Prestressed pipe pile construction method

Abstract

The invention relates to a prestressed pipe pile construction method, which belongs to the field of construction engineering pile foundation construction, and comprises the following steps: carrying out geological exploration on a pile position to obtain exploration data, and constructing a pile position three-dimensional geological model based on the exploration data; and on the basis of the three-dimensional geologic model, the pile position is preprocessed so as to weaken the soil squeezing effect. Through fine geological supplementary survey and three-dimensional modeling, the soil layer sequence and the rock surface elevation of each pile position are accurately predicted, then soil body pretreatment is correspondingly carried out, and the problems that the soil squeezing effect is remarkable, and pile sinking is difficult and deviates are solved. After the tubular pile is driven, cement-based slurry is injected into a pile-liquefied sand interface to form a consolidation body, so that the liquefaction resistance of soil around the pile and the pile side friction resistance are improved, and the problem that liquefied sand threatens the stability of a pile foundation is solved. Intelligent pile pressing equipment which has a real-time data acquisition function and interacts with refined geological supplementary survey and three-dimensional modeling data is used, comprehensive monitoring and feedback of the pipe pile driving process are achieved, and it is guaranteed that construction is safe and smooth.

Description

Technical Field

[0001] This application relates to the field of pile foundation construction in building engineering, and in particular to a method for constructing prestressed pipe piles. Background Technology

[0002] Prestressed concrete pipe piles are widely used in building foundations due to their advantages such as factory production, high strength, and fast construction speed. However, in coastal areas, where marine-continental transitional sedimentary layers are widespread and geological conditions are extremely complex, traditional pipe pile construction methods still face many unresolved problems, such as: 1. Significant soil squeezing effect: Driving piles in deep soft soil will severely squeeze the surrounding soil, causing the driven piles to float, deviate, or even break, posing a threat to nearby buildings and underground pipelines.

[0003] 2. Difficulty and deviation in pile driving: Obstacles (stones, concrete blocks) in the upper fill and hard weathered rock interlayers in the bearing layer can easily lead to pile head damage, pile tilting, or failure to drive to the design elevation.

[0004] 3. Liquefaction of sand threatens the stability of pile foundation: Under the action of earthquake, the liquefaction of sand will significantly reduce the frictional resistance around the pile, and even generate negative frictional resistance, which seriously affects the vertical and horizontal bearing capacity of the pile foundation.

[0005] 4. Construction parameters rely on experience: Existing technology lacks precise control over the pile driving process, making it difficult to adjust construction strategies in real time according to complex and ever-changing strata, resulting in poor controllability of project quality.

[0006] Therefore, there is an urgent need for a new prestressed concrete pipe pile construction technology that can specifically solve the above problems. Summary of the Invention

[0007] To address the significant soil squeezing effect, this application provides a prestressed pipe pile construction method.

[0008] In one aspect of this disclosure, a method for constructing prestressed pipe piles is provided, comprising: Geological exploration was conducted at the pile location to obtain exploration data, and a three-dimensional geological model of the pile location was constructed based on the exploration data. Based on a three-dimensional geological model, the pile locations are pre-processed to mitigate the soil squeezing effect.

[0009] By adopting the above technical solutions, relying on refined geological exploration and three-dimensional modeling, the soil layer sequence and rock surface elevation of each pile location can be accurately predicted. Then, corresponding soil pretreatment is carried out to solve the problems of significant soil squeezing effect, difficulty in pile driving, and deviation.

[0010] Preferably, the pretreatment includes arranging stress relief holes around the pile location, the depth of which penetrates the soft soil layer, and filling the holes with sand and gravel.

[0011] By adopting the technical scheme, the problem of significant soil squeezing effect is solved.

[0012] Preferably, the geological exploration includes micro-static sounding and light dynamic sounding. The exploration data includes one or more of the following: obstacles within the pile diameter range, soft soil layer thickness, and hard layer position.

[0013] By adopting the technical scheme, a three-dimensional geological model of the pile position is constructed, and the soil layer sequence and rock surface elevation of each pile position are accurately predicted.

[0014] Preferably, the pretreatment further includes drilling a hole at the pile position to eliminate obstacles within the pile diameter range and hard layers. The diameter of the drilled hole is not greater than the pile diameter.

[0015] By adopting the technical scheme, the problems of difficult pile sinking and deviation are solved.

[0016] Preferably, the prestressed pipe pile used in construction has a semi-closed steel pile tip, and the side wall of the pile tip is provided with a pressure relief hole.

[0017] By adopting the technical scheme, part of the soil can enter the inside of the pipe pile during pile sinking, forming a "soil plug effect", which can provide partial end resistance in sand layers and reduce soil squeezing effect in soft soil.

[0018] Preferably, the prestressed pipe pile construction method further includes: Real-time acquisition of pile pressing data; Interactive analysis of the pile pressing data and the three-dimensional geological model to obtain an analysis result; In response to an abnormal analysis result, adjusting the pile pressing construction state.

[0019] By adopting the technical scheme, intelligent pile sinking control is realized, that is, fine control of the pile sinking process, which facilitates flexible real-time adjustment of construction strategies according to complex and variable strata, and the controllability of engineering quality is high.

[0020] Preferably, the prestressed pipe pile construction method further includes: Real-time monitoring of the constructed pile body and the surrounding soil to obtain a monitoring result; In response to an abnormal monitoring result, adjusting the position of the constructed pile body.

[0021] By adopting the technical scheme, pile foundation construction process monitoring and feedback are realized, that is, fine control of the pile sinking process, which facilitates flexible real-time adjustment of construction strategies according to complex and variable strata, and the controllability of engineering quality is high.

[0022] Preferably, the prestressed pipe pile construction method further includes: Monitoring the soft soil layer pore water pressure; Adjusting the pile sinking sequence and / or construction interval time in response to abnormal pore water pressure.

[0023] By adopting the technical scheme, the pile foundation construction process monitoring and feedback are realized, that is, the fine control of the pile sinking process is realized, the construction strategy can be flexibly adjusted in real time according to the complex and changeable stratum, and the engineering quality controllability is high.

[0024] Preferably, the prestressed pipe pile construction method further comprises injecting cement-based slurry to the interface between the pipe pile and the liquefied sand soil after the pipe pile is driven to form a consolidated body.

[0025] By adopting the technical scheme, the liquefaction resistance of the soil around the pile and the pile side friction are improved, and the problem that the liquefied sand soil threatens the stability of the pile foundation is solved.

[0026] Preferably, the low-pressure slow cement-based slurry injection is adopted.

[0027] By adopting the technical scheme, the forming quality of the consolidated body is improved.

[0028] Beneficial technical effects: Through fine geological re-prospecting and three-dimensional modeling, the soil layer sequence and rock surface elevation of each pile position are accurately predicted, and then the soil pretreatment is correspondingly performed, so that the problems of significant soil squeezing effect, pile sinking difficulty and pile position deviation are solved.

[0029] After the pipe pile is driven, cement-based slurry is injected to the interface between the pile and the liquefied sand soil to form a consolidated body, the liquefaction resistance of the soil around the pile and the pile side friction are improved, and the problem that the liquefied sand soil threatens the stability of the pile foundation is solved.

[0030] The intelligent pile pressing equipment with real-time data acquisition and interaction with fine geological re-prospecting and three-dimensional modeling data is used to realize comprehensive monitoring and feedback of the pipe pile driving process, ensure the safety and smoothness of construction, improve the pile forming quality and one-time qualification rate, reduce the rework and processing cost, shorten the construction period, and is especially suitable for large construction projects in high-risk geological areas as described in the report. The intelligent pile pressing equipment comprises a pile pressing device (such as a static pile press) for pile pressing operation and a data detection device for detecting pile pressing data, monitoring the constructed pile body and surrounding soil in real time, and monitoring the excess pore water pressure in soft soil. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a flowchart of the prestressed pipe pile construction method in Embodiment One of the present application.

[0032] Figure 2 is a flowchart of the prestressed pipe pile construction method in Embodiment Two of the present application.

[0033] Figure 3This is a flowchart of the prestressed pipe pile construction method in Embodiment 3 of this application.

[0034] Figure 4 This is a flowchart of the prestressed pipe pile construction method in Embodiment 4 of this application.

[0035] Figure 5 This is a flowchart of the prestressed pipe pile construction method in Embodiment 5 of this application.

[0036] Figure 6 This is a flowchart of the prestressed pipe pile construction method in Embodiment Six of this application. Detailed Implementation

[0037] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. Example

[0038] like Figure 1 As shown in the embodiments of this disclosure, a method for constructing prestressed pipe piles is proposed, including: S1. Conduct geological exploration of the pile location, obtain exploration data, and construct a three-dimensional geological model of the pile location based on the exploration data; S2. Based on the three-dimensional geological model, the pile locations are pre-processed to weaken the soil squeezing effect.

[0039] By adopting the above technical solutions, relying on refined geological exploration and three-dimensional modeling, the soil layer sequence and rock surface elevation of each pile location can be accurately predicted. Then, corresponding soil pretreatment is carried out to solve the problems of significant soil squeezing effect, difficulty in pile driving, and deviation.

[0040] The reason it is called supplementary exploration is that a detailed exploration had been carried out on the site before the construction of prestressed pipe piles, and a detailed exploration report had been issued. However, because the content of the detailed exploration report was not detailed enough, it was impossible to build a three-dimensional geological model of the pile location based on the content of the detailed exploration report. Therefore, the geological exploration carried out at each pile location in this embodiment is called refined geological supplementary exploration. The purpose is to accurately determine the location of obstacles, soft soil thickness and hard interlayer within the pile diameter range, so as to build a three-dimensional geological model of the pile location based on the refined geological supplementary exploration data.

[0041] Specifically, the S1 performs geological exploration on the pile position, including micro static sounding and light dynamic sounding, and the exploration data includes one or more of the obstacles in the pile diameter range, the thickness of the soft soil layer, and the position of the hard interlayer, so as to construct a three-dimensional geological model of the pile position and accurately predict the soil layer sequence and rock surface elevation of each pile position.

[0042] Specifically, the pre-treatment in the S2 includes arranging stress release holes around the pile position, the depth of the holes penetrating the soft soil layer, and filling the holes with gravel, so that the problem of significant soil squeezing effect can be solved. Because the stress release holes are arranged around the pile position, the depth of the holes penetrates the soft soil layer, and the holes are filled with gravel, the excess pore water pressure generated by pile sinking can be released, and the soil squeezing effect can be reduced.

[0043] Optionally, the diameter of the stress release hole is 200-300 mm.

[0044] Further, in the embodiment of the present disclosure, the pre-treatment further includes drilling the pile position to eliminate the obstacles and the hard interlayer in the pile diameter range; at the same time, the diameter of the drilled hole is not greater than the pile diameter, so as not to affect the subsequent prestressed pipe pile construction. In this way, the problems of pile sinking difficulty and deviation are solved, and the pile sinking obstacles and soil squeezing risks are reduced from the source.

[0045] In specific implementation, for the obstacles in the pile diameter range, a small-diameter (slightly smaller than the pile diameter) pilot hole can be drilled by using a spiral drill or the like to remove obstacles such as gravel and concrete blocks. For the hard interlayer, a down-the-hole hammer or a roller bit can be used for pre-drilling, and the drilling depth is determined by penetrating the hard interlayer and entering the relatively soft soil layer or stable bearing layer below.

[0046] Because the pile position is drilled in advance to eliminate the obstacles and the hard interlayer in the pile diameter range, the problems of pile head damage, pile body inclination, or inability to sink to the design elevation do not occur in the subsequent prestressed pipe pile construction process, and the problems of pile sinking difficulty and deviation are solved.

[0047] Further, the prestressed pipe pile used in the prestressed pipe pile construction method of the embodiment has a semi-closed steel pile tip, and the side wall of the pile tip is provided with a pressure relief hole. In this way, part of the soil can enter the inside of the pipe pile during pile sinking to form a "soil plug effect", which can provide partial end resistance in the sand layer and reduce the soil squeezing effect in the soft soil. Embodiment

[0048] The present embodiment is a further improvement based on the first embodiment.

[0049] As shown in Figure 2 In the embodiment of the present disclosure, the prestressed pipe pile construction method further includes: S3, real-time acquisition of pile pressing data; S4, interactive analysis of the pile pressing data and the three-dimensional geological model to obtain an analysis result. S5, adjusting the pile pressing construction state in response to the analysis result of the abnormality.

[0050] By adopting the technical scheme, intelligent pile pressing control is realized, that is, fine control of the pile pressing process, and the construction strategy can be conveniently and flexibly adjusted in real time according to complex and changeable strata, the engineering quality controllability is high, the strata change can be responded in real time, quality accidents such as broken piles and inclined piles are effectively avoided, the pile pressing precision is ensured, the pile quality and the first-time qualification rate are improved, the rework and processing cost are reduced, and the construction period is shortened, and the method is especially suitable for large construction projects in high-risk geological areas as described in the report.

[0051] Specifically, the pile pressing data in S3 include pile pressing force, penetration depth, pile body verticality and the like, and the data can be collected in real time by using a pile pressing device with a real-time data collection function.

[0052] S4 is used to interactively analyze the pile pressing data and the three-dimensional geological model, and the purpose is to determine whether the current construction condition is the same as the predicted condition, for example, the expected pile pressing resistance curve can be predicted by the three-dimensional geological model, the real-time collected pile pressing data is compared with the expected pile pressing resistance curve, and when the actual pile pressing force deviates from the expected pile pressing resistance curve significantly, the analysis result of the abnormality is output. Otherwise, if the actual pile pressing force is consistent with the expected pile pressing resistance curve, the normal pile pressing construction can be continued.

[0053] In S5, when the analysis result is abnormal, the pile pressing construction state needs to be adjusted, for example, the pile pressing speed is adjusted, or the corresponding preprocessing step in S2 is started, and the root cause of the abnormality is eliminated by solving the problem of significant soil squeezing effect or difficult pile pressing and deviation, so that the detected pile pressing data returns to normal.

[0054] In addition, in S5, when the analysis result is abnormal, an alarm can also be given to prompt the operator to check the reason (such as encountering an obstacle or a hard interlayer). Embodiment

[0055] The embodiment is a further improvement based on Embodiment Two.

[0056] As shown in Figure 3 In the embodiment of the present disclosure, the prestressed pipe pile construction method further includes: S6a, real-time monitoring of the constructed pile body and the surrounding soil body is performed to obtain a monitoring result; S7a, the position of the constructed pile body is adjusted in response to the abnormal monitoring result.

[0057] By adopting the technical scheme, pile foundation construction process monitoring and feedback are realized, that is, fine control of the pile sinking process is realized, construction strategies can be flexibly adjusted in real time according to complex and changeable strata, the controllability of engineering quality is high, and construction safety is ensured.

[0058] Specifically, the monitoring content in S6a includes pile body inclination, surrounding soil settlement and the like. In specific implementation, high-precision instruments such as inclinometers and settlement marks can be used to monitor the constructed pile body and surrounding soil in real time. Once an abnormality is detected, corresponding processing can be performed according to the specific abnormality, and the position of the constructed pile body is adjusted, so as to ensure the construction quality of the prestressed pipe pile, realize fine control of the pile sinking process, and the controllability of engineering quality is high. Embodiment

[0059] This embodiment is a further improvement based on Embodiment Two.

[0060] As shown in Figure 4 The prestressed pipe pile construction method further includes: S6b, monitoring the soft soil layer pore water pressure; S7b, in response to the abnormal pore water pressure, adjusting the pile sinking order and / or construction intermittent time.

[0061] By adopting the technical scheme, pile foundation construction process monitoring and feedback are realized, that is, fine control of the pile sinking process is realized, construction strategies can be flexibly adjusted in real time according to complex and changeable strata, and the controllability of engineering quality is high.

[0062] Specifically, the dissipation of excess pore water pressure in soft soil can be monitored by a pore water pressure gauge. If an abnormality is detected, the pile sinking order and / or construction intermittent time can be adjusted to wait for the abnormality to be eliminated before continuing construction.

[0063] The adjustment of the pile sinking order includes different construction methods such as skip driving method and driving from center to periphery. Embodiment

[0064] This embodiment is a further improvement based on Embodiment Two.

[0065] As shown in Figure 5 The prestressed pipe pile construction method further includes: S6c, after pipe pile driving is completed, cement-based slurry is injected to the interface between the pipe pile and liquefied sand soil to form a consolidated body.

[0066] Preferably, low-pressure slow cement-based slurry injection is adopted to improve the forming quality of the consolidated body.

[0067] By adopting the technical scheme, the liquefaction resistance of the soil around the pile and the side friction of the pile are improved, and the problem that liquefied sand threatens the stability of the pile foundation is solved.

[0068] For a distribution area of seriously liquefied sand, after the pipe pile is driven, low-pressure slow grouting (for example, cement-based grout) is performed on the pipe pile and the liquefied sand interface to form a consolidated body, thereby significantly improving the liquefaction resistance of the soil around the pile and the side friction of the pile, and solving the problem that liquefied sand threatens the stability of the pile foundation. Embodiment

[0069] The embodiment is a further improvement based on Embodiments Two to Five.

[0070] As shown in Figure 6 In the embodiment, the prestressed pipe pile construction method comprises: S1, performing geological exploration on a pile site to obtain exploration data, and constructing a three-dimensional geological model of the pile site based on the exploration data; S2, based on the three-dimensional geological model, pre-processing the pile site to weaken the soil squeezing effect; S3, obtaining pressure pile data in real time; S4, performing interactive analysis on the pressure pile data and the three-dimensional geological model to obtain an analysis result; S5, adjusting the pressure pile construction state in response to an abnormal analysis result; S6a, monitoring the constructed pile body and the surrounding soil in real time to obtain a monitoring result; S7a, adjusting the position of the constructed pile body in response to an abnormal monitoring result; S6b, monitoring the pore water pressure of the soft soil layer; S7b, adjusting the pile sinking sequence and / or construction interval time in response to an abnormal pore water pressure; S6c, after the pipe pile is driven, cement-based grout is injected into the interface between the pipe pile and the liquefied sand to form a consolidated body.

[0071] It can be seen that the prestressed pipe pile construction method of the embodiment integrates all the technical means of Embodiments Two to Five, and therefore has all the beneficial effects of the technical solutions of Embodiments Two to Five, which will not be described again.

[0072] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Unless otherwise defined, the terms "first", "second" or "third" and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms "one", "another", "an" or "some" as well as similar referents in the context of describing the specification and claims are to be construed to be open-ended, i.e., to cover both singular and plural referents unless otherwise indicated. The terms "including", "containing" or "comprising" and the like are not intended to exclude other integers or steps, but to "include" or "comprise" other integers or steps unless otherwise indicated. The terms "connected", "coupled" or "pathway" are not restricted to direct connections, couplings or pathways but include indirect connections, couplings or pathways unless otherwise indicated. The terms "above", "below", "left", "right" and the like are only used to express relative positions such that if an absolute position of a described object is changed, the relative positions can also be changed accordingly.

[0073] The above are only preferred embodiments of the present application, not intended to limit the protection scope of the present application, therefore: any equivalent changes made according to the structure, shape, principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A method for constructing prestressed concrete pipe piles, characterized in that, include: Geological exploration was conducted at the pile location to obtain exploration data, and a three-dimensional geological model of the pile location was constructed based on the exploration data. Based on a three-dimensional geological model, the pile locations are pre-processed to mitigate the soil squeezing effect.

2. The prestressed pipe pile construction method according to claim 1, characterized in that: The pretreatment includes arranging stress relief holes around the pile location, with the holes penetrating the soft soil layer and filled with sand and gravel.

3. The prestressed pipe pile construction method according to claim 1, characterized in that: The geological exploration includes micro static cone penetration testing and lightweight dynamic cone penetration testing. The exploration data includes one or more of the following: obstacles within the pile diameter range, soft soil layer thickness, and hard interlayer location.

4. The prestressed pipe pile construction method according to claim 1, characterized in that: The pretreatment also includes drilling at the pile location to eliminate obstacles and hard interlayers within the pile diameter range; The borehole diameter is not greater than the pile diameter.

5. The prestressed pipe pile construction method according to claim 1, characterized in that: The prestressed pipe piles used in the construction have semi-enclosed steel pile tips, and pressure relief holes are provided on the sidewalls of the pile tips.

6. The prestressed pipe pile construction method according to claim 1, characterized in that, Also includes: Real-time acquisition of pile driving data; The pile driving data is interactively analyzed with the three-dimensional geological model to obtain the analysis results; In response to abnormal analysis results, adjust the pile driving construction status.

7. The prestressed pipe pile construction method according to claim 1, characterized in that, Also includes: Real-time monitoring of the constructed piles and surrounding soil was conducted to obtain monitoring results; In response to abnormal monitoring results, the position of the constructed piles is adjusted.

8. The prestressed pipe pile construction method according to claim 1, characterized in that, Also includes: Monitor pore water pressure in soft soil layers; In response to abnormal pore water pressure, adjust the pile driving sequence and / or construction intervals.

9. The prestressed pipe pile construction method according to claim 1, characterized in that, This also includes injecting cement-based grout into the interface between the pipe pile and the liquefied sand after the pipe pile is driven to form a solidified body.

10. The prestressed pipe pile construction method according to claim 9, characterized in that: Low-pressure, slow-speed injection of cement-based grout is employed.

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