CN109868807B

CN109868807B - Expansion uplift anchor pile suitable for soft soil and loose rock soil

Info

Publication number: CN109868807B
Application number: CN201910186661.0A
Authority: CN
Inventors: 王智群; 殷树芳; 楼耀威
Original assignee: Geotechnical Technology Co ltd
Current assignee: Geotechnical Technology Co ltd
Priority date: 2019-03-13
Filing date: 2019-03-13
Publication date: 2021-08-31
Anticipated expiration: 2039-03-13
Also published as: CN109868807A

Abstract

The invention relates to an expansion uplift anchor rod pile suitable for soft soil and loose rock soil, and solves the problem that the existing uplift anchor rod pile has unobvious effect on foundation pit support, side slope support and tunnel reinforcement under the geological conditions of the soft soil and the loose rock soil. This device stock bottom center is the slip casting pipe, and slip casting pipe overcoat is equipped with cylinder type geotechnique bag, and the upper end and the lower extreme of geotechnique bag are sealed, and the outside of geotechnique bag is provided with the axial steel strand wires that a plurality of axes extend, and axial steel strand wires's upper end or lower extreme are fixed with the stock, and the other end is the free end, offer the slip casting hole along the helix around the pipe wall on the pipe wall of slip casting pipe, spiral steel strand wires have been tied up to the outside spiral of geotechnique bag, the slip casting hole screw direction that spiral steel strand wires and spiral were offered is unanimous, the pitch is the same, helix position misplaces each other. According to the invention, the spiral segment type with the alternative expansion degree is formed in the pattern layer, and the wave-shaped axial steel strand is matched, so that a more reliable anti-pulling effect can be provided.

Description

Expansion uplift anchor pile suitable for soft soil and loose rock soil

Technical Field

The invention belongs to the field of constructional engineering, relates to an anti-pulling anchor cable structure, and particularly relates to an expansion anti-pulling anchor rod pile suitable for soft soil and loose rock soil.

Background

The anchor rod is a rod piece system structure for reinforcing the rock-soil body, overcomes the defect that the tensile capacity of the rock-soil body is far lower than the compressive capacity through the longitudinal tension action of the anchor rod body, and increases the cohesiveness of the rock-soil body. From the mechanical point of view, the cohesive force C and the internal friction angle phi of the surrounding rock body are mainly improved. The anchor rod is used as a tension member penetrating into the stratum, one end of the anchor rod is connected with an engineering structure, the other end of the anchor rod penetrates into the stratum, the whole anchor rod is divided into a free section and an anchoring section, the free section is an area for transmitting the tension at the head of the anchor rod to an anchoring body, and the anchor rod is used for applying prestress to the anchor rod. In engineering technology, the side slope, the tunnel and the dam body can be reinforced. In actual construction engineering, the anchor rod is widely applied to foundation pit enclosure engineering, tunnel reinforcement and support engineering as a support mode. One end of the anchor rod is connected with the enclosure wall or the enclosure beam, and the other end of the anchor rod is anchored in the stable stratum, so that the water and soil pressure acting on the enclosure structure is transmitted to the anchoring section through the free section, and then the tension of the anchor rod is transmitted to the stable soil layer through the anchoring section. At present, urban construction is rapidly developed, urban land is gradually scarce, and engineering construction is carried out under the condition of increasingly poor soil bodies. Under the poor geological conditions, such as the geological conditions of soft soil and loose rock soil, the uplift resistance of the traditional anchor bolt support is greatly influenced by the geological conditions and can not meet the requirements any more, and the effect on foundation pit support, side slope support and tunnel reinforcement is not obvious.

Disclosure of Invention

The invention aims to solve the problems that the uplift capacity of the traditional anchor rod support is greatly influenced by geological conditions under the poor geological conditions, such as the geological conditions of soft soil and loose rock soil, the requirements can not be met any more and the effect on foundation pit support, side slope support and tunnel reinforcement is not obvious in the conventional uplift rod pile, and provides an expansion uplift anchor rod pile suitable for soft soil and loose rock soil, so that the uplift capacity of the whole uplift rod pile is improved, and the uplift rod pile has better support and reinforcement effects.

The technical scheme adopted by the invention for solving the technical problems is as follows: the utility model provides an inflation resistance to plucking stock stake suitable for weak soil and loose ground, includes the stock that the bottom inserted in the soil layer, its characterized in that: the stock is hollow structure, and stock bottom center is the slip casting pipe, and slip casting pipe overcoat is equipped with cylinder type geotechnological bag, and the upper end and the lower extreme of geotechnological bag are sealed, and the outside of geotechnological bag is evenly provided with the axial steel strand wires that a plurality of axes extend all around, and the upper end of axial steel strand wires or lower extreme are fixed with the stock, and the other end is the free end, offer the slip casting hole along the helix around the pipe wall on the pipe wall of slip casting pipe, spiral steel strand wires have been tied up to the outside spiral of geotechnological bag, the slip casting hole screw direction that spiral steel strand wires and spiral were seted up is unanimous, the pitch is the same, the helix position misplaces each other. The device is suitable for soft soil strata and loose rock soil, and the reinforcing steel bars and the grouting pipes are vibrated into the soil in the soft soil strata only by the vibrating machine; and need drill hole in advance in loose ground, the drilling depth will surpass about anchor rod design length 0.5m, after the drilling, with a polyethylene pipe recheck the hole depth to blow the hole with high-pressure wind, wait that downthehole dust blows totally, and when the hole depth was no less than anchor rod design length, extract the polyethylene pipe, the good drill way of stopper. The outer surface of the geotextile bag is adhered with an axial steel strand, and if the construction step of firstly drilling and then inserting the anchor rod is adopted, the upper end and the lower end of the axial steel strand can be selected to be fixed with the anchor rod; if the insertion is a vibration insertion, the axial steel strand is preferably fixed at the lower end to the anchor rod. The spiral steel strand can be tensioned and loose. In the grouting process, the geotextile bags are rapidly expanded at the positions aligned with the spiral lines of the grouting holes, and the positions aligned with the spiral steel strands are limited and cannot be expanded or slowly expanded, so that the geotextile bags form spiral section types with alternating expansion degrees after grouting is finished, and the axial steel strands are in wave shapes along the axial direction of the expansion sections. The occlusion effect of the structure and the soil layer is better, and a more reliable uplift resistant effect can be provided. In the prior art, the lower end of the anchor rod is generally an integrally expanded columnar expansion section which is easy to slide in soft soil and loose rock soil; in contrast, the spiral expanded geotextile bag expansion structure of the present application is more advantageous for bonding with soil layers. And the scheme grouting amount of this application is still less, and the underground soil layer receives the disturbance littleer, is more difficult for appearing the condition that ground gushed.

Preferably, the axial dislocation distance between the spiral steel strand and the grouting hole formed in the spiral is half of the pitch of the spiral steel strand.

Preferably, the spiral steel strand is disposed inside the axial steel strand. The axial steel strand and the outer surface of the earth bag slide relatively in the expansion process and are not limited by the spiral steel strand.

Preferably, the outer wall of the geotextile bag is also provided with a spiral threading loop arranged along the direction of the spiral steel strand. The spiral threading loop limits the running line of the spiral steel strand.

Preferably, the outer wall of the geotextile bag is further provided with an axial threading loop arranged along the direction of the axial steel strand. The axial threading loop limits the running line of the axial steel strand.

Preferably, the free ends of the axial steel strands are tied to the anchor rods by elastic tying bands. The elastic strapping tape prevents the free end of the axial steel strand from being scattered in the process of inserting the anchor rod into the soil layer; during grouting, the free ends of the axial steel strands can be pulled out of the elastic strapping tapes.

After grouting is completed, the geotextile bag forms a spiral segment type with alternating expansion degree, is matched with a wave-shaped axial steel strand, has a better occlusion effect with a soil layer, and can provide a more reliable uplift resistant effect; in addition, the grouting amount of the scheme of the invention is less, the underground soil layer is disturbed less, and the ground is difficult to gush.

Drawings

The invention will be further described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of one configuration of the present invention.

Fig. 2 is a schematic diagram of the structure of the spiral steel strand of the outer wall of the geotextile bag of the present invention.

Figure 3 is a schematic view of an expanded configuration of the present invention.

In the figure: 1. grouting pipe, 2 grouting holes, 3 geotextile bags, 4 axial steel strands, 5 spiral steel strands, 6 spiral threading loops.

Detailed Description

The invention is further illustrated by the following specific examples in conjunction with the accompanying drawings.

Example (b): an expansion uplift anchor pile suitable for soft soil and loose rock soil is shown in figures 1 and 2. This device includes that the bottom inserts the stock in the soil layer, the stock is hollow structure, and stock bottom center is slip casting pipe 1, and the slip casting outside of tubes cover is equipped with cylinder type geotechnological bag 3, and the upper end and the lower extreme of geotechnological bag seal, and the outside of geotechnological bag is surrounded and evenly is provided with the axial steel strand wires 4 that a plurality of axes extend, and the lower extreme and the stock of axial steel strand wires are fixed, and the other end is the free end. The grouting hole 2 is formed in the pipe wall of the grouting pipe 1 along a spiral line surrounding the pipe wall, the spiral steel strand 5 is spirally bound on the outer side of the geotextile bag, the spiral direction of the spiral steel strand is consistent with that of the grouting hole formed by the spiral, the screw pitch is the same, the positions of the spiral lines are staggered mutually, and the axial dislocation distance is half of the screw pitch of the spiral steel strand. The spiral steel strand 5 is arranged inside the axial steel strand 4. The outer wall of the geotextile bag is also provided with a spiral threading loop 6 arranged along the direction of the spiral steel strand. The outer wall of the geotextile bag can be provided with an axial threading loop arranged along the direction of the axial steel strand. The free ends of the axial steel strands are tied up on the anchor rods through elastic strapping tapes.

The device is suitable for soft soil strata and loose rock soil, and the reinforcing steel bars and the grouting pipes are vibrated into the soil in the soft soil strata only by the vibrating machine; and need drill hole in advance in loose ground, the drilling depth will surpass about anchor rod design length 0.5m, after the drilling, with a polyethylene pipe recheck the hole depth to blow the hole with high-pressure wind, wait that downthehole dust blows totally, and when the hole depth was no less than anchor rod design length, extract the polyethylene pipe, the good drill way of stopper. The outer surface of the geotextile bag is adhered with an axial steel strand, and if the construction step of firstly drilling and then inserting the anchor rod is adopted, the upper end and the lower end of the axial steel strand can be selected to be fixed with the anchor rod; if the insertion is a vibration insertion, the axial steel strand is preferably fixed at the lower end to the anchor rod. The spiral steel strand can be tensioned and loose. In the grouting process, the geotextile bags are rapidly expanded at the positions aligned with the spiral lines of the grouting holes, and the positions aligned with the spiral steel strands are limited and cannot be expanded or slowly expanded, so that the geotextile bags form spiral section types with alternating expansion degrees after grouting is finished, and the axial steel strands are in wave shapes along the axial direction of the expansion sections. The occlusion effect of the structure and the soil layer is better, and a more reliable uplift resistant effect can be provided.

Claims

1. The utility model provides an inflation resistance to plucking stock stake suitable for weak soil and loose ground, includes the stock that the bottom inserted in the soil layer, its characterized in that: the anchor rod is of a hollow structure, a grouting pipe is arranged in the center of the bottom end of the anchor rod, a cylindrical geotextile bag is sleeved outside the grouting pipe, the upper end and the lower end of the geotextile bag are sealed, a plurality of axially extending axial steel strands are uniformly arranged on the periphery of the outer side of the geotextile bag, the upper end or the lower end of each axial steel strand is fixed with the anchor rod, the other end of each axial steel strand is a free end, grouting holes are formed in the pipe wall of the grouting pipe along a spiral line surrounding the pipe wall, spiral steel strands are spirally tied up on the outer side of the geotextile bag, the spiral steel strands and the spirally formed grouting holes are consistent in spiral direction, the thread pitches are the same, and the positions of the spiral lines are staggered; spiral steel strand wires set up the inboard at axial steel strand wires, and the geotechnological bag forms the spiral segmental type that the inflation degree size is alternative after the slip casting is accomplished, and axial steel strand wires then are the wave type along the axial along the inflation segmental type.

2. The expansive uplift anchor pile suitable for soft soil and loose rock soil according to claim 1, wherein: the axial dislocation distance between the spiral steel strand and the grouting hole formed in the spiral is half of the pitch of the spiral steel strand.

3. An expansion uplift anchor pile suitable for soft soil and loose rock soil according to claim 1 or 2, wherein: the outer wall of the geotextile bag is also provided with a spiral threading loop arranged along the direction of the spiral steel strand.

4. An expansion uplift anchor pile suitable for soft soil and loose rock soil according to claim 1 or 2, wherein: the outer wall of the geotextile bag is also provided with an axial threading loop arranged along the direction of the axial steel strand.

5. An expansion uplift anchor pile suitable for soft soil and loose rock soil according to claim 1 or 2, wherein: the free ends of the axial steel strands are tied up on the anchor rods through elastic tying bands.