 500mm, the length of the common anchoring end is 6m, the enlarged head anchoring end 35 extends into the silt layer, the diameter is 800mm, the length of the enlarged head is 5m, and the tension at the prestressed steel strand free end 34 is transmitted to the anchoring end area to; the bonding area of the soil layer is increased through the common anchoring end 34 and the enlarged head anchoring end 35, the bonding friction acting force of the anchoring body and the soil layer is increased, and therefore the bearing effect is increased, and the pulling force of the free end 33 is transmitted to the deep position of the soil body 4.

Referring to fig. 3 and 4, the cast-in-situ bored pile 1 is obtained by pouring longitudinal bars 11, stiffening bars 12, spiral stirrups 13 and concrete 14 at longitudinal intervals, specifically, the stiffening bars 12 and the longitudinal bars 11 are bound and fixed by binding wires to form a steel bar framework, then the spiral stirrups 13 are arranged, the prestressed expanded-head anchor cables 3 are embedded in the soil body 4, and an anchor backing plate 32 and an anchor 31 are sequentially installed at the other ends of the prestressed expanded-head anchor cables 3 for fixation, so that the anti-overturning capacity of the cast-in-situ bored pile 1 can be improved.

To sum up, the utility model provides a pile anchor underground structure for weak soil area utilizes bored concrete pile and prestressing force enlarged footing anchor rope to strut jointly, and the ground body is consolidated in the initiative, implements effective control foundation ditch deformation through the prestressing force. Furthermore, by increasing the contact area between the poured concrete of the prestressed expanded head anchor cable and the soil body, the frictional resistance between the soil body and the poured concrete is effectively increased, the length of the prestressed expanded head anchor cable is shortened, and the construction difficulty is reduced. Furthermore, the shear strength of the foundation soil outside the foundation pit is utilized to increase the anchoring force of the prestressed expanded-head anchor cable and provide horizontal resistance, so that the anti-overturning capability of the cast-in-situ bored pile structure is enhanced.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The pile anchor foundation pit supporting structure for the soft soil area is characterized by comprising a cast-in-situ bored pile and a plurality of parallel prestressed expanded head anchor cables, wherein each prestressed expanded head anchor cable is 45 degrees in number^oThe anchor cable comprises a sleeve, a steel strand free end, a common anchoring end and an expanded head anchoring end, wherein the sleeve is pre-embedded in the steel strand free end, the steel strand free end is fixed on a waist beam or a crown beam of the cast-in-situ bored pile through an anchor backing plate and an anchorage device, the diameter of the common anchoring end is 500mm, the diameter of the expanded head anchoring end is 800mm, and the expanded head anchoring end extends into a silt layer in a soil body.

2. A pile anchor foundation pit supporting structure for a soft soil area according to claim 1, wherein the bored pile is obtained by longitudinally and intermittently pouring longitudinal bars, stiffening bars, spiral stirrups and concrete.

3. The pile-anchor foundation pit supporting structure for the soft soil area according to claim 1, wherein a waterproof curtain is arranged on one side of the cast-in-situ bored pile close to the soil body, and the height of the cast-in-situ bored pile is larger than that of the waterproof curtain, so that a side wall waterproof structure of the excavated surface is formed.

4. The pile-anchor foundation pit supporting structure for the soft soil area according to claim 1, wherein a concrete layer is sprayed on one side of the cast-in-situ bored pile, which is far away from the soil body, and a drainage ditch is formed at the bottom of the foundation pit corresponding to the concrete layer, so that a water stop structure at the bottom of the foundation pit is formed.

5. The pile anchor foundation pit supporting structure for the soft soil area of claim 1, wherein the length of the common anchoring end is 6m, and the length of the enlarged head anchoring end is 5 m.

6. The pile-anchor foundation pit supporting structure for the soft soil area according to claim 1, wherein the soil body is a miscellaneous fill layer, a mucky soil layer, a cohesive soil layer and a silt layer in sequence from top to bottom.