Construction method for foundation pile in settlement sensitive area

Abstract

The invention relates to the technical field of foundation pile construction, and discloses a foundation pile construction method in a settlement sensitive area, which comprises the following steps: step 1, prefabricating a debonding sleeve; secondly, the top and the bottom of the outer wall of the debonding sleeve are wrapped with compressible materials respectively, and a grouting pipe and an exhaust pipe are installed on the debonding sleeve in advance; thirdly, a temporary pile casing is installed in the foundation pile; fourthly, drilling is conducted in the foundation pile; fifthly, the debonding sleeve is fixed to the outer ring of the reinforcement cage through welding; sixthly, a debonding sleeve and a reinforcement cage are put down, and grouting is conducted through a grouting pipeline till the exhaust pipe returns grout; seventhly, a concrete pouring guide pipe is installed, and concrete is poured; and 8, the concrete pouring guide pipe and the temporary pile casing are pulled out. The pile side friction resistance around the foundation pile can be reduced, disturbance to a surrounding soil body structure is reduced, and therefore the construction difficulty and risk in a settlement sensitive area are reduced, the construction efficiency is improved, and the safety and reliability of engineering are guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pile construction, in particular to a pile construction method in a settlement sensitive area. BACKGROUND

[0002] In modern urban construction, piles are a key component of supporting structures, and their construction quality is crucial to the stability of the overall structure. However, pile construction in settlement sensitive areas often faces severe challenges. Because the foundation soil in settlement sensitive areas is prone to excessive settlement or deformation during construction, it can lead to instability or even damage to the structure. Traditional construction methods are not ideal in reducing pile side friction, leading to longer construction periods, increased costs, and even affecting the long-term stability of the structure.

[0003] Currently, there are limited means to address the problem of pile side friction. Common methods include applying lubricants to the pile side surface or using a vibrator to reduce friction, but these methods have obvious limitations in practical application and are less effective in eliminating pile side friction.

[0004] Therefore, a pile construction method in a settlement sensitive area is proposed. SUMMARY

[0005] The purpose of the present application is to provide a pile construction method in a settlement sensitive area, aiming to solve or improve at least one of the above technical problems.

[0006] To achieve the above purpose, the present application provides the following scheme: the present application provides a pile construction method in a settlement sensitive area, comprising the following steps:

[0007] Step one, prefabricate a debonding sleeve;

[0008] Step two, wrap the top and bottom of the outer wall of the debonding sleeve with compressible material, and pre-install a grouting pipe and an exhaust pipe on the debonding sleeve;

[0009] Step three, install a temporary casing in the pile;

[0010] Step four, drill a hole in the pile;

[0011] Step five, fix the debonding sleeve to the outer ring of the steel reinforcement cage by welding;

[0012] Step six, lower the debonding sleeve and the steel reinforcement cage, and perform grouting through the grouting pipe until the exhaust pipe returns the grout;

[0013] Step seven, after the debonding sleeve grouting is completed, install a concrete pouring guide pipe and pour concrete;

[0014] Step eight, after the concrete pouring is completed, the concrete pouring guide pipe and the temporary pile casing are pulled out, the debonding sleeve pipe is left in the original position as the permanent pile casing, and the pile construction is completed.

[0015] According to the pile construction method in the settlement sensitive area provided by the application, the outer wall of the debonding sleeve pipe is provided with a self-adhesive asphalt film.

[0016] According to the pile construction method in the settlement sensitive area provided by the application, the specific operation of step five is that a positioning point is marked on the first reinforcement cage, and the debonding sleeve pipe is installed on the first reinforcement cage and fixed to the outer ring of the reinforcement cage through welding.

[0017] According to the pile construction method in the settlement sensitive area provided by the application, the specific operation of step four is that a drilling device is used to drill a hole in the pile, and the drilling depth is greater than the height of the debonding sleeve pipe.

[0018] According to the pile construction method in the settlement sensitive area provided by the application, the size of the drill bit of the drilling device is matched with the size of the temporary pile casing.

[0019] According to the pile construction method in the settlement sensitive area provided by the application, the spacing between the compressible material at the top and the outer wall top of the debonding sleeve pipe is 80mm-120mm.

[0020] The spacing between the compressible material at the bottom and the outer wall bottom of the debonding sleeve pipe is 80mm-120mm.

[0021] According to the pile construction method in the settlement sensitive area provided by the application, in step six, a high-pressure grouting device is used to perform grouting through a grouting pipeline, so that the interlayer between the debonding sleeve pipe and the temporary pile casing is filled with grouting.

[0022] According to the pile construction method in the settlement sensitive area provided by the application, in step eight, after the temporary pile casing is pulled out, the pulled-out temporary pile casing is checked.

[0023] According to the pile construction method in the settlement sensitive area provided by the application, the compressible material is a compressed sponge.

[0024] The application discloses the following technical effects:

[0025] By using the debonding sleeve pipe, the pile side friction around the pile can be reduced, the disturbance to the surrounding soil structure can be reduced, the construction efficiency can be improved, the construction period can be shortened, the cost can be reduced, the safety and reliability in the construction process can be ensured, more effective technical support is provided for the pile construction in the settlement sensitive area, and the steady progress of urban construction is ensured.

[0026] The present application reduces the friction between the foundation pile and the soil by installing the debonding sleeve, forms a slip surface between the foundation pile and the soil around the foundation pile, thereby forms an isolation between the soil layer and the foundation pile, the movement of any stratum around will not exert stress on the isolated foundation pile, on the contrary, the foundation pile will not exert stress on the stratum, and then the side friction resistance of the foundation pile can be significantly reduced, thereby reducing the construction difficulty and risk in the settlement sensitive area.

[0027] The present application avoids the cumbersome process of on-site processing, makes the construction process more simple and efficient, reduces the influence of the foundation pile construction on the overall structure in the settlement sensitive area by effectively reducing the side friction resistance around the foundation pile, and ensures the safety and reliability of the project. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only represent some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0029] Figure 1 Construction schematic of the present application Figure I ;

[0030] Figure 2 Construction schematic of the present application Figure II ;

[0031] Figure 3 Structure schematic of the debonding sleeve in the present application.

[0032] 1, debonding sleeve; 2, compressible material; 3, grouting pipe; 4, exhaust pipe; 5, temporary casing; 6, ground elevation; 7, steel reinforcement cage; 8, self-adhesive asphalt film. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only represent some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the scope of protection of the present application.

[0034] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0035] With reference to Figures 1-3 , the present application provides a foundation pile construction method in a settlement sensitive area, comprising the following steps:

[0036] Step one, prefabricate the debonding sleeve 1;

[0037] Step two, wrap the debonding sleeve 1 with compressible material 2 on the top and bottom of the outer wall, and pre-install the grouting pipe 3 and exhaust pipe 4 on the debonding sleeve 1;

[0038] Step three, install the temporary casing 5 in the pile;

[0039] Step four, drill a hole in the pile;

[0040] Step five, fix the debonding sleeve 1 to the outer ring of the reinforcement cage 7 by welding;

[0041] Step six, lower the debonding sleeve 1 and the reinforcement cage 7, and grout through the grouting pipe 3 until the exhaust pipe 4 returns the grout;

[0042] Step seven, after the debonding sleeve 1 is grouted, install the concrete pouring guide pipe and pour concrete;

[0043] Step eight, after the concrete pouring is completed, remove the concrete pouring guide pipe and the temporary casing 5, and leave the debonding sleeve 1 as a permanent casing in place, and complete the pile construction;

[0044] By using the debonding sleeve 1, the pile side friction resistance around the pile can be reduced, the disturbance to the surrounding soil structure can be reduced, the construction efficiency can be improved, the construction period can be shortened, the cost can be reduced, and the safety and reliability during construction can be ensured, which provides more effective technical support for pile construction in settlement sensitive areas, and ensures the steady progress of urban construction;

[0045] By installing the debonding sleeve 1, the friction between the pile and the soil is reduced, a slip surface is formed between the pile and the surrounding soil, the soil layer and the pile are isolated, any movement of the surrounding stratum does not exert stress on the isolated pile, and vice versa, the side friction resistance of the pile can be significantly reduced, thereby reducing the construction difficulty and risk in the settlement sensitive area;

[0046] By prefabricating the debonding sleeve 1, the cumbersome process of on-site processing is avoided, the construction process is more simple and efficient, the side friction resistance around the pile is effectively reduced, the influence of pile construction on the overall structure in the settlement sensitive area is reduced, and the safety and reliability of the project are ensured.

[0047] To further optimize the solution, the outer wall of the debonding sleeve 1 is provided with a self-adhesive asphalt film 8; the high adhesion and low friction characteristics of the asphalt material are utilized to play a dual role in the foundation pile construction and subsequent use. During the construction stage, when the self-adhesive asphalt film 8 contacts the surrounding soil, it can fit tightly to the surface of the soil, forming a continuous isolation layer, reducing the friction generated by the direct contact between the soil particles and the debonding sleeve 1. At the same time, the asphalt material has good flexibility and ductility, and can adapt to slight deformations of the soil, avoiding damage to the debonding sleeve 1 due to soil squeezing. During the foundation pile use stage, when the stratum moves, the low friction characteristics of the self-adhesive asphalt film 8 make it easier for the debonding sleeve 1 and the soil to slide relative to each other, further reducing the pile side friction resistance, enhancing the isolation effect of the debonding sleeve 1, ensuring stress isolation between the foundation pile and the stratum, effectively reducing the impact of stratum movement on the foundation pile, and also reducing the reaction force of the foundation pile on the stratum.

[0048] To further optimize the solution, the specific operation of step five is: mark the positioning point on the first section of the steel cage 7, and install the debonding sleeve 1 on the first section of the steel cage 7, and fix the debonding sleeve 1 to the outer ring of the steel cage 7 by welding; the positioning point determines the specific position of the debonding sleeve 1 on the outer ring of the steel cage 7 according to the design requirements to ensure the accuracy and consistency of its installation position. During the installation process, the construction personnel use the positioning point as a reference to accurately place the debonding sleeve 1 and fix it by welding. This operation method avoids the arbitrariness of the installation of the debonding sleeve 1, and prevents the debonding sleeve 1 from being unevenly stressed or affecting the overall performance of the pile due to deviation in the installation position. By installing it on the first section of the steel cage 7, the debonding sleeve 1 and the steel cage 7 can work better together during the subsequent lowering process, ensuring the stability and reliability of the debonding sleeve 1 in the pile, and also facilitating quality control and inspection during the construction process.

[0049] To further optimize the solution, the specific operation of step four is: use drilling equipment to drill a hole in the foundation pile, and the drilling depth is greater than the height of the debonding sleeve 1; provide sufficient space for the lowering of the debonding sleeve 1 and the steel cage 7. A deeper drilling depth ensures that the debonding sleeve 1 can be smoothly lowered to the predetermined position, avoiding the situation where the bottom of the debonding sleeve 1 cannot reach the designed depth due to the drilling being too shallow, affecting the isolation effect and bearing performance of the foundation pile. At the same time, the reserved depth space can accommodate the sediment that may be generated during the grouting process, preventing the accumulation of sediment from affecting the contact between the debonding sleeve 1 and the soil at the bottom of the foundation pile, and ensuring the grouting quality and the stability of the foundation pile. In addition, sufficient drilling depth can also buffer the impact force of the debonding sleeve 1 and the steel cage 7 during the lowering process to a certain extent, reduce the disturbance to the soil of the hole wall, and help maintain the stability of the hole wall, creating good conditions for subsequent grouting and concrete pouring processes.

[0050] Further optimization scheme, the drill bit size of the drilling equipment is matched with the size of the temporary casing 5; during the drilling process, the appropriate drill bit size can ensure that the drilled hole wall is regular and closely fits the temporary casing 5, preventing the hole wall from collapsing. The temporary casing 5 can effectively protect the hole mouth, avoid the hole mouth soil from being affected by factors such as water flow scouring and vibration to collapse or deform, and maintain the stability of the drilled hole. At the same time, the matched size makes the temporary casing 5 be able to be smoothly lowered into the hole and keep a vertical state, providing accurate guidance for the subsequent lowering of the debonding casing 1 and the reinforcement cage 7, and ensuring the accuracy of the installation position of each component. In addition, the matched size can better control the flow of grout and concrete during grouting and concrete pouring, prevent grout or concrete from flowing out from the gap between the temporary casing 5 and the hole wall, and ensure the construction quality.

[0051] Further optimization scheme, the distance between the compressible material 2 at the top and the outer wall of the debonding casing 1 at the top is 80mm-120mm; in this embodiment, it is preferably 100mm;

[0052] The distance between the compressible material 2 at the bottom and the outer wall of the debonding casing 1 at the bottom is 80mm-120mm; in this embodiment, it is preferably 100mm.

[0053] Further optimization scheme, in step six, high-pressure grouting equipment is used to grout through the grouting pipe 3, so that the interlayer between the debonding casing 1 and the temporary casing 5 is filled with grout; the grout is injected into the interlayer between the debonding casing 1 and the temporary casing 5 by high pressure. High-pressure grouting can make the grout have stronger fluidity and permeability, ensure that the grout can fully fill every corner in the interlayer, and discharge the air in the interlayer to avoid the formation of cavities or voids. Sufficient grouting pressure makes the grout tightly combined with the debonding casing 1, the temporary casing 5 and the surrounding soil, enhances the integrity and density of the interlayer, improves the connection strength between the debonding casing 1 and the temporary casing 5, and also strengthens the isolation effect of the debonding casing 1 and the surrounding soil. This high-pressure grouting method can also reinforce the surrounding soil to a certain extent, reduce the porosity of the soil, and reduce the compressibility of the soil, further ensuring the stability of the foundation pile in the settlement sensitive area.

[0054] Further optimization scheme, in step eight, after removing the temporary casing 5, the removed temporary casing 5 is checked; the purpose is to evaluate the use state and performance of the temporary casing 5 in the construction process. By checking the appearance of the temporary casing 5, such as whether there is deformation, damage, corrosion and the like, it can be judged whether the temporary casing 5 is subjected to excessive external force during the drilling protection process, and whether it affects the stability of the drilling and the construction quality. Check the inner wall of the temporary casing 5 to see if there is residual grout, wear and tear, etc., to understand the interaction between the temporary casing 5 and the grout and concrete during the grouting and concrete pouring process, to determine whether the construction process is smooth and whether there are problems such as grout leakage. The inspection results of the temporary casing 5 can provide a reference for subsequent construction, and if problems are found, the construction process can be adjusted or the temporary casing 5 can be replaced to ensure construction quality and safety, while also helping to reuse the temporary casing 5 and reduce construction costs.

[0055] Further optimization scheme, the compressible material 2 adopts compressed sponge; the compressed sponge can prevent concrete debris from falling in, and utilizes the high elasticity and good compression-rebound performance of the compressed sponge. When subjected to soil pressure, the compressed sponge can quickly compress and deform, absorb the stress of the soil, effectively buffer the pressure of the soil on the debonding sleeve 1, and protect the debonding sleeve 1 from being damaged. When the soil pressure decreases or disappears, the compressed sponge can quickly rebound to restore part of the volume and maintain the protection of the debonding sleeve 1. Moreover, the compressed sponge is soft and will not scratch or wear the outer wall of the debonding sleeve 1.

[0056] Further optimization scheme, during the construction of the foundation pile, a plurality of high-precision settlement monitoring points are arranged around the construction area, and automatic settlement monitoring equipment is used to collect data in real time. When the drilling, lowering of the debonding sleeve 1 and steel reinforcement cage 7, grouting and other processes are carried out, the settlement changes of the surrounding soil are continuously monitored, and the construction is suspended when the settlement rate exceeds the preset threshold.

[0057] Further optimization scheme, during the concrete pouring process, ultrasonic pile body integrity detection is carried out in stages. When the concrete is poured to a certain height (such as 3-5 meters each time), the ultrasonic detection probe is placed in the embedded detection pipe, ultrasonic waves are emitted and reflected signals are received. According to the signals, the density of the pile body concrete, whether there are cavities or cracks and other defects are analyzed.

[0058] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0059] Obviously, the above-mentioned embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation manners of the present application. Based on the above description, other different forms of changes or variations can also be made by those skilled in the art. Here, it is not necessary and also impossible to enumerate all the implementation manners. Any modification, equivalent replacement and improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for constructing foundation piles in a settlement-sensitive area, characterized in that: The following steps are involved: Step 1, prefabricating a debonding casing (1); Step 2: Wrap the top and bottom of the outer wall of the debonding sleeve (1) with compressible material (2), and pre-install a grouting pipe (3) and an exhaust pipe (4) on the debonding sleeve (1); Step 3: Install the temporary casing (5) in the foundation pile; Step 4: Drill holes in the foundation piles; Step 5: Fix the debonding sleeve (1) to the outer ring of the steel cage (7) by welding; Step 6: Lower the debonding sleeve (1) and the steel cage (7), and grout through the grouting pipe (3) until the exhaust pipe (4) returns to grout; Step 7: After the grouting of the debonding casing (1) is completed, the concrete pouring conduit is installed and concrete is poured; Step 8: After the concrete pouring is completed, the concrete pouring conduit and the temporary casing (5) are removed, and the debonding sleeve (1) is left in its original position as a permanent casing, completing the foundation pile construction.

2. The method for constructing foundation piles in a settlement-sensitive area according to claim 1, characterized in that: The outer wall of the debonding sleeve (1) is provided with a self-adhesive asphalt film (8).

3. The method for constructing foundation piles in a settlement-sensitive area according to claim 1, characterized in that: The specific operation of step five is: marking a positioning point on the first section of the steel cage (7), installing a debonding sleeve (1) on the first section of the steel cage (7), and fixing the debonding sleeve (1) to the outer ring of the steel cage (7) by welding.

4. The method for constructing foundation piles in a settlement-sensitive area according to claim 1, characterized in that: The specific operation of step 4 is: using drilling equipment to drill a hole in the foundation pile, and the drilling depth is greater than the height of the debonding casing (1).

5. The method for constructing foundation piles in a settlement-sensitive area according to claim 4, characterized in that: The size of the drill bit of the drilling equipment is adapted to the size of the temporary casing (5).

6. The method for constructing foundation piles in a settlement-sensitive area according to claim 1, characterized in that: The distance between the compressible material (2) at the top and the top of the outer wall of the debonding sleeve (1) is 80 mm to 120 mm; The distance between the compressible material (2) at the bottom and the bottom of the outer wall of the debonding sleeve (1) is 80 mm to 120 mm.

7. The method for constructing foundation piles in a settlement-sensitive area according to claim 1, characterized in that: In the step six, high-pressure grouting equipment is used to perform grouting through the grouting pipe (3), so that the grouting fills the interlayer between the debonding casing (1) and the temporary casing (5).

8. The method for constructing foundation piles in a settlement-sensitive area according to claim 1, characterized in that: In the step eight, after the temporary casing (5) is removed, the removed temporary casing (5) is inspected.

9. The method for constructing foundation piles in a settlement-sensitive area according to claim 1, characterized in that: The compressible material (2) is a compressed sponge.

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