Cement soil mixing pile repair pile head scheme, cement soil mixing pile construction scheme?

Pro, the scheme of cement-soil mixing pile to supplement the pile head can be determined according to the specific situation, and the following are some common schemes:1Enlargement of pile diameter:

If the cause of the pile head is insufficient pile diameter, it can be solved by expanding the pile diameter. The specific method is to reinforce the original pile head, and then use the cement-soil mixing pile to expand the pile diameter. 2.

Increase the pile length: If the cause of the pile head is insufficient pile length, it can be solved by increasing the pile length. The specific method is to reinforce the original pile head, and then use the cement-soil mixing pile to extend the pile length.

3.Reinforcement of the pile head: If the reason for the pile head is that the pile head strength is insufficient, it can be solved by reinforcing the pile head.

The specific method is to reinforce the original pile head, and can use reinforced concrete reinforcement or steel casing reinforcement and other methods. 4.Replace the pile head:

If the reason for the early pile head is that the pile head has been damaged and cannot be repaired, you can replace the pile head with consideration. This is done by removing the original pile head and then pouring a new one. It should be noted that when carrying out pile filling, it is necessary to choose the appropriate scheme according to the condition of the Gunatan body, and operate in strict accordance with the relevant specifications and standards to ensure the quality and safety of the pile filler.

The basic principle of the elimination of cement reinforced soil is based on the physical and chemical reaction process of cement reinforced soil, which is different from the hardening mechanism of concrete, due to the small amount of cement, cement is reacted under the surrounding of soil with a certain active medium, the hardening speed is slow, and the effect is complex, after cement hydrolysis and hydration generate various water compounds, some of them have ion exchange and agglomeration and solidification reaction, so that the strength of cement soil is greatly improved.

Construction method of cement-soil mixing pile:

1) Pile driver positioning, centering, leveling.

After the mixing pile position is placed, move the pile or move the mixing pile machine to reach the designated pile position, center, and level (level with a level).

2) Adjust the verticality of the guide frame.

The verticality of the guide frame is controlled in both directions by theodolite or wire hammer. According to the design and standard judgment requirements, the verticality is less than the pile length.

3) Pre-mix the slurry.

At the same time as the deep mixer is pre-stirred and sinking, the cement slurry is mixed in the background, and the slurry is put into the aggregate hopper before the slurry is pressed. Cement grade 425 ordinary silicate cement is selected to mix slurry, the water-cement ratio is controlled within the range, and the cement dosage per meter of deep mixing pile is not less than 50kg according to the design requirements.

4) Stir to sink.

Start the deep mixing pile driver turntable, and after the speed of the mixing head is normal, the drill pipe can be stirred along the side of the guide frame while sinking, and the sinking speed can be adjusted by the gear, and the working current should not be greater than the rated value.

5) Spraying stirring and lifting.

After sinking to the design depth, the mortar pump is opened, the slurry is sent to the slurry outlet of the mixing head through the pipeline, and the mixing pile driver and the chain tensioning device are started after the slurry is discharged, and the lifting speed determined by the design (the drill pipe is lifted while spraying and stirring, so that the grout and the soil are fully mixed.

6) Stir repeatedly to sink.

After the mixing drill bit is lifted to a height of 500mm above the pile top, the mortar pump is turned off, and the repeated stirring sinks to the design depth, and the sinking speed is carried out according to the design requirements.

7) Spraying repeated stirring and lifting.

After the sinking reaches the design depth, the spraying is repeatedly stirred and lifted until it reaches the ground.

8) Pile driver displacement.

After the construction of a pile, move the pile driver to the next pile position, and repeat the above steps to carry out the construction of the next pile.

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The production scheme of the precast concrete pile is as follows: (1) The pile-making project controls the tung burning system to do a good job in the overall control of the raw materials of the finished pile of the component factory and the overall control of the transportation quality of the pile-making process, which meets the requirements of the specification and the atlas. 1. Production procedures for concrete precast piles:

Make the site compacting and leveling, a formwork, binding, steel reinforcement, skeleton, installation of lifting rings, pouring concrete, curing to 30% strength - demoulding, supporting the spacer end template, brushing the isolation agent, tying steel bars, pouring spacer piles, concrete, overlapping the second layer of piles, curing to 70% strength, hoisting, 100% strength, transportation and stacking. 2. Production method (1), concrete prefabricated piles are prefabricated in the factory. (2) The long pile is made in sections, and the length of a single section is produced according to the design requirements of the drawings.

3) The position of the pile reinforcement should be strictly ensured, the pile tip should be aligned with the longitudinal axis, the main reinforcement connection of the reinforcement skeleton should be butt welding or arc welding, and the number of main reinforcement joints configured in the same section shall not exceed 50%; The distance between the cross-sections of the two adjacent main reinforcement joints should not be greater than 35dg (dg is the diameter of the main reinforcement), and the output should not be less than 500mm. There should be no joints within 1m of the pile top. The position of the reinforcement mesh at the top of the pile should be accurate, the protective layer at the top of the longitudinal reinforcement should not be too thick, and the distance of the reinforcement grid should be correct to prevent the pile head from being broken when hammering, and the top surface of the pile and the end face of the joint should be flat, and the tilt between the top plane of the pile and the longitudinal axis of the pile should not be greater than 3mm

4), pile concrete strength grade of C30, coarse aggregate with 5-40mm gravel or pebbles, with mechanical mixing concrete slump water greater than 6cm, pile concrete pouring should be from the top of the pile to the direction of the tip of the pile continuous pouring, shall not be interrupted, and should prevent the other end of the mortar accumulation too much, and with a vibrator he tired tamping. The joints of the piles should be flattened, so that the upper and lower piles can be aligned with each other, I hope mine can help you <>

Do you have any other questions?

The construction plan of bored pile repair should be determined according to the site situation. Generally, the distance from the center of the original pile is not less than the diameter of the pile (smaller pile.

The rotary digging method is the use of rotary digging pile driver operation, which is mainly used in the bridge and address situation is more complex and is not conducive to the conditions of manual digging pile construction. The advantage is that the hole forming efficiency is high, and the construction period can be considered if the construction period is relatively tight. The use of mud wall protection, after the hole, under the reinforcement cage, the use of underwater pouring into piles.

The disadvantage is that it is easy to perforate, collapse holes and encounter unknown obstacles (old pile foundation, granite) in the construction process, and the amount of concrete is not easy to control.

After the completion of the construction of the general pile foundation, the test is unqualified, and the pile may be designed, and the bearing capacity of the original pile foundation is generally not considered when the design and calculation of the pile is repaired, so the original pile you think does not exist, and the reason why the original pile is not taken out is that the cost cannot be drawn, right? When it does not exist, just build according to the new pile, use the original pile if you can use it, and scrap it if you can't use it.

Just follow the pile repair drawings issued by the design institute.

The construction of cement mixing pile is a complex work, in addition to the basic construction steps and specific schemes, considering the complexity of the site environment, it is necessary to be equipped with a set of professional cement mixing pile construction information monitoring system. Our job is to develop the construction monitoring system of various cement mixing piles, whether it is three-axis or five-axis, or single-shaft and double-shaft, it can be monitored, and the information can be uploaded to the cloud server in real time, and it can also be printed and exported remotely, which is very convenient.

1. It should be impossible to find the steel bar in general, unless your hole is deep, it should be impossible for the person who punches the hole, of course, if it can be sure that it is below, then keep looking for it, and then connect it to the elevation.

2. The cage is high, indicating that the time to pour underwater concrete is fast, and the cage is floating, strictly speaking, it should be reported to the supervisor and the owner, and the design representative to decide what to do.

3. Look at the degree of compactness, as well as whether the coarse aggregate is exposed, whether the mortar is too little, etc., not to take a hammer to knock it.

4. Regardless of whether it is reasonable or not, the scene generally does not seem to deal with much, directly connected to the reinforcement cage of the above column, and find a way to screw it over, I have seen the old bridge after the demolition of the pillar and the pile difference of half a pile diameter.

5. It is a good thing that the cushion has more points, as long as it does not increase its own weight excessively, it can better disperse the load, and think of the cushion as another layer of steps under the cushion cap.

6. Tamping is certain, as for the material, look at the drawing requirements, if there is no requirement, it doesn't matter, however, the general backfill material is better, otherwise, tamping this thing is not easy to do.

7. It should be dealt with, at least it should be leveled, otherwise how to pave the cushion, but what to overdig depends on the description of the drawings, if there is no special description on the drawings, who will pay you for the over-digging? In addition, if the silt is already the soil quality given on the drawings, from the design point of view, it is better not to disturb the undisturbed soil in general, so it is good to do it according to the drawings.

The first question, the key is to control the punching skill, if the impact can be too low, repeatedly hit the pile head, the pile can not go down but will break the pile head.

The second question, the unqualified quality of the hole is mainly due to insufficient hole depth, unsatisfactory hole verticality, too small hole diameter, or too large local hole diameter. The control verticality is mainly caused by the horizontal placement of the drilling rig, and the hole diameter is mainly caused by the insufficient diameter of the drill bit and the depth of the hole, mainly caused by measurement errors. The aperture is too large, which is generally caused by a collapsed hole.

The third question, formwork defects, the convention is mainly the formwork deformation, which is generally caused by the insufficient stiffness of the formwork or the use of the old formwork. There is also the template contaminated with oil, or the surface of the template has cement slurry.

First of all, it is predicted that the pile should be made in strict accordance with the design, and secondly, it can not be damaged during transportation and storage, and the pile cap and pile hammer should be on a vertical line to ensure its accurate position during construction.