Construction method of environment-friendly recyclable precast beam yard beam storage pile foundation

Abstract

The invention relates to the technical field of railway bridge construction, in particular to a construction method of an environment-friendly recyclable precast beam yard beam storage pile foundation, which comprises the following steps of: firstly, after geological investigation, designing the pile diameter of the pile foundation and the buried depth of the pile foundation; the produced pile foundation is transported to a site and then driven into a soil body by using a machine according to the pre-calculated buried depth, then the prefabricated box girder is stored after pile cap construction, settlement initial value collection and pile cap pre-pressing, the prefabricated girder is produced after settlement observation, and after a girder field production task is finished, the prefabricated box girder can be produced by using the prefabricated box girder after the pile cap construction, settlement initial value collection and pile cap pre-pressing. And the pile foundation can be pulled out and recycled by using a preface machine. Therefore, the construction method of the green, environment-friendly and recyclable precast beam field beam storage pile foundation has the advantages that construction is convenient and fast, the construction investment is small, the pile foundation can be recycled, secondary ploughing is easy, the original fertile field standard is not affected, the whole construction process can be recycled, energy is saved, and pollution is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of railway bridge construction, and in particular to a construction method for a green, environment-friendly, recyclable prefabricated beam yard stored beam pile foundation. Background Art

[0002] The pile foundation for storing beams in a precast beam yard is an infrastructure used to store prestressed concrete box beams. It is mainly composed of piles and pile caps connected to the top of the piles. The pile foundation transfers the load of the beam yard to the soil layer with good bearing performance deep underground by driving or pressing the piles into the soil to meet the requirements of bearing capacity and settlement.

[0003] There are many construction methods for the pile foundation of the beams stored in the precast beam yard, mainly including precast piles and cast-in-place piles. Precast piles are precast reinforced concrete piles driven into the ground by a pile driver. They are suitable for buildings with higher requirements, but the construction is more difficult. Cast-in-place piles are drilled at the construction site, and then reinforced skeletons are placed and concrete is poured. The construction difficulty is lower, but the bearing capacity is lower.

[0004] At present, the foundation of the beams in the prefabricated beam yard of high-speed railways generally adopts the following methods: the combination of bored cast-in-place piles and independent foundations, and the combination of CFG piles and expansion technology. Among them, CFG piles are short for cement fly ash gravel piles, which are variable strength piles made of crushed stone, stone chips, sand, fly ash, cement and water, and are made by various pile-making machines.

[0005] However, in the prior art, pile foundations such as bored cast-in-place piles and CFG piles have the defects of large one-time investment and non-recyclability, and the mud or concrete of bored piles and CFG piles during construction can easily cause pollution to nearby basic farmland, and after the project is completed, a large amount of manpower and material resources are required to dig them out for reclamation, and it is difficult to restore them to the original good farmland standards before construction. Summary of the invention

[0006] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a green and environmentally friendly recyclable construction method for prefabricated beam yard pile foundations. The green and environmentally friendly recyclable construction method for prefabricated beam yard pile foundations has the advantages of convenient construction, small construction investment, recyclable pile foundations, easy reclamation, and no impact on the original fertile land standards. The entire construction process can be recycled, energy-saving and pollution-free.

[0007] In order to achieve the purpose of the above invention, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides a green, environmentally friendly and recyclable prefabricated beam field storage beam pile foundation construction method, comprising the following steps:

[0009] S1. On-site geological survey: determine the location of the prefabricated beam yard, conduct geological survey on the location of the prefabricated beam yard, and issue a geological survey report;

[0010] S2. Design pile diameter and burial depth: Determine the pile diameter and burial depth of the pile foundation according to the weight of the prefabricated box beam and the geological survey report of step S1;

[0011] S3, making pile foundation: according to the pile foundation material, pile foundation diameter, and pile foundation burial depth provided in step S2, a pile foundation drawing is drawn, and then the pile foundation is processed;

[0012] S4, pile foundation transportation: transport the pile foundation made and processed in step S3 to the selected prefabricated beam site;

[0013] S5, driving the pile foundation into the soil: driving the pile foundation into the soil by a driving machine, and the driving depth is according to the soil depth of the pile foundation calculated in step S2;

[0014] S6, pile cap construction: after the pile foundation of step S5 is driven into the soil, steel bars are tied on the upper part of the pile foundation, formwork is erected, and pile caps are cast;

[0015] S7. Collection of initial settlement values: After the pile cap construction is completed, the pile cap elevation is immediately collected as the initial data for settlement observation;

[0016] S8, preloading of pile cap: preloading the pile cap, collecting the elevation data of the pile cap in real time during the preloading process, and comparing it with the initial settlement observation data of step S7, and unloading the preloading after the settlement tends to be stable;

[0017] S9, storing the prefabricated box beam: after the preload in step S8 is unloaded and the pile cap elevation changes are observed to be stable, the prefabricated box beam can be stored;

[0018] S10, settlement observation: after starting to store the prefabricated box beam, observe the elevation change of the pile cap and compare it with the final elevation value measured in step S8 to ensure a certain elevation difference;

[0019] S11. After the production of precast beams is completed, the pile foundations are pulled out and recycled: After the precast beams are produced and erected, and the beam yard production task is completed, when the beam yard needs to be dismantled and reclaimed, the pile foundations are pulled out using a tamping machine and then transferred to the next precast beam yard for reuse.

[0020] The invention discloses a green, environment-friendly and recyclable construction method for prefabricated beam field storage pile foundation. The method comprises the following steps: firstly, the pile diameter and the buried depth of the pile foundation are designed after geological survey; then, the produced pile foundation is transported to the site and driven into the soil by a tamping machine according to the buried depth calculated in advance; then, the pile cap is constructed, the initial settlement value is collected, the prefabricated box beam is stored after the pile cap is pre-compressed, and the prefabricated beam is produced after the settlement observation; and after the production task of the beam field is completed, the pile foundation can be pulled out by a tamping machine and can be recycled.

[0021] Furthermore, in the step S1, the geological survey includes surveying the type of soil and the physical properties of the soil. The types of soil include clay, silty clay, and sand; and the physical properties of the soil include internal friction angle, cohesion, and the like.

[0022] Furthermore, in the step S2, the material of the pile foundation is selected from Q235 steel;

[0023] The pile foundation diameter and the pile foundation burial depth are determined by formula I, formula II and formula III:

[0024] Q UK =Q SK +Q PK =U∑q si'k l i +q pk λ p A P Formula I;

[0025] When h b / d<5,λp=0.16h b / d Formula II;

[0026] When h b / d≧5,λp=0.8 Formula III;

[0027] Where Quk is the standard value of the ultimate bearing capacity of a single pile; Q SK is the standard value of total limit lateral resistance; Q PK is the standard value of total limit end resistance; q si'k is the standard value of the ultimate lateral resistance of the pile foundation; q pk is the standard value of the ultimate end resistance of the pile foundation; l i = thickness of the i-th layer of soil around the pile; λ p A is the soil plug effect coefficient at the pile end; p = pile end surface area; h b is the depth of the pile foundation into the soil; d is the diameter of the pile foundation.

[0028] Specifically, by substituting Formula II or Formula III into Formula I so that the equation of Formula I holds, the pile foundation diameter and the depth of the pile foundation into the ground are determined.

[0029] Furthermore, in step S5, the driving depth of the pile foundation is controlled by elevation control, which can ensure that each part of the pile foundation is highly accurate, vertical and flat.

[0030] Furthermore, in step S6, the steel bars on the top of the pile cap are made of HRB40016mm threaded steel with a tying spacing of 100mm, the left and right sides and the bottom of the pile cap are made of HRB40012mm threaded steel with a tying spacing of 100mm, and the stirrups of the pile cap are made of HRB40012mm threaded steel with a tying spacing of 100mm.

[0031] Furthermore, the formwork is made of wooden plywood, and is reinforced with M6 tension screws.

[0032] Furthermore, the strength grade of the concrete used for pouring the pile cap is not less than C40.

[0033] Furthermore, in step S8, after the preloading is completed, the deformation value of the pile cap elevation is measured every 6 hours until the settlement of two consecutive measurements is less than 2 mm, which means that the settlement is stable, and the preloading is unloaded. When the settlement of two consecutive measurements is less than 2 mm, it indicates that the settlement has stabilized.

[0034] Furthermore, in the step S9, after the prefabricated box girders are started to be stored, if the change in the pile cap elevation is observed to be ≦±2mm, the prefabricated box girders can be stored.

[0035] Furthermore, in the step S10, after the prefabricated box beam is stored, the elevation change of the pile cap is observed and compared with the four elevation values ​​of the four piers finally measured in step S8 to ensure that the four elevation differences of the four piers are no more than 2 mm. In the observation of the elevation change of the pile cap, it is necessary to observe the elevation change of the four piers of the pile cap respectively to ensure that the four elevation differences of the four piers are no more than 2 mm before the prefabricated box beam can continue to be stored.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) The green and environmentally friendly recyclable prefabricated beam field storage pile foundation construction method of the present invention is that the pile diameter and the depth of the pile foundation are designed after geological survey, and then the produced pile foundation is transported to the site and driven into the soil by a tamping machine according to the pre-calculated depth of the pile foundation. Then, the pile cap is constructed, the initial settlement value is collected, and the prefabricated box beam is stored after the pile cap is pre-pressed. After the settlement observation, the prefabricated beam is produced. After the production task of the beam field is completed, the pile foundation can be pulled out by a tamping machine and can be recycled. Therefore, the green and environmentally friendly recyclable prefabricated beam field storage pile foundation construction method has the advantages of convenient construction, small construction investment, recyclable pile foundation, easy reclamation, and no impact on the original fertile land standard. The entire construction process can be repeated, energy-saving and pollution-free.

[0038] (2) The present invention provides a green and environmentally friendly recyclable prefabricated beam pile foundation construction method, which uses Q235 steel, which is centrally processed into standard pipe pile foundations in the factory, and is driven into the soil by a pulling machine or static pressure, and uses the friction of the soil to withstand the force transmitted from the upper part. After the project is completed, the pile foundation can be pulled out by a pulling machine, and the pile foundation can be completely recovered and transferred to the next project site for reuse. The whole process is not only cyclical, but also green, environmentally friendly, energy-saving and pollution-free.

[0039] (3) The present invention provides a green and environmentally friendly recyclable prefabricated beam field pile foundation construction method. By investigating the on-site geological conditions and fully considering environmental impacts and engineering economic factors, the entire construction method is made green and environmentally friendly, and the recyclable pile foundation greatly reduces investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 The invention discloses a process flow chart of a green, environment-friendly and recyclable prefabricated beam yard storage beam pile foundation construction method.

[0042] Figure 2 It is a schematic diagram of the top view structure of the pile foundation layout of the beam storage pedestal designed by using the construction method of the beam storage pile foundation in Example 2 of the present invention.

[0043] Figure 3 This is a schematic diagram of the front view structure of the pile foundation layout of the beam storage pedestal designed using the construction method of the beam storage pile foundation in Example 2 of the present invention.

[0044] Figure 4 It is a left-side structural schematic diagram of the pile foundation layout of the beam storage pedestal designed using the construction method of the beam storage pile foundation in Example 2 of the present invention.

[0045] Reference numerals:

[0046] ①Pile foundation, ②Pile cap. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0048] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. In the present invention, the singular forms "a", "said" and "the" used in the embodiments and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0049] The following describes the invention in conjunction with specific embodiments.

[0050] Example 1

[0051] A green and environmentally friendly construction method for recyclable prefabricated beam pile foundation in the embodiment of the present invention is as follows: Figure 1 As shown, the following steps are included:

[0052] S1. On-site geological survey: determine the location of the prefabricated beam yard, conduct geological survey on the location of the prefabricated beam yard, and issue a geological survey report; in this embodiment, the geological survey includes the type of soil survey and the physical properties of the soil. The types of soil survey include clay, silty clay, and sand; the physical properties of the soil include internal friction angle, cohesion, etc.;

[0053] S2, design pile diameter, and burial depth: According to the weight of the prefabricated box beam and the geological survey report of step S1, determine the pile foundation diameter and the burial depth of the pile foundation; in this embodiment, the material of the pile foundation is Q235 steel; in this embodiment, the pile foundation diameter and the burial depth of the pile foundation are determined by formula I, formula II and formula III:

[0054] Q UK =Q SK +Q PK =U∑q si'k l i +q pk λ p A P Formula I;

[0055] When h b / d<5,λp=0.16h b / d Formula II;

[0056] When h b / d≧5,λp=0.8 Formula III;

[0057] Where Quk is the standard value of the ultimate bearing capacity of a single pile; Q SK is the standard value of total limit lateral resistance; Q PK is the standard value of total limit end resistance; q si'k is the standard value of the ultimate lateral resistance of the pile foundation; q pk is the standard value of the ultimate end resistance of the pile foundation; l i = thickness of the i-th layer of soil around the pile; λ p A is the soil plug effect coefficient at the pile end;p = pile end surface area; h b is the depth of the pile foundation into the soil; d is the diameter of the pile foundation.

[0058] Specifically, by substituting Formula II or Formula III into Formula I so that the equation of Formula I holds, the pile foundation diameter and the depth of the pile foundation into the ground are determined.

[0059] S3, making pile foundation: according to the pile foundation material, pile foundation diameter, and pile foundation burial depth provided in step S2, a pile foundation drawing is drawn, and then the pile foundation is processed;

[0060] S4, pile foundation transportation: transport the pile foundation made and processed in step S3 to the selected prefabricated beam site using a flatbed truck;

[0061] S5, driving the pile foundation into the soil: The pile foundation is driven into the soil by a driving machine, and the driving depth is based on the soil depth of the pile foundation calculated in step S2; in this embodiment, the driving depth of the pile foundation is controlled by elevation control. The elevation control can ensure that each part of the pile foundation is highly accurate, vertical and flat;

[0062] S6, pile cap construction: after the pile foundation of step S5 is driven into the soil, the steel bars are tied, the formwork is erected, and the pile cap is poured on the upper part of the pile foundation; in this embodiment, the steel bars on the top of the pile cap are HRB40016mm threaded steel with a tying spacing of 100mm, the left and right sides and the bottom of the pile cap are HRB40012mm threaded steel with a tying spacing of 100mm, and the pile cap's frame stirrups are HRB40012mm threaded steel with a tying spacing of 100mm; the formwork is made of wooden plywood, and the formwork is reinforced with a tension screw of model M6; the strength grade of the concrete poured into the pile cap is not less than C40;

[0063] S7. Collection of initial settlement values: After the pile cap construction is completed, the pile cap elevation is immediately collected as the initial data for settlement observation;

[0064] S8, preloading of pile cap: preloading the pile cap, collecting the elevation data of the pile cap in real time during the preloading process, and comparing it with the initial data of the settlement observation in step S7, and unloading the preloading after the settlement tends to be stable; in this embodiment, after the preloading is completed, the deformation value of the pile cap elevation is measured every 6 hours until the settlement of two consecutive times is less than 2mm, that is, it is determined that the settlement tends to be stable, and then the preloading is unloaded. Among them, when the settlement of two consecutive measurements is less than 2mm, it indicates that the settlement has tended to be stable;

[0065] S9, storing the prefabricated box beam: after the preload in step S8 is unloaded, the prefabricated box beam can be stored after the pile cap elevation change is observed to be stable; in this embodiment, after the prefabricated box beam is stored, the prefabricated box beam can be stored after the pile cap elevation change value is observed to be ≦±2mm;

[0066] S10, settlement observation: after starting to store the prefabricated box beam, observe the elevation change of the pile cap, and compare it with the final measured elevation value observed in step S8 to ensure a certain elevation difference; in this embodiment, after starting to store the prefabricated box beam, observe the elevation change of the pile cap, and compare it with the four elevation values ​​of the four piers finally measured in step S8 to ensure that the four elevation differences of the four piers are no more than 2mm. Among them, to observe the elevation change of the pile cap, it is necessary to observe the elevation change of the four piers of the pile cap respectively, and ensure that the four elevation differences of the four piers are no more than 2mm before continuing to store the prefabricated box beam;

[0067] S11. After the production of precast beams is completed, the pile foundations are pulled out and recycled: After the precast beams are produced and erected, and the beam yard production task is completed, when the beam yard needs to be dismantled and reclaimed, the pile foundations are pulled out using a tamping machine and then transferred to the next precast beam yard for reuse.

[0068] A green, environmentally friendly and recyclable prefabricated beam yard storage pile foundation construction method is disclosed in the embodiment. The pile foundation diameter and the depth of the pile foundation into the ground are designed after geological survey. The produced pile foundation is then transported to the site and driven into the soil by a tamping machine according to the pre-calculated depth of the pile foundation. The pile cap is then constructed and the initial settlement value is collected. The prefabricated box beams are stored after the pile cap is pre-compressed. The prefabricated beams are produced after the settlement observation. After the production task of the beam yard is completed, the pile foundation can be pulled out by a tamping machine and can be recycled.

[0069] Example 2

[0070] This embodiment 2 is a green and environmentally friendly construction method for recyclable prefabricated beam pile foundation, such as Figures 1 to 4 As shown, according to the on-site geological survey report, it is determined as follows Figure 4 The diameter of the pile foundation ① shown is 630mm, and the pile foundation ① is determined to use a spiral steel pipe with a wall thickness of 8mm to 10mm; then the length of the pile foundation ① is designed, and a flatbed truck carrying the pile foundation drawing ① is selected, and the pile foundation drawing ① is transported to the site by the flatbed truck; the power of the vibrating hammer or static press is selected according to the geological conditions, and the power of the vibrating hammer or static press is not less than the standard value of the ultimate bearing capacity of a single pile foundation, and then according to Figures 2 to 4 The pile foundation layout diagram of the beam storage pedestal shown in the figure is to use a vibrating hammer or static press to drive or press the pile foundation ① into the soil until it reaches the designed elevation. After the pile foundation ① is constructed, Figures 2 to 4The structure shown is subjected to pile cap ② construction. In this embodiment, the length and width of pile cap ② are 800mm*800mm, and the height of pile cap ② does not exceed 1000mm. In this embodiment, the height of pile cap ② is 800mm. In addition, the arrangement of pile foundation ① is based on the type of beam type and the number of existing beams on site. The types of beam types include single-track bridges and double-track bridges. The arrangement of pile foundation gives priority to the setting of beam types with a large number of existing beams, while taking into account the setting of beam types with a small number of existing beams. In this embodiment, pile foundation ① is arranged to be shared by single-track and double-track bridges, thereby saving land and costs.

[0071] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A green and environmentally friendly recyclable prefabricated beam field storage beam pile foundation construction method, characterized in that: The following steps are involved: S1. On-site geological survey: determine the location of the prefabricated beam yard, conduct geological survey on the location of the prefabricated beam yard, and issue a geological survey report; S2. Design pile diameter and burial depth: Determine the pile diameter and burial depth of the pile foundation according to the weight of the prefabricated box beam and the geological survey report of step S1; S3, making pile foundation: according to the pile foundation material, pile foundation diameter, and pile foundation burial depth provided in step S2, a pile foundation drawing is drawn, and then the pile foundation is processed; S4, pile foundation transportation: transport the pile foundation made and processed in step S3 to the selected prefabricated beam site; S5, driving the pile foundation into the soil: driving the pile foundation into the soil by a driving machine, and the driving depth is according to the soil depth of the pile foundation calculated in step S2; S6, pile cap construction: after the pile foundation of step S5 is driven into the soil, steel bars are tied on the upper part of the pile foundation, formwork is erected, and pile caps are cast; S7. Collection of initial settlement values: After the pile cap construction is completed, the pile cap elevation is immediately collected as the initial data for settlement observation; S8, preloading of pile cap: preloading the pile cap, collecting the elevation data of the pile cap in real time during the preloading process, and comparing it with the initial settlement observation data of step S7, and unloading the preloading after the settlement tends to be stable; S9, storing the prefabricated box beam: after the preload in step S8 is unloaded and the pile cap elevation changes are observed to be stable, the prefabricated box beam can be stored; S10, settlement observation: after starting to store the prefabricated box beam, observe the elevation change of the pile cap and compare it with the final elevation value measured in step S8 to ensure a certain elevation difference; S11. After the production of precast beams is completed, the pile foundations are pulled out and recycled: After the precast beams are produced and erected, and the beam yard production task is completed, when the beam yard needs to be dismantled and reclaimed, the pile foundations are pulled out using a tamping machine and then transferred to the next precast beam yard for reuse.

2. A green and environmentally friendly recyclable prefabricated beam field pile foundation construction method as claimed in claim 1, characterized in that: In the step S1, the geological survey includes surveying the type of soil and the physical properties of the soil.

3. The construction method of a green and environmentally friendly recyclable prefabricated beam field pile foundation as claimed in claim 1, characterized in that: In the step S2, the material of the pile foundation is Q235 steel; The pile foundation diameter and the pile foundation burial depth are determined by formula I, formula II and formula III: Q UK = Q SK + Q PK = UΣq si'k l i + q pk λ p A P Formula I; When h b / d<5,λp=0.16h b / d Formula II; When h b / d≧5,λp=0.8 Formula III; Where Quk is the standard value of the ultimate bearing capacity of a single pile; Q SK is the standard value of total limit lateral resistance; Q PK is the standard value of total limit end resistance; q si'k is the standard value of the ultimate lateral resistance of the pile foundation; q pk is the standard value of the ultimate end resistance of the pile foundation; l i = thickness of the i-th layer of soil around the pile; λ p A is the soil plug effect coefficient at the pile end; p = pile end surface area; h b is the depth of the pile foundation into the soil; d is the diameter of the pile foundation.

4. The green and environmentally friendly recyclable prefabricated beam field pile foundation construction method as claimed in claim 1, characterized in that: In the step S5, the driving depth of the pile foundation is controlled by elevation control.

5. The green and environmentally friendly recyclable prefabricated beam field pile foundation construction method as claimed in claim 1, characterized in that: In step S6, the reinforcement on the top of the pile cap is HRB40016mm threaded steel with a tying spacing of 100mm, the left and right sides and the bottom of the pile cap are HRB40012mm threaded steel with a tying spacing of 100mm, and the stirrups of the pile cap are HRB40012mm threaded steel with a tying spacing of 100mm.

6. The green and environmentally friendly recyclable prefabricated beam field pile foundation construction method as claimed in claim 1, characterized in that: In the step S6, the formwork is made of wooden plywood and is reinforced with M6 tension screws.

7. The green and environmentally friendly recyclable prefabricated beam field pile foundation construction method as claimed in claim 1, characterized in that: In the step S6, the strength grade of the concrete used for pouring the pile cap is not less than C40.

8. The green and environmentally friendly recyclable prefabricated beam field pile foundation construction method as claimed in claim 1, characterized in that: In the step S8, after the preloading is completed, the deformation value of the pile cap elevation is measured every 6 hours until the settlement of two consecutive times is less than 2 mm, that is, it is determined that the settlement tends to be stable, and the preloading is unloaded.

9. The green and environmentally friendly recyclable prefabricated beam field pile foundation construction method as claimed in claim 1, characterized in that: In the step S9, if the change in pile cap elevation is observed to be ≦±2mm, the prefabricated box girder can be stored.

10. The green and environmentally friendly recyclable prefabricated beam field pile foundation construction method as claimed in claim 1, characterized in that: In the step S10, after the prefabricated box beams are stored, the elevation change of the pile cap is observed and compared with the four elevation values ​​of the four piers finally measured in step S8 to ensure that the four elevation differences of the four piers are no more than 2 mm.

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