What is the difference between a jet grouting pile and a pendulum grouting pile?

The difference between the jet grouting pile and the pendulum spraying pile is that the rotary grouting pile should be rotated and lifted when working, and the pipeline can be inserted when the pendulum spraying pile is working.

High-pressure jet grouting pile.

It is to drill to the depth of the bottom of the designed pile with a drilling rig, and then use a high-pressure pump to spray the cement slurry into the soil layer horizontally through a special transverse nozzle at the end of the drill pipe. When the nozzle sprays the cement slurry, the rod rotates slowly on one side and slowly lifts on the other side, and the horizontal jet of the high-pressure cement slurry continuously cuts the soil layer and mixes with it. Finally, within the effective range of the jet force, a spiral disc is formed into a mixed solid, high-pressure jet grouting pile.

The construction of high-pressure pendulum spraying pile is completed by drilling with a drilling rig, and then inserting a rotary grouting pipe to spray cement slurry, and its construction process mainly includes hole lofting, drilling, grout preparation, and pendulum spraying grouting.

With the continuous development of engineering technology, new steel piles and reinforced concrete piles are more and more widely used in engineering construction. The characteristics of different pile types are also different.

I have experienced the rotary spray, but I have never done the pendulum spray, so I will talk about my views and we will communicate.

Let's talk about the drill pipe first, the rotary spraying is a 360° rotating spraying of cement slurry, while the pendulum spraying is only a swing at a certain angle, not a circle; In fact, I feel that there is still a difference in process and construction control factors, such as pressure; Besides, they serve different purposes, and I think what you're doing now is just spraying, right? Hope to communicate with you.

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Powder spraying pile and jet grouting pile are both commonly used foundation treatment methods in civil engineering, and they have some differences in construction principles and applications.

1.Construction Principle:

Powder spraying pile: Powder spraying pile is formed by mixing cement, lime and other materials with water to form a slurry, and the slurry is injected into the ground through a high-pressure pump to form a vertical or inclined pile body. The slurry solidifies in the ground to form a solid pile body, which is used to increase the bearing capacity and stability of the foundation.

Jet grouting pile: The jet grouting pile is formed by squeezing the soil into the hole by rotating the spray of high-pressure water and cement slurry while drilling in the ground. The pile body of the jet grouting pile is mainly composed of soil and cement slurry, which is used to improve the compactness and bearing capacity of the soil.

2.Construction Method:

Powder spraying pile: The construction of powder spraying pile requires the use of special spraying equipment to inject slurry into the ground to form a pile body. It is usually necessary to pre-drill or excavate the pit and spray it in the hole.

Jet grouting pile: I regret that the construction of jet grouting pile requires the use of a rotary grouting drilling rig, which squeezes the soil into a pile body by rotating the drill pipe and spraying water and cement slurry at the same time. The construction of the jet grouting pile does not need to be drilled in advance and can be carried out directly on the ground.

3.Applications:

Powder spraying pile: Powder spraying pile is suitable for all kinds of soil layers, especially for soft soil layers, silt layers and aquifers. It can be used for foundation treatment, underground engineering reinforcement, slope reinforcement, etc.

Jet grouting pile: Rotary grouting pile is suitable for all kinds of soil layers, especially for squeezable soil layers such as sand, silt and clay. It can be used for foundation treatment, underground engineering reinforcement, wall retaining construction, etc.

It should be noted that powder spraying pile and jet grouting pile are both a kind of foundation treatment method, and the specific choice of which method needs to be evaluated and selected according to the specific situation of the project, soil conditions and design requirements.

When it comes to the role of jet grouting piles, under normal circumstances, how do the personnel of China's construction enterprises carry out the construction of jet grouting pile projects, and what is the basic construction technology? The following is the relevant content of the professional construction terminology of jet grouting piles compiled by Zhongda Consulting, and the basic situation is as follows:

The jet grouting pile is to use the drilling rig to place the jet grouting pipe and the nozzle drill at the bottom of the pile at the design elevation, and the pre-prepared slurry is sprayed out of the nozzle at the side of the grouting pipe at high speed after the liquid flow obtains huge energy through the high-pressure generating device, forming a liquid flow with a high concentration of energy, which directly destroys the soil, and in the process of spraying, the drill pipe is lifted while rotating, so that the grout is fully stirred and mixed with the soil, and a columnar consolidation body of a certain diameter is formed in the soil, so that the foundation is reinforced. In construction, Jianhu is generally divided into two workflows, that is, drilling first and then spraying, then drilling and spraying, and then lifting and stirring to ensure the proportion and quality of slurry per meter. So under normal circumstances, how to carry out the construction of jet grouting piles in China, the main role is as follows:

Construction technology of rotary grouting pile:

1.High-pressure jet spraying will produce a large amount of cement slurry due to high-pressure air and high-pressure water cutting and replacement, and mud sedimentation sites should be set up on the spot.

2.Arrange high-pressure pumps, mud pump mixers, pulping material yards and water, electricity, slurry pipelines, etc., and carry out maintenance and debugging of machinery and equipment.

3.Hole lofting.

According to the design drawings and instructions, the hole position is lofting, and the method of skipping hole spraying is adopted.

4.Drilling puts the rig in place.

The drill bit is accurately positioned and centered, and the deviation between the drilling position and the design position is less than 10cm. The drill frame is corrected and flattened, the drill pipe is vertical, the inclination is less than or equal to, start drilling, and pay attention to the deviation of the drill pipe during the drilling process, and correct it in time. The borehole orifice is protected by a casing.

5.Prepare the slurry.

Use a mixer to fully stir the water and ordinary Portland cement according to the water-cement ratio of 1:1, prepare cement slurry, mix and spray at any time.

6.Intubation spraying.

The rotary grouting machine is in place, the levelness of the frame and the verticality of the spray main pipe are corrected, the medium pressure test spraying is used before the filling pipe is inserted into the high spray hole to check whether the spraying and grouting system is unblocked, and then the infusion pipe is inserted into the borehole design depth with a winch, and the jet grouting operation is started, the lifting speed and rotation speed are determined according to the pile formation experiment, and the rotation speed is determined by the pile formation experiment, and the sprinkler irrigation pipe is rotated while being lifted, and the spraying is stopped when the nozzle reaches the design length range, and the pouring pipe is put out of the orifice, and the static pressure grouting is carried out in the borehole to prevent the consolidation body from forming a concave shape.

7.Move the rack and flush the lines.

After the pouring is completed, the frame is moved, the piping equipment is flushed, and the construction of the next hole begins.

Zhongda Consulting takes the role of high-pressure jet grouting pile as an example, and the basic role is as follows:

The high-pressure jet grouting method can be used for the foundation reinforcement treatment of existing buildings and new buildings, the waterproof curtain of deep foundation pits, the slope soil retaining or water retention, the bottom of the foundation pit reinforcement, the prevention of pipe gushing and uplifting, the enclosure and reinforcement of underground large-diameter pipelines, the soil reinforcement or waterproofing of subway projects, reservoir dams, seawalls, river embankments, dam body dam foundation seepage prevention and reinforcement, and the construction of underground reservoir seepage interception dams and other projects.

<> high-pressure jet grouting pile is a high-pressure rotating nozzle to spray cement slurry into the soil layer and mix with the soil to form a continuous lap cement solidification. The high-pressure jet grouting pile is corrosive for the stratum with skeleton structure of pebbles, blocks and boulders in the bedrock and gravel soil, and the groundwater flow rate is too large and the groundwater has gushed water, and the groundwater is corrosive and should be used cautiously. The construction of high-pressure jet grouting pile occupies less land and has less vibration, but it is easy to pollute the environment and the cost is high.

1) The high-pressure jet grouting method is suitable for the treatment of silt, silty soil, flow plastic, soft plastic or plastic cohesive soil.

Silt, sand, loess, plain fill and gravel soil and other foundations.

2) When the soil contains more large particle size stones, hard clay soil, a large number of plant rhizomes or too much organic matter, the reinforcement of silt and peat soil and the collapsible loess foundation of existing buildings should be determined according to the field test results. Its applicability and technical parameters should be determined by high-pressure jet grouting test.

3) High-pressure jet grouting method, for the bedrock and gravel soil in the pebbles, stones, boulders in the skeleton structure of the formation, the groundwater flow rate is too large and the water has gushed out of the foundation engineering, the groundwater is corrosive, and the travel should be used carefully.

4) The high-pressure jet grouting method can be used for the foundation reinforcement treatment of existing buildings and new buildings, the waterproof curtain of deep foundation pits, the slope retaining soil or water retention, the bottom of the foundation pit with the town spike reinforcement, the prevention of pipe gushing and uplifting, the enclosure and reinforcement of underground large-diameter pipelines, the soil reinforcement or waterproofing of subway projects, reservoir dams, Peibu seawalls, river embankments, dam body dam foundation seepage prevention and reinforcement, and the construction of underground reservoir seepage interception dams and other projects.