CN205369234U - Freeze high pressure jet grouting pile - Google Patents

Abstract

The utility model discloses a frozen high-pressure rotary spraying pile, which comprises a high-pressure rotary spraying pile body, and a plurality of freezing pipes parallel to the center line of the pile body are uniformly arranged on the circumference of the high-pressure rotary spraying pile body and its center equidistant. The upper port of the pipe is higher than the upper end surface of the high-pressure rotary grouting pile body, and the upper end of the frozen pipe passes through the reinforced concrete ballast plate on the upper end surface of the high-pressure rotary grouting pile body, and is fixed by the reinforced concrete ballast plate. The utility model inserts a freezing pipe into the high-pressure rotary grouting pile for freezing to form a frozen high-pressure rotary grouting pile, which can effectively suppress the phenomenon of frost heaving and thawing, and can improve the high-pressure rotary grouting pile on the basis of ensuring the bearing capacity and waterproof performance of the stratum. Excellent shear resistance and bending resistance can also reduce the amount of cement used and save costs. The utility model can be applied to the enclosure structure of the foundation pit engineering, the soil body reinforcement at the end of the shield entrance and exit hole, and the foundation treatment engineering.

Description

Freezing high pressure rotary grouting pile

technical field

The utility model relates to a civil engineering technology, in particular to a frozen high-pressure rotary spraying pile.

Background technique

Artificial Ground Freezing (AGF) (referred to as "freezing method") is the use of artificial refrigeration technology to freeze the water in the formation, turn the natural rock and soil into frozen soil, increase its strength and stability, and isolate groundwater and The connection of underground engineering is a special construction technology for underground engineering construction under the protection of frozen walls. Its essence is to use artificial refrigeration to temporarily change the properties of rock and soil to strengthen the formation. The artificial soil freezing method is basically not limited by the support range and depth, and can effectively prevent water gushing and deformation of the adjacent upper body during urban excavation and drilling construction. One of the technical means.

The formation process of the artificial strata freezing frozen soil curtain (wall) is: circulating low-temperature refrigerant (salt water) in the freezing pipe, and continuously exchanging heat with the surrounding stratum through the freezing pipe. At the beginning, a frozen soil cylinder is formed around the freezing pipe. With the continuous supply of cooling capacity, the permafrost cylinders continue to expand, and the adjacent permafrost cylinders intersect to form a curtain of permafrost with a certain thickness and expand to both sides.

However, after the construction of artificial freezing method, frost heaving and thawing will occur in the surrounding strata. For the surrounding environment, the engineering properties of the soil and adjacent buildings will be adversely affected, such as causing foundation instability, causing adjacent buildings to tilt, When the cracks are serious, it will lead to accidents such as the collapse of buildings, or damage to underground pipelines and other adverse consequences.

Utility model content

The purpose of this utility model is to overcome the deficiencies of the prior art above, and provide a frozen high-pressure jet-spray pile, which adopts the method of inserting a freezing tube into the high-pressure jet-spray pile to freeze, forming a frozen high-pressure jet-spray pile, which can effectively suppress freezing The expansion, melting and settlement phenomenon, while ensuring the bearing capacity and waterproof performance of the ground, can not only improve the shear resistance and bending resistance of the high-pressure rotary grouting pile, but also reduce the amount of cement used, saving costs.

In order to achieve the above object, the utility model adopts the following technical solutions:

A frozen high-pressure rotary grouting pile, comprising a high-pressure rotary grouting pile body, a freezing tube parallel to the center line of the pile body is arranged at the center of the high-pressure rotary grouting pile body, and the upper port of the freezing tube is higher than the high-pressure rotary grouting pile body. Spray the upper end face of the pile body, and the upper end of the freezing pipe passes through the reinforced concrete ballast plate on the upper end face of the high-pressure rotary sprayed pile body, and is fixed by the reinforced concrete ballast plate.

A frozen high-pressure rotary grouting pile, comprising a high-pressure rotary grouting pile body, a number of freezing tubes parallel to the center line of the pile body are uniformly arranged on the circumference of the high-pressure rotary grouting pile body and its center, and the upper port of the freezing tube is as high as The upper end surface of the high-pressure rotary grouting pile body is released, and the upper end of the freezing pipe passes through the reinforced concrete ballast plate on the upper end surface of the high-pressure rotary grouting pile body, and is fixed by the reinforced concrete ballast plate.

A frozen high-pressure rotary grouting pile, comprising a high-pressure rotary grouting pile body, a freezing tube parallel to the centerline of the pile body is arranged at the center of the high-pressure rotary grouting pile body, A number of freezing pipes parallel to the center line of the pile body are evenly arranged on the equidistant circumference, the upper port of the freezing pipe is higher than the upper end surface of the high-pressure rotary grouting pile body, and the upper end of the freezing pipe passes through the upper end surface of the high-pressure rotary grouting pile body. Reinforced concrete township, and fixed by reinforced concrete township.

The diameter of the freezing tube is 89mm, 108mm, 127mm, 146mm, 159mm or 168mm.

The bottom of the freezing pipe is located 0.5-1m above the bottom of the pile body.

The freezing pipe is a seamless low-carbon steel pipe, PVC pipe, PPR pipe, ABS pipe or PE pipe.

The section of the freezing tube is circular, I-shaped, X-shaped, T-shaped or Y-shaped.

The bottom of the freezing tube is closed, and the upper opening of the freezing tube is blocked.

The joint of the frozen pipe adopts a threaded and welded structure, and the tensile strength is not less than 75% of the parent pipe.

After the construction of the reinforced frozen high-pressure rotary grouting pile is completed, the loose and broken part of the pile head is excavated to expose the 20cm~30cm frozen pipe head.

The high-pressure rotary grouting pile uses a high-pressure pump as the power source, and sprays the prepared slurry into the soil through the drill pipe of the drilling rig and the nozzle. The jet stream penetrates the soil within a certain range with huge energy, and slowly rotates in the nozzle. Cut the soil while advancing and retreating, and force the soil particles to mix with the slurry. After the slurry is solidified, a cylindrical cement-soil consolidation body, that is, a high-pressure jet grouting pile, is formed, which can significantly improve the strength and structural properties of the soil. When the high-pressure jet grouting piles are engaged with each other, a closed jet grouting curtain body is formed to play a role Anti-quick sand, anti-slip, anti-seepage, anti-slump effect.

The utility model implements the artificial freezing method in the high-pressure rotary spraying pile, which can effectively suppress the phenomena of frost heaving and thawing. At the same time, the high-pressure rotary grouting piles have insufficient shear and bending resistance. A freezing tube is inserted into the high-pressure rotary grouting piles to freeze, forming frozen high-pressure rotary grouting piles. On the basis of ensuring the bearing capacity and waterproof performance of the ground, it can not only improve the high-pressure The shear resistance and bending resistance of the rotary grouting pile can also reduce the amount of cement used and save costs. The utility model can be applied to the enclosure structure of the foundation pit engineering, the soil body reinforcement at the end of the shield entrance and exit hole, and the foundation treatment engineering.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment 1;

Fig. 2 is the structural representation of the utility model embodiment 2;

Fig. 3 is the structural representation of the utility model embodiment 3;

Fig. 4 is the construction process flowchart of an embodiment of the utility model;

Among them, 1. Frozen pipe, 2. High-pressure rotary grouting pile body,

detailed description

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Example 1:

As shown in Figure 1, a kind of frozen high-pressure rotary grouting pile comprises a high-pressure rotary grouting pile body 2, and a freezing pipe 1 parallel to the center line of the pile body is arranged at the center of the high-pressure rotary grouting pile body 2, The upper port of the freezing pipe 1 is higher than the upper end surface of the high-pressure rotary grouting pile body 2, and the upper end of the freezing pipe 1 passes through the reinforced concrete ballast plate on the upper end surface of the high-pressure rotary grouting pile body 2, and is fixed by the reinforced concrete ballast plate.

The freezing tube 1 has a diameter of 89mm, 108mm, 127mm, 146mm, 159mm or 168mm, and is inserted in the center of the pile body.

The upper end of the freezing pipe 1 is 0.5-1m higher than the upper end surface of the external high-pressure rotary grouting pile body 2 .

The bottom of the freezing pipe is located 0.5-1m above the bottom of the pile body.

The freezing pipe 1 is a seamless low-carbon steel pipe, PVC pipe, PPR pipe, ABS pipe or PE pipe. The section of the freezing tube is circular, I-shaped, X-shaped, T-shaped or Y-shaped. By circulating cold media such as low-temperature salt water and liquid nitrogen into the freezing pipe 1, the water in the formation is frozen into ice, and the rock and soil are turned into frozen soil.

The bottom of the freezing tube is closed, and the upper opening of the freezing tube is sealed. The joint of the frozen pipe adopts a threaded and welded structure, and the tensile strength is not less than 75% of the parent pipe. After the construction of the reinforced high-pressure rotary grouting pile is completed, the loose and broken part of the pile head is excavated to expose the 20cm-30cm frozen pipe head, and the frozen pipe is connected with a steel mesh along the pile top, and the township plate is poured with C20 concrete.

Example 2:

As shown in Figure 2, a frozen high-pressure jet grouting pile includes a high-pressure jet grouting pile body 2, and in the high-pressure jet grouting pile body 2, two holes parallel to the center line of the pile body are symmetrically arranged on a circumference equidistant from the center of the high-pressure jet grouting pile body 2. The freezing pipe 1, the upper port of the freezing pipe 1 is higher than the upper end surface of the high-pressure rotary grouting pile body 2, the upper end of the freezing pipe 1 passes through the reinforced concrete ballast plate on the upper end surface of the high-pressure rotary grouting pile body 2, and is formed by the reinforced concrete ballast plate fixed.

The freezing tube 1 has a diameter of 89mm, 108mm, 127mm, 146mm, 159mm or 168mm, and is inserted in the center of the pile body.

The upper end of the freezing pipe 1 is 0.5-1m higher than the upper end surface of the external high-pressure rotary grouting pile body 2 .

The bottom of the freezing pipe is located 0.5-1m above the bottom of the pile body.

The freezing pipe 1 is a seamless low-carbon steel pipe, PVC pipe, PPR pipe, ABS pipe or PE pipe. The section of the freezing tube is circular, I-shaped, X-shaped, T-shaped or Y-shaped. By circulating cold media such as low-temperature salt water and liquid nitrogen into the freezing pipe 1, the water in the formation is frozen into ice, and the rock and soil are turned into frozen soil.

The bottom of the freezing tube is closed, and the upper opening of the freezing tube is sealed. The joint of the frozen pipe adopts a threaded and welded structure, and the tensile strength is not less than 75% of the parent pipe. After the construction of the reinforced high-pressure rotary grouting pile is completed, the loose and broken part of the pile head is excavated to expose the 20cm-30cm frozen pipe head, and the frozen pipe is connected with a steel mesh along the pile top, and the township plate is poured with C20 concrete.

Example 3:

As shown in Fig. 3, a kind of frozen high-pressure rotary grouting pile comprises a high-pressure rotary grouting pile body 2, and a freezing pipe 1 parallel to the centerline of the pile body is arranged at the center of the high-pressure rotary grouting pile body 2, At the same time, six freezing pipes 1 parallel to the center line of the pile body are evenly arranged on the circumference equidistant from the center of the high-pressure rotary grouting pile body 2, and the upper ports of the freezing pipes 1 are higher than the upper end surface of the high-pressure rotary grouting pile body 2. , the upper end of the freezing pipe 1 passes through the reinforced concrete ballast plate on the upper end surface of the high-pressure rotary grouting pile body 2, and is fixed by the reinforced concrete ballast plate.

The freezing tube 1 has a diameter of 89mm, 108mm, 127mm, 146mm, 159mm or 168mm, and is inserted in the center of the pile body.

The upper end of the freezing pipe 1 is 0.5-1m higher than the upper end surface of the external high-pressure rotary grouting pile body 2 .

The bottom of the freezing pipe 1 is located 0.5-1 m above the bottom of the pile body 2 .

The freezing pipe 1 is a seamless low-carbon steel pipe, PVC pipe, PPR pipe, ABS pipe or PE pipe. The section of the freezing tube is circular, I-shaped, X-shaped, T-shaped or Y-shaped. By circulating cold media such as low-temperature salt water and liquid nitrogen into the freezing pipe 1, the water in the formation is frozen into ice, and the rock and soil are turned into frozen soil.

The bottom of the freezing tube is closed, and the upper opening of the freezing tube is sealed. The joint of the frozen pipe adopts a threaded and welded structure, and the tensile strength is not less than 75% of the parent pipe. After the construction of the reinforced high-pressure rotary grouting pile is completed, the loose and broken part of the pile head is excavated to expose the 20cm-30cm frozen pipe head, and the frozen pipe is connected with a steel mesh along the pile top, and the township plate is poured with C20 concrete.

The construction process of frozen high-pressure rotary grouting piles is shown in Figure 4.

1. The construction process of high-pressure rotary grouting piles is as follows:

(1) Rig positioning

Move the rotary grouting pile machine to the designated pile position, align the drill bit to the center of the hole position, and level the drilling machine at the same time, place it stably and horizontally, and the verticality deviation of the drill pipe is not more than 1% to 1.5%. After being in place, first conduct a low-pressure (0.5MPa) water jet test to check whether the nozzle is unblocked and whether the pressure is normal.

(2) Preparation of cement slurry

When the pile driver is shifted, it starts to mix the cement slurry according to the mix ratio determined by the design. First add water into the bucket, then pour in cement and external admixture, start the mixer and stir for 10 to 20 minutes, then unscrew the valve at the bottom of the mixing bucket, put in the first screen (aperture 0.8mm), filter and flow into The slurry pool is then pumped into the second filter screen (0.8 mm in aperture) by the mud pump, and flows into the slurry tank after the second filtration, and is ready for use when grouting.

(3) Drilling (triple pipe method)

When using a geological drilling rig to drill holes, the drill bit drills to the design elevation at the predetermined pile position (the pre-drilled hole diameter is 15cm).

(4) Intubation (single tube method, double tube method)

When the rotary jet grouting pipe is used for drilling operations, the two processes of drilling and intubation can be combined into one. When the first stage penetrates into the soil, it can be penetrated with the injection or vibration of the injection pipe itself. The process is: start the drilling rig, and at the same time turn on the high-pressure mud pump to deliver the cement slurry at low pressure, so that the drill pipe will vibrate along the guide frame, and the jet will sink into the hole; until the design elevation of the pile bottom, observe that the working current should not be greater than the rated value. After the triple tube drilling rig drills the hole, pull out the drill pipe, and then insert the rotary nozzle. During the intubation process, in order to prevent mud and sand from clogging the nozzle, a small pressure (0.5-1.0 MPa) can be used to inject water while lowering the tube.

(5) Lift the spray pipe and stir

After the spray pipe sinks to the design depth, stop drilling and rotate continuously, the pressure of the high-pressure mud pump increases to the construction design value (20-40MPa), and after sitting on the bottom for 30s, spray and rotate while strictly following the Lift the drill pipe at the lifting speed determined by design and test piles. If the double pipe method or triple pipe method is used for construction, after reaching the design depth, connect the high-pressure water pipe and air pressure pipe, start the high-pressure clean water pump, mud pump, air compressor and drilling rig to rotate, and use instruments to control the pressure, flow and When the air volume reaches the predetermined value, it starts to increase, and continues to rotate and increase until it reaches the expected reinforcement height and then stops.

(6) Treatment of the pile head

When the rotary nozzle is lifted close to the top of the pile, it should start from 1.0m below the pile top, slowly lift the rotary nozzle for a few seconds, and then slowly raise it upwards by 0.5m until the slurry stop on the pile top.

(7) In case of gravel stratum, in order to ensure the diameter of the pile, spraying and stirring can be repeated: repeat the steps of (4) to (6) above until the spraying pipe is raised to the stop surface, and then turn off the high-pressure mud pump (clear water pump, air compressor), stop the conveying of cement slurry (water, wind), rotate and lift the jet grout pipe out of the ground, and close the drilling rig.

(8) cleaning

Pour an appropriate amount of water into the slurry tank, turn on the high-pressure pump, and clean the remaining cement slurry in all pipelines until it is basically clean. And clean the soil adhering to the spray pipe head.

(9) shift

Move the pile driver to carry out the construction of the next pile.

(10) Filling slurry

After the jet grouting operation is completed, due to the water separation effect of the grout, there are generally different degrees of shrinkage, which makes the top of the consolidated body appear concave, and the cement grout with a water-cement ratio of 1.0 must be replenished in time.

2. Main construction technical parameters recommended for high-pressure rotary grouting piles

(1) Single tube method

The slurry pressure is 20-40MPa, the slurry specific gravity is 1.30-1.49, the rotary spray speed is 20r/min, the lifting speed is 0.2-0.25m/min, the nozzle diameter is 2-3mm, the slurry flow rate is 80-100L/min (depending on the diameter of the pile, the flow rate can be increased) .

(2) Double pipe method

The slurry pressure is 20-40MPa, and the compressed air pressure is 0.7-0.8MPa.

(3) triple tube method

The slurry pressure is 0.2-0.8MPa, the slurry specific gravity is 1.60-1.80, the compressed air pressure is 0.5-0.8MPa, and the high-pressure water pressure is 30-50MPa.

3. The construction method and precautions of the freezing pipe are as follows:

(1) Construction method

After the construction of each high-pressure rotary grouting pile is completed, reinforcement materials will be constructed immediately. The reinforced material is frozen pipe, and the diameter of the frozen pipe is usually 89, 108, 127, 146, 159 and 168mm, which is selected according to the diameter of the high-pressure jet grouting pile. The freezing tube is inserted in the center of the pile body, or is set around the circumference of the center of the pile body. The insertion depth of the freezing tube is generally 0.5-1m shorter than that of the external jet grouting pile. The material of the freezing pipe is usually seamless low-carbon steel pipe, and plastic pipes such as PVC, PPR, ABS, PE, etc. can also be used; the cross section of the freezing pipe is usually round, and can also be "I-shaped", "X-shaped", "T-shaped" , "Y-shaped" and other special-shaped sections.

The freezing pipe must be inserted before the cement soil of the jet grouting pile hardens. The outer surface of the selected frozen pipe must be straight and smooth. First, manually press a part of the frozen pipe into the center of the pile, and then use a pile driver to press all the remaining part of the frozen pipe into the cement soil. After the construction of the reinforced high-pressure rotary grouting pile is completed, the loose and broken part of the pile head is excavated to expose the 20cm-30cm frozen pipe head, and the frozen pipe is connected with a steel mesh along the pile top, and the township plate is poured with C20 concrete.

(2) Precautions

A. The freezing pipe 1 must be inserted immediately after the drill pipe of the rotary grouting pile machine is raised, so as to ensure that it is completed before the cement soil is not condensed.

B. The joint of frozen pipe 1 is threaded and welded, and the tensile strength is not less than 75% of the main pipe.

C. Before the freezing tube 1 is inserted, the piping must be installed to ensure that the concentric axes of the freezing tube coincide.

D. After the freezing tube 1 is inserted, block the tube opening with a wooden plug to prevent foreign matter from falling into the freezing tube.

Although the specific implementation of the utility model has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the utility model. Those skilled in the art should understand that on the basis of the technical solution of the utility model, those skilled in the art do not need to Various modifications or deformations that can be made with creative efforts are still within the protection scope of the present utility model.

Claims (7)

1. a kind of freezing high-pressure rotary grouting pile, it is characterized in that, comprise high-pressure rotary grouting pile body, be evenly provided with some freezing pipes parallel to the centerline of described pile body on the circumference equidistant from the center of high-pressure rotary grouting pile body, The upper port of the freezing pipe is higher than the upper end surface of the high-pressure rotary grouting pile body, and the upper end of the freezing pipe passes through the reinforced concrete ballast plate on the upper end surface of the high-pressure rotary grouting pile body, and is fixed by the reinforced concrete ballast plate. 2. a kind of freezing high-pressure rotary grouting pile, it is characterized in that, comprise high-pressure rotary grouting pile body, a freezing pipe parallel with the center line of described pile body is set at the center of described high-pressure rotary grouting pile body, simultaneously at high pressure A number of freezing pipes parallel to the center line of the pile body are evenly arranged on the circumference of the jet grouting pile body equidistant from the center. The reinforced concrete township plate on the upper end face of the sprayed pile body is fixed by the reinforced concrete township board. 3. The frozen high-pressure jet grouting pile according to claim 1 or 2, wherein the diameter of the frozen pipe is 89mm, 108mm, 127mm, 146mm, 159mm or 168mm. 4. The frozen high-pressure jet grouting pile according to claim 1 or 2, wherein the bottom of the frozen pipe is located 0.5-1 m above the bottom of the pile body. 5. The frozen high-pressure jet grouting pile as claimed in claim 1 or 2, wherein the frozen pipe is a seamless low-carbon steel pipe, a PVC pipe, a PPR pipe, an ABS pipe or a PE pipe. 6. The frozen high-pressure jet grouting pile according to claim 1 or 2, wherein the section of the frozen pipe is circular, I-shaped, X-shaped, T-shaped or Y-shaped. 7. The frozen high-pressure jet grouting pile according to claim 1 or 2, characterized in that, the bottom of the frozen pipe is closed, and the upper opening of the frozen pipe is blocked.